Add ProxySocketFactory

Co-authored-by: Jeroen van Erp <jeroen@hierynomus.com>

.gitattributes

@@ -1 +1,2 @@
 *.bat text eol=crlf
+src/itest/docker-image/** eol=lf

.github/workflows/gradle.yml

@@ -24,19 +24,8 @@ jobs:
       run: chmod +x gradlew
     - name: Build with Gradle
       run: ./gradlew check
-  # java10:
-  #   name: Build with Java 10
-  #   runs-on: ubuntu-latest
-  #   steps:
-  #   - uses: actions/checkout@v2
-  #   - name: Set up JDK 10
-  #     uses: actions/setup-java@v1
-  #     with:
-  #       java-version: 10
-  #   - name: Grant execute permission for gradlew
-  #     run: chmod +x gradlew
-  #   - name: Build with Gradle
-  #     run: ./gradlew check -xanimalsnifferMain -xanimalsnifferTest
+    - name: Codecov
+      uses: codecov/codecov-action@v2
 
   integration:
     name: Integration test

.github/workflows/release.yml

@@ -0,0 +1,49 @@
+name: SSHJ Release
+
+on:
+  push:
+    tags:
+      - '*'
+
+permissions:
+  contents: write
+
+jobs:
+  java12:
+    name: Build with Java 12
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Set up JDK 12
+        uses: actions/setup-java@v1
+        with:
+          java-version: 12
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: Build with Gradle
+        run: ./gradlew check
+  release:
+    name: Release
+    needs: [java12]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 12
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: Release
+        run: ./gradlew release -Prelease.disableChecks -Prelease.pushTagsOnly -Prelease.customUsername=${{ github.actor }} -Prelease.customPassword=${{ github.token }}
+        env:
+          ORG_GRADLE_PROJECT_signingKey: ${{ secrets.SIGNINGKEY }}
+          ORG_GRADLE_PROJECT_signingKeyId: ${{ secrets.SIGNINGKEYID }}
+          ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.SIGNINGPASSWORD }}
+          ORG_GRADLE_PROJECT_sonatypeUsername: ${{ secrets.OSSRH_USERNAME }}
+          ORG_GRADLE_PROJECT_sonatypePassword: ${{ secrets.OSSRH_PASSWORD }}
+
+

.vscode/settings.json

@@ -2,5 +2,6 @@
     "java.checkstyle.configuration": "${workspaceFolder}/gradle/config/checkstyle/checkstyle.xml",
     "files.watcherExclude": {
         "**/target": true
-    }
+    },
+    "java.configuration.updateBuildConfiguration": "automatic"
 }

README.adoc

@@ -1,12 +1,11 @@
 = sshj - SSHv2 library for Java
 Jeroen van Erp
 :sshj_groupid: com.hierynomus
-:sshj_version: 0.31.0
+:sshj_version: 0.32.0
 :source-highlighter: pygments
 
-image:https://api.bintray.com/packages/hierynomus/maven/sshj/images/download.svg[link="https://bintray.com/hierynomus/maven/sshj/_latestVersion"]
-image:https://travis-ci.org/hierynomus/sshj.svg?branch=master[link="https://travis-ci.org/hierynomus/sshj"]
-image:https://api.codacy.com/project/badge/Grade/14a0a316bb9149739b5ea26dbfa8da8a["Codacy code quality", link="https://www.codacy.com/app/jeroen_2/sshj?utm_source=github.com&utm_medium=referral&utm_content=hierynomus/sshj&utm_campaign=Badge_Grade"]
+image:https://github.com/hierynomus/sshj/actions/workflows/gradle.yml/badge.svg[link="https://github.com/hierynomus/sshj/actions/workflows/gradle.yml"]
+image:https://app.codacy.com/project/badge/Grade/2c8a5a67c6a54ed89c9a699fd6b27305["Codacy Grade", link="https://app.codacy.com/gh/hierynomus/sshj"]
 image:https://codecov.io/gh/hierynomus/sshj/branch/master/graph/badge.svg["codecov", link="https://codecov.io/gh/hierynomus/sshj"]
 image:http://www.javadoc.io/badge/com.hierynomus/sshj.svg?color=blue["JavaDocs", link="http://www.javadoc.io/doc/com.hierynomus/sshj"]
 image:https://maven-badges.herokuapp.com/maven-central/com.hierynomus/sshj/badge.svg["Maven Central",link="https://maven-badges.herokuapp.com/maven-central/com.hierynomus/sshj"]
@@ -96,7 +95,7 @@ If you need something that is not included, it shouldn't be too hard to add (do
 http://ssh-comparison.quendi.de/comparison.html[SSH Implementation Comparison]
 
 == Dependencies
-Java 6+. http://www.slf4j.org/download.html[slf4j] is required. http://www.bouncycastle.org/java.html[bouncycastle] is highly recommended and required for using some of the crypto algorithms. http://www.jcraft.com/jzlib/[jzlib] is required for using zlib compression.
+Java 7+. http://www.slf4j.org/download.html[slf4j] is required. http://www.bouncycastle.org/java.html[bouncycastle] is highly recommended and required for using some of the crypto algorithms.
 
 == Reporting bugs
 Issue tracker: https://github.com/hierynomus/sshj/issues
@@ -105,6 +104,48 @@ Issue tracker: https://github.com/hierynomus/sshj/issues
 Fork away!
 
 == Release history
+SSHJ 0.35.0 (2023-01-30)::
+* Merged https://github.com/hierynomus/sshj/pull/835[#835]: TimeoutException message improved
+* Merged https://github.com/hierynomus/sshj/pull/815[#815]: Support authPassword on FreeBSD
+* Merged https://github.com/hierynomus/sshj/pull/813[#813]: Prevent `CHANNEL_CLOSE` between isOpen and write call.
+* Merged https://github.com/hierynomus/sshj/pull/811[#811]: Add `Transport.isKeyExchangeREquired` to prevent unnecessary KEXINIT
+SSHJ 0.34.0 (2022-08-10)::
+* Merged https://github.com/hierynomus/sshj/pull/743[#743]: Use default client credentials for AuthGssApiWithMic
+* Merged https://github.com/hierynomus/sshj/pull/801[#801]: Restore thread interrupt status after catching InterruptedException
+* Merged https://github.com/hierynomus/sshj/pull/793[#793]: Merge PKCS5 and PKCS8 classes
+* Upgraded dependencies SLF4J (1.7.36) and Logback (1.2.11)
+* Merged https://github.com/hierynomus/sshj/pull/791[#791]: Update KeepAlive examples
+* Merged https://github.com/hierynomus/sshj/pull/775[#775]: Add SFTP resume support
+SSHJ 0.33.0 (2022-04-22)::
+* Upgraded dependencies BouncyCastle (1.70)
+* Merged https://github.com/hierynomus/sshj/pull/687[#687]: Correctly close connection when remote closes connection.
+* Merged https://github.com/hierynomus/sshj/pull/741[#741]: Add support for testcontainers in test setup to test more scenarios
+* Merged https://github.com/hierynomus/sshj/pull/733[#733]: Send correct key proposal if client knows CA key
+* Merged https://github.com/hierynomus/sshj/pull/746[#746]: Fix bug in reading Putty private key file with passphrase
+* Merged https://github.com/hierynomus/sshj/pull/742[#742]: Use Config.keyAlgorithms to determine rsa-sha2 support
+* Merged https://github.com/hierynomus/sshj/pull/754[#754]: Use SFTP protocol version to set FXP rename flags conditionally
+* Merged https://github.com/hierynomus/sshj/pull/752[#752]: Correctly start and terminate KeepAlive thread
+* Merged https://github.com/hierynomus/sshj/pull/753[#753]: Provide better thread names
+* Merged https://github.com/hierynomus/sshj/pull/724[#724]: Add parameter to limit read ahead length
+* Merged https://github.com/hierynomus/sshj/pull/763[#763]: Try all public key algorithms for a specific key type
+* Merged https://github.com/hierynomus/sshj/pull/756[#756]: Remove deprecated proxy connect methods
+* Merged https://github.com/hierynomus/sshj/pull/770[#770]: Add support for `ed25519` `aes-128-cbc` keys
+* Merged https://github.com/hierynomus/sshj/pull/773[#773]: Fix NPE when reading empty OpenSSHKeyV1KeyFile
+* Merged https://github.com/hierynomus/sshj/pull/777[#777]: Don't request too many read-ahead packets
+
+SSHJ 0.32.0 (2021-10-12)::
+* Send EOF on channel close (Fixes https://github.com/hierynomus/sshj/issues/143[#143], https://github.com/hierynomus/sshj/issues/496[#496], https://github.com/hierynomus/sshj/issues/553[#553], https://github.com/hierynomus/sshj/issues/554[#554])
+* Merged https://github.com/hierynomus/sshj/pull/726[#726]: Parse OpenSSH v1 keys with full CRT information present
+* Merged https://github.com/hierynomus/sshj/pull/721[#721]: Prefer known host key algorithm for host key verification
+* Merged https://github.com/hierynomus/sshj/pull/716[#716], https://github.com/hierynomus/sshj/pull/729[#729] and https://github.com/hierynomus/sshj/pull/730[#730]: Add full support for PuTTY v3 key files.
+* Merged https://github.com/hierynomus/sshj/pull/708[#708] and https://github.com/hierynomus/sshj/pull/713[#71]: Add support for PKCS#8 private keys
+* Merged https://github.com/hierynomus/sshj/pull/703[#703]: Support host certificate keys
+* Upgraded dependencies BouncyCastle (1.69), SLF4j (1.7.32), Logback (1.2.6), asn-one (0.6.0)
+* Merged https://github.com/hierynomus/sshj/pull/702[#702]: Support Public key authentication using certificates
+* Merged https://github.com/hierynomus/sshj/pull/691[#691]: Fix for writing negative unsigned integers to Buffer
+* Merged https://github.com/hierynomus/sshj/pull/682[#682]: Support for chacha20-poly1305@openssh.com cipher
+* Merged https://github.com/hierynomus/sshj/pull/680[#680]: Configurable preserve mtimes for SCP transfers
+
 SSHJ 0.31.0 (2021-02-08)::
 * Bump dependencies (asn-one 0.5.0, BouncyCastle 1.68, slf4j-api 1.7.30)
 * Merged https://github.com/hierynomus/sshj/pull/660[#660]: Support ED25519 and ECDSA keys in PuTTY format

build-publishing.gradle

@@ -23,7 +23,6 @@ dependencies {
   compile "org.slf4j:slf4j-api:1.7.7"
   compile "org.bouncycastle:bcprov-jdk15on:$bouncycastleVersion"
   compile "org.bouncycastle:bcpkix-jdk15on:$bouncycastleVersion"
-  compile "com.jcraft:jzlib:1.1.3"
 
   testCompile "junit:junit:4.11"
   testCompile "org.mockito:mockito-core:1.9.5"

build.gradle

@@ -1,23 +1,23 @@
-import java.text.SimpleDateFormat
-import com.bmuschko.gradle.docker.tasks.container.*
-import com.bmuschko.gradle.docker.tasks.image.*
-
 plugins {
   id "java"
   id "groovy"
   id "jacoco"
-  id "com.github.blindpirate.osgi" version '0.0.3'
+  id "com.github.blindpirate.osgi" version '0.0.6'
   id "maven-publish"
-  id 'pl.allegro.tech.build.axion-release' version '1.11.0'
-  id "com.bmuschko.docker-remote-api" version "6.4.0"
-  id "com.github.hierynomus.license" version "0.12.1"
-  id "com.jfrog.bintray" version "1.8.5"
-  id 'ru.vyarus.java-lib' version '1.0.5'
-  // id 'ru.vyarus.pom' version '1.0.3'
-  id 'ru.vyarus.github-info' version '1.1.0'
+  id "signing"
+  id 'pl.allegro.tech.build.axion-release' version '1.13.3'
+  id "com.bmuschko.docker-remote-api" version "7.1.0"
+  id "com.github.hierynomus.license" version "0.16.1"
+  id 'ru.vyarus.github-info' version '1.2.0'
+  id "io.github.gradle-nexus.publish-plugin" version "1.0.0"
+}
+
+repositories {
+  mavenCentral()
 }
 
 group = "com.hierynomus"
+defaultTasks ["build"]
 ext.moduleName = "${project.group}.${project.name}"
 
 scmVersion {
@@ -33,36 +33,29 @@ scmVersion {
 
 project.version = scmVersion.version
 
-defaultTasks "build"
+configurations.implementation.transitive = false
 
-repositories {
-  mavenCentral()
-}
-
-configurations.compile.transitive = false
-
-def bouncycastleVersion = "1.69"
-def sshdVersion = "2.1.0"
+def bouncycastleVersion = "1.70"
+def sshdVersion = "2.8.0"
 
 dependencies {
-  implementation "org.slf4j:slf4j-api:1.7.30"
+  implementation "org.slf4j:slf4j-api:1.7.36"
   implementation "org.bouncycastle:bcprov-jdk15on:$bouncycastleVersion"
   implementation "org.bouncycastle:bcpkix-jdk15on:$bouncycastleVersion"
-  implementation "com.jcraft:jzlib:1.1.3"
-  implementation "com.hierynomus:asn-one:0.5.0"
+  implementation "com.hierynomus:asn-one:0.6.0"
 
   implementation "net.i2p.crypto:eddsa:0.3.0"
 
-  testImplementation "junit:junit:4.12"
+  testImplementation "junit:junit:4.13.2"
   testImplementation 'org.spockframework:spock-core:1.3-groovy-2.4'
-  testImplementation "org.mockito:mockito-core:2.28.2"
+  testImplementation "org.mockito:mockito-core:4.2.0"
   testImplementation "org.apache.sshd:sshd-core:$sshdVersion"
   testImplementation "org.apache.sshd:sshd-sftp:$sshdVersion"
   testImplementation "org.apache.sshd:sshd-scp:$sshdVersion"
-  testRuntimeOnly "ch.qos.logback:logback-classic:1.2.3"
+  testImplementation "ch.qos.logback:logback-classic:1.2.11"
   testImplementation 'org.glassfish.grizzly:grizzly-http-server:2.4.4'
-  testImplementation 'org.apache.httpcomponents:httpclient:4.5.9'
-
+  testImplementation 'org.apache.httpcomponents:httpclient:4.5.13'
+  testImplementation 'org.testcontainers:testcontainers:1.16.2'
 }
 
 license {
@@ -71,7 +64,11 @@ license {
   mapping {
     java = 'SLASHSTAR_STYLE'
   }
-  excludes(['**/djb/Curve25519.java', '**/sshj/common/Base64.java', '**/org/mindrot/jbcrypt/*.java'])
+  excludes([
+    '**/sshj/common/Base64.java',
+    '**/com/hierynomus/sshj/userauth/keyprovider/bcrypt/*.java',
+    '**/files/test_file_*.txt',
+  ])
 }
 
 if (!JavaVersion.current().isJava9Compatible()) {
@@ -85,7 +82,6 @@ if (JavaVersion.current().isJava8Compatible()) {
   }
 }
 
-
 compileJava {
   options.compilerArgs.addAll(['--release', '7'])
 }
@@ -123,6 +119,12 @@ jar {
   }
 }
 
+
+java {
+	withJavadocJar()
+	withSourcesJar()
+}
+
 sourcesJar {
   manifest {
     attributes(
@@ -188,71 +190,82 @@ github {
   license 'Apache'
 }
 
-pom {
-  description "SSHv2 library for Java"
-  url "https://github.com/hierynomus/sshj"
-  inceptionYear "2009"
-  developers {
-    developer {
-      id "hierynomus"
-      name "Jeroen van Erp"
-      email "jeroen@javadude.nl"
-      roles {
-        role "Lead developer"
-      }
-    }
-    developer {
-      id "shikhar"
-      name "Shikhar Bhushan"
-      email "shikhar@schmizz.net"
-      url "http://schmizz.net"
-      roles {
-        role "Previous lead developer"
-      }
-    }
-    developer {
-      id "iterate"
-      name "David Kocher"
-      email "dkocher@iterate.ch"
-      organization "iterage GmbH"
-      organizationUrl "https://iterate.ch"
-      roles {
-        role "Developer"
-      }
-    }
-  }
+publishing {
+	publications {
+		maven(MavenPublication) {
+			from(components.java)
+		}
+	}
 }
 
-if (project.hasProperty("bintrayUsername") && project.hasProperty("bintrayApiKey")) {
-  bintray {
-    user = project.property("bintrayUsername")
-    key = project.property("bintrayApiKey")
-    publish = true
-    publications = ["maven"]
-    pkg {
-      repo = "maven"
-      name = "${project.name}"
-      licenses = ["Apache-2.0"]
-      vcsUrl = "https://github.com/hierynomus/sshj.git"
-      labels = ["ssh", "sftp", "secure-shell", "network", "file-transfer"]
-      githubRepo = "hierynomus/sshj"
-      version {
-        name = "${project.version}"
-        vcsTag = "v${project.version}"
-        released = new SimpleDateFormat('yyyy-MM-dd\'T\'HH:mm:ss.SSSZZ').format(new Date())
-        gpg {
-          sign = true
-          passphrase = project.property("signing.password")
-        }
-        mavenCentralSync {
-          sync = true
-          user = project.property("sonatypeUsername")
-          password = project.property("sonatypePassword")
-          close = 1
+project.signing {
+  required { project.gradle.taskGraph.hasTask("release") }
+	sign publishing.publications.maven
+
+  if (project.hasProperty("signingKeyId") || project.hasProperty("signingKey")) {
+		def signingKeyId = project.findProperty("signingKeyId")
+		def signingKey = project.findProperty("signingKey")
+		def signingPassword = project.findProperty("signingPassword")
+		if (signingKeyId) {
+			useInMemoryPgpKeys(signingKeyId, signingKey, signingPassword)
+		} else if (signingKey) {
+			useInMemoryPgpKeys(signingKey, signingPassword)
+		}
+	}
+}
+
+project.plugins.withType(MavenPublishPlugin).all {
+	PublishingExtension publishing = project.extensions.getByType(PublishingExtension)
+	publishing.publications.withType(MavenPublication).all { mavenPublication ->
+		mavenPublication.pom {
+			name = "${project.name}"
+      description = 'SSHv2 library for Java'
+      inceptionYear = '2009'
+      url = "https://github.com/hierynomus/${project.name}"
+			licenses {
+				license {
+					name = "The Apache License, Version 2.0"
+					url = "https://www.apache.org/licenses/LICENSE-2.0"
+				}
+			}
+			developers {
+				developer {
+					id = "hierynomus"
+					name = "Jeroen van Erp"
+					email = "jeroen@hierynomus.com"
+				}
+				developer {
+					id = "shikhar"
+					name = "Shikhar Bhushan"
+					email = "shikhar@schmizz.net"
+          url = "http://schmizz.net"
+          roles = ["Previous Lead developer"]
+				}
+        developer {
+          id = "iterate"
+          name = "David Kocher"
+          email = "dkocher@iterate.ch"
+          organization = "iterate GmbH"
+          organizationUrl = "https://iterate.ch"
+          roles = ["Developer"]
         }
+			}
+      scm {
+        url = "https://github.com/hierynomus/${project.name}"
+        connection = "scm:git@github.com:hierynomus/${project.name}.git"
+        developerConnection = "scm:git@github.com:hierynomus/${project.name}.git"
       }
-    }
-  }
+		}
+	}
+}
+
+nexusPublishing {
+	repositories {
+		sonatype()    //sonatypeUsername and sonatypePassword properties are used automatically
+	}
+
+	connectTimeout = Duration.ofMinutes(3)
+	clientTimeout = Duration.ofMinutes(3)
 }
 
 jacocoTestReport {
@@ -262,48 +275,11 @@ jacocoTestReport {
     }
 }
 
-
-task buildItestImage(type: DockerBuildImage) {
-    inputDir = file('src/itest/docker-image')
-    images.add('sshj/sshd-itest:latest')
-}
-
-task createItestContainer(type: DockerCreateContainer) {
-    dependsOn buildItestImage
-    targetImageId buildItestImage.getImageId()
-    hostConfig.portBindings = ['2222:22']
-    hostConfig.autoRemove = true
-}
-
-task startItestContainer(type: DockerStartContainer) {
-    dependsOn createItestContainer
-    targetContainerId createItestContainer.getContainerId()
-}
-
-task logItestContainer(type: DockerLogsContainer) {
-    dependsOn createItestContainer
-    targetContainerId createItestContainer.getContainerId()
-    showTimestamps = true
-    stdErr = true
-    stdOut = true
-    tailAll = true
-}
-
-task stopItestContainer(type: DockerStopContainer) {
-    targetContainerId createItestContainer.getContainerId()
-}
-
 task forkedUploadRelease(type: GradleBuild) {
   buildFile = project.buildFile
-  tasks = ["bintrayUpload"]
+  tasks = ["clean", "publishToSonatype", "closeAndReleaseSonatypeStagingRepository"]
 }
 
-project.tasks.integrationTest.dependsOn(startItestContainer)
-project.tasks.integrationTest.finalizedBy(stopItestContainer)
-
-// Being enabled, it pollutes logs on CI. Uncomment when debugging some test to get sshd logs.
-// project.tasks.stopItestContainer.dependsOn(logItestContainer)
-
 project.tasks.release.dependsOn([project.tasks.integrationTest, project.tasks.build])
 project.tasks.release.finalizedBy(project.tasks.forkedUploadRelease)
 project.tasks.jacocoTestReport.dependsOn(project.tasks.test)

examples/pom.xml

@@ -24,7 +24,7 @@
     <groupId>com.hierynomus</groupId>
     <artifactId>sshj-examples</artifactId>
     <packaging>jar</packaging>
-    <version>0.19.1</version>
+    <version>0.33.0</version>
 
     <name>sshj-examples</name>
     <description>Examples for SSHv2 library for Java</description>
@@ -55,7 +55,7 @@
         <dependency>
             <groupId>com.hierynomus</groupId>
             <artifactId>sshj</artifactId>
-            <version>0.31.0</version>
+            <version>0.33.0</version>
         </dependency>
     </dependencies>
 

examples/src/main/java/net/schmizz/sshj/examples/KeepAlive.java

@@ -19,8 +19,9 @@ public class KeepAlive {
         final SSHClient ssh = new SSHClient(defaultConfig);
         try {
             ssh.addHostKeyVerifier(new PromiscuousVerifier());
+            // Set interval to enable keep-alive before connecting
+            ssh.getConnection().getKeepAlive().setKeepAliveInterval(5);
             ssh.connect(args[0]);
-            ssh.getConnection().getKeepAlive().setKeepAliveInterval(5); //every 60sec
             ssh.authPassword(args[1], args[2]);
             Session session = ssh.startSession();
             session.allocateDefaultPTY();

examples/src/main/java/net/schmizz/sshj/examples/RemotePF.java

@@ -19,6 +19,7 @@ public class RemotePF {
         client.loadKnownHosts();
 
         client.connect("localhost");
+        client.getConnection().getKeepAlive().setKeepAliveInterval(5);
         try {
 
             client.authPublickey(System.getProperty("user.name"));
@@ -33,8 +34,6 @@ public class RemotePF {
                     // what we do with incoming connections that are forwarded to us
                     new SocketForwardingConnectListener(new InetSocketAddress("google.com", 80)));
 
-            client.getTransport().setHeartbeatInterval(30);
-
             // Something to hang on to so that the forwarding stays
             client.getTransport().join();
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/itest/docker-image/Dockerfile

@@ -1,24 +0,0 @@
-FROM sickp/alpine-sshd:7.5-r2
-
-ADD authorized_keys /home/sshj/.ssh/authorized_keys
-
-ADD test-container/ssh_host_ecdsa_key     /etc/ssh/ssh_host_ecdsa_key
-ADD test-container/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub
-ADD test-container/ssh_host_ed25519_key   /etc/ssh/ssh_host_ed25519_key
-ADD test-container/ssh_host_ed25519_key.pub   /etc/ssh/ssh_host_ed25519_key.pub
-ADD test-container/sshd_config /etc/ssh/sshd_config
-COPY test-container/trusted_ca_keys /etc/ssh/trusted_ca_keys
-COPY test-container/host_keys/* /etc/ssh/
-
-RUN apk add --no-cache tini
-RUN \
-  echo "root:smile" | chpasswd && \
-  adduser -D -s /bin/ash sshj && \
-  passwd -u sshj && \
-  echo "sshj:ultrapassword" | chpasswd && \
-  chmod 600 /home/sshj/.ssh/authorized_keys && \
-  chmod 600 /etc/ssh/ssh_host_*_key && \
-  chmod 644 /etc/ssh/*.pub && \
-  chown -R sshj:sshj /home/sshj
-
-ENTRYPOINT ["/sbin/tini", "/entrypoint.sh", "-o", "LogLevel=DEBUG2"]

src/itest/docker-image/authorized_keys

@@ -3,6 +3,7 @@ ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBHQiZm0w
 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDAdJiRkkBM8yC8seTEoAn2PfwbLKrkcahZ0xxPoWICJ root@sshj
 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJ8ww4hJG/gHJYdkjTTBDF1GNz+228nuWprPV+NbQauA ajvanerp@Heimdall.local
 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOaWrwt3drIOjeBq2LSHRavxAT7ja2f+5soOUJl/zKSI ajvanerp@Heimdall.xebialabs.com
+ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICYfPGSYFOHuSzTJ67H0ynvKJDfgDmwPOj7iJaLGbIBi sshjtest@TranceLove
 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAoZ9l6Tkm2aL1tSBy2yw4xU5s8BE9MfqS/4J7DzvsYJxF6oQmTIjmStuhH/CT7UjuDtKXdXZUsIhKtafiizxGO8kHSzKDeitpth2RSr8ddMzZKyD6RNs7MfsgjA3UTtrrSrCXEY6O43S2cnuJrWzkPxtwxaQ3zOvDbS2tiulzyq0VzYmuhA/a4CyuQtJBuu+P2oqmu6pU/VB6IzONpvBvYbNPsH1WDmP7zko5wHPihXPCliztspKxS4DRtOZ7BGXyvg44UmIy0Kf4jOkaBV/eCCA4qH7ZHz71/5ceMOpszPcNOEmLGGYhwI+P3OuGMpkrSAv1f8IY6R8spZNncP6UaQ== no-passphrase
 ssh-rsa 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 ajvanerp@Heimdall.local
 ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBMvfRYSe44VQGwxexOMibcM3+fWeUP1jrBofOxFDRRrzRF8dK/vll2svqTPXMRnITnT1UoemEcB5OHtvH4hzfh/HFeDxJ5S7UncYxoClTSa8MeMFG2Zj9CoUZs1SHbwSGg== root@sshj

src/itest/docker-image/test-container/sshd_config

@@ -1,158 +0,0 @@
-#	$OpenBSD: sshd_config,v 1.101 2017/03/14 07:19:07 djm Exp $
-
-# This is the sshd server system-wide configuration file.  See
-# sshd_config(5) for more information.
-
-# This sshd was compiled with PATH=/bin:/usr/bin:/sbin:/usr/sbin
-
-# The strategy used for options in the default sshd_config shipped with
-# OpenSSH is to specify options with their default value where
-# possible, but leave them commented.  Uncommented options override the
-# default value.
-
-#Port 22
-#AddressFamily any
-#ListenAddress 0.0.0.0
-#ListenAddress ::
-
-#HostKey /etc/ssh/ssh_host_rsa_key
-#HostKey /etc/ssh/ssh_host_dsa_key
-#HostKey /etc/ssh/ssh_host_ecdsa_key
-#HostKey /etc/ssh/ssh_host_ed25519_key
-
-# Ciphers and keying
-#RekeyLimit default none
-
-# Logging
-#SyslogFacility AUTH
-#LogLevel INFO
-
-# Authentication:
-
-#LoginGraceTime 2m
-PermitRootLogin yes
-#StrictModes yes
-#MaxAuthTries 6
-#MaxSessions 10
-
-#PubkeyAuthentication yes
-
-# The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2
-# but this is overridden so installations will only check .ssh/authorized_keys
-AuthorizedKeysFile	.ssh/authorized_keys
-
-#AuthorizedPrincipalsFile none
-
-#AuthorizedKeysCommand none
-#AuthorizedKeysCommandUser nobody
-
-# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
-#HostbasedAuthentication no
-# Change to yes if you don't trust ~/.ssh/known_hosts for
-# HostbasedAuthentication
-#IgnoreUserKnownHosts no
-# Don't read the user's ~/.rhosts and ~/.shosts files
-#IgnoreRhosts yes
-
-# To disable tunneled clear text passwords, change to no here!
-#PasswordAuthentication yes
-#PermitEmptyPasswords no
-
-# Change to no to disable s/key passwords
-#ChallengeResponseAuthentication yes
-
-# Kerberos options
-#KerberosAuthentication no
-#KerberosOrLocalPasswd yes
-#KerberosTicketCleanup yes
-#KerberosGetAFSToken no
-
-# GSSAPI options
-#GSSAPIAuthentication no
-#GSSAPICleanupCredentials yes
-
-# Set this to 'yes' to enable PAM authentication, account processing,
-# and session processing. If this is enabled, PAM authentication will
-# be allowed through the ChallengeResponseAuthentication and
-# PasswordAuthentication.  Depending on your PAM configuration,
-# PAM authentication via ChallengeResponseAuthentication may bypass
-# the setting of "PermitRootLogin without-password".
-# If you just want the PAM account and session checks to run without
-# PAM authentication, then enable this but set PasswordAuthentication
-# and ChallengeResponseAuthentication to 'no'.
-#UsePAM no
-
-#AllowAgentForwarding yes
-#AllowTcpForwarding yes
-#GatewayPorts no
-#X11Forwarding no
-#X11DisplayOffset 10
-#X11UseLocalhost yes
-#PermitTTY yes
-#PrintMotd yes
-#PrintLastLog yes
-#TCPKeepAlive yes
-#UseLogin no
-#PermitUserEnvironment no
-#Compression delayed
-#ClientAliveInterval 0
-#ClientAliveCountMax 3
-#UseDNS no
-#PidFile /run/sshd.pid
-#MaxStartups 10:30:100
-#PermitTunnel no
-#ChrootDirectory none
-#VersionAddendum none
-
-# no default banner path
-#Banner none
-
-# override default of no subsystems
-Subsystem	sftp	/usr/lib/ssh/sftp-server
-
-# the following are HPN related configuration options
-# tcp receive buffer polling. disable in non autotuning kernels
-#TcpRcvBufPoll yes
-
-# disable hpn performance boosts
-#HPNDisabled no
-
-# buffer size for hpn to non-hpn connections
-#HPNBufferSize 2048
-
-
-# Example of overriding settings on a per-user basis
-#Match User anoncvs
-#	X11Forwarding no
-#	AllowTcpForwarding no
-#	PermitTTY no
-#	ForceCommand cvs server
-
-KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1
-macs umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com
-
-TrustedUserCAKeys /etc/ssh/trusted_ca_keys
-
-Ciphers 3des-cbc,blowfish-cbc,aes128-cbc,aes192-cbc,aes256-cbc,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com
-
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
-HostKey /etc/ssh/ssh_host_ecdsa_key
-HostKey /etc/ssh/ssh_host_ed25519_key
-
-HostKey /etc/ssh/ssh_host_ecdsa_256_key
-HostCertificate /etc/ssh/ssh_host_ecdsa_256_key-cert.pub
-
-HostKey /etc/ssh/ssh_host_ecdsa_384_key
-HostCertificate /etc/ssh/ssh_host_ecdsa_384_key-cert.pub
-
-HostKey /etc/ssh/ssh_host_ecdsa_521_key
-HostCertificate /etc/ssh/ssh_host_ecdsa_521_key-cert.pub
-
-HostKey /etc/ssh/ssh_host_ed25519_384_key
-HostCertificate /etc/ssh/ssh_host_ed25519_384_key-cert.pub
-
-HostKey /etc/ssh/ssh_host_rsa_2048_key
-HostCertificate /etc/ssh/ssh_host_rsa_2048_key-cert.pub
-
-LogLevel DEBUG2

src/itest/groovy/com/hierynomus/sshj/IntegrationBaseSpec.groovy

@@ -1,42 +0,0 @@
-/*
- * Copyright (C)2009 - SSHJ Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.hierynomus.sshj
-
-import net.schmizz.sshj.Config
-import net.schmizz.sshj.DefaultConfig
-import net.schmizz.sshj.SSHClient
-import net.schmizz.sshj.transport.verification.PromiscuousVerifier
-import spock.lang.Specification
-
-class IntegrationBaseSpec extends Specification {
-    protected static final int DOCKER_PORT = 2222
-    protected static final String USERNAME = "sshj"
-    protected static final String KEYFILE = "src/itest/resources/keyfiles/id_rsa"
-    protected final static String SERVER_IP = System.getProperty("serverIP", "127.0.0.1")
-
-    protected static SSHClient getConnectedClient(Config config) {
-        SSHClient sshClient = new SSHClient(config)
-        sshClient.addHostKeyVerifier(new PromiscuousVerifier())
-        sshClient.connect(SERVER_IP, DOCKER_PORT)
-
-        return sshClient
-    }
-
-    protected static SSHClient getConnectedClient() throws IOException {
-        return getConnectedClient(new DefaultConfig())
-    }
-
-}

src/itest/groovy/com/hierynomus/sshj/IntegrationSpec.groovy

@@ -20,9 +20,15 @@ import net.schmizz.sshj.DefaultConfig
 import net.schmizz.sshj.SSHClient
 import net.schmizz.sshj.transport.TransportException
 import net.schmizz.sshj.userauth.UserAuthException
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class IntegrationSpec extends IntegrationBaseSpec {
+class IntegrationSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "should accept correct key for #signatureName"() {
@@ -33,7 +39,7 @@ class IntegrationSpec extends IntegrationBaseSpec {
         sshClient.addHostKeyVerifier(fingerprint) // test-containers/ssh_host_ecdsa_key's fingerprint
 
         when:
-        sshClient.connect(SERVER_IP, DOCKER_PORT)
+        sshClient.connect(sshd.containerIpAddress, sshd.firstMappedPort)
 
         then:
         sshClient.isConnected()
@@ -50,7 +56,7 @@ class IntegrationSpec extends IntegrationBaseSpec {
         sshClient.addHostKeyVerifier("d4:6a:a9:52:05:ab:b5:48:dd:73:60:18:0c:3a:f0:a3")
 
         when:
-        sshClient.connect(SERVER_IP, DOCKER_PORT)
+        sshClient.connect(sshd.containerIpAddress, sshd.firstMappedPort)
 
         then:
         thrown(TransportException.class)
@@ -59,11 +65,11 @@ class IntegrationSpec extends IntegrationBaseSpec {
     @Unroll
     def "should authenticate with key #key"() {
         given:
-        SSHClient client = getConnectedClient()
+        SSHClient client = sshd.getConnectedClient()
 
         when:
         def keyProvider = passphrase != null ? client.loadKeys("src/itest/resources/keyfiles/$key", passphrase) : client.loadKeys("src/itest/resources/keyfiles/$key")
-        client.authPublickey(USERNAME, keyProvider)
+        client.authPublickey(IntegrationTestUtil.USERNAME, keyProvider)
 
         then:
         client.isAuthenticated()
@@ -74,6 +80,7 @@ class IntegrationSpec extends IntegrationBaseSpec {
         "id_ecdsa_opensshv1" | null
         "id_ed25519_opensshv1" | null
         "id_ed25519_opensshv1_aes256cbc.pem" | "foobar"
+        "id_ed25519_opensshv1_aes128cbc.pem" | "sshjtest"
         "id_ed25519_opensshv1_protected" | "sshjtest"
         "id_rsa" | null
         "id_rsa_opensshv1" | null
@@ -83,7 +90,7 @@ class IntegrationSpec extends IntegrationBaseSpec {
 
    def "should not authenticate with wrong key"() {
         given:
-        SSHClient client = getConnectedClient()
+        SSHClient client = sshd.getConnectedClient()
 
         when:
         client.authPublickey("sshj", "src/itest/resources/keyfiles/id_unknown_key")

src/itest/groovy/com/hierynomus/sshj/IntegrationTestUtil.groovy

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj
+
+class IntegrationTestUtil {
+    static final String USERNAME = "sshj"
+    static final String KEYFILE = "src/itest/resources/keyfiles/id_rsa"
+}

src/itest/groovy/com/hierynomus/sshj/ManyChannelsSpec.groovy

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj
+
+import net.schmizz.sshj.SSHClient
+import net.schmizz.sshj.common.IOUtils
+import net.schmizz.sshj.connection.channel.direct.Session
+import spock.lang.Specification
+
+import java.util.concurrent.*
+
+import static org.codehaus.groovy.runtime.IOGroovyMethods.withCloseable
+
+class ManyChannelsSpec extends Specification {
+
+    def "should work with many channels without nonexistent channel error (GH issue #805)"() {
+        given:
+        SshdContainer sshd = new SshdContainer.Builder()
+                .withSshdConfig("""${SshdContainer.Builder.DEFAULT_SSHD_CONFIG}
+                MaxSessions 200
+                """.stripMargin())
+                .build()
+        sshd.start()
+        SSHClient client = sshd.getConnectedClient()
+        client.authPublickey("sshj", "src/test/resources/id_rsa")
+
+        when:
+        List<Future<Exception>> futures = []
+        ExecutorService executorService = Executors.newCachedThreadPool()
+
+        for (int i in 0..20) {
+            futures.add(executorService.submit((Callable<Exception>) {
+                return execute(client)
+            }))
+        }
+        executorService.shutdown()
+        executorService.awaitTermination(1, TimeUnit.DAYS)
+
+        then:
+        futures*.get().findAll { it != null }.empty
+
+        cleanup:
+        client.close()
+    }
+
+
+    private static Exception execute(SSHClient sshClient) {
+        try {
+            for (def i in 0..100) {
+                withCloseable (sshClient.startSession()) {sshSession ->
+                    Session.Command sshCommand = sshSession.exec("ls -la")
+                    IOUtils.readFully(sshCommand.getInputStream()).toString()
+                    sshCommand.close()
+                }
+            }
+        } catch (Exception e) {
+            return e
+        }
+        return null
+    }
+}

src/itest/groovy/com/hierynomus/sshj/RsaShaKeySignatureTest.groovy

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj
+
+import com.hierynomus.sshj.key.KeyAlgorithms
+import net.schmizz.sshj.Config
+import net.schmizz.sshj.DefaultConfig
+import org.testcontainers.images.builder.dockerfile.DockerfileBuilder
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import java.nio.file.Paths
+
+/**
+ * Checks that SSHJ is able to work with OpenSSH 8.8, which removed ssh-rsa signature from the default setup.
+ */
+class RsaShaKeySignatureTest extends Specification {
+    private static final Map<String, KeyAlgorithms.Factory> SSH_HOST_KEYS_AND_FACTORIES = [
+        'ssh_host_ecdsa_256_key': KeyAlgorithms.ECDSASHANistp256(),
+        'ssh_host_ecdsa_384_key': KeyAlgorithms.ECDSASHANistp384(),
+        'ssh_host_ecdsa_521_key': KeyAlgorithms.ECDSASHANistp521(),
+        'ssh_host_ed25519_384_key': KeyAlgorithms.EdDSA25519(),
+        'ssh_host_rsa_2048_key': KeyAlgorithms.RSASHA512(),
+    ]
+
+    private static void dockerfileBuilder(DockerfileBuilder it, String hostKey, String pubkeyAcceptedAlgorithms) {
+        it.from("archlinux:base")
+        it.run('yes | pacman -Sy core/openssh' +
+                ' && (' +
+                '  V=$(echo $(/usr/sbin/sshd -h 2>&1) | grep -o \'OpenSSH_[0-9][0-9]*[.][0-9][0-9]*p[0-9]\');' +
+                '  if [[ "$V" < OpenSSH_8.8p1 ]]; then' +
+                '    echo $V is too old 1>&2;' +
+                '    exit 1;' +
+                '   fi' +
+                ')' +
+                ' && set -o pipefail ' +
+                ' && useradd --create-home sshj' +
+                ' && echo \"sshj:ultrapassword\" | chpasswd')
+        it.add("authorized_keys", "/home/sshj/.ssh/")
+        it.add(hostKey, '/etc/ssh/')
+        it.run('chmod go-rwx /etc/ssh/ssh_host_*' +
+                ' && chown -R sshj /home/sshj/.ssh' +
+                ' && chmod -R go-rwx /home/sshj/.ssh')
+        it.expose(22)
+
+        def cmd = [
+                '/usr/sbin/sshd',
+                '-D',
+                '-e',
+                '-f', '/dev/null',
+                '-o', 'LogLevel=DEBUG2',
+                '-o', "HostKey=/etc/ssh/$hostKey",
+        ]
+        if (pubkeyAcceptedAlgorithms != null) {
+            cmd += ['-o', "PubkeyAcceptedAlgorithms=$pubkeyAcceptedAlgorithms"]
+        }
+        it.cmd(cmd as String[])
+    }
+
+    private static SshdContainer makeSshdContainer(String hostKey, String pubkeyAcceptedAlgorithms) {
+        return new SshdContainer(new SshdContainer.DebugLoggingImageFromDockerfile()
+                .withFileFromPath("authorized_keys", Paths.get("src/itest/docker-image/authorized_keys"))
+                .withFileFromPath(hostKey, Paths.get("src/itest/docker-image/test-container/host_keys/$hostKey"))
+                .withDockerfileFromBuilder {
+                    dockerfileBuilder(it, hostKey, pubkeyAcceptedAlgorithms)
+                })
+    }
+
+    @Unroll
+    def "connect to a server with host key #hostKey that does not support ssh-rsa"() {
+        given:
+        SshdContainer sshd = makeSshdContainer(hostKey, "rsa-sha2-512,rsa-sha2-256,ssh-ed25519")
+        sshd.start()
+
+        and:
+        Config config = new DefaultConfig()
+        config.keyAlgorithms = [
+                KeyAlgorithms.RSASHA512(),
+                KeyAlgorithms.RSASHA256(),
+                SSH_HOST_KEYS_AND_FACTORIES[hostKey],
+        ]
+
+        when:
+        def sshClient = sshd.getConnectedClient(config)
+        sshClient.authPublickey("sshj", "src/itest/resources/keyfiles/id_rsa_opensshv1")
+
+        then:
+        sshClient.isAuthenticated()
+
+        cleanup:
+        sshClient?.disconnect()
+        sshd.stop()
+
+        where:
+        hostKey << SSH_HOST_KEYS_AND_FACTORIES.keySet()
+    }
+
+    @Unroll
+    def "connect to a default server with host key #hostKey using a default config"() {
+        given:
+        SshdContainer sshd = makeSshdContainer(hostKey, null)
+        sshd.start()
+
+        when:
+        def sshClient = sshd.getConnectedClient()
+        sshClient.authPublickey("sshj", "src/itest/resources/keyfiles/id_rsa_opensshv1")
+
+        then:
+        sshClient.isAuthenticated()
+
+        cleanup:
+        sshClient?.disconnect()
+        sshd.stop()
+
+        where:
+        hostKey << SSH_HOST_KEYS_AND_FACTORIES.keySet()
+    }
+
+    @Unroll
+    def "connect to a server with host key #hostkey that supports only ssh-rsa"() {
+        given:
+        SshdContainer sshd = makeSshdContainer(hostKey, "ssh-rsa,ssh-ed25519")
+        sshd.start()
+
+        and:
+        Config config = new DefaultConfig()
+        config.keyAlgorithms = [
+                KeyAlgorithms.SSHRSA(),
+                SSH_HOST_KEYS_AND_FACTORIES[hostKey],
+        ]
+
+        when:
+        def sshClient = sshd.getConnectedClient(config)
+        sshClient.authPublickey("sshj", "src/itest/resources/keyfiles/id_rsa_opensshv1")
+
+        then:
+        sshClient.isAuthenticated()
+
+        cleanup:
+        sshClient.disconnect()
+        sshd.stop()
+
+        where:
+        hostKey << SSH_HOST_KEYS_AND_FACTORIES.keySet()
+    }
+}

src/itest/groovy/com/hierynomus/sshj/SshServerWaitStrategy.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj;
+
+import org.testcontainers.containers.wait.strategy.WaitStrategy;
+import org.testcontainers.containers.wait.strategy.WaitStrategyTarget;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.util.Arrays;
+
+/**
+ * A wait strategy designed for {@link SshdContainer} to wait until the SSH server is ready, to avoid races when a test
+ * tries to connect to a server before the server has started.
+ */
+public class SshServerWaitStrategy implements WaitStrategy {
+    private Duration startupTimeout = Duration.ofMinutes(1);
+
+    @Override
+    public void waitUntilReady(WaitStrategyTarget waitStrategyTarget) {
+        long expectedEnd = System.nanoTime() + startupTimeout.toNanos();
+        while (waitStrategyTarget.isRunning()) {
+            long attemptStart = System.nanoTime();
+            IOException error = null;
+            byte[] buffer = new byte[7];
+            try (Socket socket = new Socket()) {
+                socket.setSoTimeout(500);
+                socket.connect(new InetSocketAddress(
+                        waitStrategyTarget.getHost(), waitStrategyTarget.getFirstMappedPort()));
+                // Haven't seen any SSH server that sends the version in two or more packets.
+                //noinspection ResultOfMethodCallIgnored
+                socket.getInputStream().read(buffer);
+                if (!Arrays.equals(buffer, "SSH-2.0".getBytes(StandardCharsets.UTF_8))) {
+                    error = new IOException("The version message doesn't look like an SSH server version");
+                }
+            } catch (IOException err) {
+                error = err;
+            }
+
+            if (error == null) {
+                break;
+            } else if (System.nanoTime() >= expectedEnd) {
+                throw new RuntimeException(error);
+            }
+
+            try {
+                //noinspection BusyWait
+                Thread.sleep(Math.max(0L, 500L - (System.nanoTime() - attemptStart) / 1_000_000));
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                break;
+            }
+        }
+    }
+
+    @Override
+    public WaitStrategy withStartupTimeout(Duration startupTimeout) {
+        this.startupTimeout = startupTimeout;
+        return this;
+    }
+}

src/itest/groovy/com/hierynomus/sshj/SshdContainer.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import net.schmizz.sshj.Config;
+import net.schmizz.sshj.DefaultConfig;
+import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.transport.verification.PromiscuousVerifier;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.LoggerFactory;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.images.builder.ImageFromDockerfile;
+import org.testcontainers.images.builder.dockerfile.DockerfileBuilder;
+import org.testcontainers.utility.DockerLoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.concurrent.Future;
+
+/**
+ * A JUnit4 rule for launching a generic SSH server container.
+ */
+public class SshdContainer extends GenericContainer<SshdContainer> {
+    /**
+     * A workaround for strange logger names of testcontainers. They contain no dots, but contain slashes,
+     * square brackets, and even emoji. It's uneasy to set the logging level via the XML file of logback, the
+     * result would be less readable than the code below.
+     */
+    public static class DebugLoggingImageFromDockerfile extends ImageFromDockerfile {
+        public DebugLoggingImageFromDockerfile() {
+            super();
+            Logger logger = (Logger) LoggerFactory.getILoggerFactory()
+                    .getLogger(DockerLoggerFactory.getLogger(getDockerImageName()).getName());
+            logger.setLevel(Level.DEBUG);
+        }
+    }
+
+    public static class Builder {
+        public static final String DEFAULT_SSHD_CONFIG = "" +
+                "PermitRootLogin yes\n" +
+                "AuthorizedKeysFile .ssh/authorized_keys\n" +
+                "Subsystem sftp /usr/lib/ssh/sftp-server\n" +
+                "KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1\n" +
+                "macs umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com\n" +
+                "TrustedUserCAKeys /etc/ssh/trusted_ca_keys\n" +
+                "Ciphers 3des-cbc,blowfish-cbc,aes128-cbc,aes192-cbc,aes256-cbc,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com\n" +
+                "HostKey /etc/ssh/ssh_host_rsa_key\n" +
+                "HostKey /etc/ssh/ssh_host_dsa_key\n" +
+                "HostKey /etc/ssh/ssh_host_ecdsa_key\n" +
+                "HostKey /etc/ssh/ssh_host_ed25519_key\n" +
+                "HostKey /etc/ssh/ssh_host_ecdsa_256_key\n" +
+                "HostCertificate /etc/ssh/ssh_host_ecdsa_256_key-cert.pub\n" +
+                "HostKey /etc/ssh/ssh_host_ecdsa_384_key\n" +
+                "HostCertificate /etc/ssh/ssh_host_ecdsa_384_key-cert.pub\n" +
+                "HostKey /etc/ssh/ssh_host_ecdsa_521_key\n" +
+                "HostCertificate /etc/ssh/ssh_host_ecdsa_521_key-cert.pub\n" +
+                "HostKey /etc/ssh/ssh_host_ed25519_384_key\n" +
+                "HostCertificate /etc/ssh/ssh_host_ed25519_384_key-cert.pub\n" +
+                "HostKey /etc/ssh/ssh_host_rsa_2048_key\n" +
+                "HostCertificate /etc/ssh/ssh_host_rsa_2048_key-cert.pub\n" +
+                "LogLevel DEBUG2\n";
+
+        public static void defaultDockerfileBuilder(@NotNull DockerfileBuilder builder) {
+            builder.from("sickp/alpine-sshd:7.5-r2");
+
+            builder.add("authorized_keys", "/home/sshj/.ssh/authorized_keys");
+
+            builder.add("test-container/ssh_host_ecdsa_key", "/etc/ssh/ssh_host_ecdsa_key");
+            builder.add("test-container/ssh_host_ecdsa_key.pub", "/etc/ssh/ssh_host_ecdsa_key.pub");
+            builder.add("test-container/ssh_host_ed25519_key", "/etc/ssh/ssh_host_ed25519_key");
+            builder.add("test-container/ssh_host_ed25519_key.pub", "/etc/ssh/ssh_host_ed25519_key.pub");
+            builder.copy("test-container/trusted_ca_keys", "/etc/ssh/trusted_ca_keys");
+            builder.copy("test-container/host_keys/*", "/etc/ssh/");
+
+            builder.run("apk add --no-cache tini"
+                    + " && echo \"root:smile\" | chpasswd"
+                    + " && adduser -D -s /bin/ash sshj"
+                    + " && passwd -u sshj"
+                    + " && echo \"sshj:ultrapassword\" | chpasswd"
+                    + " && chmod 600 /home/sshj/.ssh/authorized_keys"
+                    + " && chmod 600 /etc/ssh/ssh_host_*_key"
+                    + " && chmod 644 /etc/ssh/*.pub"
+                    + " && chown -R sshj:sshj /home/sshj");
+            builder.entryPoint("/sbin/tini", "/entrypoint.sh", "-o", "LogLevel=DEBUG2");
+
+            builder.add("sshd_config", "/etc/ssh/sshd_config");
+        }
+
+        private @NotNull String sshdConfig = DEFAULT_SSHD_CONFIG;
+
+        public @NotNull Builder withSshdConfig(@NotNull String sshdConfig) {
+            this.sshdConfig = sshdConfig;
+            return this;
+        }
+
+        public @NotNull SshdContainer build() {
+            return new SshdContainer(buildInner());
+        }
+
+        private @NotNull Future<String> buildInner() {
+            return new DebugLoggingImageFromDockerfile()
+                    .withDockerfileFromBuilder(Builder::defaultDockerfileBuilder)
+                    .withFileFromPath(".", Paths.get("src/itest/docker-image"))
+                    .withFileFromString("sshd_config", sshdConfig);
+        }
+    }
+
+    @SuppressWarnings("unused")  // Used dynamically by Spock
+    public SshdContainer() {
+        this(new SshdContainer.Builder().buildInner());
+    }
+
+    public SshdContainer(@NotNull Future<String> future) {
+        super(future);
+        withExposedPorts(22);
+        setWaitStrategy(new SshServerWaitStrategy());
+        withLogConsumer(outputFrame -> {
+            switch (outputFrame.getType()) {
+                case STDOUT:
+                    logger().info("sshd stdout: {}", outputFrame.getUtf8String().stripTrailing());
+                    break;
+                case STDERR:
+                    logger().info("sshd stderr: {}", outputFrame.getUtf8String().stripTrailing());
+                    break;
+            }
+        });
+    }
+
+    public SSHClient getConnectedClient(Config config) throws IOException {
+        SSHClient sshClient = new SSHClient(config);
+        sshClient.addHostKeyVerifier(new PromiscuousVerifier());
+        sshClient.connect("127.0.0.1", getFirstMappedPort());
+
+        return sshClient;
+    }
+
+    public SSHClient getConnectedClient() throws IOException {
+        return getConnectedClient(new DefaultConfig());
+    }
+}

src/itest/groovy/com/hierynomus/sshj/sftp/FileWriteSpec.groovy

@@ -15,21 +15,28 @@
  */
 package com.hierynomus.sshj.sftp
 
-import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.SSHClient
 import net.schmizz.sshj.sftp.OpenMode
 import net.schmizz.sshj.sftp.RemoteFile
 import net.schmizz.sshj.sftp.SFTPClient
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 
 import java.nio.charset.StandardCharsets
 
 import static org.codehaus.groovy.runtime.IOGroovyMethods.withCloseable
 
-class FileWriteSpec extends IntegrationBaseSpec {
+class FileWriteSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     def "should append to file (GH issue #390)"() {
         given:
-        SSHClient client = getConnectedClient()
+        SSHClient client = sshd.getConnectedClient()
         client.authPublickey("sshj", "src/test/resources/id_rsa")
         SFTPClient sftp = client.newSFTPClient()
         def file = "/home/sshj/test.txt"

src/itest/groovy/com/hierynomus/sshj/signature/HostKeyWithCertificateSpec.groovy

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj.signature
+
+import com.hierynomus.sshj.SshdContainer
+import net.schmizz.sshj.DefaultConfig
+import net.schmizz.sshj.SSHClient
+import net.schmizz.sshj.transport.verification.OpenSSHKnownHosts
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import java.nio.file.Files
+
+/**
+ * This is a brief test for verifying connection to a server using keys with certificates.
+ *
+ * Also, take a look at the unit test {@link net.schmizz.sshj.transport.verification.KeyWithCertificateUnitSpec}.
+ */
+class HostKeyWithCertificateSpec extends Specification {
+    @Unroll
+    def "accepting a signed host public key #hostKey"() {
+        given:
+        SshdContainer sshd = new SshdContainer.Builder()
+            .withSshdConfig("""
+                PasswordAuthentication yes
+                HostKey /etc/ssh/$hostKey
+                HostCertificate /etc/ssh/${hostKey}-cert.pub
+                """.stripMargin())
+            .build()
+        sshd.start()
+
+        and:
+        File knownHosts = Files.createTempFile("known_hosts", "").toFile()
+        knownHosts.deleteOnExit()
+
+        and:
+        File caPubKey = new File("src/itest/resources/keyfiles/certificates/CA_rsa.pem.pub")
+        def address = "127.0.0.1"
+        String knownHostsFileContents = "" +
+                "@cert-authority ${ address} ${caPubKey.text}" +
+                "\n@cert-authority [${address}]:${sshd.firstMappedPort} ${caPubKey.text}"
+        knownHosts.write(knownHostsFileContents)
+
+        and:
+        SSHClient sshClient = new SSHClient(new DefaultConfig())
+        sshClient.addHostKeyVerifier(new OpenSSHKnownHosts(knownHosts))
+        sshClient.connect(address, sshd.firstMappedPort)
+
+        when:
+        sshClient.authPassword("sshj", "ultrapassword")
+
+        then:
+        sshClient.authenticated
+
+        and:
+        knownHosts.getText() == knownHostsFileContents
+
+        cleanup:
+        sshd.stop()
+
+        where:
+        hostKey << [
+                "ssh_host_ecdsa_256_key",
+                "ssh_host_ecdsa_384_key",
+                "ssh_host_ecdsa_521_key",
+                "ssh_host_ed25519_384_key",
+                "ssh_host_rsa_2048_key",
+        ]
+    }
+}

src/itest/groovy/com/hierynomus/sshj/signature/PublicKeyAuthWithCertificateSpec.groovy

@@ -15,29 +15,34 @@
  */
 package com.hierynomus.sshj.signature
 
-import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
 import net.schmizz.sshj.SSHClient
-import net.schmizz.sshj.transport.verification.OpenSSHKnownHosts
+import net.schmizz.sshj.transport.verification.PromiscuousVerifier
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-import java.nio.file.Files
-import java.util.stream.Collectors
-
 /**
  * This is a brief test for verifying connection to a server using keys with certificates.
  *
  * Also, take a look at the unit test {@link net.schmizz.sshj.transport.verification.KeyWithCertificateUnitSpec}.
  */
-class KeyWithCertificateSpec extends IntegrationBaseSpec {
+class PublicKeyAuthWithCertificateSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "authorising with a signed public key #keyName"() {
         given:
-        def client = getConnectedClient()
+        SSHClient client = new SSHClient(new DefaultConfig())
+        client.addHostKeyVerifier(new PromiscuousVerifier())
+        client.connect("127.0.0.1", sshd.firstMappedPort)
 
         when:
-        client.authPublickey(USERNAME, "src/itest/resources/keyfiles/certificates/$keyName")
+        client.authPublickey("sshj", "src/itest/resources/keyfiles/certificates/$keyName")
 
         then:
         client.authenticated
@@ -73,43 +78,4 @@ class KeyWithCertificateSpec extends IntegrationBaseSpec {
                 "id_ed25519_384_rfc4716_signed_by_rsa",
         ]
     }
-
-    @Unroll
-    def "accepting a signed host public key with type #hostKeyAlgo"() {
-        given:
-        File knownHosts = Files.createTempFile("known_hosts", "").toFile()
-        knownHosts.deleteOnExit()
-
-        and:
-        File caPubKey = new File("src/itest/resources/keyfiles/certificates/CA_rsa.pem.pub")
-        String knownHostsFileContents = "" +
-                "@cert-authority $SERVER_IP ${caPubKey.text}" +
-                "\n@cert-authority [$SERVER_IP]:$DOCKER_PORT ${caPubKey.text}"
-        knownHosts.write(knownHostsFileContents)
-
-        and:
-        def config = new DefaultConfig()
-        config.keyAlgorithms = config.keyAlgorithms.stream()
-                .filter { it.name == hostKeyAlgo }
-                .collect(Collectors.toList())
-        SSHClient sshClient = new SSHClient(config)
-        sshClient.addHostKeyVerifier(new OpenSSHKnownHosts(knownHosts))
-        sshClient.connect(SERVER_IP, DOCKER_PORT)
-
-        when:
-        sshClient.authPassword("sshj", "ultrapassword")
-
-        then:
-        sshClient.authenticated
-
-        and:
-        knownHosts.getText() == knownHostsFileContents
-
-        where:
-        hostKeyAlgo << [
-                "ecdsa-sha2-nistp256-cert-v01@openssh.com",
-                "ssh-ed25519-cert-v01@openssh.com",
-                "ssh-rsa-cert-v01@openssh.com",
-        ]
-    }
 }

src/itest/groovy/com/hierynomus/sshj/signature/RsaSignatureClientKeySpec.groovy

@@ -15,18 +15,25 @@
  */
 package com.hierynomus.sshj.signature
 
-import com.hierynomus.sshj.IntegrationBaseSpec
-import net.schmizz.sshj.DefaultConfig
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class RsaSignatureClientKeySpec extends IntegrationBaseSpec {
+class RsaSignatureClientKeySpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
+
     @Unroll
     def "should correctly connect using publickey auth with RSA key with signature"() {
         given:
-        def client = getConnectedClient(new DefaultConfig())
+        def client = sshd.getConnectedClient()
 
         when:
-        client.authPublickey(USERNAME, "src/itest/resources/keyfiles/id_rsa2")
+        client.authPublickey(IntegrationTestUtil.USERNAME, "src/itest/resources/keyfiles/id_rsa2")
 
         then:
         client.authenticated

src/itest/groovy/com/hierynomus/sshj/signature/SignatureSpec.groovy

@@ -15,22 +15,29 @@
  */
 package com.hierynomus.sshj.signature
 
-import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
 import com.hierynomus.sshj.key.KeyAlgorithms
 import net.schmizz.sshj.DefaultConfig
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class SignatureSpec extends IntegrationBaseSpec {
+class SignatureSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "should correctly connect with #sig Signature"() {
         given:
         def cfg = new DefaultConfig()
         cfg.setKeyAlgorithms(Collections.singletonList(sigFactory))
-        def client = getConnectedClient(cfg)
+        def client = sshd.getConnectedClient(cfg)
 
         when:
-        client.authPublickey(USERNAME, KEYFILE)
+        client.authPublickey(IntegrationTestUtil.USERNAME, IntegrationTestUtil.KEYFILE)
 
         then:
         client.authenticated

src/itest/groovy/com/hierynomus/sshj/transport/cipher/CipherSpec.groovy

@@ -15,21 +15,28 @@
  */
 package com.hierynomus.sshj.transport.cipher
 
-import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class CipherSpec extends IntegrationBaseSpec {
+class CipherSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "should correctly connect with #cipher Cipher"() {
         given:
         def cfg = new DefaultConfig()
         cfg.setCipherFactories(cipherFactory)
-        def client = getConnectedClient(cfg)
+        def client = sshd.getConnectedClient(cfg)
 
         when:
-        client.authPublickey(USERNAME, KEYFILE)
+        client.authPublickey(IntegrationTestUtil.USERNAME, IntegrationTestUtil.KEYFILE)
 
         then:
         client.authenticated

src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy

@@ -15,29 +15,32 @@
  */
 package com.hierynomus.sshj.transport.kex
 
-import com.hierynomus.sshj.IntegrationBaseSpec
-import com.hierynomus.sshj.transport.mac.Macs
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
-import net.schmizz.sshj.transport.kex.Curve25519DH
 import net.schmizz.sshj.transport.kex.Curve25519SHA256
-import net.schmizz.sshj.transport.kex.DH
 import net.schmizz.sshj.transport.kex.DHGexSHA1
 import net.schmizz.sshj.transport.kex.DHGexSHA256
-import net.schmizz.sshj.transport.kex.ECDH
 import net.schmizz.sshj.transport.kex.ECDHNistP
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class KexSpec extends IntegrationBaseSpec {
+class KexSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "should correctly connect with #kex Key Exchange"() {
         given:
         def cfg = new DefaultConfig()
         cfg.setKeyExchangeFactories(kexFactory)
-        def client = getConnectedClient(cfg)
+        def client = sshd.getConnectedClient(cfg)
 
         when:
-        client.authPublickey(USERNAME, KEYFILE)
+        client.authPublickey(IntegrationTestUtil.USERNAME, IntegrationTestUtil.KEYFILE)
 
         then:
         client.authenticated

src/itest/groovy/com/hierynomus/sshj/transport/mac/MacSpec.groovy

@@ -15,21 +15,28 @@
  */
 package com.hierynomus.sshj.transport.mac
 
-import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.IntegrationTestUtil
+import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
+import org.junit.ClassRule
+import spock.lang.Shared
+import spock.lang.Specification
 import spock.lang.Unroll
 
-class MacSpec extends IntegrationBaseSpec {
+class MacSpec extends Specification {
+    @Shared
+    @ClassRule
+    SshdContainer sshd
 
     @Unroll
     def "should correctly connect with #mac MAC"() {
         given:
         def cfg = new DefaultConfig()
         cfg.setMACFactories(macFactory)
-        def client = getConnectedClient(cfg)
+        def client = sshd.getConnectedClient(cfg)
 
         when:
-        client.authPublickey(USERNAME, KEYFILE)
+        client.authPublickey(IntegrationTestUtil.USERNAME, IntegrationTestUtil.KEYFILE)
 
         then:
         client.authenticated
@@ -47,10 +54,10 @@ class MacSpec extends IntegrationBaseSpec {
         given:
         def cfg = new DefaultConfig()
         cfg.setMACFactories(macFactory)
-        def client = getConnectedClient(cfg)
+        def client = sshd.getConnectedClient(cfg)
 
         when:
-        client.authPublickey(USERNAME, KEYFILE)
+        client.authPublickey(IntegrationTestUtil.USERNAME, IntegrationTestUtil.KEYFILE)
 
         then:
         client.authenticated

src/itest/resources/keyfiles/id_ed25519_opensshv1_aes128cbc.pem

@@ -0,0 +1,3 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAACmFlczEyOC1jYmMAAAAGYmNyeXB0AAAAGAAAABDfrL8SxDyrkNlsJdAmc7Z0AAAAEAAAAAEAAAAzAAAAC3NzaC1lZDI1NTE5AAAAICYfPGSYFOHuSzTJ67H0ynvKJDfgDmwPOj7iJaLGbIBiAAAAkLVqaDIfs+sPBNyy7ytdLnP/xH7Nt5FIXx3Upw6wKuMGdBzbFQLcvu60Le+SFP3uUfXE8TcHramXbH0n+UBMW6raCAKOkHUU1BtrKxPG1eKU/LBx3Bk5FxyKm7fo0XsCUmqSVK25EHOJfYq1QwIbWICkvQUNu+2Hg8/MQKoFJMentI+GqjdaG76f6Wf+aj9UwA==
+-----END OPENSSH PRIVATE KEY-----

src/main/java/com/hierynomus/sshj/common/ProxySocketFactory.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj.common;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.net.Socket;
+import java.net.UnknownHostException;
+
+import javax.net.SocketFactory;
+
+/**
+ * A {@link SocketFactory} that creates sockets using a {@link Proxy}.
+ */
+class ProxySocketFactory extends SocketFactory {
+
+    private Proxy proxy;
+
+    public ProxySocketFactory(Proxy proxy) {
+        this.proxy = proxy;
+    }
+
+    public ProxySocketFactory(Proxy.Type proxyType, InetSocketAddress proxyAddress) {
+        this(new Proxy(proxyType, proxyAddress));
+    }
+
+    @Override
+    public Socket createSocket() throws IOException {
+        return new Socket(proxy);
+    }
+
+    @Override
+    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort)
+            throws IOException {
+        Socket s = createSocket();
+        s.bind(new InetSocketAddress(localAddress, localPort));
+        s.connect(new InetSocketAddress(address, port));
+        return s;
+    }
+
+    @Override
+    public Socket createSocket(InetAddress host, int port) throws IOException {
+        Socket s = createSocket();
+        s.connect(new InetSocketAddress(host, port));
+        return s;
+    }
+
+    @Override
+    public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
+        Socket s = createSocket();
+        s.connect(new InetSocketAddress(host, port));
+        return s;
+    }
+
+    @Override
+    public Socket createSocket(String host, int port, InetAddress localHost, int localPort)
+            throws IOException, UnknownHostException {
+        Socket s = createSocket();
+        s.bind(new InetSocketAddress(localHost, localPort));
+        s.connect(new InetSocketAddress(host, port));
+        return s;
+    }
+}

src/main/java/com/hierynomus/sshj/common/RemoteAddressProvider.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj.common;
+
+import java.net.InetSocketAddress;
+
+public interface RemoteAddressProvider {
+    /**
+     * Get Remote Socket Address associated with transport connection
+     *
+     * @return Remote Socket Address or null when not connected
+     */
+    InetSocketAddress getRemoteSocketAddress();
+}

src/main/java/com/hierynomus/sshj/common/ThreadNameProvider.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj.common;
+
+import java.net.InetSocketAddress;
+
+public class ThreadNameProvider {
+    private static final String DISCONNECTED = "DISCONNECTED";
+
+    /**
+     * Set Thread Name prefixed with sshj followed by class and remote address when connected
+     *
+     * @param thread Class of Thread being named
+     * @param remoteAddressProvider Remote Address Provider associated with Thread
+     */
+    public static void setThreadName(final Thread thread, final RemoteAddressProvider remoteAddressProvider) {
+        final InetSocketAddress remoteSocketAddress = remoteAddressProvider.getRemoteSocketAddress();
+        final String address = remoteSocketAddress == null ? DISCONNECTED : remoteSocketAddress.toString();
+        final long started = System.currentTimeMillis();
+        final String threadName = String.format("sshj-%s-%s-%d", thread.getClass().getSimpleName(), address, started);
+        thread.setName(threadName);
+    }
+}

src/main/java/com/hierynomus/sshj/key/KeyAlgorithms.java

@@ -27,8 +27,6 @@ import java.util.List;
 
 public class KeyAlgorithms {
 
-    public static List<String> SSH_RSA_SHA2_ALGORITHMS = Arrays.asList("rsa-sha2-512", "rsa-sha2-256");
-
     public static Factory SSHRSA() { return new Factory("ssh-rsa", new SignatureRSA.FactorySSHRSA(), KeyType.RSA); }
     public static Factory SSHRSACertV01() { return new Factory("ssh-rsa-cert-v01@openssh.com", new SignatureRSA.FactoryCERT(), KeyType.RSA_CERT); }
     public static Factory RSASHA256() { return new Factory("rsa-sha2-256", new SignatureRSA.FactoryRSASHA256(), KeyType.RSA); }
@@ -61,6 +59,10 @@ public class KeyAlgorithms {
             return algorithmName;
         }
 
+        public KeyType getKeyType() {
+            return keyType;
+        }
+
         @Override
         public KeyAlgorithm create() {
             return new BaseKeyAlgorithm(algorithmName, signatureFactory, keyType);

src/main/java/com/hierynomus/sshj/userauth/keyprovider/OpenSSHKeyV1KeyFile.java

@@ -30,7 +30,7 @@ import net.schmizz.sshj.userauth.keyprovider.KeyFormat;
 import org.bouncycastle.asn1.nist.NISTNamedCurves;
 import org.bouncycastle.asn1.x9.X9ECParameters;
 import org.bouncycastle.jce.spec.ECNamedCurveSpec;
-import org.mindrot.jbcrypt.BCrypt;
+import com.hierynomus.sshj.userauth.keyprovider.bcrypt.BCrypt;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -45,7 +45,7 @@ import java.nio.CharBuffer;
 import java.nio.charset.Charset;
 import java.security.*;
 import java.security.spec.ECPrivateKeySpec;
-import java.security.spec.RSAPrivateKeySpec;
+import java.security.spec.RSAPrivateCrtKeySpec;
 import java.util.Arrays;
 
 /**
@@ -177,11 +177,11 @@ public class OpenSSHKeyV1KeyFile extends BaseFileKeyProvider {
                 Arrays.fill(charBuffer.array(), '\u0000');
                 Arrays.fill(byteBuffer.array(), (byte) 0);
             }
-            byte[] keyiv = new byte[48];
+            byte[] keyiv = new byte[cipher.getIVSize()+ cipher.getBlockSize()];
             new BCrypt().pbkdf(passphrase, opts.readBytes(), opts.readUInt32AsInt(), keyiv);
             Arrays.fill(passphrase, (byte) 0);
-            byte[] key = Arrays.copyOfRange(keyiv, 0, 32);
-            byte[] iv = Arrays.copyOfRange(keyiv, 32, 48);
+            byte[] key = Arrays.copyOfRange(keyiv, 0, cipher.getBlockSize());
+            byte[] iv = Arrays.copyOfRange(keyiv, cipher.getBlockSize(), cipher.getIVSize() + cipher.getBlockSize());
             cipher.init(Cipher.Mode.Decrypt, key, iv);
         } else {
             throw new IllegalStateException("No support for KDF '" + kdfName + "'.");
@@ -193,6 +193,8 @@ public class OpenSSHKeyV1KeyFile extends BaseFileKeyProvider {
             return BlockCiphers.AES256CTR().create();
         } else if (cipherName.equals(BlockCiphers.AES256CBC().getName())) {
             return BlockCiphers.AES256CBC().create();
+        } else if (cipherName.equals(BlockCiphers.AES128CBC().getName())) {
+            return BlockCiphers.AES128CBC().create();
         }
         throw new IllegalStateException("Cipher '" + cipherName + "' not currently implemented for openssh-key-v1 format");
     }
@@ -216,6 +218,9 @@ public class OpenSSHKeyV1KeyFile extends BaseFileKeyProvider {
         while (line != null && !line.startsWith(BEGIN)) {
             line = reader.readLine();
         }
+        if (line == null) {
+            return false;
+        }
         line = line.substring(BEGIN.length());
         return line.startsWith(OPENSSH_PRIVATE_KEY);
     }
@@ -245,13 +250,9 @@ public class OpenSSHKeyV1KeyFile extends BaseFileKeyProvider {
                 kp = new KeyPair(publicKey, new EdDSAPrivateKey(new EdDSAPrivateKeySpec(privKey, EdDSANamedCurveTable.getByName("Ed25519"))));
                 break;
             case RSA:
-                BigInteger n = keyBuffer.readMPInt(); // Modulus
-                keyBuffer.readMPInt(); // Public Exponent
-                BigInteger d = keyBuffer.readMPInt(); // Private Exponent
-                keyBuffer.readMPInt(); // iqmp (q^-1 mod p)
-                keyBuffer.readMPInt(); // p (Prime 1)
-                keyBuffer.readMPInt(); // q (Prime 2)
-                kp = new KeyPair(publicKey, SecurityUtils.getKeyFactory(KeyAlgorithm.RSA).generatePrivate(new RSAPrivateKeySpec(n, d)));
+                final RSAPrivateCrtKeySpec rsaPrivateCrtKeySpec = readRsaPrivateKeySpec(keyBuffer);
+                final PrivateKey privateKey = SecurityUtils.getKeyFactory(KeyAlgorithm.RSA).generatePrivate(rsaPrivateCrtKeySpec);
+                kp = new KeyPair(publicKey, privateKey);
                 break;
             case ECDSA256:
                 kp = new KeyPair(publicKey, createECDSAPrivateKey(kt, keyBuffer, "P-256"));
@@ -284,6 +285,35 @@ public class OpenSSHKeyV1KeyFile extends BaseFileKeyProvider {
         ECNamedCurveSpec ecCurveSpec = new ECNamedCurveSpec(name, ecParams.getCurve(), ecParams.getG(), ecParams.getN());
         ECPrivateKeySpec pks = new ECPrivateKeySpec(s, ecCurveSpec);
         return SecurityUtils.getKeyFactory(KeyAlgorithm.ECDSA).generatePrivate(pks);
+    }
 
+    /**
+     * Read RSA Private CRT Key Spec according to OpenSSH sshkey_private_deserialize in sshkey.c
+     *
+     * @param buffer Buffer
+     * @return RSA Private CRT Key Specification
+     * @throws Buffer.BufferException Thrown on failure to read from buffer
+     */
+    private RSAPrivateCrtKeySpec readRsaPrivateKeySpec(final PlainBuffer buffer) throws Buffer.BufferException {
+        final BigInteger modulus = buffer.readMPInt();
+        final BigInteger publicExponent = buffer.readMPInt();
+        final BigInteger privateExponent = buffer.readMPInt();
+        final BigInteger crtCoefficient = buffer.readMPInt(); // iqmp (q^-1 mod p)
+        final BigInteger primeP = buffer.readMPInt();
+        final BigInteger primeQ = buffer.readMPInt();
+
+        // Calculate Prime Exponent P and Prime Exponent Q according to RFC 8017 Section 3.2
+        final BigInteger primeExponentP = privateExponent.remainder(primeP.subtract(BigInteger.ONE));
+        final BigInteger primeExponentQ = privateExponent.remainder(primeQ.subtract(BigInteger.ONE));
+        return new RSAPrivateCrtKeySpec(
+                modulus,
+                publicExponent,
+                privateExponent,
+                primeP,
+                primeQ,
+                primeExponentP,
+                primeExponentQ,
+                crtCoefficient
+        );
     }
 }

src/main/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCrypt.java

@@ -12,7 +12,7 @@
 // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-package org.mindrot.jbcrypt;
+package com.hierynomus.sshj.userauth.keyprovider.bcrypt;
 
 import java.io.UnsupportedEncodingException;
 import java.security.DigestException;

src/main/java/djb/Curve25519.java

@@ -1,918 +0,0 @@
-/* Ported from C to Java by Dmitry Skiba [sahn0], 23/02/08.
- * Original: http://cds.xs4all.nl:8081/ecdh/
- */
-/* Generic 64-bit integer implementation of Curve25519 ECDH
- * Written by Matthijs van Duin, 200608242056
- * Public domain.
- *
- * Based on work by Daniel J Bernstein, http://cr.yp.to/ecdh.html
- */
-package djb;
-
-public class Curve25519 {
-
-	/* key size */
-	public static final int KEY_SIZE = 32;
-	
-	/* 0 */
-	public static final byte[] ZERO = {
-		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
-	};
-	
-	/* the prime 2^255-19 */
-	public static final byte[] PRIME = {
-		(byte)237, (byte)255, (byte)255, (byte)255,
-		(byte)255, (byte)255, (byte)255, (byte)255,
-		(byte)255, (byte)255, (byte)255, (byte)255,
-		(byte)255, (byte)255, (byte)255, (byte)255,
-		(byte)255, (byte)255, (byte)255, (byte)255,
-		(byte)255, (byte)255, (byte)255, (byte)255,
-	    (byte)255, (byte)255, (byte)255, (byte)255,
-	    (byte)255, (byte)255, (byte)255, (byte)127
-	};
-	
-	/* group order (a prime near 2^252+2^124) */
-	public static final byte[] ORDER = {
-		(byte)237, (byte)211, (byte)245, (byte)92,
-		(byte)26,  (byte)99,  (byte)18,  (byte)88,
-		(byte)214, (byte)156, (byte)247, (byte)162,
-		(byte)222, (byte)249, (byte)222, (byte)20,
-		(byte)0,   (byte)0,   (byte)0,   (byte)0, 
-		(byte)0,   (byte)0,   (byte)0,   (byte)0,
-		(byte)0,   (byte)0,   (byte)0,   (byte)0, 
-		(byte)0,   (byte)0,   (byte)0,   (byte)16
-	};
-	
-	/********* KEY AGREEMENT *********/
-	
-	/* Private key clamping
-	 *   k [out] your private key for key agreement
-	 *   k  [in]  32 random bytes
-	 */
-	public static final void clamp(byte[] k) {
-		k[31] &= 0x7F;
-		k[31] |= 0x40;
-		k[ 0] &= 0xF8;
-	}
-	
-	/* Key-pair generation
-	 *   P  [out] your public key
-	 *   s  [out] your private key for signing
-	 *   k  [out] your private key for key agreement
-	 *   k  [in]  32 random bytes
-	 * s may be NULL if you don't care
-	 *
-	 * WARNING: if s is not NULL, this function has data-dependent timing */
-	public static final void keygen(byte[] P, byte[] s, byte[] k) {
-		clamp(k);
-		core(P, s, k, null);
-	}
-
-	/* Key agreement
-	 *   Z  [out] shared secret (needs hashing before use)
-	 *   k  [in]  your private key for key agreement
-	 *   P  [in]  peer's public key
-	 */
-	public static final void curve(byte[] Z, byte[] k, byte[] P) {
-		core(Z, null, k, P);
-	}
-	
-	/********* DIGITAL SIGNATURES *********/
-
-	/* deterministic EC-KCDSA
-	 *
-	 *    s is the private key for signing
-	 *    P is the corresponding public key
-	 *    Z is the context data (signer public key or certificate, etc)
-	 *
-	 * signing:
-	 *
-	 *    m = hash(Z, message)
-	 *    x = hash(m, s)
-	 *    keygen25519(Y, NULL, x);
-	 *    r = hash(Y);
-	 *    h = m XOR r
-	 *    sign25519(v, h, x, s);
-	 *
-	 *    output (v,r) as the signature
-	 *
-	 * verification:
-	 *
-	 *    m = hash(Z, message);
-	 *    h = m XOR r
-	 *    verify25519(Y, v, h, P)
-	 *
-	 *    confirm  r == hash(Y)
-	 *
-	 * It would seem to me that it would be simpler to have the signer directly do 
-	 * h = hash(m, Y) and send that to the recipient instead of r, who can verify 
-	 * the signature by checking h == hash(m, Y).  If there are any problems with 
-	 * such a scheme, please let me know.
-	 *
-	 * Also, EC-KCDSA (like most DS algorithms) picks x random, which is a waste of 
-	 * perfectly good entropy, but does allow Y to be calculated in advance of (or 
-	 * parallel to) hashing the message.
-	 */
-	
-	/* Signature generation primitive, calculates (x-h)s mod q
-	 *   v  [out] signature value
-	 *   h  [in]  signature hash (of message, signature pub key, and context data)
-	 *   x  [in]  signature private key
-	 *   s  [in]  private key for signing
-	 * returns true on success, false on failure (use different x or h)
-	 */
-	public static final boolean sign(byte[] v, byte[] h, byte[] x, byte[] s) {
-		// v = (x - h) s  mod q
-		int w, i;
-		byte[] h1 = new byte[32], x1 = new byte[32];
-		byte[] tmp1 = new byte[64];
-		byte[] tmp2 = new byte[64];
-
-		// Don't clobber the arguments, be nice!
-		cpy32(h1, h);
-		cpy32(x1, x);
-
-		// Reduce modulo group order
-		byte[] tmp3=new byte[32];
-		divmod(tmp3, h1, 32, ORDER, 32);
-		divmod(tmp3, x1, 32, ORDER, 32);
-
-		// v = x1 - h1
-		// If v is negative, add the group order to it to become positive.
-		// If v was already positive we don't have to worry about overflow
-		// when adding the order because v < ORDER and 2*ORDER < 2^256
-		mula_small(v, x1, 0, h1, 32, -1);
-		mula_small(v, v , 0, ORDER, 32, 1);
-
-		// tmp1 = (x-h)*s mod q
-		mula32(tmp1, v, s, 32, 1);
-		divmod(tmp2, tmp1, 64, ORDER, 32);
-
-		for (w = 0, i = 0; i < 32; i++)
-			w |= v[i] = tmp1[i];
-		return w != 0;
-	}
-
-	/* Signature verification primitive, calculates Y = vP + hG
-	 *   Y  [out] signature public key
-	 *   v  [in]  signature value
-	 *   h  [in]  signature hash
-	 *   P  [in]  public key
-	 */
-	public static final void verify(byte[] Y, byte[] v, byte[] h, byte[] P) {
-		/* Y = v abs(P) + h G  */
-		byte[] d=new byte[32];
-	    long10[] 
-	        p=new long10[]{new long10(),new long10()},
-	    	s=new long10[]{new long10(),new long10()},
-		    yx=new long10[]{new long10(),new long10(),new long10()},
-		    yz=new long10[]{new long10(),new long10(),new long10()},
-		    t1=new long10[]{new long10(),new long10(),new long10()},
-		    t2=new long10[]{new long10(),new long10(),new long10()};
-		
-		int vi = 0, hi = 0, di = 0, nvh=0, i, j, k;
-
-		/* set p[0] to G and p[1] to P  */
-
-		set(p[0], 9);
-		unpack(p[1], P);
-
-		/* set s[0] to P+G and s[1] to P-G  */
-
-		/* s[0] = (Py^2 + Gy^2 - 2 Py Gy)/(Px - Gx)^2 - Px - Gx - 486662  */
-		/* s[1] = (Py^2 + Gy^2 + 2 Py Gy)/(Px - Gx)^2 - Px - Gx - 486662  */
-
-		x_to_y2(t1[0], t2[0], p[1]);	/* t2[0] = Py^2  */
-		sqrt(t1[0], t2[0]);	/* t1[0] = Py or -Py  */
-		j = is_negative(t1[0]);		/*      ... check which  */
-		t2[0]._0 += 39420360;		/* t2[0] = Py^2 + Gy^2  */
-		mul(t2[1], BASE_2Y, t1[0]);/* t2[1] = 2 Py Gy or -2 Py Gy  */
-		sub(t1[j], t2[0], t2[1]);	/* t1[0] = Py^2 + Gy^2 - 2 Py Gy  */
-		add(t1[1-j], t2[0], t2[1]);/* t1[1] = Py^2 + Gy^2 + 2 Py Gy  */
-		cpy(t2[0], p[1]);		/* t2[0] = Px  */
-		t2[0]._0 -= 9;			/* t2[0] = Px - Gx  */
-		sqr(t2[1], t2[0]);		/* t2[1] = (Px - Gx)^2  */
-		recip(t2[0], t2[1], 0);	/* t2[0] = 1/(Px - Gx)^2  */
-		mul(s[0], t1[0], t2[0]);	/* s[0] = t1[0]/(Px - Gx)^2  */
-		sub(s[0], s[0], p[1]);	/* s[0] = t1[0]/(Px - Gx)^2 - Px  */
-		s[0]._0 -= 9 + 486662;		/* s[0] = X(P+G)  */
-		mul(s[1], t1[1], t2[0]);	/* s[1] = t1[1]/(Px - Gx)^2  */
-		sub(s[1], s[1], p[1]);	/* s[1] = t1[1]/(Px - Gx)^2 - Px  */
-		s[1]._0 -= 9 + 486662;		/* s[1] = X(P-G)  */
-		mul_small(s[0], s[0], 1);	/* reduce s[0] */
-		mul_small(s[1], s[1], 1);	/* reduce s[1] */
-
-
-		/* prepare the chain  */
-		for (i = 0; i < 32; i++) {
-			vi = (vi >> 8) ^ (v[i] & 0xFF) ^ ((v[i] & 0xFF) << 1);
-			hi = (hi >> 8) ^ (h[i] & 0xFF) ^ ((h[i] & 0xFF) << 1);
-			nvh = ~(vi ^ hi);
-			di = (nvh & (di & 0x80) >> 7) ^ vi;
-			di ^= nvh & (di & 0x01) << 1;
-			di ^= nvh & (di & 0x02) << 1;
-			di ^= nvh & (di & 0x04) << 1;
-			di ^= nvh & (di & 0x08) << 1;
-			di ^= nvh & (di & 0x10) << 1;
-			di ^= nvh & (di & 0x20) << 1;
-			di ^= nvh & (di & 0x40) << 1;
-			d[i] = (byte)di;
-		}
-
-		di = ((nvh & (di & 0x80) << 1) ^ vi) >> 8;
-
-		/* initialize state */
-		set(yx[0], 1);
-		cpy(yx[1], p[di]);
-		cpy(yx[2], s[0]);
-		set(yz[0], 0);
-		set(yz[1], 1);
-		set(yz[2], 1);
-
-		/* y[0] is (even)P + (even)G
-		 * y[1] is (even)P + (odd)G  if current d-bit is 0
-		 * y[1] is (odd)P + (even)G  if current d-bit is 1
-		 * y[2] is (odd)P + (odd)G
-		 */
-
-		vi = 0;
-		hi = 0;
-
-		/* and go for it! */
-		for (i = 32; i--!=0; ) {
-			vi = (vi << 8) | (v[i] & 0xFF);
-			hi = (hi << 8) | (h[i] & 0xFF);
-			di = (di << 8) | (d[i] & 0xFF);
-
-			for (j = 8; j--!=0; ) {
-				mont_prep(t1[0], t2[0], yx[0], yz[0]);
-				mont_prep(t1[1], t2[1], yx[1], yz[1]);
-				mont_prep(t1[2], t2[2], yx[2], yz[2]);
-
-				k = ((vi ^ vi >> 1) >> j & 1)
-				  + ((hi ^ hi >> 1) >> j & 1);
-				mont_dbl(yx[2], yz[2], t1[k], t2[k], yx[0], yz[0]);
-
-				k = (di >> j & 2) ^ ((di >> j & 1) << 1);
-				mont_add(t1[1], t2[1], t1[k], t2[k], yx[1], yz[1],
-						p[di >> j & 1]);
-
-				mont_add(t1[2], t2[2], t1[0], t2[0], yx[2], yz[2],
-						s[((vi ^ hi) >> j & 2) >> 1]);
-			}
-		}
-
-		k = (vi & 1) + (hi & 1);
-		recip(t1[0], yz[k], 0);
-		mul(t1[1], yx[k], t1[0]);
-
-		pack(t1[1], Y);
-	}
-	
-	/////////////////////////////////////////////////////////////////////////// 
-	
-	/* sahn0:
-	 * Using this class instead of long[10] to avoid bounds checks. */
-	private static final class long10 {
-		public long10() {}
-		public long10(
-			long _0, long _1, long _2, long _3, long _4,
-			long _5, long _6, long _7, long _8, long _9)
-		{
-			this._0=_0; this._1=_1; this._2=_2;
-			this._3=_3; this._4=_4; this._5=_5;
-			this._6=_6; this._7=_7; this._8=_8;
-			this._9=_9;
-		}
-		public long _0,_1,_2,_3,_4,_5,_6,_7,_8,_9;
-	}
-	
-	/********************* radix 2^8 math *********************/
-	
-	private static final void cpy32(byte[] d, byte[] s) {
-		int i;
-		for (i = 0; i < 32; i++)
-			d[i] = s[i];
-	}
-	
-	/* p[m..n+m-1] = q[m..n+m-1] + z * x */
-	/* n is the size of x */
-	/* n+m is the size of p and q */
-	private static final int mula_small(byte[] p,byte[] q,int m,byte[] x,int n,int z) {
-		int v=0;
-		for (int i=0;i<n;++i) {
-			v+=(q[i+m] & 0xFF)+z*(x[i] & 0xFF);
-			p[i+m]=(byte)v;
-			v>>=8;
-		}
-		return v;		
-	}
-	
-	/* p += x * y * z  where z is a small integer
-	 * x is size 32, y is size t, p is size 32+t
-	 * y is allowed to overlap with p+32 if you don't care about the upper half  */
-	private static final int mula32(byte[] p, byte[] x, byte[] y, int t, int z) {
-		final int n = 31;
-		int w = 0;
-		int i = 0;
-		for (; i < t; i++) {
-			int zy = z * (y[i] & 0xFF);
-			w += mula_small(p, p, i, x, n, zy) +
-				(p[i+n] & 0xFF) + zy * (x[n] & 0xFF);
-			p[i+n] = (byte)w;
-			w >>= 8;
-		}
-		p[i+n] = (byte)(w + (p[i+n] & 0xFF));
-		return w >> 8;
-	}
-	
-	/* divide r (size n) by d (size t), returning quotient q and remainder r
-	 * quotient is size n-t+1, remainder is size t
-	 * requires t > 0 && d[t-1] != 0
-	 * requires that r[-1] and d[-1] are valid memory locations
-	 * q may overlap with r+t */
-	private static final void divmod(byte[] q, byte[] r, int n, byte[] d, int t) {
-		int rn = 0;
-		int dt = ((d[t-1] & 0xFF) << 8);
-		if (t>1) {
-			dt |= (d[t-2] & 0xFF);
-		}
-		while (n-- >= t) {
-			int z = (rn << 16) | ((r[n] & 0xFF) << 8);
-			if (n>0) {
-				z |= (r[n-1] & 0xFF);
-			}
-			z/=dt;
-			rn += mula_small(r,r, n-t+1, d, t, -z);
-			q[n-t+1] = (byte)((z + rn) & 0xFF); /* rn is 0 or -1 (underflow) */
-			mula_small(r,r, n-t+1, d, t, -rn);
-			rn = (r[n] & 0xFF);
-			r[n] = 0;
-		}
-		r[t-1] = (byte)rn;
-	}
-	
-	private static final int numsize(byte[] x,int n) {
-		while (n--!=0 && x[n]==0)
-			;
-		return n+1;
-	}
-	
-	/* Returns x if a contains the gcd, y if b.
-	 * Also, the returned buffer contains the inverse of a mod b,
-	 * as 32-byte signed.
-	 * x and y must have 64 bytes space for temporary use.
-	 * requires that a[-1] and b[-1] are valid memory locations  */
-	private static final byte[] egcd32(byte[] x,byte[] y,byte[] a,byte[] b) {
-		int an, bn = 32, qn, i;
-		for (i = 0; i < 32; i++)
-			x[i] = y[i] = 0;
-		x[0] = 1;
-		an = numsize(a, 32);
-		if (an==0)
-			return y;	/* division by zero */
-		byte[] temp=new byte[32];
-		while (true) {
-			qn = bn - an + 1;
-			divmod(temp, b, bn, a, an);
-			bn = numsize(b, bn);
-			if (bn==0)
-				return x;
-			mula32(y, x, temp, qn, -1);
-
-			qn = an - bn + 1;
-			divmod(temp, a, an, b, bn);
-			an = numsize(a, an);
-			if (an==0)
-				return y;
-			mula32(x, y, temp, qn, -1);
-		}
-	}
-	
-	/********************* radix 2^25.5 GF(2^255-19) math *********************/	
-	
-	private static final int P25=33554431;	/* (1 << 25) - 1 */
-	private static final int P26=67108863;	/* (1 << 26) - 1 */
-	
-	/* Convert to internal format from little-endian byte format */
-	private static final void unpack(long10 x,byte[] m) {
-		x._0 = ((m[0] & 0xFF))         | ((m[1] & 0xFF))<<8 |
-				(m[2] & 0xFF)<<16      | ((m[3] & 0xFF)& 3)<<24;
-		x._1 = ((m[3] & 0xFF)&~ 3)>>2  | (m[4] & 0xFF)<<6 |
-				(m[5] & 0xFF)<<14 | ((m[6] & 0xFF)& 7)<<22;
-		x._2 = ((m[6] & 0xFF)&~ 7)>>3  | (m[7] & 0xFF)<<5 |
-				(m[8] & 0xFF)<<13 | ((m[9] & 0xFF)&31)<<21;
-		x._3 = ((m[9] & 0xFF)&~31)>>5  | (m[10] & 0xFF)<<3 |
-				(m[11] & 0xFF)<<11 | ((m[12] & 0xFF)&63)<<19;
-		x._4 = ((m[12] & 0xFF)&~63)>>6 | (m[13] & 0xFF)<<2 |
-				(m[14] & 0xFF)<<10 |  (m[15] & 0xFF)    <<18;
-		x._5 =  (m[16] & 0xFF)         | (m[17] & 0xFF)<<8 |
-				(m[18] & 0xFF)<<16 | ((m[19] & 0xFF)& 1)<<24;
-		x._6 = ((m[19] & 0xFF)&~ 1)>>1 | (m[20] & 0xFF)<<7 |
-				(m[21] & 0xFF)<<15 | ((m[22] & 0xFF)& 7)<<23;
-		x._7 = ((m[22] & 0xFF)&~ 7)>>3 | (m[23] & 0xFF)<<5 |
-				(m[24] & 0xFF)<<13 | ((m[25] & 0xFF)&15)<<21;
-		x._8 = ((m[25] & 0xFF)&~15)>>4 | (m[26] & 0xFF)<<4 |
-				(m[27] & 0xFF)<<12 | ((m[28] & 0xFF)&63)<<20;
-		x._9 = ((m[28] & 0xFF)&~63)>>6 | (m[29] & 0xFF)<<2 |
-				(m[30] & 0xFF)<<10 |  (m[31] & 0xFF)    <<18;
-	}
-	
-	/* Check if reduced-form input >= 2^255-19 */
-	private static final boolean is_overflow(long10 x) {
-		return (
-			((x._0 > P26-19)) &&
-			((x._1 & x._3 & x._5 & x._7 & x._9) == P25) &&
-			((x._2 & x._4 & x._6 & x._8) == P26)
-			) || (x._9 > P25);
-	}
-	
-	/* Convert from internal format to little-endian byte format.  The 
-	 * number must be in a reduced form which is output by the following ops:
-	 *     unpack, mul, sqr
-	 *     set --  if input in range 0 .. P25
-	 * If you're unsure if the number is reduced, first multiply it by 1.  */
-	private static final void pack(long10 x,byte[] m) {
-		int ld = 0, ud = 0;
-		long t;
-		ld = (is_overflow(x)?1:0) - ((x._9 < 0)?1:0);
-		ud = ld * -(P25+1);
-		ld *= 19;
-		t = ld + x._0 + (x._1 << 26);
-		m[ 0] = (byte)t;
-		m[ 1] = (byte)(t >> 8);
-		m[ 2] = (byte)(t >> 16);
-		m[ 3] = (byte)(t >> 24);
-		t = (t >> 32) + (x._2 << 19);
-		m[ 4] = (byte)t;
-		m[ 5] = (byte)(t >> 8);
-		m[ 6] = (byte)(t >> 16);
-		m[ 7] = (byte)(t >> 24);
-		t = (t >> 32) + (x._3 << 13);
-		m[ 8] = (byte)t;
-		m[ 9] = (byte)(t >> 8);
-		m[10] = (byte)(t >> 16);
-		m[11] = (byte)(t >> 24);
-		t = (t >> 32) + (x._4 <<  6);
-		m[12] = (byte)t;
-		m[13] = (byte)(t >> 8);
-		m[14] = (byte)(t >> 16);
-		m[15] = (byte)(t >> 24);
-		t = (t >> 32) + x._5 + (x._6 << 25);
-		m[16] = (byte)t;
-		m[17] = (byte)(t >> 8);
-		m[18] = (byte)(t >> 16);
-		m[19] = (byte)(t >> 24);
-		t = (t >> 32) + (x._7 << 19);
-		m[20] = (byte)t;
-		m[21] = (byte)(t >> 8);
-		m[22] = (byte)(t >> 16);
-		m[23] = (byte)(t >> 24);
-		t = (t >> 32) + (x._8 << 12);
-		m[24] = (byte)t;
-		m[25] = (byte)(t >> 8);
-		m[26] = (byte)(t >> 16);
-		m[27] = (byte)(t >> 24);
-		t = (t >> 32) + ((x._9 + ud) << 6);
-		m[28] = (byte)t;
-		m[29] = (byte)(t >> 8);
-		m[30] = (byte)(t >> 16);
-		m[31] = (byte)(t >> 24);
-	}
-
-	/* Copy a number */
-	private static final void cpy(long10 out, long10 in) {
-		out._0=in._0;	out._1=in._1;
-		out._2=in._2;	out._3=in._3;
-		out._4=in._4;	out._5=in._5;
-		out._6=in._6;	out._7=in._7;
-		out._8=in._8;	out._9=in._9;		
-	}
-
-	/* Set a number to value, which must be in range -185861411 .. 185861411 */
-	private static final void set(long10 out, int in) {
-		out._0=in;	out._1=0;
-		out._2=0;	out._3=0;
-		out._4=0;	out._5=0;
-		out._6=0;	out._7=0;
-		out._8=0;	out._9=0;		
-	}
-	
-	/* Add/subtract two numbers.  The inputs must be in reduced form, and the 
-	 * output isn't, so to do another addition or subtraction on the output, 
-	 * first multiply it by one to reduce it. */
-	private static final void add(long10 xy, long10 x, long10 y) {
-		xy._0 = x._0 + y._0;	xy._1 = x._1 + y._1;
-		xy._2 = x._2 + y._2;	xy._3 = x._3 + y._3;
-		xy._4 = x._4 + y._4;	xy._5 = x._5 + y._5;
-		xy._6 = x._6 + y._6;	xy._7 = x._7 + y._7;
-		xy._8 = x._8 + y._8;	xy._9 = x._9 + y._9;
-	}
-	private static final void sub(long10 xy, long10 x, long10 y) {
-		xy._0 = x._0 - y._0;	xy._1 = x._1 - y._1;
-		xy._2 = x._2 - y._2;	xy._3 = x._3 - y._3;
-		xy._4 = x._4 - y._4;	xy._5 = x._5 - y._5;
-		xy._6 = x._6 - y._6;	xy._7 = x._7 - y._7;
-		xy._8 = x._8 - y._8;	xy._9 = x._9 - y._9;
-	}
-	
-	/* Multiply a number by a small integer in range -185861411 .. 185861411.
-	 * The output is in reduced form, the input x need not be.  x and xy may point
-	 * to the same buffer. */
-	private static final long10 mul_small(long10 xy, long10 x, long y) {
-		long t;
-		t = (x._8*y);
-		xy._8 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x._9*y);
-		xy._9 = (t & ((1 << 25) - 1));
-		t = 19 * (t >> 25) + (x._0*y);
-		xy._0 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x._1*y);
-		xy._1 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x._2*y);
-		xy._2 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x._3*y);
-		xy._3 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x._4*y);
-		xy._4 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x._5*y);
-		xy._5 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x._6*y);
-		xy._6 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x._7*y);
-		xy._7 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + xy._8;
-		xy._8 = (t & ((1 << 26) - 1));
-		xy._9 += (t >> 26);
-		return xy;
-	}
-
-	/* Multiply two numbers.  The output is in reduced form, the inputs need not 
-	 * be. */
-	private static final long10 mul(long10 xy, long10 x, long10 y) {
-		/* sahn0:
-		 * Using local variables to avoid class access.
-		 * This seem to improve performance a bit...
-		 */
-		long
-			x_0=x._0,x_1=x._1,x_2=x._2,x_3=x._3,x_4=x._4,
-			x_5=x._5,x_6=x._6,x_7=x._7,x_8=x._8,x_9=x._9;
-		long
-			y_0=y._0,y_1=y._1,y_2=y._2,y_3=y._3,y_4=y._4,
-			y_5=y._5,y_6=y._6,y_7=y._7,y_8=y._8,y_9=y._9;
-		long t;
-		t = (x_0*y_8) + (x_2*y_6) + (x_4*y_4) + (x_6*y_2) +
-			(x_8*y_0) + 2 * ((x_1*y_7) + (x_3*y_5) +
-					(x_5*y_3) + (x_7*y_1)) + 38 *
-			(x_9*y_9);
-		xy._8 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x_0*y_9) + (x_1*y_8) + (x_2*y_7) +
-			(x_3*y_6) + (x_4*y_5) + (x_5*y_4) +
-			(x_6*y_3) + (x_7*y_2) + (x_8*y_1) +
-			(x_9*y_0);
-		xy._9 = (t & ((1 << 25) - 1));
-		t = (x_0*y_0) + 19 * ((t >> 25) + (x_2*y_8) + (x_4*y_6)
-				+ (x_6*y_4) + (x_8*y_2)) + 38 *
-			((x_1*y_9) + (x_3*y_7) + (x_5*y_5) +
-			 (x_7*y_3) + (x_9*y_1));
-		xy._0 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x_0*y_1) + (x_1*y_0) + 19 * ((x_2*y_9)
-				+ (x_3*y_8) + (x_4*y_7) + (x_5*y_6) +
-				(x_6*y_5) + (x_7*y_4) + (x_8*y_3) +
-				(x_9*y_2));
-		xy._1 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x_0*y_2) + (x_2*y_0) + 19 * ((x_4*y_8)
-				+ (x_6*y_6) + (x_8*y_4)) + 2 * (x_1*y_1)
-				+ 38 * ((x_3*y_9) + (x_5*y_7) +
-						(x_7*y_5) + (x_9*y_3));
-		xy._2 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x_0*y_3) + (x_1*y_2) + (x_2*y_1) +
-			(x_3*y_0) + 19 * ((x_4*y_9) + (x_5*y_8) +
-					(x_6*y_7) + (x_7*y_6) +
-					(x_8*y_5) + (x_9*y_4));
-		xy._3 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x_0*y_4) + (x_2*y_2) + (x_4*y_0) + 19 *
-			((x_6*y_8) + (x_8*y_6)) + 2 * ((x_1*y_3) +
-								 (x_3*y_1)) + 38 *
-			((x_5*y_9) + (x_7*y_7) + (x_9*y_5));
-		xy._4 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x_0*y_5) + (x_1*y_4) + (x_2*y_3) +
-			(x_3*y_2) + (x_4*y_1) + (x_5*y_0) + 19 *
-			((x_6*y_9) + (x_7*y_8) + (x_8*y_7) +
-			 (x_9*y_6));
-		xy._5 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x_0*y_6) + (x_2*y_4) + (x_4*y_2) +
-			(x_6*y_0) + 19 * (x_8*y_8) + 2 * ((x_1*y_5) +
-					(x_3*y_3) + (x_5*y_1)) + 38 *
-			((x_7*y_9) + (x_9*y_7));
-		xy._6 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + (x_0*y_7) + (x_1*y_6) + (x_2*y_5) +
-			(x_3*y_4) + (x_4*y_3) + (x_5*y_2) +
-			(x_6*y_1) + (x_7*y_0) + 19 * ((x_8*y_9) +
-					(x_9*y_8));
-		xy._7 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + xy._8;
-		xy._8 = (t & ((1 << 26) - 1));
-		xy._9 += (t >> 26);
-		return xy;
-	}
-
-	/* Square a number.  Optimization of  mul25519(x2, x, x)  */
-	private static final long10 sqr(long10 x2, long10 x) {
-		long
-			x_0=x._0,x_1=x._1,x_2=x._2,x_3=x._3,x_4=x._4,
-			x_5=x._5,x_6=x._6,x_7=x._7,x_8=x._8,x_9=x._9;
-		long t;
-		t = (x_4*x_4) + 2 * ((x_0*x_8) + (x_2*x_6)) + 38 *
-			(x_9*x_9) + 4 * ((x_1*x_7) + (x_3*x_5));
-		x2._8 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + 2 * ((x_0*x_9) + (x_1*x_8) + (x_2*x_7) +
-				(x_3*x_6) + (x_4*x_5));
-		x2._9 = (t & ((1 << 25) - 1));
-		t = 19 * (t >> 25) + (x_0*x_0) + 38 * ((x_2*x_8) +
-				(x_4*x_6) + (x_5*x_5)) + 76 * ((x_1*x_9)
-				+ (x_3*x_7));
-		x2._0 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + 2 * (x_0*x_1) + 38 * ((x_2*x_9) +
-				(x_3*x_8) + (x_4*x_7) + (x_5*x_6));
-		x2._1 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + 19 * (x_6*x_6) + 2 * ((x_0*x_2) +
-				(x_1*x_1)) + 38 * (x_4*x_8) + 76 *
-				((x_3*x_9) + (x_5*x_7));
-		x2._2 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + 2 * ((x_0*x_3) + (x_1*x_2)) + 38 *
-			((x_4*x_9) + (x_5*x_8) + (x_6*x_7));
-		x2._3 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + (x_2*x_2) + 2 * (x_0*x_4) + 38 *
-			((x_6*x_8) + (x_7*x_7)) + 4 * (x_1*x_3) + 76 *
-			(x_5*x_9);
-		x2._4 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + 2 * ((x_0*x_5) + (x_1*x_4) + (x_2*x_3))
-			+ 38 * ((x_6*x_9) + (x_7*x_8));
-		x2._5 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + 19 * (x_8*x_8) + 2 * ((x_0*x_6) +
-				(x_2*x_4) + (x_3*x_3)) + 4 * (x_1*x_5) +
-				76 * (x_7*x_9);
-		x2._6 = (t & ((1 << 26) - 1));
-		t = (t >> 26) + 2 * ((x_0*x_7) + (x_1*x_6) + (x_2*x_5) +
-				(x_3*x_4)) + 38 * (x_8*x_9);
-		x2._7 = (t & ((1 << 25) - 1));
-		t = (t >> 25) + x2._8;
-		x2._8 = (t & ((1 << 26) - 1));
-		x2._9 += (t >> 26);
-		return x2;
-	}
-	
-	/* Calculates a reciprocal.  The output is in reduced form, the inputs need not 
-	 * be.  Simply calculates  y = x^(p-2)  so it's not too fast. */
-	/* When sqrtassist is true, it instead calculates y = x^((p-5)/8) */
-	private static final void recip(long10 y, long10 x, int sqrtassist) {
-		long10
-		    t0=new long10(),
-			t1=new long10(),
-			t2=new long10(),
-			t3=new long10(),
-			t4=new long10();
-		int i;
-		/* the chain for x^(2^255-21) is straight from djb's implementation */
-		sqr(t1, x);	/*  2 == 2 * 1	*/
-		sqr(t2, t1);	/*  4 == 2 * 2	*/
-		sqr(t0, t2);	/*  8 == 2 * 4	*/
-		mul(t2, t0, x);	/*  9 == 8 + 1	*/
-		mul(t0, t2, t1);	/* 11 == 9 + 2	*/
-		sqr(t1, t0);	/* 22 == 2 * 11	*/
-		mul(t3, t1, t2);	/* 31 == 22 + 9
-					== 2^5   - 2^0	*/
-		sqr(t1, t3);	/* 2^6   - 2^1	*/
-		sqr(t2, t1);	/* 2^7   - 2^2	*/
-		sqr(t1, t2);	/* 2^8   - 2^3	*/
-		sqr(t2, t1);	/* 2^9   - 2^4	*/
-		sqr(t1, t2);	/* 2^10  - 2^5	*/
-		mul(t2, t1, t3);	/* 2^10  - 2^0	*/
-		sqr(t1, t2);	/* 2^11  - 2^1	*/
-		sqr(t3, t1);	/* 2^12  - 2^2	*/
-		for (i = 1; i < 5; i++) {
-			sqr(t1, t3);
-			sqr(t3, t1);
-		} /* t3 */		/* 2^20  - 2^10	*/
-		mul(t1, t3, t2);	/* 2^20  - 2^0	*/
-		sqr(t3, t1);	/* 2^21  - 2^1	*/
-		sqr(t4, t3);	/* 2^22  - 2^2	*/
-		for (i = 1; i < 10; i++) {
-			sqr(t3, t4);
-			sqr(t4, t3);
-		} /* t4 */		/* 2^40  - 2^20	*/
-		mul(t3, t4, t1);	/* 2^40  - 2^0	*/
-		for (i = 0; i < 5; i++) {
-			sqr(t1, t3);
-			sqr(t3, t1);
-		} /* t3 */		/* 2^50  - 2^10	*/
-		mul(t1, t3, t2);	/* 2^50  - 2^0	*/
-		sqr(t2, t1);	/* 2^51  - 2^1	*/
-		sqr(t3, t2);	/* 2^52  - 2^2	*/
-		for (i = 1; i < 25; i++) {
-			sqr(t2, t3);
-			sqr(t3, t2);
-		} /* t3 */		/* 2^100 - 2^50 */
-		mul(t2, t3, t1);	/* 2^100 - 2^0	*/
-		sqr(t3, t2);	/* 2^101 - 2^1	*/
-		sqr(t4, t3);	/* 2^102 - 2^2	*/
-		for (i = 1; i < 50; i++) {
-			sqr(t3, t4);
-			sqr(t4, t3);
-		} /* t4 */		/* 2^200 - 2^100 */
-		mul(t3, t4, t2);	/* 2^200 - 2^0	*/
-		for (i = 0; i < 25; i++) {
-			sqr(t4, t3);
-			sqr(t3, t4);
-		} /* t3 */		/* 2^250 - 2^50	*/
-		mul(t2, t3, t1);	/* 2^250 - 2^0	*/
-		sqr(t1, t2);	/* 2^251 - 2^1	*/
-		sqr(t2, t1);	/* 2^252 - 2^2	*/
-		if (sqrtassist!=0) {
-			mul(y, x, t2);	/* 2^252 - 3 */
-		} else {
-			sqr(t1, t2);	/* 2^253 - 2^3	*/
-			sqr(t2, t1);	/* 2^254 - 2^4	*/
-			sqr(t1, t2);	/* 2^255 - 2^5	*/
-			mul(y, t1, t0);	/* 2^255 - 21	*/
-		}
-	}
-	
-	/* checks if x is "negative", requires reduced input */
-	private static final int is_negative(long10 x) {
-		return (int)(((is_overflow(x) || (x._9 < 0))?1:0) ^ (x._0 & 1));
-	}
-	
-	/* a square root */
-	private static final void sqrt(long10 x, long10 u) {
-		long10 v=new long10(), t1=new long10(), t2=new long10();
-		add(t1, u, u);	/* t1 = 2u		*/
-		recip(v, t1, 1);	/* v = (2u)^((p-5)/8)	*/
-		sqr(x, v);		/* x = v^2		*/
-		mul(t2, t1, x);	/* t2 = 2uv^2		*/
-		t2._0--;		/* t2 = 2uv^2-1		*/
-		mul(t1, v, t2);	/* t1 = v(2uv^2-1)	*/
-		mul(x, u, t1);	/* x = uv(2uv^2-1)	*/
-	}
-	
-	/********************* Elliptic curve *********************/
-	
-	/* y^2 = x^3 + 486662 x^2 + x  over GF(2^255-19) */
-	
-	/* t1 = ax + az
-	 * t2 = ax - az  */
-	private static final void mont_prep(long10 t1, long10 t2, long10 ax, long10 az) {
-		add(t1, ax, az);
-		sub(t2, ax, az);
-	}
-	
-	/* A = P + Q   where
-	 *  X(A) = ax/az
-	 *  X(P) = (t1+t2)/(t1-t2)
-	 *  X(Q) = (t3+t4)/(t3-t4)
-	 *  X(P-Q) = dx
-	 * clobbers t1 and t2, preserves t3 and t4  */
-	private static final void mont_add(long10 t1, long10 t2, long10 t3, long10 t4,long10 ax, long10 az, long10 dx) {
-		mul(ax, t2, t3);
-		mul(az, t1, t4);
-		add(t1, ax, az);
-		sub(t2, ax, az);
-		sqr(ax, t1);
-		sqr(t1, t2);
-		mul(az, t1, dx);
-	}
-	
-	/* B = 2 * Q   where
-	 *  X(B) = bx/bz
-	 *  X(Q) = (t3+t4)/(t3-t4)
-	 * clobbers t1 and t2, preserves t3 and t4  */
-	private static final void mont_dbl(long10 t1, long10 t2, long10 t3, long10 t4,long10 bx, long10 bz) {
-		sqr(t1, t3);
-		sqr(t2, t4);
-		mul(bx, t1, t2);
-		sub(t2, t1, t2);
-		mul_small(bz, t2, 121665);
-		add(t1, t1, bz);
-		mul(bz, t1, t2);
-	}
-	
-	/* Y^2 = X^3 + 486662 X^2 + X
-	 * t is a temporary  */
-	private static final void x_to_y2(long10 t, long10 y2, long10 x) {
-		sqr(t, x);
-		mul_small(y2, x, 486662);
-		add(t, t, y2);
-		t._0++;
-		mul(y2, t, x);
-	}
-	
-	/* P = kG   and  s = sign(P)/k  */
-	private static final void core(byte[] Px, byte[] s, byte[] k, byte[] Gx) {
-		long10 
-		    dx=new long10(),
-		    t1=new long10(),
-		    t2=new long10(),
-		    t3=new long10(),
-		    t4=new long10();
-	    long10[] 
-	        x=new long10[]{new long10(),new long10()},
-	    	z=new long10[]{new long10(),new long10()};
-		int i, j;
-
-		/* unpack the base */
-		if (Gx!=null)
-			unpack(dx, Gx);
-		else
-			set(dx, 9);
-
-		/* 0G = point-at-infinity */
-		set(x[0], 1);
-		set(z[0], 0);
-
-		/* 1G = G */
-		cpy(x[1], dx);
-		set(z[1], 1);
-
-		for (i = 32; i--!=0; ) {
-			if (i==0) {
-				i=0;
-			}
-			for (j = 8; j--!=0; ) {
-				/* swap arguments depending on bit */
-				int bit1 = (k[i] & 0xFF) >> j & 1;
-				int bit0 = ~(k[i] & 0xFF) >> j & 1;
-				long10 ax = x[bit0];
-				long10 az = z[bit0];
-				long10 bx = x[bit1];
-				long10 bz = z[bit1];
-
-				/* a' = a + b	*/
-				/* b' = 2 b	*/
-				mont_prep(t1, t2, ax, az);
-				mont_prep(t3, t4, bx, bz);
-				mont_add(t1, t2, t3, t4, ax, az, dx);
-				mont_dbl(t1, t2, t3, t4, bx, bz);
-			}
-		}
-
-		recip(t1, z[0], 0);
-		mul(dx, x[0], t1);
-		pack(dx, Px);
-
-		/* calculate s such that s abs(P) = G  .. assumes G is std base point */
-		if (s!=null) {
-			x_to_y2(t2, t1, dx);	/* t1 = Py^2  */
-			recip(t3, z[1], 0);	/* where Q=P+G ... */
-			mul(t2, x[1], t3);	/* t2 = Qx  */
-			add(t2, t2, dx);	/* t2 = Qx + Px  */
-			t2._0 += 9 + 486662;	/* t2 = Qx + Px + Gx + 486662  */
-			dx._0 -= 9;		/* dx = Px - Gx  */
-			sqr(t3, dx);	/* t3 = (Px - Gx)^2  */
-			mul(dx, t2, t3);	/* dx = t2 (Px - Gx)^2  */
-			sub(dx, dx, t1);	/* dx = t2 (Px - Gx)^2 - Py^2  */
-			dx._0 -= 39420360;	/* dx = t2 (Px - Gx)^2 - Py^2 - Gy^2  */
-			mul(t1, dx, BASE_R2Y);	/* t1 = -Py  */
-			if (is_negative(t1)!=0)	/* sign is 1, so just copy  */
-				cpy32(s, k);
-			else			/* sign is -1, so negate  */
-				mula_small(s, ORDER_TIMES_8, 0, k, 32, -1);
-
-			/* reduce s mod q
-			 * (is this needed?  do it just in case, it's fast anyway) */
-			//divmod((dstptr) t1, s, 32, order25519, 32);
-
-			/* take reciprocal of s mod q */
-			byte[] temp1=new byte[32];
-			byte[] temp2=new byte[64];
-			byte[] temp3=new byte[64];
-			cpy32(temp1, ORDER);
-			cpy32(s, egcd32(temp2, temp3, s, temp1));
-			if ((s[31] & 0x80)!=0)
-				mula_small(s, s, 0, ORDER, 32, 1);
-		}
-	}
-
-	/* smallest multiple of the order that's >= 2^255 */
-	private static final byte[] ORDER_TIMES_8 = {
-		(byte)104, (byte)159, (byte)174, (byte)231,
-		(byte)210, (byte)24,  (byte)147, (byte)192,
-		(byte)178, (byte)230, (byte)188, (byte)23,
-		(byte)245, (byte)206, (byte)247, (byte)166,
-		(byte)0,   (byte)0,   (byte)0,   (byte)0,  
-		(byte)0,   (byte)0,   (byte)0,   (byte)0,
-		(byte)0,   (byte)0,   (byte)0,   (byte)0,  
-		(byte)0,   (byte)0,   (byte)0,   (byte)128
-	};
-	
-	/* constants 2Gy and 1/(2Gy) */
-	private static final long10 BASE_2Y = new long10(
-		39999547, 18689728, 59995525, 1648697, 57546132,
-		24010086, 19059592, 5425144, 63499247, 16420658
-	);
-	private static final long10 BASE_R2Y = new long10(
-		5744, 8160848, 4790893, 13779497, 35730846,
-		12541209, 49101323, 30047407, 40071253, 6226132
-	);
-}

src/main/java/net/schmizz/concurrent/Promise.java

@@ -136,7 +136,7 @@ public class Promise<V, T extends Throwable> {
             throws T {
         final V value = tryRetrieve(timeout, unit);
         if (value == null)
-            throw chainer.chain(new TimeoutException("Timeout expired"));
+            throw chainer.chain(new TimeoutException("Timeout expired: " + timeout + " " + unit));
         else
             return value;
     }
@@ -176,6 +176,7 @@ public class Promise<V, T extends Throwable> {
             }
             return val;
         } catch (InterruptedException ie) {
+            Thread.currentThread().interrupt();
             throw chainer.chain(ie);
         } finally {
             lock.unlock();

src/main/java/net/schmizz/keepalive/Heartbeater.java

@@ -24,7 +24,7 @@ final class Heartbeater
         extends KeepAlive {
 
     Heartbeater(ConnectionImpl conn) {
-        super(conn, "heartbeater");
+        super(conn, "sshj-Heartbeater");
     }
 
     @Override

src/main/java/net/schmizz/keepalive/KeepAlive.java

@@ -20,6 +20,8 @@ import net.schmizz.sshj.connection.ConnectionImpl;
 import net.schmizz.sshj.transport.TransportException;
 import org.slf4j.Logger;
 
+import java.util.concurrent.TimeUnit;
+
 public abstract class KeepAlive extends Thread {
     protected final Logger log;
     protected final ConnectionImpl conn;
@@ -33,40 +35,49 @@ public abstract class KeepAlive extends Thread {
         setDaemon(true);
     }
 
+    /**
+     * KeepAlive enabled based on KeepAlive interval
+     *
+     * @return Enabled when KeepInterval is greater than 0
+     */
+    public boolean isEnabled() {
+        return keepAliveInterval > 0;
+    }
+
+    /**
+     * Get KeepAlive interval in seconds
+     *
+     * @return KeepAlive interval in seconds defaults to 0
+     */
     public synchronized int getKeepAliveInterval() {
         return keepAliveInterval;
     }
 
+    /**
+     * Set KeepAlive interval in seconds
+     *
+     * @param keepAliveInterval KeepAlive interval in seconds
+     */
     public synchronized void setKeepAliveInterval(int keepAliveInterval) {
         this.keepAliveInterval = keepAliveInterval;
-        if (keepAliveInterval > 0 && getState() == State.NEW) {
-            start();
-        }
-        notify();
-    }
-
-    synchronized protected int getPositiveInterval()
-            throws InterruptedException {
-        while (keepAliveInterval <= 0) {
-            wait();
-        }
-        return keepAliveInterval;
     }
 
     @Override
     public void run() {
-        log.debug("Starting {}, sending keep-alive every {} seconds", getClass().getSimpleName(), keepAliveInterval);
+        log.debug("{} Started with interval [{} seconds]", getClass().getSimpleName(), keepAliveInterval);
         try {
             while (!isInterrupted()) {
-                final int hi = getPositiveInterval();
+                final int interval = getKeepAliveInterval();
                 if (conn.getTransport().isRunning()) {
-                    log.debug("Sending keep-alive since {} seconds elapsed", hi);
+                    log.debug("{} Sending after interval [{} seconds]", getClass().getSimpleName(), interval);
                     doKeepAlive();
                 }
-                Thread.sleep(hi * 1000);
+                TimeUnit.SECONDS.sleep(interval);
             }
         } catch (InterruptedException e) {
-            // Interrupt signal may be catched when sleeping.      
+            // this is almost certainly a planned interruption, but even so, no harm in setting the interrupt flag
+            Thread.currentThread().interrupt();
+            log.trace("{} Interrupted while sleeping", getClass().getSimpleName());
         } catch (Exception e) {
             // If we weren't interrupted, kill the transport, then this exception was unexpected.
             // Else we're in shutdown-mode already, so don't forcibly kill the transport.
@@ -74,9 +85,7 @@ public abstract class KeepAlive extends Thread {
                 conn.getTransport().die(e);
             }
         }
-
-        log.debug("Stopping {}", getClass().getSimpleName());
-
+        log.debug("{} Stopped", getClass().getSimpleName());
     }
 
     protected abstract void doKeepAlive() throws TransportException, ConnectionException;

src/main/java/net/schmizz/keepalive/KeepAliveRunner.java

@@ -37,7 +37,7 @@ public class KeepAliveRunner extends KeepAlive {
             new LinkedList<Promise<SSHPacket, ConnectionException>>();
 
     KeepAliveRunner(ConnectionImpl conn) {
-        super(conn, "keep-alive");
+        super(conn, "sshj-KeepAliveRunner");
     }
 
     synchronized public int getMaxAliveCount() {

src/main/java/net/schmizz/sshj/ConfigImpl.java

@@ -26,6 +26,7 @@ import net.schmizz.sshj.transport.mac.MAC;
 import net.schmizz.sshj.transport.random.Random;
 import net.schmizz.sshj.userauth.keyprovider.FileKeyProvider;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -188,4 +189,30 @@ public class ConfigImpl
     public void setVerifyHostKeyCertificates(boolean value) {
         verifyHostKeyCertificates = value;
     }
+
+    /**
+     * Modern servers neglect the key algorithm ssh-rsa. OpenSSH 8.8 even dropped its support by default in favour
+     * of rsa-sha2-*. However, there are legacy servers like Apache SSHD that don't support the newer replacements
+     * for ssh-rsa.
+     *
+     * If ssh-rsa factory is in {@link #getKeyAlgorithms()}, this methods makes ssh-rsa key algorithm more preferred
+     * than any of rsa-sha2-*. Otherwise, nothing happens.
+     */
+    public void prioritizeSshRsaKeyAlgorithm() {
+        List<Factory.Named<KeyAlgorithm>> keyAlgorithms = getKeyAlgorithms();
+        for (int sshRsaIndex = 0; sshRsaIndex < keyAlgorithms.size(); ++ sshRsaIndex) {
+            if ("ssh-rsa".equals(keyAlgorithms.get(sshRsaIndex).getName())) {
+                for (int i = 0; i < sshRsaIndex; ++i) {
+                    final String algo = keyAlgorithms.get(i).getName();
+                    if ("rsa-sha2-256".equals(algo) || "rsa-sha2-512".equals(algo)) {
+                        keyAlgorithms = new ArrayList<>(keyAlgorithms);
+                        keyAlgorithms.add(i, keyAlgorithms.remove(sshRsaIndex));
+                        setKeyAlgorithms(keyAlgorithms);
+                        break;
+                    }
+                }
+                break;
+            }
+        }
+    }
 }

src/main/java/net/schmizz/sshj/DefaultConfig.java

@@ -36,11 +36,9 @@ import net.schmizz.sshj.transport.kex.Curve25519SHA256;
 import net.schmizz.sshj.transport.kex.DHGexSHA1;
 import net.schmizz.sshj.transport.kex.DHGexSHA256;
 import net.schmizz.sshj.transport.kex.ECDHNistP;
-import net.schmizz.sshj.transport.random.BouncyCastleRandom;
 import net.schmizz.sshj.transport.random.JCERandom;
 import net.schmizz.sshj.transport.random.SingletonRandomFactory;
 import net.schmizz.sshj.userauth.keyprovider.OpenSSHKeyFile;
-import net.schmizz.sshj.userauth.keyprovider.PKCS5KeyFile;
 import net.schmizz.sshj.userauth.keyprovider.PKCS8KeyFile;
 import net.schmizz.sshj.userauth.keyprovider.PuTTYKeyFile;
 import org.slf4j.Logger;
@@ -162,7 +160,6 @@ public class DefaultConfig
             setFileKeyProviderFactories(
                     new OpenSSHKeyV1KeyFile.Factory(),
                     new PKCS8KeyFile.Factory(),
-                    new PKCS5KeyFile.Factory(),
                     new OpenSSHKeyFile.Factory(),
                     new PuTTYKeyFile.Factory());
         }

src/main/java/net/schmizz/sshj/SSHClient.java

@@ -15,6 +15,8 @@
  */
 package net.schmizz.sshj;
 
+import net.schmizz.keepalive.KeepAlive;
+import com.hierynomus.sshj.common.ThreadNameProvider;
 import net.schmizz.sshj.common.*;
 import net.schmizz.sshj.connection.Connection;
 import net.schmizz.sshj.connection.ConnectionException;
@@ -55,6 +57,7 @@ import javax.security.auth.login.LoginContext;
 import java.io.Closeable;
 import java.io.File;
 import java.io.IOException;
+import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.nio.charset.Charset;
 import java.security.KeyPair;
@@ -140,7 +143,7 @@ public class SSHClient
         super(DEFAULT_PORT);
 	loggerFactory = config.getLoggerFactory();
 	log = loggerFactory.getLogger(getClass());
-        this.trans = new TransportImpl(config, this);
+        this.trans = new TransportImpl(config);
         this.auth = new UserAuthImpl(trans);
         this.conn = new ConnectionImpl(trans, config.getKeepAliveProvider());
     }
@@ -424,6 +427,7 @@ public class SSHClient
     @Override
     public void disconnect()
             throws IOException {
+        conn.getKeepAlive().interrupt();
         for (LocalPortForwarder forwarder : forwarders) {
             try {
                 forwarder.close();
@@ -441,6 +445,16 @@ public class SSHClient
         return conn;
     }
 
+    /**
+     * Get Remote Socket Address from Transport
+     *
+     * @return Remote Socket Address or null when not connected
+     */
+    @Override
+    public InetSocketAddress getRemoteSocketAddress() {
+        return trans.getRemoteSocketAddress();
+    }
+
     /**
      * Returns the character set used to communicate with the remote machine for certain strings (like paths).
      *
@@ -537,7 +551,7 @@ public class SSHClient
      * Creates a {@link KeyProvider} instance from given location on the file system. Currently the following private key files are supported:
      * <ul>
      *     <li>PKCS8 (OpenSSH uses this format)</li>
-     *     <li>PKCS5</li>
+     *     <li>PEM-encoded PKCS1</li>
      *     <li>Putty keyfile</li>
      *     <li>openssh-key-v1 (New OpenSSH keyfile format)</li>
      * </ul>
@@ -791,7 +805,17 @@ public class SSHClient
             throws IOException {
         super.onConnect();
         trans.init(getRemoteHostname(), getRemotePort(), getInputStream(), getOutputStream());
-        doKex();
+        final KeepAlive keepAliveThread = conn.getKeepAlive();
+        if (keepAliveThread.isEnabled()) {
+            ThreadNameProvider.setThreadName(conn.getKeepAlive(), trans);
+            keepAliveThread.start();
+        }
+        if (trans.isKeyExchangeRequired()) {
+            log.debug("Initiating Key Exchange for new connection");
+            doKex();
+        } else {
+            log.debug("Key Exchange already completed for new connection");
+        }
     }
 
     /**

src/main/java/net/schmizz/sshj/SocketClient.java

@@ -15,8 +15,6 @@
  */
 package net.schmizz.sshj;
 
-import com.hierynomus.sshj.backport.JavaVersion;
-import com.hierynomus.sshj.backport.Jdk7HttpProxySocket;
 import net.schmizz.sshj.connection.channel.Channel;
 import net.schmizz.sshj.connection.channel.direct.DirectConnection;
 
@@ -26,7 +24,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
-import java.net.Proxy;
 import java.net.Socket;
 
 public abstract class SocketClient {
@@ -57,73 +54,6 @@ public abstract class SocketClient {
         return new InetSocketAddress(hostname, port);
     }
 
-    /**
-     * Connect to a host via a proxy.
-     * @param hostname The host name to connect to.
-     * @param proxy The proxy to connect via.
-     * @deprecated This method will be removed after v0.12.0. If you want to connect via a proxy, you can do this by injecting a {@link javax.net.SocketFactory}
-     *             into the SocketClient. The SocketFactory should create sockets using the {@link java.net.Socket#Socket(java.net.Proxy)} constructor.
-     */
-    @Deprecated
-    public void connect(String hostname, Proxy proxy) throws IOException {
-        connect(hostname, defaultPort, proxy);
-    }
-
-    /**
-     * Connect to a host via a proxy.
-     * @param hostname The host name to connect to.
-     * @param port The port to connect to.
-     * @param proxy The proxy to connect via.
-     * @deprecated This method will be removed after v0.12.0. If you want to connect via a proxy, you can do this by injecting a {@link javax.net.SocketFactory}
-     *             into the SocketClient. The SocketFactory should create sockets using the {@link java.net.Socket#Socket(java.net.Proxy)} constructor.
-     */
-    @Deprecated
-    public void connect(String hostname, int port, Proxy proxy) throws IOException {
-        this.hostname = hostname;
-        this.port = port;
-        if (JavaVersion.isJava7OrEarlier() && proxy.type() == Proxy.Type.HTTP) {
-            // Java7 and earlier have no support for HTTP Connect proxies, return our custom socket.
-            socket = new Jdk7HttpProxySocket(proxy);
-        } else {
-            socket = new Socket(proxy);
-        }
-        socket.connect(makeInetSocketAddress(hostname, port), connectTimeout);
-        onConnect();
-    }
-
-    /**
-     * Connect to a host via a proxy.
-     * @param host The host address to connect to.
-     * @param proxy The proxy to connect via.
-     * @deprecated This method will be removed after v0.12.0. If you want to connect via a proxy, you can do this by injecting a {@link javax.net.SocketFactory}
-     *             into the SocketClient. The SocketFactory should create sockets using the {@link java.net.Socket#Socket(java.net.Proxy)} constructor.
-     */
-    @Deprecated
-    public void connect(InetAddress host, Proxy proxy) throws IOException {
-        connect(host, defaultPort, proxy);
-    }
-
-    /**
-     * Connect to a host via a proxy.
-     * @param host The host address to connect to.
-     * @param port The port to connect to.
-     * @param proxy The proxy to connect via.
-     * @deprecated This method will be removed after v0.12.0. If you want to connect via a proxy, you can do this by injecting a {@link javax.net.SocketFactory}
-     *             into the SocketClient. The SocketFactory should create sockets using the {@link java.net.Socket#Socket(java.net.Proxy)} constructor.
-     */
-    @Deprecated
-    public void connect(InetAddress host, int port, Proxy proxy) throws IOException {
-        this.port = port;
-        if (JavaVersion.isJava7OrEarlier() && proxy.type() == Proxy.Type.HTTP) {
-            // Java7 and earlier have no support for HTTP Connect proxies, return our custom socket.
-            socket = new Jdk7HttpProxySocket(proxy);
-        } else {
-            socket = new Socket(proxy);
-        }
-        socket.connect(new InetSocketAddress(host, port), connectTimeout);
-        onConnect();
-    }
-
     public void connect(String hostname) throws IOException {
         connect(hostname, defaultPort);
     }

src/main/java/net/schmizz/sshj/common/StreamCopier.java

@@ -145,8 +145,14 @@ public class StreamCopier {
         final double sizeKiB = count / 1024.0;
         log.debug(String.format("%1$,.1f KiB transferred in %2$,.1f seconds (%3$,.2f KiB/s)", sizeKiB, timeSeconds, (sizeKiB / timeSeconds)));
 
-        if (length != -1 && read == -1)
-            throw new IOException("Encountered EOF, could not transfer " + length + " bytes");
+        // Did we encounter EOF?
+        if (read == -1) {
+            // If InputStream was closed we should also close OutputStream
+            out.close();
+
+            if (length != -1)
+                throw new IOException("Encountered EOF, could not transfer " + length + " bytes");
+        }
 
         return count;
     }

src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java

@@ -304,6 +304,25 @@ public abstract class AbstractChannel
         }
     }
 
+    // Prevent CHANNEL_CLOSE to be sent between isOpen and a Transport.write call in the runnable, otherwise
+    // a disconnect with a "packet referred to nonexistent channel" message can occur.
+    //
+    // This particularly happens when the transport.Reader thread passes an eof from the server to the
+    // ChannelInputStream, the reading library-user thread returns, and closes the channel at the same time as the
+    // transport.Reader thread receives the subsequent CHANNEL_CLOSE from the server.
+    boolean whileOpen(TransportRunnable runnable) throws TransportException, ConnectionException {
+        openCloseLock.lock();
+        try {
+            if (isOpen()) {
+                runnable.run();
+                return true;
+            }
+        } finally {
+            openCloseLock.unlock();
+        }
+        return false;
+    }
+
     private void gotChannelRequest(SSHPacket buf)
             throws ConnectionException, TransportException {
         final String reqType;
@@ -427,5 +446,8 @@ public abstract class AbstractChannel
                 + rwin + " >";
     }
 
+    public interface TransportRunnable {
+        void run() throws TransportException, ConnectionException;
+    }
 
 }

src/main/java/net/schmizz/sshj/connection/channel/ChannelInputStream.java

@@ -105,6 +105,7 @@ public final class ChannelInputStream
                 try {
                     buf.wait();
                 } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
                     throw (IOException) new InterruptedIOException().initCause(e);
                 }
             }

src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java

@@ -22,6 +22,7 @@ import net.schmizz.sshj.transport.TransportException;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * {@link OutputStream} for channels. Buffers data upto the remote window's maximum packet size. Data can also be
@@ -29,14 +30,14 @@ import java.io.OutputStream;
  */
 public final class ChannelOutputStream extends OutputStream implements ErrorNotifiable {
 
-    private final Channel chan;
+    private final AbstractChannel chan;
     private final Transport trans;
     private final Window.Remote win;
 
     private final DataBuffer buffer = new DataBuffer();
     private final byte[] b = new byte[1];
 
-    private boolean closed;
+    private AtomicBoolean closed;
     private SSHException error;
 
     private final class DataBuffer {
@@ -46,6 +47,12 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
 
         private final SSHPacket packet = new SSHPacket(Message.CHANNEL_DATA);
         private final Buffer.PlainBuffer leftOvers = new Buffer.PlainBuffer();
+        private final AbstractChannel.TransportRunnable packetWriteRunnable = new AbstractChannel.TransportRunnable() {
+            @Override
+            public void run() throws TransportException {
+                trans.write(packet);
+            }
+        };
 
         DataBuffer() {
             headerOffset = packet.rpos();
@@ -98,8 +105,9 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
                 if (leftOverBytes > 0) {
                     leftOvers.putRawBytes(packet.array(), packet.wpos(), leftOverBytes);
                 }
-
-                trans.write(packet);
+                if (!chan.whileOpen(packetWriteRunnable)) {
+                    throwStreamClosed();
+                }
                 win.consume(writeNow);
 
                 packet.rpos(headerOffset);
@@ -118,10 +126,11 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
 
     }
 
-    public ChannelOutputStream(Channel chan, Transport trans, Window.Remote win) {
+    public ChannelOutputStream(AbstractChannel chan, Transport trans, Window.Remote win) {
         this.chan = chan;
         this.trans = trans;
         this.win = win;
+        this.closed = new AtomicBoolean(false);
     }
 
     @Override
@@ -151,24 +160,26 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
 
     private void checkClose() throws SSHException {
         // Check whether either the Stream is closed, or the underlying channel is closed
-        if (closed || !chan.isOpen()) {
-            if (error != null)
+        if (closed.get() || !chan.isOpen()) {
+            if (error != null) {
                 throw error;
-            else
-                throw new ConnectionException("Stream closed");
+            } else {
+                throwStreamClosed();
+            }
         }
     }
 
     @Override
     public synchronized void close() throws IOException {
         // Not closed yet, and underlying channel is open to flush the data to.
-        if (!closed && chan.isOpen()) {
-            try {
-                buffer.flush(false);
-//                trans.write(new SSHPacket(Message.CHANNEL_EOF).putUInt32(chan.getRecipient()));
-            } finally {
-                closed = true;
-            }
+        if (!closed.getAndSet(true)) {
+            chan.whileOpen(new AbstractChannel.TransportRunnable() {
+                @Override
+                public void run() throws TransportException, ConnectionException {
+                    buffer.flush(false);
+                    trans.write(new SSHPacket(Message.CHANNEL_EOF).putUInt32(chan.getRecipient()));
+                }
+            });
         }
     }
 
@@ -189,4 +200,7 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
         return "< ChannelOutputStream for Channel #" + chan.getID() + " >";
     }
 
+    private static void throwStreamClosed() throws ConnectionException {
+        throw new ConnectionException("Stream closed");
+    }
 }

src/main/java/net/schmizz/sshj/connection/channel/Window.java

@@ -93,6 +93,7 @@ public abstract class Window {
                             throw new ConnectionException("Timeout when trying to expand the window size");
                         }
                     } catch (InterruptedException ie) {
+                        Thread.currentThread().interrupt();
                         throw new ConnectionException(ie);
                     }
                 }

src/main/java/net/schmizz/sshj/connection/channel/direct/SessionFactory.java

@@ -15,10 +15,11 @@
  */
 package net.schmizz.sshj.connection.channel.direct;
 
+import com.hierynomus.sshj.common.RemoteAddressProvider;
 import net.schmizz.sshj.common.SSHException;
 
 /** A factory interface for creating SSH {@link Session session channels}. */
-public interface SessionFactory {
+public interface SessionFactory extends RemoteAddressProvider {
 
     /**
      * Opens a {@code session} channel. The returned {@link Session} instance allows {@link Session#exec(String)
@@ -27,7 +28,7 @@ public interface SessionFactory {
      *
      * @return the opened {@code session} channel
      *
-     * @throws SSHException
+     * @throws SSHException Thrown on session initialization failures
      * @see Session
      */
     Session startSession()

src/main/java/net/schmizz/sshj/connection/channel/forwarded/RemotePortForwarder.java

@@ -142,6 +142,10 @@ public class RemotePortForwarder
                 // Listen on all IPv4
                 return true;
             }
+            if ("0.0.0.0".equals(address) && "0:0:0:0:0:0:0:0".equals(channelForward.address)) {
+                // Handle IPv4 requests on IPv6 channel forward
+                return true;
+            }
             return false;
         }
 

src/main/java/net/schmizz/sshj/sftp/PacketReader.java

@@ -41,7 +41,7 @@ public class PacketReader extends Thread {
         this.engine = engine;
         log = engine.getLoggerFactory().getLogger(getClass());
         this.in = engine.getSubsystem().getInputStream();
-        setName("sftp reader");
+        setName("sshj-PacketReader");
         setDaemon(true);
     }
 

src/main/java/net/schmizz/sshj/sftp/RemoteFile.java

@@ -23,6 +23,8 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.LinkedList;
 import java.util.Queue;
 import java.util.concurrent.TimeUnit;
@@ -220,49 +222,104 @@ public class RemoteFile
 
     public class ReadAheadRemoteFileInputStream
             extends InputStream {
+        private class UnconfirmedRead {
+            private final long offset;
+            private final Promise<Response, SFTPException> promise;
+            private final int length;
+
+            private UnconfirmedRead(long offset, int length, Promise<Response, SFTPException> promise) {
+                this.offset = offset;
+                this.length = length;
+                this.promise = promise;
+            }
+
+            UnconfirmedRead(long offset, int length) throws IOException {
+                this(offset, length, RemoteFile.this.asyncRead(offset, length));
+            }
+
+            public long getOffset() {
+                return offset;
+            }
+
+            public Promise<Response, SFTPException> getPromise() {
+                return promise;
+            }
+
+            public int getLength() {
+                return length;
+            }
+        }
 
         private final byte[] b = new byte[1];
 
         private final int maxUnconfirmedReads;
-        private final Queue<Promise<Response, SFTPException>> unconfirmedReads = new LinkedList<Promise<Response, SFTPException>>();
-        private final Queue<Long> unconfirmedReadOffsets = new LinkedList<Long>();
+        private final long readAheadLimit;
+        private final Deque<UnconfirmedRead> unconfirmedReads = new ArrayDeque<>();
 
-        private long requestOffset;
-        private long responseOffset;
+        private long currentOffset;
+        private int maxReadLength = Integer.MAX_VALUE;
         private boolean eof;
 
         public ReadAheadRemoteFileInputStream(int maxUnconfirmedReads) {
-            assert 0 <= maxUnconfirmedReads;
-
-            this.maxUnconfirmedReads = maxUnconfirmedReads;
+            this(maxUnconfirmedReads, 0L);
+        }
+        
+        /**
+         *
+         * @param maxUnconfirmedReads Maximum number of unconfirmed requests to send
+         * @param fileOffset Initial offset in file to read from
+         */
+        public ReadAheadRemoteFileInputStream(int maxUnconfirmedReads, long fileOffset) {
+            this(maxUnconfirmedReads, fileOffset, -1L);
         }
 
-        public ReadAheadRemoteFileInputStream(int maxUnconfirmedReads, long fileOffset) {
+        /**
+         *
+         * @param maxUnconfirmedReads Maximum number of unconfirmed requests to send
+         * @param fileOffset Initial offset in file to read from
+         * @param readAheadLimit Read ahead is disabled after this limit has been reached
+         */
+        public ReadAheadRemoteFileInputStream(int maxUnconfirmedReads, long fileOffset, long readAheadLimit) {
             assert 0 <= maxUnconfirmedReads;
             assert 0 <= fileOffset;
 
             this.maxUnconfirmedReads = maxUnconfirmedReads;
-            this.requestOffset = this.responseOffset = fileOffset;
+            this.currentOffset = fileOffset;
+            this.readAheadLimit = readAheadLimit > 0 ? fileOffset + readAheadLimit : Long.MAX_VALUE;
         }
 
         private ByteArrayInputStream pending = new ByteArrayInputStream(new byte[0]);
 
         private boolean retrieveUnconfirmedRead(boolean blocking) throws IOException {
-            if (unconfirmedReads.size() <= 0) {
+            final UnconfirmedRead unconfirmedRead = unconfirmedReads.peek();
+            if (unconfirmedRead == null || !blocking && !unconfirmedRead.getPromise().isDelivered()) {
                 return false;
             }
+            unconfirmedReads.remove(unconfirmedRead);
 
-            if (!blocking && !unconfirmedReads.peek().isDelivered()) {
-                return false;
-            }
-
-            unconfirmedReadOffsets.remove();
-            final Response res = unconfirmedReads.remove().retrieve(requester.getTimeoutMs(), TimeUnit.MILLISECONDS);
+            final Response res = unconfirmedRead.promise.retrieve(requester.getTimeoutMs(), TimeUnit.MILLISECONDS);
             switch (res.getType()) {
                 case DATA:
                     int recvLen = res.readUInt32AsInt();
-                    responseOffset += recvLen;
-                    pending = new ByteArrayInputStream(res.array(), res.rpos(), recvLen);
+                    if (unconfirmedRead.offset == currentOffset) {
+                        currentOffset += recvLen;
+                        pending = new ByteArrayInputStream(res.array(), res.rpos(), recvLen);
+
+                        if (recvLen < unconfirmedRead.length) {
+                            // The server returned a packet smaller than the client had requested.
+                            // It can be caused by at least one of the following:
+                            // * The file has been read fully. Then, few futile read requests can be sent during
+                            //   the next read(), but the file will be downloaded correctly anyway.
+                            // * The server shapes the request length. Then, the read window will be adjusted,
+                            //   and all further read-ahead requests won't be shaped.
+                            // * The file on the server is not a regular file, it is something like fifo.
+                            //   Then, the window will shrink, and the client will start reading the file slower than it
+                            //   hypothetically can. It must be a rare case, and it is not worth implementing a sort of
+                            //   congestion control algorithm here.
+                            maxReadLength = recvLen;
+                            unconfirmedReads.clear();
+                        }
+                    }
                     break;
 
                 case STATUS:
@@ -290,40 +347,31 @@ public class RemoteFile
                 // we also need to go here for len <= 0, because pending may be at
                 // EOF in which case it would return -1 instead of 0
 
+                long requestOffset;
+                if (unconfirmedReads.isEmpty()) {
+                    requestOffset = currentOffset;
+                }
+                else {
+                    final UnconfirmedRead lastRequest = unconfirmedReads.getLast();
+                    requestOffset = lastRequest.offset + lastRequest.length;
+                }
                 while (unconfirmedReads.size() <= maxUnconfirmedReads) {
                     // Send read requests as long as there is no EOF and we have not reached the maximum parallelism
-                    int reqLen = Math.max(1024, len); // don't be shy!
-                    unconfirmedReads.add(RemoteFile.this.asyncRead(requestOffset, reqLen));
-                    unconfirmedReadOffsets.add(requestOffset);
+                    int reqLen = Math.min(Math.max(1024, len), maxReadLength);
+                    if (readAheadLimit > requestOffset) {
+                        long remaining = readAheadLimit - requestOffset;
+                        if (reqLen > remaining) {
+                            reqLen = (int) remaining;
+                        }
+                    }
+                    unconfirmedReads.add(new UnconfirmedRead(requestOffset, reqLen));
                     requestOffset += reqLen;
+                    if (requestOffset >= readAheadLimit) {
+                        break;
+                    }
                 }
 
-                long nextOffset = unconfirmedReadOffsets.peek();
-                if (responseOffset != nextOffset) {
-
-                    // the server could not give us all the data we needed, so
-                    // we try to fill the gap synchronously
-
-                    assert responseOffset < nextOffset;
-                    assert 0 < (nextOffset - responseOffset);
-                    assert (nextOffset - responseOffset) <= Integer.MAX_VALUE;
-
-                    byte[] buf = new byte[(int) (nextOffset - responseOffset)];
-                    int recvLen = RemoteFile.this.read(responseOffset, buf, 0, buf.length);
-
-                    if (recvLen < 0) {
-                        eof = true;
-                        return -1;
-                    }
-
-                    if (0 == recvLen) {
-                        // avoid infinite loops
-                        throw new SFTPException("Unexpected response size (0), bailing out");
-                    }
-
-                    responseOffset += recvLen;
-                    pending = new ByteArrayInputStream(buf, 0, recvLen);
-                } else if (!retrieveUnconfirmedRead(true /*blocking*/)) {
+                if (!retrieveUnconfirmedRead(true /*blocking*/)) {
 
                     // this may happen if we change prefetch strategy
                     // currently, we should never get here...

src/main/java/net/schmizz/sshj/sftp/RenameFlags.java

@@ -13,14 +13,20 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.hierynomus.sshj.backport;
+package net.schmizz.sshj.sftp;
 
-public class JavaVersion {
-    public static boolean isJava7OrEarlier() {
-        String property = System.getProperty("java.specification.version");
-        float diff = Float.parseFloat(property) - 1.7f;
+public enum RenameFlags {
+    OVERWRITE(1),
+    ATOMIC(2),
+    NATIVE(4);
 
-        return diff < 0.01;
+    private final long flag;
+
+    RenameFlags(long flag) {
+        this.flag = flag;
     }
 
+    public long longValue() {
+        return flag;
+    }
 }

src/main/java/net/schmizz/sshj/sftp/SFTPClient.java

@@ -115,9 +115,13 @@ public class SFTPClient
         }
     }
 
-    public void rename(String oldpath, String newpath)
+    public void rename(String oldpath, String newpath) throws IOException {
+        rename(oldpath, newpath, EnumSet.noneOf(RenameFlags.class));
+    }
+
+    public void rename(String oldpath, String newpath, Set<RenameFlags> renameFlags)
             throws IOException {
-        engine.rename(oldpath, newpath);
+        engine.rename(oldpath, newpath, renameFlags);
     }
 
     public void rm(String filename)
@@ -228,21 +232,41 @@ public class SFTPClient
             throws IOException {
         xfer.download(source, dest);
     }
+    
+    public void get(String source, String dest, long byteOffset)
+            throws IOException {
+        xfer.download(source, dest, byteOffset);
+    }
 
     public void put(String source, String dest)
             throws IOException {
         xfer.upload(source, dest);
     }
 
+    public void put(String source, String dest, long byteOffset)
+            throws IOException {
+        xfer.upload(source, dest, byteOffset);
+    }
+
     public void get(String source, LocalDestFile dest)
             throws IOException {
         xfer.download(source, dest);
     }
+    
+    public void get(String source, LocalDestFile dest, long byteOffset)
+            throws IOException {
+        xfer.download(source, dest, byteOffset);
+    }
 
     public void put(LocalSourceFile source, String dest)
             throws IOException {
         xfer.upload(source, dest);
     }
+    
+    public void put(LocalSourceFile source, String dest, long byteOffset)
+            throws IOException {
+        xfer.upload(source, dest, byteOffset);
+    }
 
     @Override
     public void close()

src/main/java/net/schmizz/sshj/sftp/SFTPEngine.java

@@ -15,6 +15,7 @@
  */
 package net.schmizz.sshj.sftp;
 
+import com.hierynomus.sshj.common.ThreadNameProvider;
 import net.schmizz.concurrent.Promise;
 import net.schmizz.sshj.common.IOUtils;
 import net.schmizz.sshj.common.LoggerFactory;
@@ -68,6 +69,7 @@ public class SFTPEngine
         sub = session.startSubsystem("sftp");
         out = sub.getOutputStream();
         reader = new PacketReader(this);
+        ThreadNameProvider.setThreadName(reader, ssh);
         pathHelper = new PathHelper(new PathHelper.Canonicalizer() {
             @Override
             public String canonicalize(String path)
@@ -230,13 +232,22 @@ public class SFTPEngine
         return stat(PacketType.LSTAT, path);
     }
 
-    public void rename(String oldPath, String newPath)
+    public void rename(String oldPath, String newPath, Set<RenameFlags> flags)
             throws IOException {
         if (operativeVersion < 1)
             throw new SFTPException("RENAME is not supported in SFTPv" + operativeVersion);
-        doRequest(
-                newRequest(PacketType.RENAME).putString(oldPath, sub.getRemoteCharset()).putString(newPath, sub.getRemoteCharset())
-        ).ensureStatusPacketIsOK();
+
+        final Request request = newRequest(PacketType.RENAME).putString(oldPath, sub.getRemoteCharset()).putString(newPath, sub.getRemoteCharset());
+        // SFTP Version 5 introduced rename flags according to Section 6.5 of the specification
+        if (operativeVersion >= 5) {
+            long renameFlagMask = 0L;
+            for (RenameFlags flag : flags) {
+                renameFlagMask = renameFlagMask | flag.longValue();
+            }
+            request.putUInt32(renameFlagMask);
+        }
+
+        doRequest(request).ensureStatusPacketIsOK();
     }
 
     public String canonicalize(String path)

src/main/java/net/schmizz/sshj/sftp/SFTPFileTransfer.java

@@ -50,25 +50,47 @@ public class SFTPFileTransfer
     @Override
     public void upload(String source, String dest)
             throws IOException {
-        upload(new FileSystemFile(source), dest);
+        upload(source, dest, 0);
+    }
+    
+    @Override
+    public void upload(String source, String dest, long byteOffset)
+            throws IOException {
+        upload(new FileSystemFile(source), dest, byteOffset);
     }
 
     @Override
     public void download(String source, String dest)
             throws IOException {
-        download(source, new FileSystemFile(dest));
+        download(source, dest, 0);
+    }
+    
+    @Override
+    public void download(String source, String dest, long byteOffset)
+            throws IOException {
+        download(source, new FileSystemFile(dest), byteOffset);
     }
 
     @Override
     public void upload(LocalSourceFile localFile, String remotePath) throws IOException {
-        new Uploader(localFile, remotePath).upload(getTransferListener());
+        upload(localFile, remotePath, 0);
+    }
+    
+    @Override
+    public void upload(LocalSourceFile localFile, String remotePath, long byteOffset) throws IOException {
+        new Uploader(localFile, remotePath).upload(getTransferListener(), byteOffset);
     }
 
     @Override
     public void download(String source, LocalDestFile dest) throws IOException {
+        download(source, dest, 0);
+    }
+    
+    @Override
+    public void download(String source, LocalDestFile dest, long byteOffset) throws IOException {
         final PathComponents pathComponents = engine.getPathHelper().getComponents(source);
         final FileAttributes attributes = engine.stat(source);
-        new Downloader().download(getTransferListener(), new RemoteResourceInfo(pathComponents, attributes), dest);
+        new Downloader().download(getTransferListener(), new RemoteResourceInfo(pathComponents, attributes), dest, byteOffset);
     }
 
     public void setUploadFilter(LocalFileFilter uploadFilter) {
@@ -92,7 +114,8 @@ public class SFTPFileTransfer
         @SuppressWarnings("PMD.MissingBreakInSwitch")
         private void download(final TransferListener listener,
                               final RemoteResourceInfo remote,
-                              final LocalDestFile local) throws IOException {
+                              final LocalDestFile local,
+                              final long byteOffset) throws IOException {
             final LocalDestFile adjustedFile;
             switch (remote.getAttributes().getType()) {
                 case DIRECTORY:
@@ -101,8 +124,9 @@ public class SFTPFileTransfer
                 case UNKNOWN:
                     log.warn("Server did not supply information about the type of file at `{}` " +
                                      "-- assuming it is a regular file!", remote.getPath());
+                    // fall through
                 case REGULAR:
-                    adjustedFile = downloadFile(listener.file(remote.getName(), remote.getAttributes().getSize()), remote, local);
+                    adjustedFile = downloadFile(listener.file(remote.getName(), remote.getAttributes().getSize()), remote, local, byteOffset);
                     break;
                 default:
                     throw new IOException(remote + " is not a regular file or directory");
@@ -119,7 +143,7 @@ public class SFTPFileTransfer
             final RemoteDirectory rd = engine.openDir(remote.getPath());
             try {
                 for (RemoteResourceInfo rri : rd.scan(getDownloadFilter()))
-                    download(listener, rri, adjusted.getChild(rri.getName()));
+                    download(listener, rri, adjusted.getChild(rri.getName()), 0); // not supporting individual byte offsets for these files
             } finally {
                 rd.close();
             }
@@ -128,13 +152,15 @@ public class SFTPFileTransfer
 
         private LocalDestFile downloadFile(final StreamCopier.Listener listener,
                                            final RemoteResourceInfo remote,
-                                           final LocalDestFile local)
+                                           final LocalDestFile local,
+                                           final long byteOffset)
                 throws IOException {
             final LocalDestFile adjusted = local.getTargetFile(remote.getName());
             final RemoteFile rf = engine.open(remote.getPath());
             try {
-                final RemoteFile.ReadAheadRemoteFileInputStream rfis = rf.new ReadAheadRemoteFileInputStream(16);
-                final OutputStream os = adjusted.getOutputStream();
+                log.debug("Attempting to download {} with offset={}", remote.getPath(), byteOffset);
+                final RemoteFile.ReadAheadRemoteFileInputStream rfis = rf.new ReadAheadRemoteFileInputStream(16, byteOffset);
+                final OutputStream os = adjusted.getOutputStream(byteOffset != 0);
                 try {
                     new StreamCopier(rfis, os, engine.getLoggerFactory())
                             .bufSize(engine.getSubsystem().getLocalMaxPacketSize())
@@ -173,17 +199,17 @@ public class SFTPFileTransfer
             this.remote = remote;
         }
 
-        private void upload(final TransferListener listener) throws IOException {
+        private void upload(final TransferListener listener, long byteOffset) throws IOException {
             if (source.isDirectory()) {
                 makeDirIfNotExists(remote); // Ensure that the directory exists
                 uploadDir(listener.directory(source.getName()), source, remote);
                 setAttributes(source, remote);
             } else if (source.isFile() && isDirectory(remote)) {
                 String adjustedRemote = engine.getPathHelper().adjustForParent(this.remote, source.getName());
-                uploadFile(listener.file(source.getName(), source.getLength()), source, adjustedRemote);
+                uploadFile(listener.file(source.getName(), source.getLength()), source, adjustedRemote, byteOffset);
                 setAttributes(source, adjustedRemote);
             } else if (source.isFile()) {
-                uploadFile(listener.file(source.getName(), source.getLength()), source, remote);
+                uploadFile(listener.file(source.getName(), source.getLength()), source, remote, byteOffset);
                 setAttributes(source, remote);
             } else {
                 throw new IOException(source + " is not a file or directory");
@@ -192,13 +218,14 @@ public class SFTPFileTransfer
 
         private void upload(final TransferListener listener,
                             final LocalSourceFile local,
-                            final String remote)
+                            final String remote,
+                            final long byteOffset)
                 throws IOException {
             final String adjustedPath;
             if (local.isDirectory()) {
                 adjustedPath = uploadDir(listener.directory(local.getName()), local, remote);
             } else if (local.isFile()) {
-                adjustedPath = uploadFile(listener.file(local.getName(), local.getLength()), local, remote);
+                adjustedPath = uploadFile(listener.file(local.getName(), local.getLength()), local, remote, byteOffset);
             } else {
                 throw new IOException(local + " is not a file or directory");
             }
@@ -217,22 +244,34 @@ public class SFTPFileTransfer
                 throws IOException {
             makeDirIfNotExists(remote);
             for (LocalSourceFile f : local.getChildren(getUploadFilter()))
-                upload(listener, f, engine.getPathHelper().adjustForParent(remote, f.getName()));
+                upload(listener, f, engine.getPathHelper().adjustForParent(remote, f.getName()), 0); // not supporting individual byte offsets for these files
             return remote;
         }
 
         private String uploadFile(final StreamCopier.Listener listener,
                                   final LocalSourceFile local,
-                                  final String remote)
+                                  final String remote,
+                                  final long byteOffset)
                 throws IOException {
-            final String adjusted = prepareFile(local, remote);
+            final String adjusted = prepareFile(local, remote, byteOffset);
             RemoteFile rf = null;
             InputStream fis = null;
             RemoteFile.RemoteFileOutputStream rfos = null;
+            EnumSet<OpenMode> modes;
             try {
-                rf = engine.open(adjusted, EnumSet.of(OpenMode.WRITE, OpenMode.CREAT, OpenMode.TRUNC));
+                if (byteOffset == 0) {
+                    // Starting at the beginning, overwrite/create
+                    modes = EnumSet.of(OpenMode.WRITE, OpenMode.CREAT, OpenMode.TRUNC);
+                } else {
+                    // Starting at some offset, append
+                    modes = EnumSet.of(OpenMode.WRITE, OpenMode.APPEND);
+                }
+                
+                log.debug("Attempting to upload {} with offset={}", local.getName(), byteOffset);
+                rf = engine.open(adjusted, modes);
                 fis = local.getInputStream();
-                rfos = rf.new RemoteFileOutputStream(0, 16);
+                fis.skip(byteOffset);
+                rfos = rf.new RemoteFileOutputStream(byteOffset, 16);
                 new StreamCopier(fis, rfos, engine.getLoggerFactory())
                         .bufSize(engine.getSubsystem().getRemoteMaxPacketSize() - rf.getOutgoingPacketOverhead())
                         .keepFlushing(false)
@@ -294,7 +333,7 @@ public class SFTPFileTransfer
             }
         }
 
-        private String prepareFile(final LocalSourceFile local, final String remote)
+        private String prepareFile(final LocalSourceFile local, final String remote, final long byteOffset)
                 throws IOException {
             final FileAttributes attrs;
             try {
@@ -309,7 +348,7 @@ public class SFTPFileTransfer
             if (attrs.getMode().getType() == FileMode.Type.DIRECTORY) {
                 throw new IOException("Trying to upload file " + local.getName() + " to path " + remote + " but that is a directory");
             } else {
-                log.debug("probeFile: {} is a {} file that will be replaced", remote, attrs.getMode().getType());
+                log.debug("probeFile: {} is a {} file that will be {}", remote, attrs.getMode().getType(), byteOffset > 0 ? "resumed" : "replaced");
                 return remote;
             }
         }

src/main/java/net/schmizz/sshj/sftp/StatefulSFTPClient.java

@@ -117,9 +117,9 @@ public class StatefulSFTPClient
     }
 
     @Override
-    public void rename(String oldpath, String newpath)
+    public void rename(String oldpath, String newpath, Set<RenameFlags> renameFlags)
             throws IOException {
-        super.rename(cwdify(oldpath), cwdify(newpath));
+        super.rename(cwdify(oldpath), cwdify(newpath), renameFlags);
     }
 
     @Override

src/main/java/net/schmizz/sshj/signature/AbstractSignatureDSA.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package net.schmizz.sshj.signature;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.hierynomus.asn1.ASN1OutputStream;
+import com.hierynomus.asn1.encodingrules.der.DEREncoder;
+import com.hierynomus.asn1.types.ASN1Object;
+import com.hierynomus.asn1.types.constructed.ASN1Sequence;
+import com.hierynomus.asn1.types.primitive.ASN1Integer;
+
+import net.schmizz.sshj.common.IOUtils;
+
+public abstract class AbstractSignatureDSA extends AbstractSignature {
+    protected AbstractSignatureDSA(String algorithm, String signatureName) {
+        super(algorithm, signatureName);
+    }
+
+    /**
+     * Get ASN.1 Signature encoded using DER Sequence of integers
+     *
+     * @param r DSA Signature R
+     * @param s DSA Signature S
+     * @return ASN.1 Encoded Signature
+     * @throws IOException Thrown when failing to write signature integers
+     */
+    @SuppressWarnings("rawtypes")
+    protected byte[] encodeAsnSignature(final BigInteger r, final BigInteger s) throws IOException {
+        List<ASN1Object> vector = new ArrayList<ASN1Object>();
+        vector.add(new com.hierynomus.asn1.types.primitive.ASN1Integer(r));
+        vector.add(new ASN1Integer(s));
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        ASN1OutputStream asn1OutputStream = new ASN1OutputStream(new DEREncoder(), baos);
+        try {
+            asn1OutputStream.writeObject(new ASN1Sequence(vector));
+            asn1OutputStream.flush();
+        } finally {
+            IOUtils.closeQuietly(asn1OutputStream);
+        }
+
+        return baos.toByteArray();
+
+    }
+}

src/main/java/net/schmizz/sshj/signature/SignatureDSA.java

@@ -15,26 +15,19 @@
  */
 package net.schmizz.sshj.signature;
 
-import com.hierynomus.asn1.encodingrules.der.DEREncoder;
-import com.hierynomus.asn1.types.ASN1Object;
-import com.hierynomus.asn1.types.constructed.ASN1Sequence;
-import com.hierynomus.asn1.types.primitive.ASN1Integer;
 import net.schmizz.sshj.common.KeyType;
 import net.schmizz.sshj.common.SSHRuntimeException;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.security.SignatureException;
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.List;
 
 /**
  * DSA {@link Signature}
  */
 public class SignatureDSA
-        extends AbstractSignature {
+        extends AbstractSignatureDSA {
 
     /**
      * A named factory for DSA signature
@@ -90,32 +83,14 @@ public class SignatureDSA
     public boolean verify(byte[] sig) {
         try {
             byte[] sigBlob = extractSig(sig, "ssh-dss");
-            return signature.verify(asnEncode(sigBlob));
+            BigInteger r = new BigInteger(1, Arrays.copyOfRange(sigBlob, 0, 20));
+            BigInteger s = new BigInteger(1, Arrays.copyOfRange(sigBlob, 20, 40));
+
+            return signature.verify(encodeAsnSignature(r, s));
         } catch (SignatureException e) {
             throw new SSHRuntimeException(e);
         } catch (IOException e) {
             throw new SSHRuntimeException(e);
         }
     }
-
-    /**
-     * Encodes the signature as a DER sequence (ASN.1 format).
-     */
-    private byte[] asnEncode(byte[] sigBlob) throws IOException {
-        BigInteger r = new BigInteger(1, Arrays.copyOfRange(sigBlob, 0, 20));
-        BigInteger s = new BigInteger(1, Arrays.copyOfRange(sigBlob, 20, 40));
-
-        List<ASN1Object> vector = new ArrayList<ASN1Object>();
-        vector.add(new com.hierynomus.asn1.types.primitive.ASN1Integer(r));
-        vector.add(new ASN1Integer(s));
-
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        com.hierynomus.asn1.ASN1OutputStream asn1OutputStream = new com.hierynomus.asn1.ASN1OutputStream(new DEREncoder(), baos);
-
-        asn1OutputStream.writeObject(new ASN1Sequence(vector));
-        asn1OutputStream.flush();
-
-
-        return baos.toByteArray();
-    }
 }

src/main/java/net/schmizz/sshj/signature/SignatureECDSA.java

@@ -15,9 +15,8 @@
  */
 package net.schmizz.sshj.signature;
 
+import com.hierynomus.asn1.ASN1InputStream;
 import com.hierynomus.asn1.encodingrules.der.DERDecoder;
-import com.hierynomus.asn1.encodingrules.der.DEREncoder;
-import com.hierynomus.asn1.types.ASN1Object;
 import com.hierynomus.asn1.types.constructed.ASN1Sequence;
 import com.hierynomus.asn1.types.primitive.ASN1Integer;
 import net.schmizz.sshj.common.Buffer;
@@ -26,15 +25,12 @@ import net.schmizz.sshj.common.KeyType;
 import net.schmizz.sshj.common.SSHRuntimeException;
 
 import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.security.SignatureException;
-import java.util.ArrayList;
-import java.util.List;
 
 /** ECDSA {@link Signature} */
-public class SignatureECDSA extends AbstractSignature {
+public class SignatureECDSA extends AbstractSignatureDSA {
 
     /** A named factory for ECDSA-256 signature */
     public static class Factory256 implements net.schmizz.sshj.common.Factory.Named<Signature> {
@@ -91,7 +87,7 @@ public class SignatureECDSA extends AbstractSignature {
     @Override
     public byte[] encode(byte[] sig) {
         ByteArrayInputStream bais = new ByteArrayInputStream(sig);
-        com.hierynomus.asn1.ASN1InputStream asn1InputStream = new com.hierynomus.asn1.ASN1InputStream(new DERDecoder(), bais);
+        ASN1InputStream asn1InputStream = new ASN1InputStream(new DERDecoder(), bais);
         try {
             ASN1Sequence sequence = asn1InputStream.readObject();
             ASN1Integer r = (ASN1Integer) sequence.get(0);
@@ -110,35 +106,14 @@ public class SignatureECDSA extends AbstractSignature {
     public boolean verify(byte[] sig) {
         try {
             byte[] sigBlob = extractSig(sig, keyTypeName);
-            return signature.verify(asnEncode(sigBlob));
+            Buffer.PlainBuffer sigbuf = new Buffer.PlainBuffer(sigBlob);
+            BigInteger r = sigbuf.readMPInt();
+            BigInteger s = sigbuf.readMPInt();
+            return signature.verify(encodeAsnSignature(r, s));
         } catch (SignatureException e) {
             throw new SSHRuntimeException(e);
         } catch (IOException e) {
             throw new SSHRuntimeException(e);
         }
     }
-
-    /**
-     * Encodes the signature as a DER sequence (ASN.1 format).
-     */
-    private byte[] asnEncode(byte[] sigBlob) throws IOException {
-        Buffer.PlainBuffer sigbuf = new Buffer.PlainBuffer(sigBlob);
-        BigInteger r = sigbuf.readMPInt();
-        BigInteger s = sigbuf.readMPInt();
-
-
-        List<ASN1Object> vector = new ArrayList<ASN1Object>();
-        vector.add(new ASN1Integer(r));
-        vector.add(new ASN1Integer(s));
-
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        com.hierynomus.asn1.ASN1OutputStream asn1OutputStream = new com.hierynomus.asn1.ASN1OutputStream(new DEREncoder(), baos);
-        try {
-            asn1OutputStream.writeObject(new ASN1Sequence(vector));
-            asn1OutputStream.flush();
-        } finally {
-            IOUtils.closeQuietly(asn1OutputStream);
-        }
-        return baos.toByteArray();
-    }
 }

src/main/java/net/schmizz/sshj/transport/KeyExchanger.java

@@ -170,11 +170,22 @@ final class KeyExchanger
     private void sendKexInit()
             throws TransportException {
         log.debug("Sending SSH_MSG_KEXINIT");
-        clientProposal = new Proposal(transport.getConfig());
+        List<String> knownHostAlgs = findKnownHostAlgs(transport.getRemoteHost(), transport.getRemotePort());
+        clientProposal = new Proposal(transport.getConfig(), knownHostAlgs);
         transport.write(clientProposal.getPacket());
         kexInitSent.set();
     }
 
+    private List<String> findKnownHostAlgs(String hostname, int port) {
+        for (HostKeyVerifier hkv : hostVerifiers) {
+            List<String> keyTypes = hkv.findExistingAlgorithms(hostname, port);
+            if (keyTypes != null && !keyTypes.isEmpty()) {
+                return keyTypes;
+            }
+        }
+        return Collections.emptyList();
+    }
+
     private void sendNewKeys()
             throws TransportException {
         log.debug("Sending SSH_MSG_NEWKEYS");
@@ -232,7 +243,6 @@ final class KeyExchanger
                                         negotiatedAlgs.getKeyExchangeAlgorithm());
         transport.setHostKeyAlgorithm(Factory.Named.Util.create(transport.getConfig().getKeyAlgorithms(),
                                       negotiatedAlgs.getSignatureAlgorithm()));
-        transport.setRSASHA2Support(negotiatedAlgs.getRSASHA2Support());
 
         try {
             kex.init(transport,

src/main/java/net/schmizz/sshj/transport/NegotiatedAlgorithms.java

@@ -26,10 +26,8 @@ public final class NegotiatedAlgorithms {
     private final String c2sComp;
     private final String s2cComp;
 
-    private final boolean rsaSHA2Support;
-
     NegotiatedAlgorithms(String kex, String sig, String c2sCipher, String s2cCipher, String c2sMAC, String s2cMAC,
-                         String c2sComp, String s2cComp, boolean rsaSHA2Support) {
+                         String c2sComp, String s2cComp) {
         this.kex = kex;
         this.sig = sig;
         this.c2sCipher = c2sCipher;
@@ -38,7 +36,6 @@ public final class NegotiatedAlgorithms {
         this.s2cMAC = s2cMAC;
         this.c2sComp = c2sComp;
         this.s2cComp = s2cComp;
-        this.rsaSHA2Support = rsaSHA2Support;
     }
 
     public String getKeyExchangeAlgorithm() {
@@ -73,10 +70,6 @@ public final class NegotiatedAlgorithms {
         return s2cComp;
     }
 
-    public boolean getRSASHA2Support() {
-        return rsaSHA2Support;
-    }
-
     @Override
     public String toString() {
         return ("[ " +
@@ -88,7 +81,6 @@ public final class NegotiatedAlgorithms {
                 "s2cMAC=" + s2cMAC + "; " +
                 "c2sComp=" + c2sComp + "; " +
                 "s2cComp=" + s2cComp + "; " +
-                "rsaSHA2Support=" + rsaSHA2Support +
                 " ]");
     }
 

src/main/java/net/schmizz/sshj/transport/Proposal.java

@@ -15,7 +15,6 @@
  */
 package net.schmizz.sshj.transport;
 
-import com.hierynomus.sshj.key.KeyAlgorithms;
 import net.schmizz.sshj.Config;
 import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.Factory;
@@ -38,9 +37,9 @@ class Proposal {
     private final List<String> s2cComp;
     private final SSHPacket packet;
 
-    public Proposal(Config config) {
+    public Proposal(Config config, List<String> knownHostAlgs) {
         kex = Factory.Named.Util.getNames(config.getKeyExchangeFactories());
-        sig = Factory.Named.Util.getNames(config.getKeyAlgorithms());
+        sig = filterKnownHostKeyAlgorithms(Factory.Named.Util.getNames(config.getKeyAlgorithms()), knownHostAlgs);
         c2sCipher = s2cCipher = Factory.Named.Util.getNames(config.getCipherFactories());
         c2sMAC = s2cMAC = Factory.Named.Util.getNames(config.getMACFactories());
         c2sComp = s2cComp = Factory.Named.Util.getNames(config.getCompressionFactories());
@@ -127,34 +126,45 @@ class Proposal {
     public NegotiatedAlgorithms negotiate(Proposal other)
             throws TransportException {
         return new NegotiatedAlgorithms(
-                firstMatch("KeyExchangeAlgorithms",
-                           this.getKeyExchangeAlgorithms(),
-                           other.getKeyExchangeAlgorithms()),
-                firstMatch("HostKeyAlgorithms",
-                           this.getHostKeyAlgorithms(),
-                           other.getHostKeyAlgorithms()),
-                firstMatch("Client2ServerCipherAlgorithms",
-                           this.getClient2ServerCipherAlgorithms(),
-                           other.getClient2ServerCipherAlgorithms()),
-                firstMatch("Server2ClientCipherAlgorithms",
-                           this.getServer2ClientCipherAlgorithms(),
-                           other.getServer2ClientCipherAlgorithms()),
-                firstMatch("Client2ServerMACAlgorithms",
-                           this.getClient2ServerMACAlgorithms(),
-                           other.getClient2ServerMACAlgorithms()),
-                firstMatch("Server2ClientMACAlgorithms",
-                           this.getServer2ClientMACAlgorithms(),
-                           other.getServer2ClientMACAlgorithms()),
-                firstMatch("Client2ServerCompressionAlgorithms",
-                           this.getClient2ServerCompressionAlgorithms(),
-                           other.getClient2ServerCompressionAlgorithms()),
-                firstMatch("Server2ClientCompressionAlgorithms",
-                           this.getServer2ClientCompressionAlgorithms(),
-                           other.getServer2ClientCompressionAlgorithms()),
-                other.getHostKeyAlgorithms().containsAll(KeyAlgorithms.SSH_RSA_SHA2_ALGORITHMS)
+                firstMatch("KeyExchangeAlgorithms", this.getKeyExchangeAlgorithms(), other.getKeyExchangeAlgorithms()),
+                firstMatch("HostKeyAlgorithms", this.getHostKeyAlgorithms(), other.getHostKeyAlgorithms()),
+                firstMatch("Client2ServerCipherAlgorithms", this.getClient2ServerCipherAlgorithms(),
+                        other.getClient2ServerCipherAlgorithms()),
+                firstMatch("Server2ClientCipherAlgorithms", this.getServer2ClientCipherAlgorithms(),
+                        other.getServer2ClientCipherAlgorithms()),
+                firstMatch("Client2ServerMACAlgorithms", this.getClient2ServerMACAlgorithms(),
+                        other.getClient2ServerMACAlgorithms()),
+                firstMatch("Server2ClientMACAlgorithms", this.getServer2ClientMACAlgorithms(),
+                        other.getServer2ClientMACAlgorithms()),
+                firstMatch("Client2ServerCompressionAlgorithms", this.getClient2ServerCompressionAlgorithms(),
+                        other.getClient2ServerCompressionAlgorithms()),
+                firstMatch("Server2ClientCompressionAlgorithms", this.getServer2ClientCompressionAlgorithms(),
+                        other.getServer2ClientCompressionAlgorithms())
         );
     }
 
+    private List<String> filterKnownHostKeyAlgorithms(List<String> configuredKeyAlgorithms, List<String> knownHostKeyAlgorithms) {
+        if (knownHostKeyAlgorithms != null && !knownHostKeyAlgorithms.isEmpty()) {
+            List<String> preferredAlgorithms = new ArrayList<String>();
+            List<String> otherAlgorithms = new ArrayList<String>();
+
+            for (String configuredKeyAlgorithm : configuredKeyAlgorithms) {
+                if (knownHostKeyAlgorithms.contains(configuredKeyAlgorithm)) {
+                    preferredAlgorithms.add(configuredKeyAlgorithm);
+                } else {
+                    otherAlgorithms.add(configuredKeyAlgorithm);
+                }
+            }
+
+            preferredAlgorithms.addAll(otherAlgorithms);
+
+            return preferredAlgorithms;
+        } else {
+            return configuredKeyAlgorithms;
+        }
+
+    }
+
     private static String firstMatch(String ofWhat, List<String> a, List<String> b)
             throws TransportException {
         for (String aa : a) {

src/main/java/net/schmizz/sshj/transport/Reader.java

@@ -29,7 +29,7 @@ public final class Reader
     public Reader(TransportImpl trans) {
         this.trans = trans;
         log = trans.getConfig().getLoggerFactory().getLogger(getClass());
-        setName("reader");
+        setName("sshj-Reader");
         setDaemon(true);
     }
 

src/main/java/net/schmizz/sshj/transport/Transport.java

@@ -15,6 +15,7 @@
  */
 package net.schmizz.sshj.transport;
 
+import com.hierynomus.sshj.common.RemoteAddressProvider;
 import com.hierynomus.sshj.key.KeyAlgorithm;
 import net.schmizz.sshj.Config;
 import net.schmizz.sshj.Service;
@@ -27,11 +28,12 @@ import net.schmizz.sshj.transport.verification.HostKeyVerifier;
 
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.List;
 import java.util.concurrent.TimeUnit;
 
 /** Transport layer of the SSH protocol. */
 public interface Transport
-        extends SSHPacketHandler {
+        extends SSHPacketHandler, RemoteAddressProvider {
 
     /**
      * Sets the host information and the streams to be used by this transport. Identification information is exchanged
@@ -69,6 +71,13 @@ public interface Transport
     void doKex()
             throws TransportException;
 
+    /**
+     * Is Key Exchange required based on current transport status
+     *
+     * @return Key Exchange required status
+     */
+    boolean isKeyExchangeRequired();
+
     /** @return the version string used by this client to identify itself to an SSH server, e.g. "SSHJ_3_0" */
     String getClientVersion();
 
@@ -85,22 +94,6 @@ public interface Transport
      */
     void setTimeoutMs(int timeout);
 
-    /**
-     * @return the interval in seconds at which a heartbeat message is sent to the server
-     * @deprecated Moved to {@link net.schmizz.keepalive.KeepAlive#getKeepAliveInterval()}. This is accessible through the {@link net.schmizz.sshj.connection.Connection}.
-     *             Scheduled to be removed in 0.12.0
-     */
-    @Deprecated
-    int getHeartbeatInterval();
-
-    /**
-     * @param interval the interval in seconds, {@code 0} means no heartbeat
-     * @deprecated Moved to {@link net.schmizz.keepalive.KeepAlive#getKeepAliveInterval()}. This is accessible through the {@link net.schmizz.sshj.connection.Connection}.
-     *             Scheduled to be removed in 0.12.0
-     */
-    @Deprecated
-    void setHeartbeatInterval(int interval);
-
     /** @return the hostname to which this transport is connected. */
     String getRemoteHost();
 
@@ -224,7 +217,7 @@ public interface Transport
     /**
      * Specify a {@code listener} that will be notified upon disconnection.
      *
-     * @param listener
+     * @param listener Disconnect Listener to be configured
      */
     void setDisconnectListener(DisconnectListener listener);
 
@@ -239,5 +232,5 @@ public interface Transport
     void die(Exception e);
 
     KeyAlgorithm getHostKeyAlgorithm();
-    KeyAlgorithm getClientKeyAlgorithm(KeyType keyType) throws TransportException;
+    List<KeyAlgorithm> getClientKeyAlgorithms(KeyType keyType) throws TransportException;
 }

src/main/java/net/schmizz/sshj/transport/TransportImpl.java

@@ -15,6 +15,7 @@
  */
 package net.schmizz.sshj.transport;
 
+import com.hierynomus.sshj.common.ThreadNameProvider;
 import com.hierynomus.sshj.key.KeyAlgorithm;
 import com.hierynomus.sshj.key.KeyAlgorithms;
 import com.hierynomus.sshj.transport.IdentificationStringParser;
@@ -22,7 +23,6 @@ import net.schmizz.concurrent.ErrorDeliveryUtil;
 import net.schmizz.concurrent.Event;
 import net.schmizz.sshj.AbstractService;
 import net.schmizz.sshj.Config;
-import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.Service;
 import net.schmizz.sshj.common.*;
 import net.schmizz.sshj.transport.verification.AlgorithmsVerifier;
@@ -32,6 +32,8 @@ import org.slf4j.Logger;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
@@ -80,20 +82,12 @@ public final class TransportImpl
 
     private final Reader reader;
 
-    /**
-     * @deprecated Moved to {@link net.schmizz.sshj.SSHClient}
-     */
-    @Deprecated
-    private final SSHClient sshClient;
-
     private final Encoder encoder;
 
     private final Decoder decoder;
 
     private KeyAlgorithm hostKeyAlgorithm;
 
-    private boolean rsaSHA2Support;
-
     private final Event<TransportException> serviceAccept;
 
     private final Event<TransportException> close;
@@ -136,8 +130,8 @@ public final class TransportImpl
     public TransportImpl(Config config) {
         this.config = config;
         this.loggerFactory = config.getLoggerFactory();
-        this.serviceAccept = new Event<TransportException>("service accept", TransportException.chainer, loggerFactory);
-        this.close = new Event<TransportException>("transport close", TransportException.chainer, loggerFactory);
+        this.serviceAccept = new Event<>("service accept", TransportException.chainer, loggerFactory);
+        this.close = new Event<>("transport close", TransportException.chainer, loggerFactory);
         this.nullService = new NullService(this);
         this.service = nullService;
         this.log = loggerFactory.getLogger(getClass());
@@ -147,29 +141,6 @@ public final class TransportImpl
         this.decoder = new Decoder(this);
         this.kexer = new KeyExchanger(this);
         this.clientID = String.format("SSH-2.0-%s", config.getVersion());
-        this.sshClient = null;
-    }
-
-    /*
-     * Temporary constructor until we remove support for the set/get Heartbeat interval from transport.
-     * @deprecated To be removed in 0.12.0
-     */
-    @Deprecated
-    public TransportImpl(Config config, SSHClient sshClient) {
-        this.config = config;
-        this.loggerFactory = config.getLoggerFactory();
-        this.serviceAccept = new Event<TransportException>("service accept", TransportException.chainer, loggerFactory);
-        this.close = new Event<TransportException>("transport close", TransportException.chainer, loggerFactory);
-        this.log = loggerFactory.getLogger(getClass());
-        this.nullService = new NullService(this);
-        this.service = nullService;
-        this.disconnectListener = this;
-        this.reader = new Reader(this);
-        this.encoder = new Encoder(config.getRandomFactory().create(), writeLock, loggerFactory);
-        this.decoder = new Decoder(this);
-        this.kexer = new KeyExchanger(this);
-        this.clientID = String.format("SSH-2.0-%s", config.getVersion());
-        this.sshClient = sshClient;
     }
 
     @Override
@@ -194,9 +165,20 @@ public final class TransportImpl
             throw new TransportException(e);
         }
 
+        ThreadNameProvider.setThreadName(reader, this);
         reader.start();
     }
 
+    /**
+     * Get Remote Socket Address using Connection Information
+     *
+     * @return Remote Socket Address or null when not connected
+     */
+    @Override
+    public InetSocketAddress getRemoteSocketAddress() {
+        return connInfo == null ? null : new InetSocketAddress(getRemoteHost(), getRemotePort());
+    }
+
     /**
      * TransportImpl implements its own default DisconnectListener.
      */
@@ -240,7 +222,7 @@ public final class TransportImpl
      *
      * @param buffer The buffer to read from.
      * @return empty string if full ident string has not yet been received
-     * @throws IOException
+     * @throws IOException Thrown when protocol version is not supported
      */
     private String readIdentification(Buffer.PlainBuffer buffer)
             throws IOException {
@@ -272,6 +254,16 @@ public final class TransportImpl
         kexer.startKex(true);
     }
 
+    /**
+     * Is Key Exchange required returns true when Key Exchange is not done and when Key Exchange is not ongoing
+     *
+     * @return Key Exchange required status
+     */
+    @Override
+    public boolean isKeyExchangeRequired() {
+        return !kexer.isKexDone() && !kexer.isKexOngoing();
+    }
+
     public boolean isKexDone() {
         return kexer.isKexDone();
     }
@@ -286,20 +278,6 @@ public final class TransportImpl
         this.timeoutMs = timeoutMs;
     }
 
-    @Override
-    @Deprecated
-    public int getHeartbeatInterval() {
-        log.warn("**Deprecated**: Please use: sshClient.getConnection().getKeepAlive().getKeepAliveInterval()");
-        return sshClient.getConnection().getKeepAlive().getKeepAliveInterval();
-    }
-
-    @Override
-    @Deprecated
-    public void setHeartbeatInterval(int interval) {
-        log.warn("**Deprecated**: Please use: sshClient.getConnection().getKeepAlive().setKeepAliveInterval()");
-        sshClient.getConnection().getKeepAlive().setKeepAliveInterval(interval);
-    }
-
     @Override
     public String getRemoteHost() {
         return connInfo.host;
@@ -587,7 +565,7 @@ public final class TransportImpl
      * Got an SSH_MSG_UNIMPLEMENTED, so lets see where we're at and act accordingly.
      *
      * @param packet The 'unimplemented' packet received
-     * @throws TransportException
+     * @throws TransportException Thrown when key exchange is ongoing
      */
     private void gotUnimplemented(SSHPacket packet)
             throws SSHException {
@@ -669,21 +647,19 @@ public final class TransportImpl
         return this.hostKeyAlgorithm;
     }
 
-    public void setRSASHA2Support(boolean rsaSHA2Support) {
-        this.rsaSHA2Support = rsaSHA2Support;
-    }
-
     @Override
-    public KeyAlgorithm getClientKeyAlgorithm(KeyType keyType) throws TransportException {
-        if (keyType != KeyType.RSA || !rsaSHA2Support) {
-            return Factory.Named.Util.create(getConfig().getKeyAlgorithms(), keyType.toString());
-        }
-
+    public List<KeyAlgorithm> getClientKeyAlgorithms(KeyType keyType) throws TransportException {
         List<Factory.Named<KeyAlgorithm>> factories = getConfig().getKeyAlgorithms();
+        List<KeyAlgorithm> available = new ArrayList<>();
         if (factories != null)
             for (Factory.Named<KeyAlgorithm> f : factories)
-                if (f.getName().equals("ssh-rsa") || KeyAlgorithms.SSH_RSA_SHA2_ALGORITHMS.contains(f.getName()))
-                    return f.create();
-        throw new TransportException("Cannot find an available KeyAlgorithm for type " + keyType);
+                if (
+                        f instanceof KeyAlgorithms.Factory && ((KeyAlgorithms.Factory) f).getKeyType().equals(keyType)
+                                || !(f instanceof KeyAlgorithms.Factory) && f.getName().equals(keyType.toString())
+                )
+                    available.add(f.create());
+        if (available.isEmpty())
+            throw new TransportException("Cannot find an available KeyAlgorithm for type " + keyType);
+        return available;
     }
 }

src/main/java/net/schmizz/sshj/transport/compression/ZlibCompression.java

@@ -15,18 +15,16 @@
  */
 package net.schmizz.sshj.transport.compression;
 
-import com.jcraft.jzlib.Deflater;
-import com.jcraft.jzlib.GZIPException;
-import com.jcraft.jzlib.Inflater;
-import com.jcraft.jzlib.JZlib;
+import java.util.zip.DataFormatException;
+import java.util.zip.Deflater;
+import java.util.zip.Inflater;
+
 import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.DisconnectReason;
-import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.transport.TransportException;
+import net.schmizz.sshj.transport.compression.Compression;
 
-/** ZLib based Compression. */
-public class ZlibCompression
-        implements Compression {
+public class ZlibCompression implements Compression {
 
     /** Named factory for the ZLib Compression. */
     public static class Factory
@@ -52,19 +50,15 @@ public class ZlibCompression
 
     @Override
     public void init(Mode mode) {
-        try {
-            switch (mode) {
-                case DEFLATE:
-                    deflater = new Deflater(JZlib.Z_DEFAULT_COMPRESSION);
-                    break;
-                case INFLATE:
-                    inflater = new Inflater();
-                    break;
-                default:
-                    assert false;
-            }
-        } catch (GZIPException gze) {
-
+        switch (mode) {
+            case DEFLATE:
+                deflater = new Deflater(Deflater.DEFAULT_COMPRESSION);
+                break;
+            case INFLATE:
+                inflater = new Inflater();
+                break;
+            default:
+                assert false;
         }
     }
 
@@ -75,43 +69,28 @@ public class ZlibCompression
 
     @Override
     public void compress(Buffer buffer) {
-        deflater.setNextIn(buffer.array());
-        deflater.setNextInIndex(buffer.rpos());
-        deflater.setAvailIn(buffer.available());
+        deflater.setInput(buffer.array(), buffer.rpos(), buffer.available());
         buffer.wpos(buffer.rpos());
         do {
-            deflater.setNextOut(tempBuf);
-            deflater.setNextOutIndex(0);
-            deflater.setAvailOut(BUF_SIZE);
-            final int status = deflater.deflate(JZlib.Z_PARTIAL_FLUSH);
-            if (status == JZlib.Z_OK) {
-                buffer.putRawBytes(tempBuf, 0, BUF_SIZE - deflater.getAvailOut());
-            } else {
-                throw new SSHRuntimeException("compress: deflate returned " + status);
-            }
-        } while (deflater.getAvailOut() == 0);
+            final int len = deflater.deflate(tempBuf, 0, BUF_SIZE, Deflater.SYNC_FLUSH);
+            buffer.putRawBytes(tempBuf, 0, len);
+        } while (!deflater.needsInput());
     }
 
-
     @Override
     public void uncompress(Buffer from, Buffer to)
             throws TransportException {
-        inflater.setNextIn(from.array());
-        inflater.setNextInIndex(from.rpos());
-        inflater.setAvailIn(from.available());
+        inflater.setInput(from.array(), from.rpos(), from.available());
         while (true) {
-            inflater.setNextOut(tempBuf);
-            inflater.setNextOutIndex(0);
-            inflater.setAvailOut(BUF_SIZE);
-            final int status = inflater.inflate(JZlib.Z_PARTIAL_FLUSH);
-            switch (status) {
-                case JZlib.Z_OK:
-                    to.putRawBytes(tempBuf, 0, BUF_SIZE - inflater.getAvailOut());
-                    break;
-                case JZlib.Z_BUF_ERROR:
+            try {
+                int len = inflater.inflate(tempBuf, 0, BUF_SIZE);
+                if(len > 0) {
+                    to.putRawBytes(tempBuf, 0, len);
+                } else {
                     return;
-                default:
-                    throw new TransportException(DisconnectReason.COMPRESSION_ERROR, "uncompress: inflate returned " + status);
+                }
+            } catch (DataFormatException e) {
+                throw new TransportException(DisconnectReason.COMPRESSION_ERROR, "uncompress: inflate returned " + e.getMessage());
             }
         }
     }

src/main/java/net/schmizz/sshj/transport/kex/Curve25519DH.java

@@ -15,50 +15,89 @@
  */
 package net.schmizz.sshj.transport.kex;
 
-import com.hierynomus.sshj.common.KeyAlgorithm;
 import net.schmizz.sshj.common.Factory;
+import net.schmizz.sshj.common.SecurityUtils;
 import net.schmizz.sshj.transport.random.Random;
-import org.bouncycastle.asn1.x9.X9ECParameters;
-import org.bouncycastle.crypto.ec.CustomNamedCurves;
-import org.bouncycastle.jce.spec.ECParameterSpec;
-
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
+import java.security.KeyFactory;
+import java.security.KeyPair;
+import java.security.PublicKey;
 import java.security.spec.AlgorithmParameterSpec;
-import java.util.Arrays;
+import java.security.spec.KeySpec;
+import java.security.spec.X509EncodedKeySpec;
 
+/**
+ * Key Exchange Method using Curve25519 as defined in RFC 8731
+ */
 public class Curve25519DH extends DHBase {
 
-    private byte[] secretKey;
+    private static final String ALGORITHM = "X25519";
+
+    private static final int ENCODED_ALGORITHM_ID_KEY_LENGTH = 44;
+
+    private static final int ALGORITHM_ID_LENGTH = 12;
+
+    private static final int KEY_LENGTH = 32;
+
+    private final byte[] algorithmId = new byte[ALGORITHM_ID_LENGTH];
 
     public Curve25519DH() {
-        super(KeyAlgorithm.ECDSA, "ECDH");
-    }
-
-    @Override
-    void computeK(byte[] f) throws GeneralSecurityException {
-        byte[] k = new byte[32];
-        djb.Curve25519.curve(k, secretKey, f);
-        setK(new BigInteger(1, k));
-    }
-
-    @Override
-    public void init(AlgorithmParameterSpec params, Factory<Random> randomFactory) throws GeneralSecurityException {
-        Random random = randomFactory.create();
-        byte[] secretBytes =  new byte[32];
-        random.fill(secretBytes);
-        byte[] publicBytes = new byte[32];
-        djb.Curve25519.keygen(publicBytes, null, secretBytes);
-        this.secretKey = Arrays.copyOf(secretBytes, secretBytes.length);
-        setE(publicBytes);
+        super(ALGORITHM, ALGORITHM);
     }
 
     /**
-     * TODO want to figure out why BouncyCastle does not work.
-     * @return The initialized curve25519 parameter spec
+     * Compute Shared Secret Key using Diffie-Hellman Curve25519 known as X25519
+     *
+     * @param peerPublicKey Peer public key bytes
+     * @throws GeneralSecurityException Thrown on key agreement failures
      */
-    public static AlgorithmParameterSpec getCurve25519Params() {
-        X9ECParameters ecP = CustomNamedCurves.getByName("curve25519");
-        return new ECParameterSpec(ecP.getCurve(), ecP.getG(), ecP.getN(), ecP.getH(), ecP.getSeed());
+    @Override
+    void computeK(final byte[] peerPublicKey) throws GeneralSecurityException {
+        final KeyFactory keyFactory = SecurityUtils.getKeyFactory(ALGORITHM);
+        final KeySpec peerPublicKeySpec = getPeerPublicKeySpec(peerPublicKey);
+        final PublicKey generatedPeerPublicKey = keyFactory.generatePublic(peerPublicKeySpec);
+
+        agreement.doPhase(generatedPeerPublicKey, true);
+        final byte[] sharedSecretKey = agreement.generateSecret();
+        final BigInteger sharedSecretNumber = new BigInteger(BigInteger.ONE.signum(), sharedSecretKey);
+        setK(sharedSecretNumber);
+    }
+
+    /**
+     * Initialize Key Agreement with generated Public and Private Key Pair
+     *
+     * @param params Parameters not used
+     * @param randomFactory Random Factory not used
+     * @throws GeneralSecurityException Thrown on key agreement initialization failures
+     */
+    @Override
+    public void init(final AlgorithmParameterSpec params, final Factory<Random> randomFactory) throws GeneralSecurityException {
+        final KeyPair keyPair = generator.generateKeyPair();
+        agreement.init(keyPair.getPrivate());
+        setPublicKey(keyPair.getPublic());
+    }
+
+    private void setPublicKey(final PublicKey publicKey) {
+        final byte[] encoded = publicKey.getEncoded();
+
+        // Encoded public key consists of the algorithm identifier and public key
+        if (encoded.length == ENCODED_ALGORITHM_ID_KEY_LENGTH) {
+            final byte[] publicKeyEncoded = new byte[KEY_LENGTH];
+            System.arraycopy(encoded, ALGORITHM_ID_LENGTH, publicKeyEncoded, 0, KEY_LENGTH);
+            setE(publicKeyEncoded);
+
+            // Save Algorithm Identifier byte array
+            System.arraycopy(encoded, 0, algorithmId, 0, ALGORITHM_ID_LENGTH);
+        } else {
+            throw new IllegalArgumentException(String.format("X25519 unsupported public key length [%d]", encoded.length));
+        }
+    }
+
+    private KeySpec getPeerPublicKeySpec(final byte[] peerPublicKey) {
+        final byte[] encodedKeySpec = new byte[ENCODED_ALGORITHM_ID_KEY_LENGTH];
+        System.arraycopy(algorithmId, 0, encodedKeySpec, 0, ALGORITHM_ID_LENGTH);
+        System.arraycopy(peerPublicKey, 0, encodedKeySpec, ALGORITHM_ID_LENGTH, KEY_LENGTH);
+        return new X509EncodedKeySpec(encodedKeySpec);
     }
 }

src/main/java/net/schmizz/sshj/transport/kex/Curve25519SHA256.java

@@ -56,6 +56,6 @@ public class Curve25519SHA256 extends AbstractDHG {
 
     @Override
     protected void initDH(DHBase dh) throws GeneralSecurityException {
-        dh.init(Curve25519DH.getCurve25519Params(), trans.getConfig().getRandomFactory());
+        dh.init(null, trans.getConfig().getRandomFactory());
     }
 }

src/main/java/net/schmizz/sshj/transport/verification/FingerprintVerifier.java

@@ -20,6 +20,8 @@ import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
 import java.security.PublicKey;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.regex.Pattern;
 
 import net.schmizz.sshj.common.Base64;
@@ -74,6 +76,11 @@ public class FingerprintVerifier implements HostKeyVerifier {
                 public boolean verify(String h, int p, PublicKey k) {
                     return SecurityUtils.getFingerprint(k).equals(md5);
                 }
+
+                @Override
+                public List<String> findExistingAlgorithms(String hostname, int port) {
+                    return Collections.emptyList();
+                }
             });
         } catch (SSHRuntimeException e) {
             throw e;
@@ -120,8 +127,13 @@ public class FingerprintVerifier implements HostKeyVerifier {
         return Arrays.equals(fingerprintData, digestData);
     }
 
+    @Override
+    public List<String> findExistingAlgorithms(String hostname, int port) {
+        return Collections.emptyList();
+    }
+
     @Override
     public String toString() {
         return "FingerprintVerifier{digestAlgorithm='" + digestAlgorithm + "'}";
     }
-}
+}

src/main/java/net/schmizz/sshj/transport/verification/HostKeyVerifier.java

@@ -16,6 +16,7 @@
 package net.schmizz.sshj.transport.verification;
 
 import java.security.PublicKey;
+import java.util.List;
 
 /** Host key verification interface. */
 public interface HostKeyVerifier {
@@ -35,4 +36,12 @@ public interface HostKeyVerifier {
      */
     boolean verify(String hostname, int port, PublicKey key);
 
+    /**
+     * It is necessary to connect with the type of algorithm that matches an existing know_host entry.
+     * This will allow a match when we later verify with the negotiated key {@code HostKeyVerifier.verify}
+     * @param hostname remote hostname
+     * @param port     remote port
+     * @return existing key types or empty list if no keys known for hostname
+     */
+    List<String> findExistingAlgorithms(String hostname, int port);
 }

src/main/java/net/schmizz/sshj/transport/verification/OpenSSHKnownHosts.java

@@ -90,6 +90,10 @@ public class OpenSSHKnownHosts
         }
     }
 
+    private String adjustHostname(final String hostname, final int port) {
+        String lowerHN = hostname.toLowerCase();
+        return (port != 22) ? "[" + lowerHN + "]:" + port : lowerHN;
+    }
 
     public File getFile() {
         return khFile;
@@ -103,7 +107,7 @@ public class OpenSSHKnownHosts
             return false;
         }
 
-        final String adjustedHostname = (port != 22) ? "[" + hostname + "]:" + port : hostname;
+        final String adjustedHostname = adjustHostname(hostname, port);
 
         boolean foundApplicableHostEntry = false;
         for (KnownHostEntry e : entries) {
@@ -127,6 +131,34 @@ public class OpenSSHKnownHosts
         return hostKeyUnverifiableAction(adjustedHostname, key);
     }
 
+    @Override
+    public List<String> findExistingAlgorithms(String hostname, int port) {
+        final String adjustedHostname = adjustHostname(hostname, port);
+        List<String> knownHostAlgorithms = new ArrayList<String>();
+        for (KnownHostEntry e : entries) {
+            try {
+                if (e.appliesTo(adjustedHostname)) {
+                    final KeyType type = e.getType();
+                    if (e instanceof HostEntry && ((HostEntry) e).marker == Marker.CA_CERT) {
+                        // Only the CA key type is known, but the type of the host key is not.
+                        // Adding all supported types for keys with certificates.
+                        for (final KeyType candidate : KeyType.values()) {
+                            if (candidate.getParent() != null) {
+                                knownHostAlgorithms.add(candidate.toString());
+                            }
+                        }
+                    }
+                    else {
+                        knownHostAlgorithms.add(type.toString());
+                    }
+                }
+            } catch (IOException ioe) {
+            }
+        }
+
+        return knownHostAlgorithms;
+    }
+
     protected boolean hostKeyUnverifiableAction(String hostname, PublicKey key) {
         return false;
     }

src/main/java/net/schmizz/sshj/transport/verification/PromiscuousVerifier.java

@@ -16,6 +16,8 @@
 package net.schmizz.sshj.transport.verification;
 
 import java.security.PublicKey;
+import java.util.Collections;
+import java.util.List;
 
 public final class PromiscuousVerifier
         implements HostKeyVerifier {
@@ -25,4 +27,9 @@ public final class PromiscuousVerifier
         return true;
     }
 
+    @Override
+    public List<String> findExistingAlgorithms(String hostname, int port) {
+        return Collections.emptyList();
+    }
+
 }

src/main/java/net/schmizz/sshj/userauth/keyprovider/KeyFormat.java

@@ -16,10 +16,9 @@
 package net.schmizz.sshj.userauth.keyprovider;
 
 /**
-* @version $Id:$
+* Key File Formats
 */
 public enum KeyFormat {
-    PKCS5,
     PKCS8,
     OpenSSH,
     OpenSSHv1,

src/main/java/net/schmizz/sshj/userauth/keyprovider/KeyProviderUtil.java

@@ -27,9 +27,9 @@ public class KeyProviderUtil {
      * <p/>
      * Return values are consistent with the {@code NamedFactory} implementations in the {@code keyprovider} package.
      *
-     * @param location
+     * @param location File Path to key
      * @return name of the key file format
-     * @throws java.io.IOException
+     * @throws java.io.IOException Thrown on file processing failures
      */
     public static KeyFormat detectKeyFileFormat(File location)
             throws IOException {
@@ -45,7 +45,7 @@ public class KeyProviderUtil {
      * @param privateKey     Private key stored in a string
      * @param separatePubKey Is the public key stored separately from the private key
      * @return name of the key file format
-     * @throws java.io.IOException
+     * @throws java.io.IOException Thrown on file processing failures
      */
     public static KeyFormat detectKeyFileFormat(String privateKey, boolean separatePubKey)
             throws IOException {
@@ -60,7 +60,7 @@ public class KeyProviderUtil {
      * @param privateKey     Private key accessible through a {@code Reader}
      * @param separatePubKey Is the public key stored separately from the private key
      * @return name of the key file format
-     * @throws java.io.IOException
+     * @throws java.io.IOException Thrown on file processing failures
      */
     public static KeyFormat detectKeyFileFormat(Reader privateKey, boolean separatePubKey)
             throws IOException {
@@ -94,10 +94,8 @@ public class KeyProviderUtil {
             } else if (separatePubKey) {
                 // Can delay asking for password since have unencrypted pubkey
                 return KeyFormat.OpenSSH;
-            } else if (header.contains("BEGIN PRIVATE KEY") || header.contains("BEGIN ENCRYPTED PRIVATE KEY")) {
-                return KeyFormat.PKCS8;
             } else {
-                return KeyFormat.PKCS5;
+                return KeyFormat.PKCS8;
             }
         } else if (header.startsWith("PuTTY-User-Key-File-")) {
             return KeyFormat.PuTTY;

src/main/java/net/schmizz/sshj/userauth/keyprovider/PKCS5KeyFile.java

@@ -1,272 +0,0 @@
-/*
- * Copyright (C)2009 - SSHJ Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package net.schmizz.sshj.userauth.keyprovider;
-
-import com.hierynomus.sshj.common.KeyAlgorithm;
-import com.hierynomus.sshj.transport.cipher.BlockCiphers;
-import net.schmizz.sshj.common.Base64;
-import net.schmizz.sshj.common.ByteArrayUtils;
-import net.schmizz.sshj.common.IOUtils;
-import net.schmizz.sshj.common.KeyType;
-import net.schmizz.sshj.transport.cipher.*;
-import net.schmizz.sshj.transport.digest.Digest;
-import net.schmizz.sshj.transport.digest.MD5;
-
-import java.io.BufferedReader;
-import java.io.EOFException;
-import java.io.IOException;
-import java.math.BigInteger;
-import java.nio.ByteBuffer;
-import java.nio.CharBuffer;
-import java.security.*;
-import java.security.spec.*;
-import java.util.Arrays;
-
-/**
- * Represents a PKCS5-encoded key file. This is the format typically used by OpenSSH, OpenSSL, Amazon, etc.
- */
-public class PKCS5KeyFile extends BaseFileKeyProvider {
-
-    public static class Factory
-            implements net.schmizz.sshj.common.Factory.Named<FileKeyProvider> {
-
-        @Override
-        public FileKeyProvider create() {
-            return new PKCS5KeyFile();
-        }
-
-        @Override
-        public String getName() {
-            return "PKCS5";
-        }
-    }
-
-    /**
-     * Indicates a format issue with PKCS5 data
-     */
-    public static class FormatException
-            extends IOException {
-
-        FormatException(String msg) {
-            super(msg);
-        }
-    }
-
-    /**
-     * Indicates a problem decrypting the data
-     */
-    public static class DecryptException
-            extends IOException {
-
-        DecryptException(String msg) {
-            super(msg);
-        }
-    }
-
-    protected byte[] data;
-
-    protected KeyPair readKeyPair()
-            throws IOException {
-
-        BufferedReader reader = new BufferedReader(resource.getReader());
-        try {
-            String line = null;
-            Cipher cipher = new NoneCipher();
-            StringBuffer sb = new StringBuffer();
-            byte[] iv = new byte[0]; // salt
-            while ((line = reader.readLine()) != null) {
-                if (line.startsWith("-----BEGIN ") && line.endsWith(" PRIVATE KEY-----")) {
-                    int end = line.length() - 17;
-                    if (end > 11) {
-                        String s = line.substring(11, line.length() - 17);
-                        if ("RSA".equals(s)) {
-                            type = KeyType.RSA;
-                        } else if ("DSA".equals(s)) {
-                            type = KeyType.DSA;
-                        } else if ("DSS".equals(s)) {
-                            type = KeyType.DSA;
-                        } else {
-                            throw new FormatException("Unrecognized PKCS5 key type");
-                        }
-                    } else {
-                        throw new FormatException("Bad header; possibly PKCS8 format?");
-                    }
-                } else if (line.startsWith("-----END")) {
-                    break;
-                } else if (type != null) {
-                    if (line.startsWith("Proc-Type: ")) {
-                        if (!"4,ENCRYPTED".equals(line.substring(11))) {
-                            throw new FormatException("Unrecognized Proc-Type");
-                        }
-                    } else if (line.startsWith("DEK-Info: ")) {
-                        int ptr = line.indexOf(",");
-                        if (ptr == -1) {
-                            throw new FormatException("Unrecognized DEK-Info");
-                        } else {
-                            String algorithm = line.substring(10, ptr);
-                            if ("DES-EDE3-CBC".equals(algorithm)) {
-                                cipher = BlockCiphers.TripleDESCBC().create();
-                            } else if ("AES-128-CBC".equals(algorithm)) {
-                                cipher = BlockCiphers.AES128CBC().create();
-                            } else if ("AES-192-CBC".equals(algorithm)) {
-                                cipher = BlockCiphers.AES192CBC().create();
-                            } else if ("AES-256-CBC".equals(algorithm)) {
-                                cipher = BlockCiphers.AES256CBC().create();
-                            } else {
-                                throw new FormatException("Not a supported algorithm: " + algorithm);
-                            }
-                            iv = Arrays.copyOfRange(ByteArrayUtils.parseHex(line.substring(ptr + 1)), 0, cipher.getIVSize());
-                        }
-                    } else if (line.length() > 0) {
-                        sb.append(line);
-                    }
-                }
-            }
-            if (type == null) {
-                throw new FormatException("PKCS5 header not found");
-            }
-            ASN1Data asn = new ASN1Data(data = decrypt(Base64.decode(sb.toString()), cipher, iv));
-            switch (type) {
-                case RSA: {
-                    KeyFactory factory = KeyFactory.getInstance(KeyAlgorithm.RSA);
-                    asn.readNext();
-                    BigInteger modulus = asn.readNext();
-                    BigInteger pubExp = asn.readNext();
-                    BigInteger prvExp = asn.readNext();
-                    PublicKey pubKey = factory.generatePublic(new RSAPublicKeySpec(modulus, pubExp));
-                    PrivateKey prvKey = factory.generatePrivate(new RSAPrivateKeySpec(modulus, prvExp));
-                    return new KeyPair(pubKey, prvKey);
-                }
-                case DSA: {
-                    KeyFactory factory = KeyFactory.getInstance(KeyAlgorithm.DSA);
-                    asn.readNext();
-                    BigInteger p = asn.readNext();
-                    BigInteger q = asn.readNext();
-                    BigInteger g = asn.readNext();
-                    BigInteger pub = asn.readNext();
-                    BigInteger prv = asn.readNext();
-                    PublicKey pubKey = factory.generatePublic(new DSAPublicKeySpec(pub, p, q, g));
-                    PrivateKey prvKey = factory.generatePrivate(new DSAPrivateKeySpec(prv, p, q, g));
-                    return new KeyPair(pubKey, prvKey);
-                }
-                default:
-                    throw new IOException("Unrecognized PKCS5 key type: " + type);
-            }
-        } catch (NoSuchAlgorithmException e) {
-            throw new IOException(e);
-        } catch (InvalidKeySpecException e) {
-            throw new IOException(e);
-        } finally {
-            reader.close();
-        }
-    }
-
-    @Override
-    public String toString() {
-        return "PKCS5KeyFile{resource=" + resource + "}";
-    }
-
-    private byte[] getPassphraseBytes() {
-        CharBuffer cb = CharBuffer.wrap(pwdf.reqPassword(resource));
-        ByteBuffer bb = IOUtils.UTF8.encode(cb);
-        byte[] result = Arrays.copyOfRange(bb.array(), bb.position(), bb.limit());
-        Arrays.fill(cb.array(), '\u0000');
-        Arrays.fill(bb.array(), (byte) 0);
-        return result;
-    }
-
-    private byte[] decrypt(byte[] raw, Cipher cipher, byte[] iv) throws DecryptException {
-        if (pwdf == null) {
-            return raw;
-        }
-        Digest md5 = new MD5();
-        int bsize = cipher.getBlockSize();
-        int hsize = md5.getBlockSize();
-        int hnlen = bsize / hsize * hsize + (bsize % hsize == 0 ? 0 : hsize);
-        do {
-            md5.init();
-            byte[] hn = new byte[hnlen];
-            byte[] tmp = null;
-            byte[] passphrase = getPassphraseBytes();
-            for (int i = 0; i + hsize <= hn.length; ) {
-                if (tmp != null) {
-                    md5.update(tmp, 0, tmp.length);
-                }
-                md5.update(passphrase, 0, passphrase.length);
-                md5.update(iv, 0, iv.length > 8 ? 8 : iv.length);
-                tmp = md5.digest();
-                System.arraycopy(tmp, 0, hn, i, tmp.length);
-                i += tmp.length;
-            }
-            Arrays.fill(passphrase, (byte) 0);
-            byte[] key = Arrays.copyOfRange(hn, 0, bsize);
-            cipher.init(Cipher.Mode.Decrypt, key, iv);
-            Arrays.fill(key, (byte) 0);
-            byte[] decrypted = Arrays.copyOf(raw, raw.length);
-            cipher.update(decrypted, 0, decrypted.length);
-            if (ASN1Data.MAGIC == decrypted[0]) {
-                return decrypted;
-            }
-        } while (pwdf.shouldRetry(resource));
-        throw new DecryptException("Decryption failed");
-    }
-
-    class ASN1Data {
-        static final byte MAGIC = (byte) 0x30;
-
-        private byte[] buff;
-        private int index, length;
-
-        ASN1Data(byte[] buff) throws FormatException {
-            this.buff = buff;
-            index = 0;
-            if (buff[index++] != MAGIC) {
-                throw new FormatException("Not ASN.1 data");
-            }
-            length = buff[index++] & 0xff;
-            if ((length & 0x80) != 0) {
-                int counter = length & 0x7f;
-                length = 0;
-                while (counter-- > 0) {
-                    length = (length << 8) + (buff[index++] & 0xff);
-                }
-            }
-            if ((index + length) > buff.length) {
-                throw new FormatException("Length mismatch: " + buff.length + " != " + (index + length));
-            }
-        }
-
-        BigInteger readNext() throws IOException {
-            if (index >= length) {
-                throw new EOFException();
-            } else if (buff[index++] != 0x02) {
-                throw new IOException("Not an int code: " + Integer.toHexString(0xff & buff[index]));
-            }
-            int length = buff[index++] & 0xff;
-            if ((length & 0x80) != 0) {
-                int counter = length & 0x7f;
-                length = 0;
-                while (counter-- > 0) {
-                    length = (length << 8) + (buff[index++] & 0xff);
-                }
-            }
-            byte[] sequence = new byte[length];
-            System.arraycopy(buff, index, sequence, 0, length);
-            index += length;
-            return new BigInteger(sequence);
-        }
-    }
-}

src/main/java/net/schmizz/sshj/userauth/keyprovider/PKCS8KeyFile.java

@@ -27,14 +27,21 @@ import org.bouncycastle.openssl.PEMEncryptedKeyPair;
 import org.bouncycastle.openssl.PEMKeyPair;
 import org.bouncycastle.openssl.PEMParser;
 import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
+import org.bouncycastle.openssl.jcajce.JceOpenSSLPKCS8DecryptorProviderBuilder;
 import org.bouncycastle.openssl.jcajce.JcePEMDecryptorProviderBuilder;
+import org.bouncycastle.operator.InputDecryptorProvider;
+import org.bouncycastle.operator.OperatorCreationException;
+import org.bouncycastle.pkcs.PKCS8EncryptedPrivateKeyInfo;
+import org.bouncycastle.pkcs.PKCSException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.security.KeyPair;
 
-/** Represents a PKCS8-encoded key file. This is the format used by (old-style) OpenSSH and OpenSSL. */
+/**
+ * Key File implementation supporting PEM-encoded PKCS8 and PKCS1 formats with or without password-based encryption
+ */
 public class PKCS8KeyFile extends BaseFileKeyProvider {
 
     public static class Factory
@@ -53,8 +60,6 @@ public class PKCS8KeyFile extends BaseFileKeyProvider {
 
     protected final Logger log = LoggerFactory.getLogger(getClass());
 
-    protected char[] passphrase; // for blanking out
-
     protected KeyPairConverter<PrivateKeyInfo> privateKeyInfoKeyPairConverter = new PrivateKeyInfoKeyPairConverter();
 
     protected KeyPair readKeyPair()
@@ -74,22 +79,19 @@ public class PKCS8KeyFile extends BaseFileKeyProvider {
 
                 if (o instanceof PEMEncryptedKeyPair) {
                     final PEMEncryptedKeyPair encryptedKeyPair = (PEMEncryptedKeyPair) o;
-                    JcePEMDecryptorProviderBuilder decryptorBuilder = new JcePEMDecryptorProviderBuilder();
-                    if (SecurityUtils.getSecurityProvider() != null) {
-                        decryptorBuilder.setProvider(SecurityUtils.getSecurityProvider());
-                    }
-                    try {
-                        passphrase = pwdf == null ? null : pwdf.reqPassword(resource);
-                        kp = pemConverter.getKeyPair(encryptedKeyPair.decryptKeyPair(decryptorBuilder.build(passphrase)));
-                    } finally {
-                        PasswordUtils.blankOut(passphrase);
-                    }
+                    final PEMKeyPair pemKeyPair = readEncryptedKeyPair(encryptedKeyPair);
+                    kp = pemConverter.getKeyPair(pemKeyPair);
                 } else if (o instanceof PEMKeyPair) {
                     kp = pemConverter.getKeyPair((PEMKeyPair) o);
                 } else if (o instanceof PrivateKeyInfo) {
                     final PrivateKeyInfo privateKeyInfo = (PrivateKeyInfo) o;
                     final PEMKeyPair pemKeyPair = privateKeyInfoKeyPairConverter.getKeyPair(privateKeyInfo);
                     kp = pemConverter.getKeyPair(pemKeyPair);
+                } else if (o instanceof PKCS8EncryptedPrivateKeyInfo) {
+                    final PKCS8EncryptedPrivateKeyInfo encryptedPrivateKeyInfo = (PKCS8EncryptedPrivateKeyInfo) o;
+                    final PrivateKeyInfo privateKeyInfo = readEncryptedPrivateKeyInfo(encryptedPrivateKeyInfo);
+                    final PEMKeyPair pemKeyPair = privateKeyInfoKeyPairConverter.getKeyPair(privateKeyInfo);
+                    kp = pemConverter.getKeyPair(pemKeyPair);
                 } else {
                     log.warn("Unexpected PKCS8 PEM Object [{}]", o);
                 }
@@ -114,4 +116,37 @@ public class PKCS8KeyFile extends BaseFileKeyProvider {
     public String toString() {
         return "PKCS8KeyFile{resource=" + resource + "}";
     }
+
+    private PEMKeyPair readEncryptedKeyPair(final PEMEncryptedKeyPair encryptedKeyPair) throws IOException {
+        final JcePEMDecryptorProviderBuilder builder = new JcePEMDecryptorProviderBuilder();
+        if (SecurityUtils.getSecurityProvider() != null) {
+            builder.setProvider(SecurityUtils.getSecurityProvider());
+        }
+        char[] passphrase = null;
+        try {
+            passphrase = pwdf == null ? null : pwdf.reqPassword(resource);
+            return encryptedKeyPair.decryptKeyPair(builder.build(passphrase));
+        } finally {
+            PasswordUtils.blankOut(passphrase);
+        }
+    }
+
+    private PrivateKeyInfo readEncryptedPrivateKeyInfo(final PKCS8EncryptedPrivateKeyInfo encryptedPrivateKeyInfo) throws EncryptionException {
+        final JceOpenSSLPKCS8DecryptorProviderBuilder builder = new JceOpenSSLPKCS8DecryptorProviderBuilder();
+        if (SecurityUtils.getSecurityProvider() != null) {
+            builder.setProvider(SecurityUtils.getSecurityProvider());
+        }
+        char[] passphrase = null;
+        try {
+            passphrase = pwdf == null ? null : pwdf.reqPassword(resource);
+            final InputDecryptorProvider inputDecryptorProvider = builder.build(passphrase);
+            return encryptedPrivateKeyInfo.decryptPrivateKeyInfo(inputDecryptorProvider);
+        } catch (final OperatorCreationException e) {
+            throw new EncryptionException("Loading Password for Encrypted Private Key Failed", e);
+        } catch (final PKCSException e) {
+            throw new EncryptionException("Reading Encrypted Private Key Failed", e);
+        } finally {
+            PasswordUtils.blankOut(passphrase);
+        }
+    }
 }

src/main/java/net/schmizz/sshj/userauth/keyprovider/PuTTYKeyFile.java

@@ -29,6 +29,8 @@ import net.schmizz.sshj.common.SecurityUtils;
 import net.schmizz.sshj.userauth.password.PasswordUtils;
 import org.bouncycastle.asn1.nist.NISTNamedCurves;
 import org.bouncycastle.asn1.x9.X9ECParameters;
+import org.bouncycastle.crypto.generators.Argon2BytesGenerator;
+import org.bouncycastle.crypto.params.Argon2Parameters;
 import org.bouncycastle.jce.spec.ECNamedCurveSpec;
 import org.bouncycastle.util.encoders.Hex;
 
@@ -40,11 +42,15 @@ import java.io.*;
 import java.math.BigInteger;
 import java.security.*;
 import java.security.spec.*;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 
 /**
  * <h2>Sample PuTTY file format</h2>
+ *
  * <pre>
  * PuTTY-User-Key-File-2: ssh-rsa
  * Encryption: none
@@ -70,8 +76,7 @@ import java.util.Map;
  */
 public class PuTTYKeyFile extends BaseFileKeyProvider {
 
-    public static class Factory
-            implements net.schmizz.sshj.common.Factory.Named<FileKeyProvider> {
+    public static class Factory implements net.schmizz.sshj.common.Factory.Named<FileKeyProvider> {
 
         @Override
         public FileKeyProvider create() {
@@ -84,38 +89,46 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
         }
     }
 
+    private Integer keyFileVersion;
     private byte[] privateKey;
     private byte[] publicKey;
+    private byte[] verifyHmac; // only used by v3 keys
 
     /**
-     * Key type. Either "ssh-rsa" for RSA key, or "ssh-dss" for DSA key.
+     * Key type
      */
     @Override
     public KeyType getType() throws IOException {
-        return KeyType.fromString(headers.get("PuTTY-User-Key-File-2"));
+        String headerName = String.format("PuTTY-User-Key-File-%d", this.keyFileVersion);
+        return KeyType.fromString(headers.get(headerName));
     }
 
-    public boolean isEncrypted() {
-        // Currently the only supported encryption types are "aes256-cbc" and "none".
-        return "aes256-cbc".equals(headers.get("Encryption"));
+    public boolean isEncrypted() throws IOException {
+        // Currently, the only supported encryption types are "aes256-cbc" and "none".
+        String encryption = headers.get("Encryption");
+        if ("none".equals(encryption)) {
+            return false;
+        }
+        if ("aes256-cbc".equals(encryption)) {
+            return true;
+        }
+        throw new IOException(String.format("Unsupported encryption: %s", encryption));
     }
 
-    private Map<String, String> payload
-            = new HashMap<String, String>();
+    private Map<String, String> payload = new HashMap<String, String>();
 
     /**
      * For each line that looks like "Xyz: vvv", it will be stored in this map.
      */
-    private final Map<String, String> headers
-            = new HashMap<String, String>();
-
+    private final Map<String, String> headers = new HashMap<String, String>();
 
     protected KeyPair readKeyPair() throws IOException {
         this.parseKeyPair();
         final Buffer.PlainBuffer publicKeyReader = new Buffer.PlainBuffer(publicKey);
         final Buffer.PlainBuffer privateKeyReader = new Buffer.PlainBuffer(privateKey);
-        publicKeyReader.readBytes();  // The first part of the payload is a human-readable key format name.
-        if (KeyType.RSA.equals(this.getType())) {
+        final KeyType keyType = this.getType();
+        publicKeyReader.readBytes(); // The first part of the payload is a human-readable key format name.
+        if (KeyType.RSA.equals(keyType)) {
             // public key exponent
             BigInteger e = publicKeyReader.readMPInt();
             // modulus
@@ -131,15 +144,13 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
                 throw new IOException(s.getMessage(), s);
             }
             try {
-                return new KeyPair(
-                        factory.generatePublic(new RSAPublicKeySpec(n, e)),
-                        factory.generatePrivate(new RSAPrivateKeySpec(n, d))
-                );
+                return new KeyPair(factory.generatePublic(new RSAPublicKeySpec(n, e)),
+                        factory.generatePrivate(new RSAPrivateKeySpec(n, d)));
             } catch (InvalidKeySpecException i) {
                 throw new IOException(i.getMessage(), i);
             }
         }
-        if (KeyType.DSA.equals(this.getType())) {
+        if (KeyType.DSA.equals(keyType)) {
             BigInteger p = publicKeyReader.readMPInt();
             BigInteger q = publicKeyReader.readMPInt();
             BigInteger g = publicKeyReader.readMPInt();
@@ -155,22 +166,20 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
                 throw new IOException(s.getMessage(), s);
             }
             try {
-                return new KeyPair(
-                        factory.generatePublic(new DSAPublicKeySpec(y, p, q, g)),
-                        factory.generatePrivate(new DSAPrivateKeySpec(x, p, q, g))
-                );
+                return new KeyPair(factory.generatePublic(new DSAPublicKeySpec(y, p, q, g)),
+                        factory.generatePrivate(new DSAPrivateKeySpec(x, p, q, g)));
             } catch (InvalidKeySpecException e) {
                 throw new IOException(e.getMessage(), e);
             }
         }
-        if (KeyType.ED25519.equals(this.getType())) {
+        if (KeyType.ED25519.equals(keyType)) {
             EdDSANamedCurveSpec ed25519 = EdDSANamedCurveTable.getByName("Ed25519");
             EdDSAPublicKeySpec publicSpec = new EdDSAPublicKeySpec(publicKeyReader.readBytes(), ed25519);
             EdDSAPrivateKeySpec privateSpec = new EdDSAPrivateKeySpec(privateKeyReader.readBytes(), ed25519);
             return new KeyPair(new EdDSAPublicKey(publicSpec), new EdDSAPrivateKey(privateSpec));
         }
         final String ecdsaCurve;
-        switch (this.getType()) {
+        switch (keyType) {
             case ECDSA256:
                 ecdsaCurve = "P-256";
                 break;
@@ -187,12 +196,12 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
         if (ecdsaCurve != null) {
             BigInteger s = new BigInteger(1, privateKeyReader.readBytes());
             X9ECParameters ecParams = NISTNamedCurves.getByName(ecdsaCurve);
-            ECNamedCurveSpec ecCurveSpec =
-                    new ECNamedCurveSpec(ecdsaCurve, ecParams.getCurve(), ecParams.getG(), ecParams.getN());
+            ECNamedCurveSpec ecCurveSpec = new ECNamedCurveSpec(ecdsaCurve, ecParams.getCurve(), ecParams.getG(),
+                    ecParams.getN());
             ECPrivateKeySpec pks = new ECPrivateKeySpec(s, ecCurveSpec);
             try {
                 PrivateKey privateKey = SecurityUtils.getKeyFactory(KeyAlgorithm.ECDSA).generatePrivate(pks);
-                return new KeyPair(getType().readPubKeyFromBuffer(publicKeyReader), privateKey);
+                return new KeyPair(keyType.readPubKeyFromBuffer(publicKeyReader), privateKey);
             } catch (GeneralSecurityException e) {
                 throw new IOException(e.getMessage(), e);
             }
@@ -201,6 +210,7 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
     }
 
     protected void parseKeyPair() throws IOException {
+        this.keyFileVersion = null;
         BufferedReader r = new BufferedReader(resource.getReader());
         // Parse the text into headers and payloads
         try {
@@ -211,6 +221,9 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
                 if (idx > 0) {
                     headerName = line.substring(0, idx);
                     headers.put(headerName, line.substring(idx + 2));
+                    if (headerName.startsWith("PuTTY-User-Key-File-")) {
+                        this.keyFileVersion = Integer.parseInt(headerName.substring(20));
+                    }
                 } else {
                     String s = payload.get(headerName);
                     if (s == null) {
@@ -226,6 +239,9 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
         } finally {
             r.close();
         }
+        if (this.keyFileVersion == null) {
+            throw new IOException("Invalid key file format: missing \"PuTTY-User-Key-File-?\" entry");
+        }
         // Retrieve keys from payload
         publicKey = Base64.decode(payload.get("Public-Lines"));
         if (this.isEncrypted()) {
@@ -236,8 +252,14 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
                 passphrase = "".toCharArray();
             }
             try {
-                privateKey = this.decrypt(Base64.decode(payload.get("Private-Lines")), new String(passphrase));
-                this.verify(new String(passphrase));
+                privateKey = this.decrypt(Base64.decode(payload.get("Private-Lines")), passphrase);
+                Mac mac;
+                if (this.keyFileVersion <= 2) {
+                    mac = this.prepareVerifyMacV2(passphrase);
+                } else {
+                    mac = this.prepareVerifyMacV3();
+                }
+                this.verify(mac);
             } finally {
                 PasswordUtils.blankOut(passphrase);
             }
@@ -247,77 +269,158 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
     }
 
     /**
-     * Converts a passphrase into a key, by following the convention that PuTTY uses.
-     * <p/>
-     * <p/>
+     * Converts a passphrase into a key, by following the convention that PuTTY
+     * uses. Only PuTTY v1/v2 key files
+     * <p><p/>
      * This is used to decrypt the private key when it's encrypted.
      */
-    private byte[] toKey(final String passphrase) throws IOException {
+    private void initCipher(final char[] passphrase, Cipher cipher) throws IOException, InvalidAlgorithmParameterException, InvalidKeyException {
+        // The field Key-Derivation has been introduced with Putty v3 key file format
+        // For v3 the algorithms are "Argon2i" "Argon2d" and "Argon2id"
+        String kdfAlgorithm = headers.get("Key-Derivation");
+        if (kdfAlgorithm != null) {
+            kdfAlgorithm = kdfAlgorithm.toLowerCase();
+            byte[] keyData = this.argon2(kdfAlgorithm, passphrase);
+            if (keyData == null) {
+                throw new IOException(String.format("Unsupported key derivation function: %s", kdfAlgorithm));
+            }
+            byte[] key = new byte[32];
+            byte[] iv = new byte[16];
+            byte[] tag = new byte[32]; // Hmac key
+            System.arraycopy(keyData, 0, key, 0, 32);
+            System.arraycopy(keyData, 32, iv, 0, 16);
+            System.arraycopy(keyData, 48, tag, 0, 32);
+            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"),
+                    new IvParameterSpec(iv));
+            verifyHmac = tag;
+            return;
+        }
+
+        // Key file format v1 + v2
         try {
             MessageDigest digest = MessageDigest.getInstance("SHA-1");
 
-            // The encryption key is derived from the passphrase by means of a succession of SHA-1 hashes.
+            // The encryption key is derived from the passphrase by means of a succession of
+            // SHA-1 hashes.
+            byte[] encodedPassphrase = PasswordUtils.toByteArray(passphrase);
 
             // Sequence number 0
             digest.update(new byte[]{0, 0, 0, 0});
-            digest.update(passphrase.getBytes());
+            digest.update(encodedPassphrase);
             byte[] key1 = digest.digest();
 
             // Sequence number 1
             digest.update(new byte[]{0, 0, 0, 1});
-            digest.update(passphrase.getBytes());
+            digest.update(encodedPassphrase);
             byte[] key2 = digest.digest();
 
-            byte[] r = new byte[32];
-            System.arraycopy(key1, 0, r, 0, 20);
-            System.arraycopy(key2, 0, r, 20, 12);
+            Arrays.fill(encodedPassphrase, (byte) 0);
+
+            byte[] expanded = new byte[32];
+            System.arraycopy(key1, 0, expanded, 0, 20);
+            System.arraycopy(key2, 0, expanded, 20, 12);
+
+            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(expanded, 0, 32, "AES"),
+                    new IvParameterSpec(new byte[16])); // initial vector=0
 
-            return r;
         } catch (NoSuchAlgorithmException e) {
             throw new IOException(e.getMessage(), e);
         }
     }
 
     /**
-     * Verify the MAC.
+     * Uses BouncyCastle Argon2 implementation
      */
-    private void verify(final String passphrase) throws IOException {
+    private byte[] argon2(String algorithm, final char[] passphrase) throws IOException {
+        int type;
+        if ("argon2i".equals(algorithm)) {
+            type = Argon2Parameters.ARGON2_i;
+        } else if ("argon2d".equals(algorithm)) {
+            type = Argon2Parameters.ARGON2_d;
+        } else if ("argon2id".equals(algorithm)) {
+            type = Argon2Parameters.ARGON2_id;
+        } else {
+            return null;
+        }
+        byte[] salt = Hex.decode(headers.get("Argon2-Salt"));
+        int iterations = Integer.parseInt(headers.get("Argon2-Passes"));
+        int memory = Integer.parseInt(headers.get("Argon2-Memory"));
+        int parallelism = Integer.parseInt(headers.get("Argon2-Parallelism"));
+
+        Argon2Parameters a2p = new Argon2Parameters.Builder(type)
+                .withVersion(Argon2Parameters.ARGON2_VERSION_13)
+                .withIterations(iterations)
+                .withMemoryAsKB(memory)
+                .withParallelism(parallelism)
+                .withSalt(salt).build();
+
+        Argon2BytesGenerator generator = new Argon2BytesGenerator();
+        generator.init(a2p);
+        byte[] output = new byte[80];
+        int bytes = generator.generateBytes(passphrase, output);
+        if (bytes != output.length) {
+            throw new IOException("Failed to generate key via Argon2");
+        }
+        return output;
+    }
+
+    /**
+     * Verify the MAC (only required for v1/v2 keys. v3 keys are automatically
+     * verified as part of the decryption process.
+     */
+    private void verify(final Mac mac) throws IOException {
+        final ByteArrayOutputStream out = new ByteArrayOutputStream(256);
+        final DataOutputStream data = new DataOutputStream(out);
+        // name of algorithm
+        String keyType = this.getType().toString();
+        data.writeInt(keyType.length());
+        data.writeBytes(keyType);
+
+        data.writeInt(headers.get("Encryption").length());
+        data.writeBytes(headers.get("Encryption"));
+
+        data.writeInt(headers.get("Comment").length());
+        data.writeBytes(headers.get("Comment"));
+
+        data.writeInt(publicKey.length);
+        data.write(publicKey);
+
+        data.writeInt(privateKey.length);
+        data.write(privateKey);
+
+        final String encoded = Hex.toHexString(mac.doFinal(out.toByteArray()));
+        final String reference = headers.get("Private-MAC");
+        if (!encoded.equals(reference)) {
+            throw new IOException("Invalid passphrase");
+        }
+    }
+
+    private Mac prepareVerifyMacV2(final char[] passphrase) throws IOException {
+        // The key to the MAC is itself a SHA-1 hash of (v1/v2 key only):
         try {
-            // The key to the MAC is itself a SHA-1 hash of:
             MessageDigest digest = MessageDigest.getInstance("SHA-1");
             digest.update("putty-private-key-file-mac-key".getBytes());
             if (passphrase != null) {
-                digest.update(passphrase.getBytes());
+                byte[] encodedPassphrase = PasswordUtils.toByteArray(passphrase);
+                digest.update(encodedPassphrase);
+                Arrays.fill(encodedPassphrase, (byte) 0);
             }
             final byte[] key = digest.digest();
-
-            final Mac mac = Mac.getInstance("HmacSHA1");
+            Mac mac = Mac.getInstance("HmacSHA1");
             mac.init(new SecretKeySpec(key, 0, 20, mac.getAlgorithm()));
+            return mac;
+        } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+            throw new IOException(e.getMessage(), e);
+        }
+    }
 
-            final ByteArrayOutputStream out = new ByteArrayOutputStream();
-            final DataOutputStream data = new DataOutputStream(out);
-            // name of algorithm
-            data.writeInt(this.getType().toString().length());
-            data.writeBytes(this.getType().toString());
-
-            data.writeInt(headers.get("Encryption").length());
-            data.writeBytes(headers.get("Encryption"));
-
-            data.writeInt(headers.get("Comment").length());
-            data.writeBytes(headers.get("Comment"));
-
-            data.writeInt(publicKey.length);
-            data.write(publicKey);
-
-            data.writeInt(privateKey.length);
-            data.write(privateKey);
-
-            final String encoded = Hex.toHexString(mac.doFinal(out.toByteArray()));
-            final String reference = headers.get("Private-MAC");
-            if (!encoded.equals(reference)) {
-                throw new IOException("Invalid passphrase");
-            }
-        } catch (GeneralSecurityException e) {
+    private Mac prepareVerifyMacV3() throws IOException {
+        // for v3 keys the hMac key is included in the Argon output
+        try {
+            Mac mac = Mac.getInstance("HmacSHA256");
+            mac.init(new SecretKeySpec(this.verifyHmac, 0, 32, mac.getAlgorithm()));
+            return mac;
+        } catch (NoSuchAlgorithmException | InvalidKeyException e) {
             throw new IOException(e.getMessage(), e);
         }
     }
@@ -325,17 +428,21 @@ public class PuTTYKeyFile extends BaseFileKeyProvider {
     /**
      * Decrypt private key
      *
+     * @param privateKey the SSH private key to be decrypted
      * @param passphrase To decrypt
      */
-    private byte[] decrypt(final byte[] key, final String passphrase) throws IOException {
+    private byte[] decrypt(final byte[] privateKey, final char[] passphrase) throws IOException {
         try {
             final Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
-            final byte[] expanded = this.toKey(passphrase);
-            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(expanded, 0, 32, "AES"),
-                    new IvParameterSpec(new byte[16])); // initial vector=0
-            return cipher.doFinal(key);
+            this.initCipher(passphrase, cipher);
+            return cipher.doFinal(privateKey);
         } catch (GeneralSecurityException e) {
             throw new IOException(e.getMessage(), e);
         }
     }
+
+    public int getKeyFileVersion() {
+        return keyFileVersion;
+    }
+
 }

src/main/java/net/schmizz/sshj/userauth/method/AuthGssApiWithMic.java

@@ -84,8 +84,7 @@ public class AuthGssApiWithMic
 
         @Override
         public GSSContext run() throws GSSException {
-            GSSName clientName = manager.createName(params.getUsername(), GSSName.NT_USER_NAME);
-            GSSCredential clientCreds = manager.createCredential(clientName, GSSContext.DEFAULT_LIFETIME, selectedOid, GSSCredential.INITIATE_ONLY);
+            GSSCredential clientCreds = manager.createCredential(GSSCredential.INITIATE_ONLY);
             GSSName peerName = manager.createName("host@" + params.getTransport().getRemoteHost(), GSSName.NT_HOSTBASED_SERVICE);
 
             GSSContext context = manager.createContext(peerName, selectedOid, clientCreds, GSSContext.DEFAULT_LIFETIME);

src/main/java/net/schmizz/sshj/userauth/method/KeyedAuthMethod.java

@@ -27,17 +27,36 @@ import net.schmizz.sshj.userauth.keyprovider.KeyProvider;
 import java.io.IOException;
 import java.security.PrivateKey;
 import java.security.PublicKey;
+import java.util.LinkedList;
+import java.util.Queue;
 
 public abstract class KeyedAuthMethod
         extends AbstractAuthMethod {
 
     protected final KeyProvider kProv;
+    private Queue<KeyAlgorithm> available;
 
     public KeyedAuthMethod(String name, KeyProvider kProv) {
         super(name);
         this.kProv = kProv;
     }
 
+    private KeyAlgorithm getPublicKeyAlgorithm(KeyType keyType) throws TransportException {
+        if (available == null) {
+            available = new LinkedList<>(params.getTransport().getClientKeyAlgorithms(keyType));
+        }
+        return available.peek();
+    }
+
+    @Override
+    public boolean shouldRetry() {
+        if (available != null) {
+            available.poll();
+            return !available.isEmpty();
+        }
+        return false;
+    }
+
     protected SSHPacket putPubKey(SSHPacket reqBuf)
             throws UserAuthException {
         PublicKey key;
@@ -50,13 +69,16 @@ public abstract class KeyedAuthMethod
         // public key as 2 strings: [ key type | key blob ]
         KeyType keyType = KeyType.fromKey(key);
         try {
-            KeyAlgorithm ka = params.getTransport().getClientKeyAlgorithm(keyType);
-            reqBuf.putString(ka.getKeyAlgorithm())
-                    .putString(new Buffer.PlainBuffer().putPublicKey(key).getCompactData());
-            return reqBuf;
+            KeyAlgorithm ka = getPublicKeyAlgorithm(keyType);
+            if (ka != null) {
+                reqBuf.putString(ka.getKeyAlgorithm())
+                        .putString(new Buffer.PlainBuffer().putPublicKey(key).getCompactData());
+                return reqBuf;
+            }
         } catch (IOException ioe) {
-            throw new UserAuthException("No KeyAlgorithm configured for key " + keyType);
+            throw new UserAuthException("No KeyAlgorithm configured for key " + keyType, ioe);
         }
+        throw new UserAuthException("No KeyAlgorithm configured for key " + keyType);
     }
 
     protected SSHPacket putSig(SSHPacket reqBuf)
@@ -71,7 +93,7 @@ public abstract class KeyedAuthMethod
         final KeyType kt = KeyType.fromKey(key);
         Signature signature;
         try {
-            signature = params.getTransport().getClientKeyAlgorithm(kt).newSignature();
+            signature = getPublicKeyAlgorithm(kt).newSignature();
         } catch (TransportException e) {
             throw new UserAuthException("No KeyAlgorithm configured for key " + kt);
         }

src/main/java/net/schmizz/sshj/userauth/method/PasswordResponseProvider.java

@@ -27,7 +27,8 @@ import java.util.regex.Pattern;
 public class PasswordResponseProvider
         implements ChallengeResponseProvider {
 
-    public static final Pattern DEFAULT_PROMPT_PATTERN = Pattern.compile(".*[pP]assword:\\s?\\z", Pattern.DOTALL);
+    // FreeBSD prompt is "Password for user@host:"
+    public static final Pattern DEFAULT_PROMPT_PATTERN = Pattern.compile(".*[pP]assword(?: for .*)?:\\s?\\z", Pattern.DOTALL);
 
     private static final char[] EMPTY_RESPONSE = new char[0];
 

src/main/java/net/schmizz/sshj/userauth/password/PasswordUtils.java

@@ -15,6 +15,9 @@
  */
 package net.schmizz.sshj.userauth.password;
 
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 
 /** Static utility method and factories */
@@ -54,4 +57,17 @@ public class PasswordUtils {
             };
     }
 
+    /**
+     * Converts a password to a UTF-8 encoded byte array
+     *
+     * @param password
+     * @return
+     */
+    public static byte[] toByteArray(char[] password) {
+        CharBuffer charBuffer = CharBuffer.wrap(password);
+        final ByteBuffer byteBuffer = StandardCharsets.UTF_8.encode(charBuffer);
+        byte[] bytes = new byte[byteBuffer.remaining()];
+        byteBuffer.get(bytes, 0, bytes.length);
+        return bytes;
+    }
 }

src/main/java/net/schmizz/sshj/xfer/FileSystemFile.java

@@ -71,7 +71,13 @@ public class FileSystemFile
     @Override
     public OutputStream getOutputStream()
             throws IOException {
-        return new FileOutputStream(file);
+        return getOutputStream(false);
+    }
+    
+    @Override
+    public OutputStream getOutputStream(boolean append)
+            throws IOException {
+        return new FileOutputStream(file, append);
     }
 
     @Override

src/main/java/net/schmizz/sshj/xfer/FileTransfer.java

@@ -31,6 +31,19 @@ public interface FileTransfer {
     void upload(String localPath, String remotePath)
             throws IOException;
 
+    /**
+     * This is meant to delegate to {@link #upload(LocalSourceFile, String)} with the {@code localPath} wrapped as e.g.
+     * a {@link FileSystemFile}. Appends to existing if {@code byteOffset} > 0.
+     *
+     * @param localPath
+     * @param remotePath
+     * @param byteOffset
+     *
+     * @throws IOException
+     */
+    void upload(String localPath, String remotePath, long byteOffset)
+            throws IOException;
+
     /**
      * This is meant to delegate to {@link #download(String, LocalDestFile)} with the {@code localPath} wrapped as e.g.
      * a {@link FileSystemFile}.
@@ -43,6 +56,19 @@ public interface FileTransfer {
     void download(String remotePath, String localPath)
             throws IOException;
 
+    /**
+     * This is meant to delegate to {@link #download(String, LocalDestFile)} with the {@code localPath} wrapped as e.g.
+     * a {@link FileSystemFile}. Appends to existing if {@code byteOffset} > 0.
+     *
+     * @param localPath
+     * @param remotePath
+     * @param byteOffset
+     *
+     * @throws IOException
+     */
+    void download(String remotePath, String localPath, long byteOffset)
+            throws IOException;
+
     /**
      * Upload {@code localFile} to {@code remotePath}.
      *
@@ -54,6 +80,18 @@ public interface FileTransfer {
     void upload(LocalSourceFile localFile, String remotePath)
             throws IOException;
 
+    /**
+     * Upload {@code localFile} to {@code remotePath}. Appends to existing if {@code byteOffset} > 0.
+     *
+     * @param localFile
+     * @param remotePath
+     * @param byteOffset
+     *
+     * @throws IOException
+     */
+    void upload(LocalSourceFile localFile, String remotePath, long byteOffset)
+            throws IOException;
+
     /**
      * Download {@code remotePath} to {@code localFile}.
      *
@@ -65,6 +103,18 @@ public interface FileTransfer {
     void download(String remotePath, LocalDestFile localFile)
             throws IOException;
 
+    /**
+     * Download {@code remotePath} to {@code localFile}. Appends to existing if {@code byteOffset} > 0.
+     *
+     * @param localFile
+     * @param remotePath
+     * @param byteOffset
+     *
+     * @throws IOException
+     */
+    void download(String remotePath, LocalDestFile localFile, long byteOffset)
+            throws IOException;
+
     TransferListener getTransferListener();
 
     void setTransferListener(TransferListener listener);

src/main/java/net/schmizz/sshj/xfer/LocalDestFile.java

@@ -20,8 +20,13 @@ import java.io.OutputStream;
 
 public interface LocalDestFile {
 
+    long getLength();
+
     OutputStream getOutputStream()
             throws IOException;
+    
+    OutputStream getOutputStream(boolean append)
+            throws IOException;
 
     /** @return A child file/directory of this directory with given {@code name}. */
     LocalDestFile getChild(String name);

src/main/java/net/schmizz/sshj/xfer/scp/SCPFileTransfer.java

@@ -52,24 +52,49 @@ public class SCPFileTransfer
     @Override
     public void upload(String localPath, String remotePath)
             throws IOException {
-        newSCPUploadClient().copy(new FileSystemFile(localPath), remotePath);
+        upload(localPath, remotePath, 0);
+    }
+
+    @Override
+    public void upload(String localFile, String remotePath, long byteOffset)
+            throws IOException {
+        upload(new FileSystemFile(localFile), remotePath, byteOffset);
     }
 
     @Override
     public void download(String remotePath, String localPath)
             throws IOException {
-        download(remotePath, new FileSystemFile(localPath));
+        download(remotePath, localPath, 0);
+    }
+
+    @Override
+    public void download(String remotePath, String localPath, long byteOffset) throws IOException {
+        download(remotePath, new FileSystemFile(localPath), byteOffset);
     }
 
     @Override
     public void download(String remotePath, LocalDestFile localFile)
             throws IOException {
+        download(remotePath, localFile, 0);
+    }
+    
+    @Override
+    public void download(String remotePath, LocalDestFile localFile, long byteOffset)
+            throws IOException {
+        checkByteOffsetSupport(byteOffset);
         newSCPDownloadClient().copy(remotePath, localFile);
     }
 
     @Override
     public void upload(LocalSourceFile localFile, String remotePath)
             throws IOException {
+        upload(localFile, remotePath, 0);
+    }
+
+    @Override
+    public void upload(LocalSourceFile localFile, String remotePath, long byteOffset)
+            throws IOException {
+        checkByteOffsetSupport(byteOffset);
         newSCPUploadClient().copy(localFile, remotePath);
     }
 
@@ -79,4 +104,11 @@ public class SCPFileTransfer
         }
         return this;
     }
+    
+    private void checkByteOffsetSupport(long byteOffset) throws IOException {
+        // TODO - implement byte offsets on SCP, if possible.
+        if (byteOffset > 0) {
+            throw new SCPException("Byte offset on SCP file transfers is not supported.");
+        } 
+    }
 }

src/test/groovy/com/hierynomus/sshj/userauth/keyprovider/FileKeyProviderSpec.groovy

@@ -16,6 +16,7 @@
 package com.hierynomus.sshj.userauth.keyprovider
 
 import com.hierynomus.sshj.test.SshFixture
+import net.schmizz.sshj.DefaultConfig
 import net.schmizz.sshj.SSHClient
 import net.schmizz.sshj.userauth.keyprovider.KeyFormat
 import org.apache.sshd.server.auth.pubkey.AcceptAllPublickeyAuthenticator
@@ -39,7 +40,14 @@ class FileKeyProviderSpec extends Specification {
   @Unroll
   def "should have #format FileKeyProvider enabled by default"() {
     given:
-    SSHClient client = fixture.setupConnectedDefaultClient()
+    // `fixture` is backed by Apache SSHD server. Looks like it doesn't support rsa-sha2-512 public key signature.
+    // Changing the default config to prioritize the former default implementation of RSA signature.
+    def config = new DefaultConfig()
+    config.prioritizeSshRsaKeyAlgorithm()
+
+    and:
+    SSHClient client = fixture.setupClient(config)
+    fixture.connectClient(client)
 
     when:
     client.authPublickey("jeroen", keyfile)
@@ -48,11 +56,11 @@ class FileKeyProviderSpec extends Specification {
     client.isAuthenticated()
 
     cleanup:
-    client.disconnect()
+    client?.disconnect()
 
     where:
     format | keyfile
-    KeyFormat.PKCS5 | "src/test/resources/keyformats/pkcs5"
+    KeyFormat.PKCS8 | "src/test/resources/keyformats/pkcs8"
     KeyFormat.OpenSSH | "src/test/resources/keyformats/openssh"
   }
 }

src/test/groovy/net/schmizz/sshj/ConfigImplSpec.groovy

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package net.schmizz.sshj
+
+import com.hierynomus.sshj.key.KeyAlgorithms
+import spock.lang.Specification
+
+class ConfigImplSpec extends Specification {
+    static def ECDSA = KeyAlgorithms.ECDSASHANistp521()
+    static def ED25519 = KeyAlgorithms.EdDSA25519()
+    static def RSA_SHA_256 = KeyAlgorithms.RSASHA256()
+    static def RSA_SHA_512 = KeyAlgorithms.RSASHA512()
+    static def SSH_RSA = KeyAlgorithms.SSHRSA()
+
+    def "prioritizeSshRsaKeyAlgorithm does nothing if there is no ssh-rsa"() {
+        given:
+        def config = new DefaultConfig()
+        config.keyAlgorithms = [RSA_SHA_512, ED25519]
+
+        when:
+        config.prioritizeSshRsaKeyAlgorithm()
+
+        then:
+        config.keyAlgorithms == [RSA_SHA_512, ED25519]
+    }
+
+    def "prioritizeSshRsaKeyAlgorithm does nothing if there is no rsa-sha2-any"() {
+        given:
+        def config = new DefaultConfig()
+        config.keyAlgorithms = [ED25519, SSH_RSA, ECDSA]
+
+        when:
+        config.prioritizeSshRsaKeyAlgorithm()
+
+        then:
+        config.keyAlgorithms == [ED25519, SSH_RSA, ECDSA]
+    }
+
+    def "prioritizeSshRsaKeyAlgorithm does nothing if ssh-rsa already has higher priority"() {
+        given:
+        def config = new DefaultConfig()
+        config.keyAlgorithms = [ED25519, SSH_RSA, RSA_SHA_512, ECDSA]
+
+        when:
+        config.prioritizeSshRsaKeyAlgorithm()
+
+        then:
+        config.keyAlgorithms == [ED25519, SSH_RSA, RSA_SHA_512, ECDSA]
+    }
+
+    def "prioritizeSshRsaKeyAlgorithm prioritizes ssh-rsa if there is one rsa-sha2-any is prioritized"() {
+        given:
+        def config = new DefaultConfig()
+        config.keyAlgorithms = [ED25519, RSA_SHA_512, ECDSA, SSH_RSA]
+
+        when:
+        config.prioritizeSshRsaKeyAlgorithm()
+
+        then:
+        config.keyAlgorithms == [ED25519, SSH_RSA, RSA_SHA_512, ECDSA]
+    }
+
+    def "prioritizeSshRsaKeyAlgorithm prioritizes ssh-rsa if there are two rsa-sha2-any is prioritized"() {
+        given:
+        def config = new DefaultConfig()
+        config.keyAlgorithms = [ED25519, RSA_SHA_512, ECDSA, RSA_SHA_256, SSH_RSA]
+
+        when:
+        config.prioritizeSshRsaKeyAlgorithm()
+
+        then:
+        config.keyAlgorithms == [ED25519, SSH_RSA, RSA_SHA_512, ECDSA, RSA_SHA_256]
+    }
+}

src/test/java/com/hierynomus/sshj/connection/channel/forwarded/LocalPortForwarderTest.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.hierynomus.sshj.connection.channel.forwarded;
+
+import com.hierynomus.sshj.test.HttpServer;
+import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.util.FileUtil;
+import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.connection.channel.direct.LocalPortForwarder;
+import net.schmizz.sshj.connection.channel.direct.Parameters;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.sshd.server.forward.AcceptAllForwardingFilter;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+public class LocalPortForwarderTest {
+    private static final Logger log = LoggerFactory.getLogger(LocalPortForwarderTest.class);
+
+    @Rule
+    public SshFixture fixture = new SshFixture();
+
+    @Rule
+    public HttpServer httpServer = new HttpServer();
+
+    @Before
+    public void setUp() throws IOException {
+        fixture.getServer().setForwardingFilter(new AcceptAllForwardingFilter());
+        File file = httpServer.getDocRoot().newFile("index.html");
+        FileUtil.writeToFile(file, "<html><head/><body><h1>Hi!</h1></body></html>");
+    }
+
+    @Test
+    public void shouldHaveWorkingHttpServer() throws IOException {
+        // Just to check that we have a working http server...
+        assertThat(httpGet("127.0.0.1", 8080), equalTo(200));
+    }
+
+    @Test
+    public void shouldHaveHttpServerThatClosesConnectionAfterResponse() throws IOException {
+        // Just to check that the test server does close connections before we try through the forwarder...
+        httpGetAndAssertConnectionClosedByServer(8080);
+    }
+
+    @Test(timeout = 10_000)
+    public void shouldCloseConnectionWhenRemoteServerClosesConnection() throws IOException {
+        SSHClient sshClient = getFixtureClient();
+
+        ServerSocket serverSocket = new ServerSocket();
+        serverSocket.setReuseAddress(true);
+        serverSocket.bind(new InetSocketAddress("0.0.0.0", 12345));
+        LocalPortForwarder localPortForwarder = sshClient.newLocalPortForwarder(new Parameters("0.0.0.0", 12345, "localhost", 8080), serverSocket);
+        new Thread(() -> {
+            try {
+                localPortForwarder.listen();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }, "local port listener").start();
+
+        // Test once to prove that the local HTTP connection is closed when the remote HTTP connection is closed.
+        httpGetAndAssertConnectionClosedByServer(12345);
+
+        // Test again to prove that the tunnel is still open, even after HTTP connection was closed.
+        httpGetAndAssertConnectionClosedByServer(12345);
+    }
+
+    public static void httpGetAndAssertConnectionClosedByServer(int port) throws IOException {
+        System.out.println("HTTP GET to port: " + port);
+        try (Socket socket = new Socket("localhost", port)) {
+            // Send a basic HTTP GET
+            // It returns 400 Bad Request because it's missing a bunch of info, but the HTTP response doesn't matter, we just want to test the connection closing.
+            OutputStream outputStream = socket.getOutputStream();
+            PrintWriter writer = new PrintWriter(outputStream);
+            writer.println("GET / HTTP/1.1");
+            writer.println("");
+            writer.flush();
+
+            // Read the HTTP response
+            InputStream inputStream = socket.getInputStream();
+            InputStreamReader reader = new InputStreamReader(inputStream);
+            int buf = -2;
+            while (true) {
+                buf = reader.read();
+                System.out.print((char)buf);
+                if (buf == -1) {
+                    break;
+                }
+            }
+
+            // Attempt to read more. If the server has closed the connection this will return -1
+            int read = inputStream.read();
+
+            // Assert input stream was closed by server.
+            Assert.assertEquals(-1, read);
+        }
+    }
+
+    private int httpGet(String server, int port) throws IOException {
+        HttpClient client = HttpClientBuilder.create().build();
+        String urlString = "http://" + server + ":" + port;
+        log.info("Trying: GET " + urlString);
+        HttpResponse execute = client.execute(new HttpGet(urlString));
+        return execute.getStatusLine().getStatusCode();
+    }
+
+    private SSHClient getFixtureClient() throws IOException {
+        SSHClient sshClient = fixture.setupConnectedDefaultClient();
+        sshClient.authPassword("jeroen", "jeroen");
+        return sshClient;
+    }
+}

src/test/java/com/hierynomus/sshj/connection/channel/forwarded/RemotePortForwarderTest.java

@@ -37,14 +37,14 @@ import java.io.File;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertEquals;
 
 public class RemotePortForwarderTest {
     private static final Logger log = LoggerFactory.getLogger(RemotePortForwarderTest.class);
 
     private static final PortRange RANGE = new PortRange(9000, 9999);
-    private static final InetSocketAddress HTTP_SERVER_SOCKET_ADDR = new InetSocketAddress("127.0.0.1", 8080);
+    private static final String LOCALHOST = "127.0.0.1";
+    private static final InetSocketAddress HTTP_SERVER_SOCKET_ADDR = new InetSocketAddress(LOCALHOST, 8080);
 
     @Rule
     public SshFixture fixture = new SshFixture();
@@ -62,61 +62,63 @@ public class RemotePortForwarderTest {
     @Test
     public void shouldHaveWorkingHttpServer() throws IOException {
         // Just to check that we have a working http server...
-        assertThat(httpGet("127.0.0.1", 8080), equalTo(200));
+        assertEquals(200, httpGet( 8080));
     }
 
     @Test
     public void shouldDynamicallyForwardPortForLocalhost() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "127.0.0.1", new SinglePort(0));
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
     }
 
     @Test
     public void shouldDynamicallyForwardPortForAllIPv4() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "0.0.0.0", new SinglePort(0));
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
     }
 
     @Test
     public void shouldDynamicallyForwardPortForAllProtocols() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "", new SinglePort(0));
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
     }
 
     @Test
     public void shouldForwardPortForLocalhost() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "127.0.0.1", RANGE);
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
     }
 
     @Test
     public void shouldForwardPortForAllIPv4() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "0.0.0.0", RANGE);
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
     }
 
     @Test
     public void shouldForwardPortForAllProtocols() throws IOException {
         SSHClient sshClient = getFixtureClient();
         RemotePortForwarder.Forward bind = forwardPort(sshClient, "", RANGE);
-        assertThat(httpGet("127.0.0.1", bind.getPort()), equalTo(200));
+        assertHttpGetSuccess(bind);
+    }
+
+    private void assertHttpGetSuccess(final RemotePortForwarder.Forward bind) throws IOException {
+        assertEquals(200, httpGet(bind.getPort()));
     }
 
     private RemotePortForwarder.Forward forwardPort(SSHClient sshClient, String address, PortRange portRange) throws IOException {
         while (true) {
             try {
-                RemotePortForwarder.Forward forward = sshClient.getRemotePortForwarder().bind(
+                return sshClient.getRemotePortForwarder().bind(
                         // where the server should listen
                         new RemotePortForwarder.Forward(address, portRange.nextPort()),
                         // what we do with incoming connections that are forwarded to us
                         new SocketForwardingConnectListener(HTTP_SERVER_SOCKET_ADDR));
-
-                return forward;
             } catch (ConnectionException ce) {
                 if (!portRange.hasNext()) {
                     throw ce;
@@ -125,9 +127,9 @@ public class RemotePortForwarderTest {
         }
     }
 
-    private int httpGet(String server, int port) throws IOException {
+    private int httpGet(int port) throws IOException {
         HttpClient client = HttpClientBuilder.create().build();
-        String urlString = "http://" + server + ":" + port;
+        String urlString = "http://" + LOCALHOST + ":" + port;
         log.info("Trying: GET " + urlString);
         HttpResponse execute = client.execute(new HttpGet(urlString));
         return execute.getStatusLine().getStatusCode();
@@ -140,7 +142,7 @@ public class RemotePortForwarderTest {
     }
 
     private static class PortRange {
-        private int upper;
+        private final int upper;
         private int current;
 
         public PortRange(int lower, int upper) {

src/test/java/com/hierynomus/sshj/keepalive/KeepAliveThreadTerminationTest.java

@@ -15,54 +15,67 @@
  */
 package com.hierynomus.sshj.keepalive;
 
-import com.hierynomus.sshj.test.KnownFailingTests;
-import com.hierynomus.sshj.test.SlowTests;
 import com.hierynomus.sshj.test.SshFixture;
+import net.schmizz.keepalive.KeepAlive;
 import net.schmizz.keepalive.KeepAliveProvider;
 import net.schmizz.sshj.DefaultConfig;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.userauth.UserAuthException;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.experimental.categories.Category;
 
 import java.io.IOException;
-import java.lang.management.ManagementFactory;
-import java.lang.management.ThreadInfo;
-import java.lang.management.ThreadMXBean;
 
-import static org.junit.Assert.fail;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
 public class KeepAliveThreadTerminationTest {
 
+    private static final int KEEP_ALIVE_SECONDS = 1;
+
+    private static final long STOP_SLEEP = 1500;
+
     @Rule
     public SshFixture fixture = new SshFixture();
 
     @Test
-    @Category({SlowTests.class, KnownFailingTests.class})
-    public void shouldCorrectlyTerminateThreadOnDisconnect() throws IOException, InterruptedException {
-        DefaultConfig defaultConfig = new DefaultConfig();
-        defaultConfig.setKeepAliveProvider(KeepAliveProvider.KEEP_ALIVE);
-        for (int i = 0; i < 10; i++) {
-            SSHClient sshClient = fixture.setupClient(defaultConfig);
-            fixture.connectClient(sshClient);
-            sshClient.getConnection().getKeepAlive().setKeepAliveInterval(1);
-            try {
-                sshClient.authPassword("bad", "credentials");
-                fail("Should not auth.");
-            } catch (UserAuthException e) {
-                // OK
-            }
-            fixture.stopClient();
-            Thread.sleep(2000);
-        }
+    public void shouldNotStartThreadOnSetKeepAliveInterval() {
+        final SSHClient sshClient = setupClient();
 
-        ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
-        for (long l : threadMXBean.getAllThreadIds()) {
-            ThreadInfo threadInfo = threadMXBean.getThreadInfo(l);
-            if (threadInfo.getThreadName().equals("keep-alive") && threadInfo.getThreadState() != Thread.State.TERMINATED) {
-                fail("Found alive keep-alive thread in state " + threadInfo.getThreadState());
-            }
-        }
+        final KeepAlive keepAlive = sshClient.getConnection().getKeepAlive();
+        assertTrue(keepAlive.isDaemon());
+        assertFalse(keepAlive.isAlive());
+        assertEquals(Thread.State.NEW, keepAlive.getState());
+    }
+
+    @Test
+    public void shouldStartThreadOnConnectAndInterruptOnDisconnect() throws IOException, InterruptedException {
+        final SSHClient sshClient = setupClient();
+
+        final KeepAlive keepAlive = sshClient.getConnection().getKeepAlive();
+        assertTrue(keepAlive.isDaemon());
+        assertEquals(Thread.State.NEW, keepAlive.getState());
+
+        fixture.connectClient(sshClient);
+
+        assertThrows(UserAuthException.class, () -> sshClient.authPassword("bad", "credentials"));
+
+        assertEquals(Thread.State.TIMED_WAITING, keepAlive.getState());
+
+        fixture.stopClient();
+        Thread.sleep(STOP_SLEEP);
+
+        assertFalse(keepAlive.isAlive());
+        assertEquals(Thread.State.TERMINATED, keepAlive.getState());
+    }
+
+    private SSHClient setupClient() {
+        final DefaultConfig defaultConfig = new DefaultConfig();
+        defaultConfig.setKeepAliveProvider(KeepAliveProvider.KEEP_ALIVE);
+        final SSHClient sshClient = fixture.setupClient(defaultConfig);
+        sshClient.getConnection().getKeepAlive().setKeepAliveInterval(KEEP_ALIVE_SECONDS);
+        return sshClient;
     }
 }

src/test/java/com/hierynomus/sshj/sftp/RemoteFileTest.java

@@ -17,21 +17,25 @@ package com.hierynomus.sshj.sftp;
 
 import com.hierynomus.sshj.test.SshFixture;
 import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.common.ByteArrayUtils;
 import net.schmizz.sshj.sftp.OpenMode;
 import net.schmizz.sshj.sftp.RemoteFile;
 import net.schmizz.sshj.sftp.SFTPEngine;
+import net.schmizz.sshj.sftp.SFTPException;
+import org.apache.sshd.common.util.io.IoUtils;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
+import java.io.*;
+import java.security.SecureRandom;
 import java.util.EnumSet;
 import java.util.Random;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 
 public class RemoteFileTest {
     @Rule
@@ -84,4 +88,141 @@ public class RemoteFileTest {
 
         assertThat("The written and received data should match", data, equalTo(test2));
     }
+
+    @Test
+    public void shouldNotReadAheadAfterLimitInputStream() throws IOException {
+        SSHClient ssh = fixture.setupConnectedDefaultClient();
+        ssh.authPassword("test", "test");
+        SFTPEngine sftp = new SFTPEngine(ssh).init();
+
+        RemoteFile rf;
+        File file = temp.newFile("SftpReadAheadLimitTest.bin");
+        rf = sftp.open(file.getPath(), EnumSet.of(OpenMode.WRITE, OpenMode.CREAT));
+        byte[] data = new byte[8192];
+        new Random(53).nextBytes(data);
+        data[3072] = 1;
+        rf.write(0, data, 0, data.length);
+        rf.close();
+
+        assertThat("The file should exist", file.exists());
+
+        rf = sftp.open(file.getPath());
+        InputStream rs = rf.new ReadAheadRemoteFileInputStream(16 /*maxUnconfirmedReads*/,0, 3072);
+
+        byte[] test = new byte[4097];
+        int n = 0;
+
+        while (n < 2048) {
+            n += rs.read(test, n, 2048 - n);
+        }
+
+        rf.close();
+
+        while (n < 3072) {
+            n += rs.read(test, n, 3072 - n);
+        }
+
+        assertThat("buffer overrun", test[3072] == 0);
+
+        try {
+            rs.read(test, n, test.length - n);
+            fail("Content must not be buffered");
+        } catch (SFTPException e){
+            // expected
+        }
+    }
+
+    @Test
+    public void limitedReadAheadInputStream() throws IOException {
+        SSHClient ssh = fixture.setupConnectedDefaultClient();
+        ssh.authPassword("test", "test");
+        SFTPEngine sftp = new SFTPEngine(ssh).init();
+
+        RemoteFile rf;
+        File file = temp.newFile("SftpReadAheadLimitedTest.bin");
+        rf = sftp.open(file.getPath(), EnumSet.of(OpenMode.WRITE, OpenMode.CREAT));
+        byte[] data = new byte[8192];
+        new Random(53).nextBytes(data);
+        data[3072] = 1;
+        rf.write(0, data, 0, data.length);
+        rf.close();
+
+        assertThat("The file should exist", file.exists());
+
+        rf = sftp.open(file.getPath());
+        InputStream rs = rf.new ReadAheadRemoteFileInputStream(16 /*maxUnconfirmedReads*/,0, 3072);
+
+        byte[] test = new byte[4097];
+        int n = 0;
+
+        while (n < 2048) {
+            n += rs.read(test, n, 2048 - n);
+        }
+
+        while (n < 3072) {
+            n += rs.read(test, n, 3072 - n);
+        }
+
+        assertThat("buffer overrun", test[3072] == 0);
+
+        n += rs.read(test, n, test.length - n); // --> ArrayIndexOutOfBoundsException
+
+        byte[] test2 = new byte[data.length];
+        System.arraycopy(test, 0, test2, 0, test.length);
+
+        while (n < data.length) {
+            n += rs.read(test2, n, data.length - n);
+        }
+
+        assertThat("The written and received data should match", data, equalTo(test2));
+    }
+
+    @Test
+    public void shouldReadCorrectlyWhenWrappedInBufferedStream_FullSizeBuffer() throws IOException {
+        doTestShouldReadCorrectlyWhenWrappedInBufferedStream(1024 * 1024, 1024 * 1024);
+    }
+
+    @Test
+    public void shouldReadCorrectlyWhenWrappedInBufferedStream_HalfSizeBuffer() throws IOException {
+        doTestShouldReadCorrectlyWhenWrappedInBufferedStream(1024 * 1024, 512 * 1024);
+    }
+
+    @Test
+    public void shouldReadCorrectlyWhenWrappedInBufferedStream_QuarterSizeBuffer() throws IOException {
+        doTestShouldReadCorrectlyWhenWrappedInBufferedStream(1024 * 1024, 256 * 1024);
+    }
+
+    @Test
+    public void shouldReadCorrectlyWhenWrappedInBufferedStream_SmallSizeBuffer() throws IOException {
+        doTestShouldReadCorrectlyWhenWrappedInBufferedStream(1024 * 1024, 1024);
+    }
+
+    private void doTestShouldReadCorrectlyWhenWrappedInBufferedStream(int fileSize, int bufferSize) throws IOException {
+        SSHClient ssh = fixture.setupConnectedDefaultClient();
+        ssh.authPassword("test", "test");
+        SFTPEngine sftp = new SFTPEngine(ssh).init();
+
+        final byte[] expected = new byte[fileSize];
+        new SecureRandom(new byte[] { 31 }).nextBytes(expected);
+
+        File file = temp.newFile("shouldReadCorrectlyWhenWrappedInBufferedStream.bin");
+        try (OutputStream fStream = new FileOutputStream(file)) {
+            IoUtils.copy(new ByteArrayInputStream(expected), fStream);
+        }
+
+        RemoteFile rf = sftp.open(file.getPath());
+        final byte[] actual;
+        try (InputStream inputStream = new BufferedInputStream(
+                rf.new ReadAheadRemoteFileInputStream(10),
+                bufferSize)
+        ) {
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            IoUtils.copy(inputStream, baos, expected.length);
+            actual = baos.toByteArray();
+        }
+
+        assertEquals("The file should be fully read", expected.length, actual.length);
+        assertThat("The file should be read correctly",
+                ByteArrayUtils.equals(expected, 0, actual, 0, expected.length));
+    }
 }

src/test/java/com/hierynomus/sshj/test/SshFixture.java

@@ -19,21 +19,18 @@ import net.schmizz.sshj.Config;
 import net.schmizz.sshj.DefaultConfig;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.util.gss.BogusGSSAuthenticator;
-import org.apache.sshd.common.NamedFactory;
 import org.apache.sshd.common.keyprovider.ClassLoadableResourceKeyPairProvider;
+import org.apache.sshd.common.util.OsUtils;
+import org.apache.sshd.scp.server.ScpCommandFactory;
 import org.apache.sshd.server.SshServer;
-import org.apache.sshd.server.auth.password.PasswordAuthenticator;
-import org.apache.sshd.server.command.Command;
-import org.apache.sshd.server.command.CommandFactory;
-import org.apache.sshd.server.scp.ScpCommandFactory;
-import org.apache.sshd.server.session.ServerSession;
 import org.apache.sshd.server.shell.ProcessShellFactory;
-import org.apache.sshd.server.subsystem.sftp.SftpSubsystemFactory;
+import org.apache.sshd.sftp.server.SftpSubsystemFactory;
 import org.junit.rules.ExternalResource;
 
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.net.ServerSocket;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
@@ -42,10 +39,11 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public class SshFixture extends ExternalResource {
     public static final String hostkey = "hostkey.pem";
     public static final String fingerprint = "ce:a7:c1:cf:17:3f:96:49:6a:53:1a:05:0b:ba:90:db";
+    public static final String listCommand = OsUtils.isWin32() ? "cmd.exe /C dir" : "ls";
 
-    private SshServer server = defaultSshServer();
+    private final SshServer server = defaultSshServer();
     private SSHClient client = null;
-    private AtomicBoolean started = new AtomicBoolean(false);
+    private final AtomicBoolean started = new AtomicBoolean(false);
     private boolean autoStart = true;
 
     public SshFixture(boolean autoStart) {
@@ -108,38 +106,23 @@ public class SshFixture extends ExternalResource {
         sshServer.setPort(randomPort());
         ClassLoadableResourceKeyPairProvider fileKeyPairProvider = new ClassLoadableResourceKeyPairProvider(hostkey);
         sshServer.setKeyPairProvider(fileKeyPairProvider);
-        sshServer.setPasswordAuthenticator(new PasswordAuthenticator() {
-            @Override
-            public boolean authenticate(String username, String password, ServerSession session) {
-                return username.equals(password);
-            }
-        });
+        sshServer.setPasswordAuthenticator((username, password, session) -> username.equals(password));
         sshServer.setGSSAuthenticator(new BogusGSSAuthenticator());
-        sshServer.setSubsystemFactories(Arrays.<NamedFactory<Command>>asList(new SftpSubsystemFactory()));
+        sshServer.setSubsystemFactories(Collections.singletonList(new SftpSubsystemFactory()));
         ScpCommandFactory commandFactory = new ScpCommandFactory();
-        commandFactory.setDelegateCommandFactory(new CommandFactory() {
-            @Override
-            public Command createCommand(String command) {
-                return new ProcessShellFactory(command.split(" ")).create();
-            }
-        });
+        commandFactory.setDelegateCommandFactory((session, command) -> new ProcessShellFactory(command, command.split(" ")).createShell(session));
         sshServer.setCommandFactory(commandFactory);
-        sshServer.setShellFactory(new ProcessShellFactory("ls"));
+        sshServer.setShellFactory(new ProcessShellFactory(listCommand, listCommand.split(" ")));
         return sshServer;
     }
 
     private int randomPort() {
         try {
-            ServerSocket s = null;
-            try {
-                s = new ServerSocket(0);
+            try (final ServerSocket s = new ServerSocket(0)) {
                 return s.getLocalPort();
-            } finally {
-                if (s != null)
-                    s.close();
             }
         } catch (IOException e) {
-            throw new RuntimeException(e);
+            throw new UncheckedIOException(e);
         }
     }
 

src/test/java/com/hierynomus/sshj/test/util/FileUtil.java

@@ -39,4 +39,8 @@ public class FileUtil {
             IOUtils.closeQuietly(fileInputStream);
         }
     }
+    
+    public static boolean compareFileContents(File f1, File f2) throws IOException {
+        return readFromFile(f1).equals(readFromFile(f2));
+    }
 }

src/test/java/com/hierynomus/sshj/transport/kex/KeyExchangeTest.java

@@ -22,9 +22,8 @@ import net.schmizz.sshj.common.Factory;
 import net.schmizz.sshj.transport.kex.DHGexSHA1;
 import net.schmizz.sshj.transport.kex.DHGexSHA256;
 import net.schmizz.sshj.transport.kex.ECDHNistP;
-import org.apache.sshd.common.NamedFactory;
 import org.apache.sshd.common.kex.BuiltinDHFactories;
-import org.apache.sshd.common.kex.KeyExchange;
+import org.apache.sshd.common.kex.KeyExchangeFactory;
 import org.apache.sshd.server.SshServer;
 import org.apache.sshd.server.kex.DHGEXServer;
 import org.apache.sshd.server.kex.DHGServer;
@@ -38,6 +37,7 @@ import java.util.Collections;
 @RunWith(Parameterized.class)
 public class KeyExchangeTest extends BaseAlgorithmTest {
 
+    @SuppressWarnings("deprecation")
     @Parameterized.Parameters(name = "algorithm={0}")
     public static Collection<Object[]> getParameters() {
         return Arrays.asList(new Object[][]{
@@ -56,10 +56,10 @@ public class KeyExchangeTest extends BaseAlgorithmTest {
         });
     }
 
-    private Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory;
-    private NamedFactory<KeyExchange> serverFactory;
+    private final Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory;
+    private final KeyExchangeFactory serverFactory;
 
-    public KeyExchangeTest(NamedFactory<KeyExchange> serverFactory, Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory) {
+    public KeyExchangeTest(KeyExchangeFactory serverFactory, Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory) {
         this.clientFactory = clientFactory;
         this.serverFactory = serverFactory;
     }

src/test/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCryptTest.java

@@ -12,19 +12,23 @@
 // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-package org.mindrot.jbcrypt;
+package com.hierynomus.sshj.userauth.keyprovider.bcrypt;
 
-import junit.framework.TestCase;
+import org.junit.Test;
 
 import java.util.Arrays;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 /**
  * JUnit unit tests for BCrypt routines
  * @author Damien Miller
  * @version 0.2
  */
-public class TestBCrypt extends TestCase {
-    String test_vectors[][] = {
+public class BCryptTest {
+    String[][] test_vectors = {
             { "",
                     "$2a$06$DCq7YPn5Rq63x1Lad4cll.",
                     "$2a$06$DCq7YPn5Rq63x1Lad4cll.TV4S6ytwfsfvkgY8jIucDrjc8deX1s." },
@@ -87,17 +91,10 @@ public class TestBCrypt extends TestCase {
                     "$2a$12$WApznUOJfkEGSmYRfnkrPOr466oFDCaj4b6HY3EXGvfxm43seyhgC" },
     };
 
-    /**
-     * Entry point for unit tests
-     * @param args unused
-     */
-    public static void main(String[] args) {
-        junit.textui.TestRunner.run(TestBCrypt.class);
-    }
-
     /**
      * Test method for 'BCrypt.hashpw(String, String)'
      */
+    @Test
     public void testHashpw() {
         System.out.print("BCrypt.hashpw(): ");
         for (int i = 0; i < test_vectors.length; i++) {
@@ -108,16 +105,16 @@ public class TestBCrypt extends TestCase {
             assertEquals(hashed, expected);
             System.out.print(".");
         }
-        System.out.println("");
     }
 
     /**
      * Test method for 'BCrypt.gensalt(int)'
      */
+    @Test
     public void testGensaltInt() {
         System.out.print("BCrypt.gensalt(log_rounds):");
         for (int i = 4; i <= 12; i++) {
-            System.out.print(" " + Integer.toString(i) + ":");
+            System.out.print(" " + i + ":");
             for (int j = 0; j < test_vectors.length; j += 4) {
                 String plain = test_vectors[j][0];
                 String salt = BCrypt.gensalt(i);
@@ -127,12 +124,12 @@ public class TestBCrypt extends TestCase {
                 System.out.print(".");
             }
         }
-        System.out.println("");
     }
 
     /**
      * Test method for 'BCrypt.gensalt()'
      */
+    @Test
     public void testGensalt() {
         System.out.print("BCrypt.gensalt(): ");
         for (int i = 0; i < test_vectors.length; i += 4) {
@@ -143,13 +140,13 @@ public class TestBCrypt extends TestCase {
             assertEquals(hashed1, hashed2);
             System.out.print(".");
         }
-        System.out.println("");
     }
 
     /**
      * Test method for 'BCrypt.checkpw(String, String)'
      * expecting success
      */
+    @Test
     public void testCheckpw_success() {
         System.out.print("BCrypt.checkpw w/ good passwords: ");
         for (int i = 0; i < test_vectors.length; i++) {
@@ -158,13 +155,13 @@ public class TestBCrypt extends TestCase {
             assertTrue(BCrypt.checkpw(plain, expected));
             System.out.print(".");
         }
-        System.out.println("");
     }
 
     /**
      * Test method for 'BCrypt.checkpw(String, String)'
      * expecting failure
      */
+    @Test
     public void testCheckpw_failure() {
         System.out.print("BCrypt.checkpw w/ bad passwords: ");
         for (int i = 0; i < test_vectors.length; i++) {
@@ -174,12 +171,12 @@ public class TestBCrypt extends TestCase {
             assertFalse(BCrypt.checkpw(plain, expected));
             System.out.print(".");
         }
-        System.out.println("");
     }
 
     /**
      * Test for correct hashing of non-US-ASCII passwords
      */
+    @Test
     public void testInternationalChars() {
         System.out.print("BCrypt.hashpw w/ international chars: ");
         String pw1 = "\u2605\u2605\u2605\u2605\u2605\u2605\u2605\u2605";
@@ -192,7 +189,6 @@ public class TestBCrypt extends TestCase {
         String h2 = BCrypt.hashpw(pw2, BCrypt.gensalt());
         assertFalse(BCrypt.checkpw(pw1, h2));
         System.out.print(".");
-        System.out.println("");
     }
 
     private static class BCryptHashTV {
@@ -242,7 +238,8 @@ public class TestBCrypt extends TestCase {
                     }),
     };
 
-    public void testBCryptHashTestVectors() throws Exception {
+    @Test
+    public void testBCryptHashTestVectors() {
         System.out.print("BCrypt.hash w/ known vectors: ");
         for (BCryptHashTV tv : bcrypt_hash_test_vectors) {
             byte[] output = new byte[tv.out.length];
@@ -250,7 +247,6 @@ public class TestBCrypt extends TestCase {
             assertEquals(Arrays.toString(tv.out), Arrays.toString(output));
             System.out.print(".");
         }
-        System.out.println("");
     }
 
     private static class BCryptPbkdfTV {
@@ -281,7 +277,8 @@ public class TestBCrypt extends TestCase {
                     (byte) 0x83, (byte) 0x3c, (byte) 0xf0, (byte) 0xdc, (byte) 0xf5, (byte) 0x6d, (byte) 0xb6, (byte) 0x56, (byte) 0x08, (byte) 0xe8, (byte) 0xf0, (byte) 0xdc, (byte) 0x0c, (byte) 0xe8, (byte) 0x82, (byte) 0xbd}),
     };
 
-    public void testBCryptPbkdfTestVectors() throws Exception {
+    @Test
+    public void testBCryptPbkdfTestVectors() {
         System.out.print("BCrypt.pbkdf w/ known vectors: ");
         for (BCryptPbkdfTV tv : bcrypt_pbkdf_test_vectors) {
             byte[] output = new byte[tv.out.length];
@@ -289,6 +286,5 @@ public class TestBCrypt extends TestCase {
             assertEquals(Arrays.toString(tv.out), Arrays.toString(output));
             System.out.print(".");
         }
-        System.out.println("");
     }
 }

src/test/java/com/hierynomus/sshj/userauth/method/AuthKeyboardInteractiveTest.java

@@ -20,12 +20,8 @@ import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.userauth.method.AuthKeyboardInteractive;
 import net.schmizz.sshj.userauth.method.ChallengeResponseProvider;
 import net.schmizz.sshj.userauth.password.Resource;
-import org.apache.sshd.client.auth.keyboard.UserAuthKeyboardInteractiveFactory;
-import org.apache.sshd.common.NamedFactory;
-import org.apache.sshd.server.auth.UserAuth;
-import org.apache.sshd.server.auth.keyboard.UserAuthKeyboardInteractive;
-import org.apache.sshd.server.auth.password.PasswordAuthenticator;
-import org.apache.sshd.server.session.ServerSession;
+import org.apache.sshd.server.auth.keyboard.UserAuthKeyboardInteractiveFactory;
+import org.apache.sshd.server.auth.password.AcceptAllPasswordAuthenticator;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -43,28 +39,8 @@ public class AuthKeyboardInteractiveTest {
 
     @Before
     public void setKeyboardInteractiveAuthenticator() throws IOException {
-        fixture.getServer().setUserAuthFactories(Collections.<NamedFactory<UserAuth>>singletonList(new NamedFactory<UserAuth>() {
-            @Override
-            public String getName() {
-                return UserAuthKeyboardInteractiveFactory.NAME;
-            }
-
-            @Override
-            public UserAuth get() {
-                return new UserAuthKeyboardInteractive();
-            }
-
-            @Override
-            public UserAuth create() {
-                return get();
-            }
-        }));
-        fixture.getServer().setPasswordAuthenticator(new PasswordAuthenticator() {
-            @Override
-            public boolean authenticate(String username, String password, ServerSession session) {
-                return password.equals(username);
-            }
-        });
+        fixture.getServer().setUserAuthFactories(Collections.singletonList(new UserAuthKeyboardInteractiveFactory()));
+        fixture.getServer().setPasswordAuthenticator(AcceptAllPasswordAuthenticator.INSTANCE);
         fixture.getServer().start();
     }
 
@@ -75,7 +51,7 @@ public class AuthKeyboardInteractiveTest {
         sshClient.auth(userAndPassword, new AuthKeyboardInteractive(new ChallengeResponseProvider() {
             @Override
             public List<String> getSubmethods() {
-                return new ArrayList<String>();
+                return new ArrayList<>();
             }
 
             @Override

src/test/java/com/hierynomus/sshj/userauth/method/AuthPasswordTest.java

@@ -21,56 +21,29 @@ import net.schmizz.sshj.userauth.UserAuthException;
 import net.schmizz.sshj.userauth.password.PasswordFinder;
 import net.schmizz.sshj.userauth.password.PasswordUpdateProvider;
 import net.schmizz.sshj.userauth.password.Resource;
-import org.apache.sshd.common.NamedFactory;
-import org.apache.sshd.common.util.buffer.Buffer;
-import org.apache.sshd.server.auth.UserAuth;
 import org.apache.sshd.server.auth.password.PasswordAuthenticator;
 import org.apache.sshd.server.auth.password.PasswordChangeRequiredException;
-import org.apache.sshd.server.auth.password.UserAuthPassword;
 import org.apache.sshd.server.auth.password.UserAuthPasswordFactory;
 import org.apache.sshd.server.session.ServerSession;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Stack;
 
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertThrows;
 
 public class AuthPasswordTest {
 
     @Rule
     public SshFixture fixture = new SshFixture(false);
 
-    @Rule
-    public ExpectedException expectedException = ExpectedException.none();
-
     @Before
     public void setPasswordAuthenticator() throws IOException {
-        fixture.getServer().setUserAuthFactories(Collections.<NamedFactory<UserAuth>>singletonList(new NamedFactory<UserAuth>() {
-            @Override
-            public String getName() {
-                return UserAuthPasswordFactory.NAME;
-            }
-
-            @Override
-            public UserAuth get() {
-                return new UserAuthPassword() {
-                    @Override
-                    protected Boolean handleClientPasswordChangeRequest(Buffer buffer, ServerSession session, String username, String oldPassword, String newPassword) throws Exception {
-                        return session.getPasswordAuthenticator().authenticate(username, newPassword, session);
-                    }
-                };
-            }
-
-            @Override
-            public UserAuth create() {
-                return get();
-            }
-        }));
+        fixture.getServer().setUserAuthFactories(Collections.singletonList(new UserAuthPasswordFactory()));
         fixture.getServer().setPasswordAuthenticator(new PasswordAuthenticator() {
             @Override
             public boolean authenticate(String username, String password, ServerSession session) {
@@ -80,6 +53,12 @@ public class AuthPasswordTest {
                     return password.equals(username);
                 }
             }
+
+            @Override
+            public boolean handleClientPasswordChangeRequest(
+                    ServerSession session, String username, String oldPassword, String newPassword) {
+                return username.equals(newPassword);
+            }
         });
         fixture.getServer().start();
     }
@@ -87,8 +66,7 @@ public class AuthPasswordTest {
     @Test
     public void shouldNotHandlePasswordChangeIfNoPasswordUpdateProviderSet() throws IOException {
         SSHClient sshClient = fixture.setupConnectedDefaultClient();
-        expectedException.expect(UserAuthException.class);
-        sshClient.authPassword("jeroen", "changeme");
+        assertThrows(UserAuthException.class, () -> sshClient.authPassword("jeroen", "changeme"));
         assertThat("Should not have authenticated", !sshClient.isAuthenticated());
     }
 
@@ -112,8 +90,7 @@ public class AuthPasswordTest {
     @Test
     public void shouldHandlePasswordChangeWithWrongPassword() throws IOException {
         SSHClient sshClient = fixture.setupConnectedDefaultClient();
-        expectedException.expect(UserAuthException.class);
-        sshClient.authPassword("jeroen", new PasswordFinder() {
+        assertThrows(UserAuthException.class, () -> sshClient.authPassword("jeroen", new PasswordFinder() {
             @Override
             public char[] reqPassword(Resource<?> resource) {
                 return "changeme".toCharArray();
@@ -123,7 +100,7 @@ public class AuthPasswordTest {
             public boolean shouldRetry(Resource<?> resource) {
                 return false;
             }
-        }, new StaticPasswordUpdateProvider("bad"));
+        }, new StaticPasswordUpdateProvider("bad")));
         assertThat("Should not have authenticated", !sshClient.isAuthenticated());
     }
 
@@ -153,7 +130,7 @@ public class AuthPasswordTest {
     }
 
     private static class StaticPasswordUpdateProvider implements PasswordUpdateProvider {
-        private Stack<String> newPasswords = new Stack<String>();
+        private final Stack<String> newPasswords = new Stack<>();
 
         public StaticPasswordUpdateProvider(String... newPasswords) {
             for (int i = newPasswords.length - 1; i >= 0; i--) {