diff --git a/README.adoc b/README.adoc
index 29ec174a..996e6e39 100644
--- a/README.adoc
+++ b/README.adoc
@@ -1,7 +1,7 @@
 = sshj - SSHv2 library for Java
 Jeroen van Erp
 :sshj_groupid: com.hierynomus
-:sshj_version: 0.32.0
+:sshj_version: 0.36.0
 :source-highlighter: pygments
 
 image:https://github.com/hierynomus/sshj/actions/workflows/gradle.yml/badge.svg[link="https://github.com/hierynomus/sshj/actions/workflows/gradle.yml"]
@@ -108,6 +108,12 @@ Issue tracker: https://github.com/hierynomus/sshj/issues
 Fork away!
 
 == Release history
+SSHJ 0.36.0 (2023-07-14)::
+* Merged https://github.com/hierynomus/sshj/pull/874[#874]: Java 8 minimum version + dependency upgrades
+* Merged https://github.com/hierynomus/sshj/pull/876[#876]: Change `newStatefulSFTPClient` to return `StatefulSFTPClient`
+* Merged https://github.com/hierynomus/sshj/pull/860[#860]: Upgrade to Gradle 7.6.1
+* Merged https://github.com/hierynomus/sshj/pull/838[#838]: Replaced Curve25519 class with X25519 Key agreement
+* Merged https://github.com/hierynomus/sshj/pull/772[#772]: Remove dependency on jzlib
 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
diff --git a/build.gradle b/build.gradle
index 4560fd25..88e05eb4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,25 +1,27 @@
 plugins {
   id "java"
+  id "jvm-test-suite"
   id "groovy"
   id "jacoco"
   id "com.github.blindpirate.osgi" version '0.0.6'
   id "maven-publish"
   id "signing"
-  id 'pl.allegro.tech.build.axion-release' version '1.13.3'
-  id "com.bmuschko.docker-remote-api" version "7.1.0"
+  id 'pl.allegro.tech.build.axion-release' version '1.15.3'
   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"
+  id "com.bmuschko.docker-remote-api" version "9.2.1"
+  id 'ru.vyarus.github-info' version '1.5.0'
+  id "io.github.gradle-nexus.publish-plugin" version "1.3.0"
 }
 
+group = "com.hierynomus"
+ext.moduleName = "${project.group}.${project.name}"
+
+defaultTasks "build"
+
 repositories {
   mavenCentral()
 }
 
-group = "com.hierynomus"
-defaultTasks ["build"]
-ext.moduleName = "${project.group}.${project.name}"
-
 scmVersion {
   tag {
     prefix = 'v'
@@ -33,6 +35,10 @@ scmVersion {
 
 project.version = scmVersion.version
 
+compileJava {
+  options.release = 8
+}
+
 configurations.implementation.transitive = false
 
 def bouncycastleVersion = "1.75"
@@ -44,20 +50,6 @@ dependencies {
   implementation "org.bouncycastle:bcpkix-jdk18on:$bouncycastleVersion"
   implementation "com.hierynomus:asn-one:0.6.0"
   implementation "net.i2p.crypto:eddsa:0.3.0"
-
-  testImplementation(platform("org.junit:junit-bom:5.9.3"))
-  testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
-  testRuntimeOnly 'org.junit.vintage:junit-vintage-engine'
-  testImplementation 'junit:junit:4.13.2'
-  testImplementation 'org.spockframework:spock-core:2.3-groovy-3.0'
-  testImplementation 'org.spockframework:spock-junit4:2.3-groovy-3.0'
-  testImplementation "org.mockito:mockito-core:4.11.0"
-  testImplementation "org.apache.sshd:sshd-core:$sshdVersion"
-  testImplementation "org.apache.sshd:sshd-sftp:$sshdVersion"
-  testImplementation "org.apache.sshd:sshd-scp:$sshdVersion"
-  testImplementation "ch.qos.logback:logback-classic:1.3.8"
-  testImplementation 'org.glassfish.grizzly:grizzly-http-server:3.0.1'
-  testImplementation 'org.testcontainers:testcontainers:1.18.3'
 }
 
 license {
@@ -73,6 +65,11 @@ license {
   ])
 }
 
+java {
+	withJavadocJar()
+	withSourcesJar()
+}
+
 if (!JavaVersion.current().isJava9Compatible()) {
   throw new GradleScriptException("Minimum compilation version is Java 9")
 }
@@ -84,10 +81,80 @@ if (JavaVersion.current().isJava8Compatible()) {
   }
 }
 
-compileJava {
-  options.compilerArgs.addAll(['--release', '8'])
+testing {
+  suites {
+    configureEach {
+      useJUnitJupiter()
+      dependencies {
+        implementation "org.slf4j:slf4j-api:2.0.7"
+        implementation 'org.spockframework:spock-core:2.3-groovy-3.0'
+        implementation "org.mockito:mockito-core:4.11.0"
+        implementation "ru.vyarus:spock-junit5:1.2.0"
+        implementation "org.apache.sshd:sshd-core:$sshdVersion"
+        implementation "org.apache.sshd:sshd-sftp:$sshdVersion"
+        implementation "org.apache.sshd:sshd-scp:$sshdVersion"
+        implementation "ch.qos.logback:logback-classic:1.3.8"
+        implementation 'org.glassfish.grizzly:grizzly-http-server:3.0.1'
+      }
+
+      targets {
+        all {
+          testTask.configure {
+            testLogging {
+              exceptionFormat = 'full'
+            }
+            include "**/*Test.*"
+            include "**/*Spec.*"
+            afterSuite { descriptor, result ->
+              def indicator = "\u001B[32m✓\u001b[0m"
+              if (result.failedTestCount > 0) {
+                indicator = "\u001B[31m✘\u001b[0m"
+              }
+              logger.lifecycle("$indicator Test ${descriptor.name}; Executed: ${result.testCount}/\u001B[32m${result.successfulTestCount}\u001B[0m/\u001B[31m${result.failedTestCount}\u001B[0m")
+            }
+          }
+        }
+      }
+    }
+
+    test {
+      sources {
+        groovy {
+          srcDirs = ['src/test/groovy']
+        }
+      }
+    }
+
+    integrationTest(JvmTestSuite) {
+      dependencies {
+        implementation project()
+        implementation 'org.testcontainers:testcontainers:1.18.3'
+        implementation 'org.testcontainers:junit-jupiter:1.18.3'
+      }
+
+      sources {
+        groovy {
+          srcDirs = ['src/itest/groovy']
+        }
+
+        resources {
+          srcDirs = ['src/itest/resources']
+        }
+      }
+
+      targets {
+        all {
+          testTask.configure {
+            shouldRunAfter(test)
+          }
+        }
+      }
+    }
+  }
 }
 
+project.tasks.compileGroovy.onlyIf { false }
+
 task writeSshjVersionProperties {
   doLast {
     project.file("${project.buildDir}/resources/main").mkdirs()
@@ -121,11 +188,6 @@ jar {
   }
 }
 
-java {
-	withJavadocJar()
-	withSourcesJar()
-}
-
 sourcesJar {
   manifest {
     attributes(
@@ -139,46 +201,6 @@ sourcesJar {
   }
 }
 
-configurations {
-  integrationTestImplementation.extendsFrom testImplementation
-  integrationTestRuntimeOnly.extendsFrom testRuntimeOnly
-}
-
-sourceSets {
-  integrationTest {
-    groovy {
-      compileClasspath += sourceSets.main.output + sourceSets.test.output
-      runtimeClasspath += sourceSets.main.output + sourceSets.test.output
-      srcDir file('src/itest/groovy')
-    }
-    resources.srcDir file('src/itest/resources')
-  }
-}
-
-task integrationTest(type: Test) {
-  testClassesDirs = sourceSets.integrationTest.output.classesDirs
-  classpath = sourceSets.integrationTest.runtimeClasspath
-}
-
-tasks.withType(Test) {
-  testLogging {
-    exceptionFormat = 'full'
-  }
-  useJUnitPlatform()
-
-  afterSuite { descriptor, result ->
-    if (descriptor.className != null) {
-      def indicator = "\u001B[32m✓\u001b[0m"
-      if (result.failedTestCount > 0) {
-        indicator = "\u001B[31m✘\u001b[0m"
-      }
-      logger.lifecycle("$indicator Test ${descriptor.name}; Executed: ${result.testCount}/\u001B[32m${result.successfulTestCount}\u001B[0m/\u001B[31m${result.failedTestCount}\u001B[0m")
-    }
-  }
-}
-
-project.tasks.compileGroovy.onlyIf { false }
-
 github {
   user 'hierynomus'
   license 'Apache'
@@ -264,17 +286,11 @@ nexusPublishing {
 
 jacocoTestReport {
     reports {
-        xml.enabled true
-        html.enabled true
+        xml.required = true
+        html.required = true
     }
 }
 
-task forkedUploadRelease(type: GradleBuild) {
-  buildFile = project.buildFile
-  tasks = ["clean", "publishToSonatype", "closeAndReleaseSonatypeStagingRepository"]
-}
-
 project.tasks.release.dependsOn([project.tasks.integrationTest, project.tasks.build])
-project.tasks.release.finalizedBy(project.tasks.forkedUploadRelease)
 project.tasks.jacocoTestReport.dependsOn(project.tasks.test)
 project.tasks.check.dependsOn(project.tasks.jacocoTestReport)
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 774fae87..15de9024 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/src/itest/groovy/com/hierynomus/sshj/IntegrationSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/IntegrationSpec.groovy
index d0843709..708c2151 100644
--- a/src/itest/groovy/com/hierynomus/sshj/IntegrationSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/IntegrationSpec.groovy
@@ -20,15 +20,17 @@ 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 org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class IntegrationSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should accept correct key for #signatureName"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/sftp/FileWriteSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/sftp/FileWriteSpec.groovy
index 95179a38..2646aa0f 100644
--- a/src/itest/groovy/com/hierynomus/sshj/sftp/FileWriteSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/sftp/FileWriteSpec.groovy
@@ -15,13 +15,15 @@
  */
 package com.hierynomus.sshj.sftp
 
-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 org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 
@@ -29,10 +31,11 @@ import java.nio.charset.StandardCharsets
 
 import static org.codehaus.groovy.runtime.IOGroovyMethods.withCloseable
 
+@Testcontainers
 class FileWriteSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     def "should append to file (GH issue #390)"() {
         given:
diff --git a/src/itest/groovy/com/hierynomus/sshj/signature/PublicKeyAuthWithCertificateSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/signature/PublicKeyAuthWithCertificateSpec.groovy
index 58df0190..2854ffd5 100644
--- a/src/itest/groovy/com/hierynomus/sshj/signature/PublicKeyAuthWithCertificateSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/signature/PublicKeyAuthWithCertificateSpec.groovy
@@ -19,7 +19,8 @@ import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
 import net.schmizz.sshj.SSHClient
 import net.schmizz.sshj.transport.verification.PromiscuousVerifier
-import org.junit.ClassRule
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
@@ -29,10 +30,11 @@ import spock.lang.Unroll
  *
  * Also, take a look at the unit test {@link net.schmizz.sshj.transport.verification.KeyWithCertificateUnitSpec}.
  */
+@Testcontainers
 class PublicKeyAuthWithCertificateSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "authorising with a signed public key #keyName"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/signature/RsaSignatureClientKeySpec.groovy b/src/itest/groovy/com/hierynomus/sshj/signature/RsaSignatureClientKeySpec.groovy
index df048763..cebbd416 100644
--- a/src/itest/groovy/com/hierynomus/sshj/signature/RsaSignatureClientKeySpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/signature/RsaSignatureClientKeySpec.groovy
@@ -17,15 +17,17 @@ package com.hierynomus.sshj.signature
 
 import com.hierynomus.sshj.IntegrationTestUtil
 import com.hierynomus.sshj.SshdContainer
-import org.junit.ClassRule
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class RsaSignatureClientKeySpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should correctly connect using publickey auth with RSA key with signature"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/signature/SignatureSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/signature/SignatureSpec.groovy
index d431738a..c8946b4e 100644
--- a/src/itest/groovy/com/hierynomus/sshj/signature/SignatureSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/signature/SignatureSpec.groovy
@@ -19,15 +19,17 @@ 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 org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class SignatureSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should correctly connect with #sig Signature"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/transport/cipher/CipherSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/transport/cipher/CipherSpec.groovy
index bc6687d8..643e5df6 100644
--- a/src/itest/groovy/com/hierynomus/sshj/transport/cipher/CipherSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/transport/cipher/CipherSpec.groovy
@@ -18,15 +18,17 @@ package com.hierynomus.sshj.transport.cipher
 import com.hierynomus.sshj.IntegrationTestUtil
 import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
-import org.junit.ClassRule
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class CipherSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should correctly connect with #cipher Cipher"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy
index 944be9f3..69f8abf6 100644
--- a/src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy
@@ -22,15 +22,15 @@ 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 org.junit.ClassRule
-import spock.lang.Shared
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class KexSpec extends Specification {
-    @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should correctly connect with #kex Key Exchange"() {
diff --git a/src/itest/groovy/com/hierynomus/sshj/transport/mac/MacSpec.groovy b/src/itest/groovy/com/hierynomus/sshj/transport/mac/MacSpec.groovy
index fe616cdd..0db84d90 100644
--- a/src/itest/groovy/com/hierynomus/sshj/transport/mac/MacSpec.groovy
+++ b/src/itest/groovy/com/hierynomus/sshj/transport/mac/MacSpec.groovy
@@ -18,15 +18,17 @@ package com.hierynomus.sshj.transport.mac
 import com.hierynomus.sshj.IntegrationTestUtil
 import com.hierynomus.sshj.SshdContainer
 import net.schmizz.sshj.DefaultConfig
-import org.junit.ClassRule
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
 import spock.lang.Shared
 import spock.lang.Specification
 import spock.lang.Unroll
 
+@Testcontainers
 class MacSpec extends Specification {
     @Shared
-    @ClassRule
-    SshdContainer sshd
+    @Container
+    static SshdContainer sshd = new SshdContainer()
 
     @Unroll
     def "should correctly connect with #mac MAC"() {
diff --git a/src/test/groovy/com/hierynomus/sshj/connection/channel/direct/LocalPortForwarderSpec.groovy b/src/test/groovy/com/hierynomus/sshj/connection/channel/direct/LocalPortForwarderSpec.groovy
index 0a3b64a9..baaa89f4 100644
--- a/src/test/groovy/com/hierynomus/sshj/connection/channel/direct/LocalPortForwarderSpec.groovy
+++ b/src/test/groovy/com/hierynomus/sshj/connection/channel/direct/LocalPortForwarderSpec.groovy
@@ -15,18 +15,18 @@
  */
 package com.hierynomus.sshj.connection.channel.direct
 
-import com.hierynomus.sshj.test.SshFixture
+import com.hierynomus.sshj.test.SshServerExtension
 import net.schmizz.sshj.connection.channel.direct.Parameters
-import org.junit.Rule
+import org.junit.jupiter.api.extension.RegisterExtension
 import spock.lang.Specification
 import spock.util.concurrent.PollingConditions
 
 class LocalPortForwarderSpec extends Specification {
-  @Rule
-  SshFixture tunnelFixture = new SshFixture()
+  @RegisterExtension
+  SshServerExtension tunnelFixture = new SshServerExtension()
 
-  @Rule
-  SshFixture realServer = new SshFixture()
+  @RegisterExtension
+  SshServerExtension realServer = new SshServerExtension()
 
   def "should not hang when disconnect tunnel"() {
     given:
diff --git a/src/test/groovy/com/hierynomus/sshj/sftp/SFTPClientSpec.groovy b/src/test/groovy/com/hierynomus/sshj/sftp/SFTPClientSpec.groovy
index 1fd48615..b3f6774c 100644
--- a/src/test/groovy/com/hierynomus/sshj/sftp/SFTPClientSpec.groovy
+++ b/src/test/groovy/com/hierynomus/sshj/sftp/SFTPClientSpec.groovy
@@ -15,25 +15,29 @@
  */
 package com.hierynomus.sshj.sftp
 
-import com.hierynomus.sshj.test.SshFixture
+import com.hierynomus.sshj.test.SshServerExtension
 import com.hierynomus.sshj.test.util.FileUtil
 import net.schmizz.sshj.SSHClient
 import net.schmizz.sshj.sftp.FileMode
 import net.schmizz.sshj.sftp.SFTPClient
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
+import org.junit.jupiter.api.extension.RegisterExtension
 import spock.lang.Specification
+import spock.lang.TempDir
 import spock.lang.Unroll
 
+import java.nio.file.Files
+import java.nio.file.Path
+
 import static org.codehaus.groovy.runtime.IOGroovyMethods.withCloseable
 
 class SFTPClientSpec extends Specification {
 
-    @Rule
-    public SshFixture fixture = new SshFixture()
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension()
 
-    @Rule
-    public TemporaryFolder temp = new TemporaryFolder()
+
+    @TempDir
+    public Path temp
 
     @Unroll
     def "should copy #sourceType->#targetType if #targetExists with #named name"() {
@@ -79,11 +83,11 @@ class SFTPClientSpec extends Specification {
 
     def "should not throw exception on close before disconnect"() {
         given:
-        File file = temp.newFile("source.txt")
+        File file = Files.createFile(temp.resolve("source.txt")).toFile()
         FileUtil.writeToFile(file, "This is the source")
 
         when:
-        doUpload(file, temp.newFile("dest.txt"))
+        doUpload(file, temp.resolve("dest.txt").toFile())
 
         then:
         noExceptionThrown()
@@ -147,10 +151,10 @@ class SFTPClientSpec extends Specification {
 
     def "should not merge same name subdirs (GH #252)"() {
         given:
-        File toto = temp.newFolder("toto")
+        File toto = Files.createDirectory(temp.resolve("toto")).toFile()
         File tutu = mkdir(toto, "tutu")
         File toto2 = mkdir(toto, "toto")
-        File dest = temp.newFolder("dest")
+        File dest = Files.createDirectory(temp.resolve("dest")).toFile()
         FileUtil.writeToFile(new File(toto, "toto.txt"), "Toto file")
         FileUtil.writeToFile(new File(tutu, "tototutu.txt"), "Toto/Tutu file")
         FileUtil.writeToFile(new File(toto2, "totototo.txt"), "Toto/Toto file")
diff --git a/src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy b/src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy
index 2fc05e68..091ae10c 100644
--- a/src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy
+++ b/src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy
@@ -18,17 +18,16 @@ package com.hierynomus.sshj.transport.verification
 import net.schmizz.sshj.common.Buffer
 import net.schmizz.sshj.transport.verification.OpenSSHKnownHosts
 import net.schmizz.sshj.util.KeyUtil
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
 import spock.lang.Specification
+import spock.lang.TempDir
 import spock.lang.Unroll
 
+import java.nio.file.Files
 import java.security.PublicKey
 
 class OpenSSHKnownHostsSpec extends Specification {
 
-    @Rule
-    public TemporaryFolder temp = new TemporaryFolder();
+    @TempDir def temp
 
     def "should parse and verify hashed host entry"() {
         given:
@@ -215,7 +214,7 @@ host1 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBL
     }
 
     def knownHosts(String s) {
-        def f = temp.newFile("known_hosts")
+        def f = Files.createFile(temp.resolve("known_hosts")).toFile()
         f.write(s)
         return f
     }
diff --git a/src/test/groovy/com/hierynomus/sshj/userauth/keyprovider/FileKeyProviderSpec.groovy b/src/test/groovy/com/hierynomus/sshj/userauth/keyprovider/FileKeyProviderSpec.groovy
index 7c85faa4..9b34eae8 100644
--- a/src/test/groovy/com/hierynomus/sshj/userauth/keyprovider/FileKeyProviderSpec.groovy
+++ b/src/test/groovy/com/hierynomus/sshj/userauth/keyprovider/FileKeyProviderSpec.groovy
@@ -15,18 +15,18 @@
  */
 package com.hierynomus.sshj.userauth.keyprovider
 
-import com.hierynomus.sshj.test.SshFixture
+import com.hierynomus.sshj.test.SshServerExtension
 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
-import org.junit.Rule
+import org.junit.jupiter.api.extension.RegisterExtension
 import spock.lang.Specification
 import spock.lang.Unroll
 
 class FileKeyProviderSpec extends Specification {
-  @Rule
-  SshFixture fixture = new SshFixture(false)
+  @RegisterExtension
+  SshServerExtension fixture = new SshServerExtension(false)
 
   def setup() {
     fixture.getServer().setPublickeyAuthenticator(AcceptAllPublickeyAuthenticator.INSTANCE)
diff --git a/src/test/groovy/net/schmizz/sshj/signature/SignatureDSASpec.groovy b/src/test/groovy/net/schmizz/sshj/signature/SignatureDSASpec.groovy
index 3032b2a7..e62eaedd 100644
--- a/src/test/groovy/net/schmizz/sshj/signature/SignatureDSASpec.groovy
+++ b/src/test/groovy/net/schmizz/sshj/signature/SignatureDSASpec.groovy
@@ -31,20 +31,12 @@
 package net.schmizz.sshj.signature
 
 import com.hierynomus.sshj.common.KeyAlgorithm
-import spock.lang.Unroll;
-
-import java.math.BigInteger;
-import java.security.KeyFactory;
-import java.security.NoSuchAlgorithmException;
-import java.security.PublicKey;
-import java.security.spec.DSAPublicKeySpec;
-import java.util.ArrayList;
-import java.util.List;
-
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
 import spock.lang.Specification
+import spock.lang.Unroll
+
+import java.security.KeyFactory
+import java.security.PublicKey
+import java.security.spec.DSAPublicKeySpec
 
 class SignatureDSASpec extends Specification {
 
diff --git a/src/test/java/com/hierynomus/sshj/connection/channel/ChannelCloseEofTest.java b/src/test/java/com/hierynomus/sshj/connection/channel/ChannelCloseEofTest.java
index 917e60c1..31b27861 100644
--- a/src/test/java/com/hierynomus/sshj/connection/channel/ChannelCloseEofTest.java
+++ b/src/test/java/com/hierynomus/sshj/connection/channel/ChannelCloseEofTest.java
@@ -15,10 +15,10 @@
  */
 package com.hierynomus.sshj.connection.channel;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.connection.channel.direct.Session;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.IOException;
 
@@ -26,8 +26,8 @@ import static org.hamcrest.MatcherAssert.assertThat;
 
 public class ChannelCloseEofTest {
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
     @Test
     public void shouldCorrectlyHandleSessionChannelEof() throws IOException, InterruptedException {
diff --git a/src/test/java/com/hierynomus/sshj/connection/channel/direct/CommandTest.java b/src/test/java/com/hierynomus/sshj/connection/channel/direct/CommandTest.java
index 3c62c9a1..813e606b 100644
--- a/src/test/java/com/hierynomus/sshj/connection/channel/direct/CommandTest.java
+++ b/src/test/java/com/hierynomus/sshj/connection/channel/direct/CommandTest.java
@@ -15,13 +15,13 @@
  */
 package com.hierynomus.sshj.connection.channel.direct;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.connection.channel.direct.Session;
 import net.schmizz.sshj.sftp.SFTPClient;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.io.TempDir;
 
 import java.io.File;
 import java.io.IOException;
@@ -30,17 +30,17 @@ import static org.hamcrest.MatcherAssert.assertThat;
 
 public class CommandTest {
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Rule
-    public TemporaryFolder temp = new TemporaryFolder();
+    @TempDir
+    public File temp;
 
     @Test
     public void shouldExecuteBackgroundCommand() throws IOException {
         SSHClient sshClient = fixture.setupConnectedDefaultClient();
         sshClient.authPassword("jeroen", "jeroen");
-        File file = new File(temp.getRoot(), "testdir");
+        File file = new File(temp, "testdir");
         assertThat("File should not exist", !file.exists());
         // TODO figure out why this does not really execute in the background.
         Session.Command exec = sshClient.startSession().exec("mkdir " + file.getPath() + " &");
diff --git a/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/LocalPortForwarderTest.java b/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/LocalPortForwarderTest.java
index e923708f..b001a98c 100644
--- a/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/LocalPortForwarderTest.java
+++ b/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/LocalPortForwarderTest.java
@@ -16,44 +16,36 @@
 package com.hierynomus.sshj.connection.channel.forwarded;
 
 import com.hierynomus.sshj.test.HttpServer;
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 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.sshd.server.forward.AcceptAllForwardingFilter;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.OutputStream;
-import java.io.PrintWriter;
-import java.net.HttpURLConnection;
-import java.net.InetSocketAddress;
-import java.net.ServerSocket;
-import java.net.Socket;
-import java.net.URL;
+import java.io.*;
+import java.net.*;
+import java.nio.file.Files;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class LocalPortForwarderTest {
     private static final String LOCALHOST_URL = "http://127.0.0.1:8080";
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Rule
+    @RegisterExtension
     public HttpServer httpServer = new HttpServer();
 
-    @Before
+    @BeforeEach
     public void setUp() throws IOException {
         fixture.getServer().setForwardingFilter(new AcceptAllForwardingFilter());
-        File file = httpServer.getDocRoot().newFile("index.html");
+        File file = Files.createFile(httpServer.getDocRoot().toPath().resolve("index.html")).toFile();
         FileUtil.writeToFile(file, "<html><head/><body><h1>Hi!</h1></body></html>");
     }
 
@@ -68,7 +60,8 @@ public class LocalPortForwarderTest {
         httpGetAndAssertConnectionClosedByServer(8080);
     }
 
-    @Test(timeout = 10_000)
+    @Test
+    @Timeout(10_000)
     public void shouldCloseConnectionWhenRemoteServerClosesConnection() throws IOException {
         SSHClient sshClient = getFixtureClient();
 
@@ -113,7 +106,7 @@ public class LocalPortForwarderTest {
             int read = inputStream.read();
 
             // Assert input stream was closed by server.
-            Assert.assertEquals(-1, read);
+            assertEquals(-1, read);
         }
     }
 
diff --git a/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/RemotePortForwarderTest.java b/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/RemotePortForwarderTest.java
index 9dda9e47..b07f2d2c 100644
--- a/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/RemotePortForwarderTest.java
+++ b/src/test/java/com/hierynomus/sshj/connection/channel/forwarded/RemotePortForwarderTest.java
@@ -16,24 +16,25 @@
 package com.hierynomus.sshj.connection.channel.forwarded;
 
 import com.hierynomus.sshj.test.HttpServer;
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import com.hierynomus.sshj.test.util.FileUtil;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.connection.ConnectionException;
 import net.schmizz.sshj.connection.channel.forwarded.RemotePortForwarder;
 import net.schmizz.sshj.connection.channel.forwarded.SocketForwardingConnectListener;
 import org.apache.sshd.server.forward.AcceptAllForwardingFilter;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.File;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.URL;
+import java.nio.file.Files;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class RemotePortForwarderTest {
     private static final PortRange RANGE = new PortRange(9000, 9999);
@@ -41,16 +42,16 @@ public class RemotePortForwarderTest {
     private static final String LOCALHOST_URL_FORMAT = "http://127.0.0.1:%d";
     private static final InetSocketAddress HTTP_SERVER_SOCKET_ADDR = new InetSocketAddress(LOCALHOST, 8080);
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Rule
+    @RegisterExtension
     public HttpServer httpServer = new HttpServer();
 
-    @Before
+    @BeforeEach
     public void setUp() throws IOException {
         fixture.getServer().setForwardingFilter(new AcceptAllForwardingFilter());
-        File file = httpServer.getDocRoot().newFile("index.html");
+        File file = Files.createFile(httpServer.getDocRoot().toPath().resolve("index.html")).toFile();
         FileUtil.writeToFile(file, "<html><head/><body><h1>Hi!</h1></body></html>");
     }
 
diff --git a/src/test/java/com/hierynomus/sshj/keepalive/KeepAliveThreadTerminationTest.java b/src/test/java/com/hierynomus/sshj/keepalive/KeepAliveThreadTerminationTest.java
index 9e743f6b..153b6dec 100644
--- a/src/test/java/com/hierynomus/sshj/keepalive/KeepAliveThreadTerminationTest.java
+++ b/src/test/java/com/hierynomus/sshj/keepalive/KeepAliveThreadTerminationTest.java
@@ -15,21 +15,18 @@
  */
 package com.hierynomus.sshj.keepalive;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 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.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.IOException;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertThrows;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class KeepAliveThreadTerminationTest {
 
@@ -37,8 +34,8 @@ public class KeepAliveThreadTerminationTest {
 
     private static final long STOP_SLEEP = 1500;
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
     @Test
     public void shouldNotStartThreadOnSetKeepAliveInterval() {
diff --git a/src/test/java/com/hierynomus/sshj/sftp/RemoteFileTest.java b/src/test/java/com/hierynomus/sshj/sftp/RemoteFileTest.java
index c69d1240..b105962b 100644
--- a/src/test/java/com/hierynomus/sshj/sftp/RemoteFileTest.java
+++ b/src/test/java/com/hierynomus/sshj/sftp/RemoteFileTest.java
@@ -15,7 +15,7 @@
  */
 package com.hierynomus.sshj.sftp;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.common.ByteArrayUtils;
 import net.schmizz.sshj.sftp.OpenMode;
@@ -23,9 +23,9 @@ 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 org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.io.TempDir;
 
 import java.io.*;
 import java.security.SecureRandom;
@@ -34,15 +34,15 @@ 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;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class RemoteFileTest {
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Rule
-    public TemporaryFolder temp = new TemporaryFolder();
+    @TempDir
+    public File temp;
 
     @Test
     public void shouldNotGoOutOfBoundsInReadAheadInputStream() throws IOException {
@@ -51,7 +51,7 @@ public class RemoteFileTest {
         SFTPEngine sftp = new SFTPEngine(ssh).init();
 
         RemoteFile rf;
-        File file = temp.newFile("SftpReadAheadTest.bin");
+        File file = new File(temp, "SftpReadAheadTest.bin");
         rf = sftp.open(file.getPath(), EnumSet.of(OpenMode.WRITE, OpenMode.CREAT));
         byte[] data = new byte[8192];
         new Random(53).nextBytes(data);
@@ -96,7 +96,7 @@ public class RemoteFileTest {
         SFTPEngine sftp = new SFTPEngine(ssh).init();
 
         RemoteFile rf;
-        File file = temp.newFile("SftpReadAheadLimitTest.bin");
+        File file = new File(temp, "SftpReadAheadLimitTest.bin");
         rf = sftp.open(file.getPath(), EnumSet.of(OpenMode.WRITE, OpenMode.CREAT));
         byte[] data = new byte[8192];
         new Random(53).nextBytes(data);
@@ -139,7 +139,7 @@ public class RemoteFileTest {
         SFTPEngine sftp = new SFTPEngine(ssh).init();
 
         RemoteFile rf;
-        File file = temp.newFile("SftpReadAheadLimitedTest.bin");
+        File file = new File(temp, "SftpReadAheadLimitedTest.bin");
         rf = sftp.open(file.getPath(), EnumSet.of(OpenMode.WRITE, OpenMode.CREAT));
         byte[] data = new byte[8192];
         new Random(53).nextBytes(data);
@@ -205,7 +205,7 @@ public class RemoteFileTest {
         final byte[] expected = new byte[fileSize];
         new SecureRandom(new byte[] { 31 }).nextBytes(expected);
 
-        File file = temp.newFile("shouldReadCorrectlyWhenWrappedInBufferedStream.bin");
+        File file = new File(temp, "shouldReadCorrectlyWhenWrappedInBufferedStream.bin");
         try (OutputStream fStream = new FileOutputStream(file)) {
             IoUtils.copy(new ByteArrayInputStream(expected), fStream);
         }
@@ -221,7 +221,7 @@ public class RemoteFileTest {
             actual = baos.toByteArray();
         }
 
-        assertEquals("The file should be fully read", expected.length, actual.length);
+        assertEquals(expected.length, actual.length, "The file should be fully read");
         assertThat("The file should be read correctly",
                 ByteArrayUtils.equals(expected, 0, actual, 0, expected.length));
     }
diff --git a/src/test/java/com/hierynomus/sshj/test/BaseAlgorithmTest.java b/src/test/java/com/hierynomus/sshj/test/BaseAlgorithmTest.java
index 975f7d9e..127ac443 100644
--- a/src/test/java/com/hierynomus/sshj/test/BaseAlgorithmTest.java
+++ b/src/test/java/com/hierynomus/sshj/test/BaseAlgorithmTest.java
@@ -21,9 +21,8 @@ import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.transport.random.JCERandom;
 import net.schmizz.sshj.transport.random.SingletonRandomFactory;
 import org.apache.sshd.server.SshServer;
-import org.junit.After;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,13 +35,8 @@ public abstract class BaseAlgorithmTest {
 
     private SingletonRandomFactory randomFactory = new SingletonRandomFactory(new JCERandom.Factory());
     private DefaultConfig config = new DefaultConfig();
-    @Rule
-    public SshFixture fixture = new SshFixture(false);
-
-    @After
-    public void stopServer() {
-        fixture.stopServer();
-    }
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension(false);
 
     @Test
     public void shouldVerifyAlgorithm() throws IOException {
diff --git a/src/test/java/com/hierynomus/sshj/test/HttpServer.java b/src/test/java/com/hierynomus/sshj/test/HttpServer.java
index 76ec2333..259235b7 100644
--- a/src/test/java/com/hierynomus/sshj/test/HttpServer.java
+++ b/src/test/java/com/hierynomus/sshj/test/HttpServer.java
@@ -15,27 +15,25 @@
  */
 package com.hierynomus.sshj.test;
 
-import org.junit.rules.ExternalResource;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+import java.io.File;
+import java.nio.file.Files;
 
 /**
  * Can be used to setup a test HTTP server
  */
-public class HttpServer extends ExternalResource {
+public class HttpServer implements BeforeEachCallback, AfterEachCallback {
 
     private org.glassfish.grizzly.http.server.HttpServer httpServer;
 
-    private TemporaryFolder docRoot = new TemporaryFolder();
+
+    private File docRoot ;
 
     @Override
-    protected void before() throws Throwable {
-        docRoot.create();
-        httpServer = org.glassfish.grizzly.http.server.HttpServer.createSimpleServer(docRoot.getRoot().getAbsolutePath());
-        httpServer.start();
-    }
-
-    @Override
-    protected void after() {
+    public void afterEach(ExtensionContext context) throws Exception {
         try {
             httpServer.shutdownNow();
         } catch (Exception e) {}
@@ -45,11 +43,18 @@ public class HttpServer extends ExternalResource {
 
     }
 
+    @Override
+    public void beforeEach(ExtensionContext context) throws Exception {
+        docRoot = Files.createTempDirectory("sshj").toFile();
+        httpServer = org.glassfish.grizzly.http.server.HttpServer.createSimpleServer(docRoot.getAbsolutePath());
+        httpServer.start();
+    }
+
     public org.glassfish.grizzly.http.server.HttpServer getHttpServer() {
         return httpServer;
     }
 
-    public TemporaryFolder getDocRoot() {
+    public File getDocRoot() {
         return docRoot;
     }
 }
diff --git a/src/test/java/com/hierynomus/sshj/test/SshFixture.java b/src/test/java/com/hierynomus/sshj/test/SshServerExtension.java
similarity index 88%
rename from src/test/java/com/hierynomus/sshj/test/SshFixture.java
rename to src/test/java/com/hierynomus/sshj/test/SshServerExtension.java
index 508fa290..1d07bbe3 100644
--- a/src/test/java/com/hierynomus/sshj/test/SshFixture.java
+++ b/src/test/java/com/hierynomus/sshj/test/SshServerExtension.java
@@ -25,8 +25,11 @@ import org.apache.sshd.scp.server.ScpCommandFactory;
 import org.apache.sshd.server.SshServer;
 import org.apache.sshd.server.shell.ProcessShellFactory;
 import org.apache.sshd.sftp.server.SftpSubsystemFactory;
-import org.junit.rules.ExternalResource;
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.net.ServerSocket;
@@ -36,7 +39,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 /**
  * Can be used as a rule to ensure the server is teared down after each test.
  */
-public class SshFixture extends ExternalResource {
+public class SshServerExtension implements BeforeEachCallback, AfterEachCallback, Closeable {
     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";
@@ -46,22 +49,28 @@ public class SshFixture extends ExternalResource {
     private final AtomicBoolean started = new AtomicBoolean(false);
     private boolean autoStart = true;
 
-    public SshFixture(boolean autoStart) {
+    public SshServerExtension(boolean autoStart) {
         this.autoStart = autoStart;
     }
 
-    public SshFixture() {
+    public SshServerExtension() {
     }
 
     @Override
-    protected void before() throws Throwable {
+    public void afterEach(ExtensionContext context) throws Exception {
+        close();
+    }
+
+    @Override
+    public void beforeEach(ExtensionContext context) throws Exception {
         if (autoStart) {
             start();
         }
     }
 
+
     @Override
-    protected void after() {
+    public void close() throws IOException {
         stopClient();
         stopServer();
     }
diff --git a/src/test/java/com/hierynomus/sshj/transport/ChachaPolyCipherTest.java b/src/test/java/com/hierynomus/sshj/transport/ChachaPolyCipherTest.java
index 6a281176..df9e8d18 100644
--- a/src/test/java/com/hierynomus/sshj/transport/ChachaPolyCipherTest.java
+++ b/src/test/java/com/hierynomus/sshj/transport/ChachaPolyCipherTest.java
@@ -15,17 +15,15 @@
  */
 package com.hierynomus.sshj.transport;
 
-import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
-
 import com.hierynomus.sshj.transport.cipher.ChachaPolyCiphers;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.transport.cipher.Cipher;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.*;
 
 public class ChachaPolyCipherTest {
 
diff --git a/src/test/java/com/hierynomus/sshj/transport/DisconnectionTest.java b/src/test/java/com/hierynomus/sshj/transport/DisconnectionTest.java
index b4522e04..d40cd497 100644
--- a/src/test/java/com/hierynomus/sshj/transport/DisconnectionTest.java
+++ b/src/test/java/com/hierynomus/sshj/transport/DisconnectionTest.java
@@ -15,30 +15,30 @@
  */
 package com.hierynomus.sshj.transport;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.common.DisconnectReason;
 import net.schmizz.sshj.connection.channel.direct.Session;
 import net.schmizz.sshj.transport.DisconnectListener;
 import net.schmizz.sshj.transport.TransportException;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class DisconnectionTest {
     private AtomicBoolean disconnected = null;
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Before
+    @BeforeEach
     public void setupFlag() throws IOException {
         disconnected = new AtomicBoolean(false);
         // Initialize the client
diff --git a/src/test/java/com/hierynomus/sshj/transport/GcmCipherDecryptSshPacketTest.java b/src/test/java/com/hierynomus/sshj/transport/GcmCipherDecryptSshPacketTest.java
index b0ed52c5..60995cb4 100644
--- a/src/test/java/com/hierynomus/sshj/transport/GcmCipherDecryptSshPacketTest.java
+++ b/src/test/java/com/hierynomus/sshj/transport/GcmCipherDecryptSshPacketTest.java
@@ -20,48 +20,58 @@ import net.schmizz.sshj.common.IOUtils;
 import net.schmizz.sshj.common.SSHPacket;
 import net.schmizz.sshj.transport.cipher.Cipher;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.junit.BeforeClass;
-import org.junit.experimental.theories.DataPoints;
-import org.junit.experimental.theories.Theories;
-import org.junit.experimental.theories.Theory;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 import java.security.Security;
 import java.util.Arrays;
+import java.util.stream.Stream;
 
-import static org.junit.Assert.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 
 /**
  * Unit test to decrypt SSH traffic with OpenSSH and Apache Mina SSHD (master) using AES-GCM ciphers, for verifying
  * cipher behaviour.
  */
-@RunWith(Theories.class)
+
 public class GcmCipherDecryptSshPacketTest {
 
-    @DataPoints
-    public static final String sets[][] = new String[][]{{"mina-sshd", "3"}, {"openssh", "4"}};
+    public static Stream<Arguments> sets() {
+        return Stream.of(Arguments.of("mina-sshd", 3), Arguments.of("openssh", 4));
+    }
 
-    @BeforeClass
+    @BeforeAll
     public static void setupBeforeClass() {
         Security.addProvider(new BouncyCastleProvider());
     }
 
-    @Theory
-    public void testDecryptPacket(String[] args) throws Exception {
+    @ParameterizedTest
+    @MethodSource("sets")
+    public void testDecryptPacket(String ssh, int nr) throws Exception {
         ClassLoader classLoader = getClass().getClassLoader();
-        byte[] iv = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/"+args[0]+"/s2c.iv.bin")).toByteArray();
-        byte[] key = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/"+args[0]+"/s2c.key.bin")).toByteArray();
+        byte[] iv = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/" + ssh + "/s2c.iv.bin"))
+                .toByteArray();
+        byte[] key = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/" + ssh + "/s2c.key.bin"))
+                .toByteArray();
         Cipher cipher = GcmCiphers.AES128GCM().create();
         cipher.init(Cipher.Mode.Decrypt, key, iv);
-        for(int i=1; i<=Integer.parseInt(args[1]); i++) {
-            byte[] data = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/"+args[0]+"/client.receive."+i+".bin")).toByteArray();
+        for (int i = 1; i <= nr; i++) {
+            byte[] data = IOUtils
+                    .readFully(classLoader
+                            .getResourceAsStream("ssh-packets/gcm/" + ssh + "/client.receive." + i + ".bin"))
+                    .toByteArray();
             SSHPacket inputBuffer = new SSHPacket(data);
             cipher.updateAAD(inputBuffer.array(), 0, 4);
             int size = inputBuffer.readUInt32AsInt();
             cipher.update(inputBuffer.array(), 4, size);
-            byte[] expected = IOUtils.readFully(classLoader.getResourceAsStream("ssh-packets/gcm/"+args[0]+"/client.decrypted."+i+".bin")).toByteArray();
-            assertArrayEquals(Arrays.copyOfRange(expected, 0, size+4),
-                    Arrays.copyOfRange(inputBuffer.array(), 0, size+4));
+            byte[] expected = IOUtils
+                    .readFully(classLoader
+                            .getResourceAsStream("ssh-packets/gcm/" + ssh + "/client.decrypted." + i + ".bin"))
+                    .toByteArray();
+            assertArrayEquals(Arrays.copyOfRange(expected, 0, size + 4),
+                    Arrays.copyOfRange(inputBuffer.array(), 0, size + 4));
         }
     }
 }
diff --git a/src/test/java/com/hierynomus/sshj/transport/GcmCipherTest.java b/src/test/java/com/hierynomus/sshj/transport/GcmCipherTest.java
index b9784d0b..e09ec6aa 100644
--- a/src/test/java/com/hierynomus/sshj/transport/GcmCipherTest.java
+++ b/src/test/java/com/hierynomus/sshj/transport/GcmCipherTest.java
@@ -18,23 +18,21 @@ package com.hierynomus.sshj.transport;
 import com.hierynomus.sshj.transport.cipher.GcmCiphers;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.transport.cipher.Cipher;
-import org.junit.experimental.theories.DataPoints;
-import org.junit.experimental.theories.Theories;
-import org.junit.experimental.theories.Theory;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 
 import javax.crypto.AEADBadTagException;
 import java.nio.charset.StandardCharsets;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
-@RunWith(Theories.class)
 public class GcmCipherTest {
 
-    public static final @DataPoints
-    GcmCiphers.Factory[] cipherFactories = { GcmCiphers.AES128GCM(), GcmCiphers.AES256GCM() };
+    public static GcmCiphers.Factory[] cipherFactories() {
+        return new GcmCiphers.Factory[] { GcmCiphers.AES128GCM(), GcmCiphers.AES256GCM() }; };
 
-    @Theory
+    @ParameterizedTest
+    @MethodSource("cipherFactories")
     public void testEncryptDecrypt(GcmCiphers.Factory factory) throws Exception {
         Cipher enc = factory.create();
         byte[] key = new byte[enc.getBlockSize()];
diff --git a/src/test/java/com/hierynomus/sshj/transport/kex/KeyExchangeTest.java b/src/test/java/com/hierynomus/sshj/transport/kex/KeyExchangeTest.java
index e82ec077..d0b61011 100644
--- a/src/test/java/com/hierynomus/sshj/transport/kex/KeyExchangeTest.java
+++ b/src/test/java/com/hierynomus/sshj/transport/kex/KeyExchangeTest.java
@@ -15,63 +15,76 @@
  */
 package com.hierynomus.sshj.transport.kex;
 
-import com.hierynomus.sshj.test.BaseAlgorithmTest;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.Config;
 import net.schmizz.sshj.DefaultConfig;
+import net.schmizz.sshj.SSHClient;
 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 net.schmizz.sshj.transport.random.JCERandom;
+import net.schmizz.sshj.transport.random.SingletonRandomFactory;
 import org.apache.sshd.common.kex.BuiltinDHFactories;
 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;
-import org.junit.runner.RunWith;
-import org.junit.runners.Parameterized;
+import org.junit.jupiter.api.DynamicTest;
+import org.junit.jupiter.api.TestFactory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.stream.Stream;
 
-@RunWith(Parameterized.class)
-public class KeyExchangeTest extends BaseAlgorithmTest {
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class KeyExchangeTest {
+    private final Logger logger = LoggerFactory.getLogger(this.getClass());
 
-    @SuppressWarnings("deprecation")
-    @Parameterized.Parameters(name = "algorithm={0}")
     public static Collection<Object[]> getParameters() {
-        return Arrays.asList(new Object[][]{
-                {DHGEXServer.newFactory(BuiltinDHFactories.dhgex), new DHGexSHA1.Factory()},
-                {DHGEXServer.newFactory(BuiltinDHFactories.dhgex256), new DHGexSHA256.Factory()},
-                {DHGServer.newFactory(BuiltinDHFactories.ecdhp256), new ECDHNistP.Factory256()},
-                {DHGServer.newFactory(BuiltinDHFactories.ecdhp384), new ECDHNistP.Factory384()},
-                {DHGServer.newFactory(BuiltinDHFactories.ecdhp521), new ECDHNistP.Factory521()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg1), DHGroups.Group1SHA1()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg14), DHGroups.Group14SHA1()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg14_256), DHGroups.Group14SHA256()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg15_512), DHGroups.Group15SHA512()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg16_512), DHGroups.Group16SHA512()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg17_512), DHGroups.Group17SHA512()},
-                {DHGServer.newFactory(BuiltinDHFactories.dhg18_512), DHGroups.Group18SHA512()},
+        return Arrays.asList(new Object[][] {
+                { DHGEXServer.newFactory(BuiltinDHFactories.dhgex), new DHGexSHA1.Factory() },
+                { DHGEXServer.newFactory(BuiltinDHFactories.dhgex256), new DHGexSHA256.Factory() },
+                { DHGServer.newFactory(BuiltinDHFactories.ecdhp256), new ECDHNistP.Factory256() },
+                { DHGServer.newFactory(BuiltinDHFactories.ecdhp384), new ECDHNistP.Factory384() },
+                { DHGServer.newFactory(BuiltinDHFactories.ecdhp521), new ECDHNistP.Factory521() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg1), DHGroups.Group1SHA1() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg14), DHGroups.Group14SHA1() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg14_256), DHGroups.Group14SHA256() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg15_512), DHGroups.Group15SHA512() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg16_512), DHGroups.Group16SHA512() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg17_512), DHGroups.Group17SHA512() },
+                { DHGServer.newFactory(BuiltinDHFactories.dhg18_512), DHGroups.Group18SHA512() },
         });
     }
 
-    private final Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory;
-    private final KeyExchangeFactory serverFactory;
+    @TestFactory
+    public Stream<DynamicTest> keyExchangeTests() {
+        return getParameters().stream().map(params -> {
+            KeyExchangeFactory serverFactory = (KeyExchangeFactory) params[0];
+            Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory = (Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange>) params[1];
+            SingletonRandomFactory randomFactory = new SingletonRandomFactory(new JCERandom.Factory());
 
-    public KeyExchangeTest(KeyExchangeFactory serverFactory, Factory.Named<net.schmizz.sshj.transport.kex.KeyExchange> clientFactory) {
-        this.clientFactory = clientFactory;
-        this.serverFactory = serverFactory;
-    }
+            return DynamicTest.dynamicTest(serverFactory.getName() + " <-> " + clientFactory.getName(), () -> {
+                try (SshServerExtension fixture = new SshServerExtension(false)) {
+                    for (int i = 0; i < 10; i++) {
+                        logger.info("--> Attempt {}", i);
+                        fixture.getServer().setKeyExchangeFactories(Collections.singletonList(serverFactory));
+                        fixture.start();
+                        Config config = new DefaultConfig();
+                        config.setRandomFactory(randomFactory);
+                        config.setKeyExchangeFactories(Collections.singletonList(clientFactory));
 
-    @Override
-    protected Config getClientConfig(DefaultConfig config) {
-        config.setKeyExchangeFactories(Collections.singletonList(clientFactory));
-        return config;
-    }
-
-    @Override
-    protected void configureServer(SshServer server) {
-        server.setKeyExchangeFactories(Collections.singletonList(serverFactory));
+                        SSHClient sshClient = fixture.connectClient(fixture.setupClient(config));
+                        assertThat("should be connected", sshClient.isConnected());
+                        sshClient.disconnect();
+                        fixture.stopClient();
+                    };
+                };
+            });
+        });
     }
 }
diff --git a/src/test/java/com/hierynomus/sshj/userauth/GssApiTest.java b/src/test/java/com/hierynomus/sshj/userauth/GssApiTest.java
index 20cf906f..2affa493 100644
--- a/src/test/java/com/hierynomus/sshj/userauth/GssApiTest.java
+++ b/src/test/java/com/hierynomus/sshj/userauth/GssApiTest.java
@@ -15,24 +15,24 @@
  */
 package com.hierynomus.sshj.userauth;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.userauth.method.AuthGssApiWithMic;
 import net.schmizz.sshj.util.gss.BogusGSSManager;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import javax.security.auth.login.AppConfigurationEntry;
 import javax.security.auth.login.Configuration;
 import javax.security.auth.login.LoginContext;
 import java.util.Collections;
 
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class GssApiTest {
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
     private static final String LOGIN_CONTEXT_NAME = "TestLoginContext";
 
diff --git a/src/test/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCryptTest.java b/src/test/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCryptTest.java
index 50bb3c7d..aa14a309 100644
--- a/src/test/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCryptTest.java
+++ b/src/test/java/com/hierynomus/sshj/userauth/keyprovider/bcrypt/BCryptTest.java
@@ -14,11 +14,11 @@
 
 package com.hierynomus.sshj.userauth.keyprovider.bcrypt;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.util.Arrays;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  * JUnit unit tests for BCrypt routines
diff --git a/src/test/java/com/hierynomus/sshj/userauth/method/AuthKeyboardInteractiveTest.java b/src/test/java/com/hierynomus/sshj/userauth/method/AuthKeyboardInteractiveTest.java
index 305afd9e..3bcaa267 100644
--- a/src/test/java/com/hierynomus/sshj/userauth/method/AuthKeyboardInteractiveTest.java
+++ b/src/test/java/com/hierynomus/sshj/userauth/method/AuthKeyboardInteractiveTest.java
@@ -15,16 +15,16 @@
  */
 package com.hierynomus.sshj.userauth.method;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 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.server.auth.keyboard.UserAuthKeyboardInteractiveFactory;
 import org.apache.sshd.server.auth.password.AcceptAllPasswordAuthenticator;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -34,10 +34,10 @@ import java.util.List;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 public class AuthKeyboardInteractiveTest {
-    @Rule
-    public SshFixture fixture = new SshFixture(false);
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension(false);
 
-    @Before
+    @BeforeEach
     public void setKeyboardInteractiveAuthenticator() throws IOException {
         fixture.getServer().setUserAuthFactories(Collections.singletonList(new UserAuthKeyboardInteractiveFactory()));
         fixture.getServer().setPasswordAuthenticator(AcceptAllPasswordAuthenticator.INSTANCE);
diff --git a/src/test/java/com/hierynomus/sshj/userauth/method/AuthPasswordTest.java b/src/test/java/com/hierynomus/sshj/userauth/method/AuthPasswordTest.java
index 49a900d1..ad5209db 100644
--- a/src/test/java/com/hierynomus/sshj/userauth/method/AuthPasswordTest.java
+++ b/src/test/java/com/hierynomus/sshj/userauth/method/AuthPasswordTest.java
@@ -15,7 +15,7 @@
  */
 package com.hierynomus.sshj.userauth.method;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.userauth.UserAuthException;
 import net.schmizz.sshj.userauth.password.PasswordFinder;
@@ -25,23 +25,23 @@ import org.apache.sshd.server.auth.password.PasswordAuthenticator;
 import org.apache.sshd.server.auth.password.PasswordChangeRequiredException;
 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.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Stack;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class AuthPasswordTest {
 
-    @Rule
-    public SshFixture fixture = new SshFixture(false);
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension(false);
 
-    @Before
+    @BeforeEach
     public void setPasswordAuthenticator() throws IOException {
         fixture.getServer().setUserAuthFactories(Collections.singletonList(new UserAuthPasswordFactory()));
         fixture.getServer().setPasswordAuthenticator(new PasswordAuthenticator() {
diff --git a/src/test/java/com/hierynomus/sshj/userauth/method/PasswordResponseProviderTest.java b/src/test/java/com/hierynomus/sshj/userauth/method/PasswordResponseProviderTest.java
index d976b69c..6389cf4d 100644
--- a/src/test/java/com/hierynomus/sshj/userauth/method/PasswordResponseProviderTest.java
+++ b/src/test/java/com/hierynomus/sshj/userauth/method/PasswordResponseProviderTest.java
@@ -19,13 +19,13 @@ import net.schmizz.sshj.userauth.method.PasswordResponseProvider;
 import net.schmizz.sshj.userauth.password.AccountResource;
 import net.schmizz.sshj.userauth.password.PasswordFinder;
 import net.schmizz.sshj.userauth.password.Resource;
-import org.jetbrains.annotations.NotNull;
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.util.Collections;
 import java.util.regex.Pattern;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 public class PasswordResponseProviderTest {
     private static final char[] PASSWORD = "the_password".toCharArray();
     private static final AccountResource ACCOUNT_RESOURCE = new AccountResource("user", "host");
@@ -64,13 +64,13 @@ public class PasswordResponseProviderTest {
 
     @Test
     public void shouldPassRetry() {
-        Assert.assertFalse(createDefaultResponseProvider(false).shouldRetry());
-        Assert.assertTrue(createDefaultResponseProvider(true).shouldRetry());
+        assertFalse(createDefaultResponseProvider(false).shouldRetry());
+        assertTrue(createDefaultResponseProvider(true).shouldRetry());
     }
 
     @Test
     public void shouldHaveNoSubmethods() {
-        Assert.assertEquals(createDefaultResponseProvider(true).getSubmethods(), Collections.emptyList());
+        assertEquals(createDefaultResponseProvider(true).getSubmethods(), Collections.emptyList());
     }
 
     @Test
@@ -91,10 +91,9 @@ public class PasswordResponseProviderTest {
     }
 
     private static void checkPrompt(PasswordResponseProvider responseProvider, String prompt, char[] expected) {
-        Assert.assertArrayEquals("Prompt '" + prompt + "'", expected, responseProvider.getResponse(prompt, false));
+        assertArrayEquals(expected, responseProvider.getResponse(prompt, false), "Prompt '" + prompt + "'");
     }
 
-    @NotNull
     private static PasswordResponseProvider createDefaultResponseProvider(final boolean shouldRetry) {
         PasswordFinder passwordFinder = new TestPasswordFinder(shouldRetry);
         PasswordResponseProvider responseProvider = new PasswordResponseProvider(passwordFinder);
@@ -111,13 +110,13 @@ public class PasswordResponseProviderTest {
 
         @Override
         public char[] reqPassword(Resource<?> resource) {
-            Assert.assertEquals(resource, ACCOUNT_RESOURCE);
+            assertEquals(resource, ACCOUNT_RESOURCE);
             return PASSWORD;
         }
 
         @Override
         public boolean shouldRetry(Resource<?> resource) {
-            Assert.assertEquals(resource, ACCOUNT_RESOURCE);
+            assertEquals(resource, ACCOUNT_RESOURCE);
             return shouldRetry;
         }
     }
diff --git a/src/test/java/net/schmizz/sshj/LoadsOfConnects.java b/src/test/java/net/schmizz/sshj/LoadsOfConnects.java
index 0bab8b5a..0602b39c 100644
--- a/src/test/java/net/schmizz/sshj/LoadsOfConnects.java
+++ b/src/test/java/net/schmizz/sshj/LoadsOfConnects.java
@@ -15,21 +15,20 @@
  */
 package net.schmizz.sshj;
 
-import com.hierynomus.sshj.test.SshFixture;
-import org.junit.Test;
+import com.hierynomus.sshj.test.SshServerExtension;
+import net.schmizz.sshj.common.IOUtils;
+import net.schmizz.sshj.connection.channel.direct.Session;
+import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import net.schmizz.sshj.common.IOUtils;
-import net.schmizz.sshj.connection.channel.direct.Session;
-
-import static org.junit.Assert.fail;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class LoadsOfConnects {
 
     protected final Logger log = LoggerFactory.getLogger(getClass());
 
-    private final SshFixture fixture = new SshFixture();
+    private final SshServerExtension fixture = new SshServerExtension();
 
     @Test
     public void loadsOfConnects() {
@@ -40,7 +39,7 @@ public class LoadsOfConnects {
                 SSHClient client = fixture.setupConnectedDefaultClient();
                 client.authPassword("test", "test");
                 Session s = client.startSession();
-                Session.Command c = s.exec(SshFixture.listCommand);
+                Session.Command c = s.exec(SshServerExtension.listCommand);
                 IOUtils.readFully(c.getErrorStream());
                 IOUtils.readFully(c.getInputStream());
                 c.close();
diff --git a/src/test/java/net/schmizz/sshj/SmokeTest.java b/src/test/java/net/schmizz/sshj/SmokeTest.java
index 468a1ec6..6a5e417e 100644
--- a/src/test/java/net/schmizz/sshj/SmokeTest.java
+++ b/src/test/java/net/schmizz/sshj/SmokeTest.java
@@ -15,30 +15,30 @@
  */
 package net.schmizz.sshj;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import net.schmizz.sshj.transport.TransportException;
 import net.schmizz.sshj.userauth.UserAuthException;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
 
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /* Kinda basic right now */
 public class SmokeTest {
 
-    private final SshFixture fixture = new SshFixture();
+    private final SshServerExtension fixture = new SshServerExtension();
 
-    @Before
+    @BeforeEach
     public void setUp()
             throws IOException {
         fixture.start();
         fixture.setupConnectedDefaultClient();
     }
 
-    @After
+    @AfterEach
     public void tearDown()
             throws IOException, InterruptedException {
         fixture.stopClient();
@@ -58,4 +58,4 @@ public class SmokeTest {
         assertTrue(fixture.getClient().isAuthenticated());
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/test/java/net/schmizz/sshj/common/BufferTest.java b/src/test/java/net/schmizz/sshj/common/BufferTest.java
index 15acb219..692f4dec 100644
--- a/src/test/java/net/schmizz/sshj/common/BufferTest.java
+++ b/src/test/java/net/schmizz/sshj/common/BufferTest.java
@@ -17,11 +17,11 @@ package net.schmizz.sshj.common;
 
 import net.schmizz.sshj.common.Buffer.BufferException;
 import net.schmizz.sshj.common.Buffer.PlainBuffer;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.math.BigInteger;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class BufferTest {
 
@@ -162,7 +162,7 @@ public class BufferTest {
         for (long value : values) {
             byte[] bytesBigInt = new PlainBuffer().putUInt64(BigInteger.valueOf(value)).getCompactData();
             byte[] bytesLong = new PlainBuffer().putUInt64(value).getCompactData();
-            assertArrayEquals("Value: " + value, bytesLong, bytesBigInt);
+            assertArrayEquals(bytesLong, bytesBigInt, "Value: " + value);
         }
     }
 
diff --git a/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java b/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
index 0b8ed95f..67cdb4cc 100644
--- a/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
+++ b/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
@@ -15,13 +15,13 @@
  */
 package net.schmizz.sshj.common;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.*;
 import java.util.Random;
 
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.mockito.Mockito.*;
 
 
diff --git a/src/test/java/net/schmizz/sshj/connection/channel/SocketStreamCopyMonitorTest.java b/src/test/java/net/schmizz/sshj/connection/channel/SocketStreamCopyMonitorTest.java
index bca7952f..56d51bb8 100644
--- a/src/test/java/net/schmizz/sshj/connection/channel/SocketStreamCopyMonitorTest.java
+++ b/src/test/java/net/schmizz/sshj/connection/channel/SocketStreamCopyMonitorTest.java
@@ -18,7 +18,7 @@ package net.schmizz.sshj.connection.channel;
 import net.schmizz.concurrent.Event;
 import net.schmizz.concurrent.ExceptionChainer;
 import net.schmizz.sshj.common.LoggerFactory;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
 import java.net.Socket;
@@ -86,4 +86,4 @@ public class SocketStreamCopyMonitorTest {
             }
         }, LoggerFactory.DEFAULT);
     }
-}
\ No newline at end of file
+}
diff --git a/src/test/java/net/schmizz/sshj/connection/channel/direct/ParametersTest.java b/src/test/java/net/schmizz/sshj/connection/channel/direct/ParametersTest.java
index f4d34535..c86a9e39 100644
--- a/src/test/java/net/schmizz/sshj/connection/channel/direct/ParametersTest.java
+++ b/src/test/java/net/schmizz/sshj/connection/channel/direct/ParametersTest.java
@@ -15,12 +15,12 @@
  */
 package net.schmizz.sshj.connection.channel.direct;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.util.HashMap;
 import java.util.Map;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class ParametersTest {
 
diff --git a/src/test/java/net/schmizz/sshj/keyprovider/KeyProviderUtilTest.java b/src/test/java/net/schmizz/sshj/keyprovider/KeyProviderUtilTest.java
index 2db7e414..f9ef3055 100644
--- a/src/test/java/net/schmizz/sshj/keyprovider/KeyProviderUtilTest.java
+++ b/src/test/java/net/schmizz/sshj/keyprovider/KeyProviderUtilTest.java
@@ -17,12 +17,12 @@ package net.schmizz.sshj.keyprovider;
 
 import net.schmizz.sshj.userauth.keyprovider.KeyFormat;
 import net.schmizz.sshj.userauth.keyprovider.KeyProviderUtil;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.File;
 import java.io.IOException;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class KeyProviderUtilTest {
 
diff --git a/src/test/java/net/schmizz/sshj/keyprovider/OpenSSHKeyFileTest.java b/src/test/java/net/schmizz/sshj/keyprovider/OpenSSHKeyFileTest.java
index 3ebfe164..1320fca2 100644
--- a/src/test/java/net/schmizz/sshj/keyprovider/OpenSSHKeyFileTest.java
+++ b/src/test/java/net/schmizz/sshj/keyprovider/OpenSSHKeyFileTest.java
@@ -26,20 +26,11 @@ import net.schmizz.sshj.userauth.password.PasswordFinder;
 import net.schmizz.sshj.userauth.password.PasswordUtils;
 import net.schmizz.sshj.userauth.password.Resource;
 import net.schmizz.sshj.util.KeyUtil;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.OutputStreamWriter;
-import java.io.StringReader;
+import java.io.*;
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
 import java.security.PrivateKey;
@@ -54,7 +45,7 @@ import java.util.*;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class OpenSSHKeyFileTest {
 
@@ -141,8 +132,8 @@ public class OpenSSHKeyFileTest {
         }
     };
 
-    @Rule
-    public TemporaryFolder temporaryFolder = new TemporaryFolder();
+    @TempDir
+    public File temporaryFolder;
 
     @Test
     public void blankingOut()
@@ -254,8 +245,9 @@ public class OpenSSHKeyFileTest {
         checkOpenSSHKeyV1("src/test/resources/keytypes/ed25519_aes128cbc.pem", "sshjtest", true);
     }
 
-    @Test(expected = KeyDecryptionFailedException.class)
+    @Test
     public void shouldFailOnIncorrectPassphraseAfterRetries() throws IOException {
+        assertThrows(KeyDecryptionFailedException.class, () -> {
         OpenSSHKeyV1KeyFile keyFile = new OpenSSHKeyV1KeyFile();
         keyFile.init(new File("src/test/resources/keytypes/ed25519_aes256cbc.pem"), new PasswordFinder() {
             private int reqCounter = 0;
@@ -272,6 +264,8 @@ public class OpenSSHKeyFileTest {
             }
         });
         keyFile.getPrivate();
+
+        });
     }
 
     @Test
@@ -295,20 +289,20 @@ public class OpenSSHKeyFileTest {
         assertTrue(privateKey instanceof RSAPrivateCrtKey);
         final RSAPrivateCrtKey rsaPrivateCrtKey = (RSAPrivateCrtKey) privateKey;
 
-        assertEquals("Public Key Exponent not matched", rsaPublicKey.getPublicExponent(), rsaPrivateCrtKey.getPublicExponent());
-        assertEquals("Public Key Modulus not matched", rsaPublicKey.getModulus(), rsaPrivateCrtKey.getModulus());
+        assertEquals(rsaPublicKey.getPublicExponent(), rsaPrivateCrtKey.getPublicExponent(), "Public Key Exponent not matched");
+        assertEquals(rsaPublicKey.getModulus(), rsaPrivateCrtKey.getModulus(), "Public Key Modulus not matched");
 
         final BigInteger privateExponent = rsaPrivateCrtKey.getPrivateExponent();
 
         final BigInteger expectedPrimeExponentP = privateExponent.mod(rsaPrivateCrtKey.getPrimeP().subtract(BigInteger.ONE));
-        assertEquals("Prime Exponent P not matched", expectedPrimeExponentP, rsaPrivateCrtKey.getPrimeExponentP());
+        assertEquals(expectedPrimeExponentP, rsaPrivateCrtKey.getPrimeExponentP(), "Prime Exponent P not matched");
 
         final BigInteger expectedPrimeExponentQ = privateExponent.mod(rsaPrivateCrtKey.getPrimeQ().subtract(BigInteger.ONE));
-        assertEquals("Prime Exponent Q not matched", expectedPrimeExponentQ, rsaPrivateCrtKey.getPrimeExponentQ());
+        assertEquals(expectedPrimeExponentQ, rsaPrivateCrtKey.getPrimeExponentQ(), "Prime Exponent Q not matched");
 
 
         final BigInteger expectedCoefficient = rsaPrivateCrtKey.getPrimeQ().modInverse(rsaPrivateCrtKey.getPrimeP());
-        assertEquals("Prime CRT Coefficient not matched", expectedCoefficient, rsaPrivateCrtKey.getCrtCoefficient());
+        assertEquals(expectedCoefficient, rsaPrivateCrtKey.getCrtCoefficient(), "Prime CRT Coefficient not matched");
     }
 
     @Test
@@ -411,7 +405,9 @@ public class OpenSSHKeyFileTest {
     public void notTrimmedKeys() throws IOException {
         File initialPrivateKey = new File("src/test/resources/id_rsa");
         File initialPublicKey = new File("src/test/resources/id_rsa.pub");
-        File corruptedPrivateKey = new File(temporaryFolder.newFolder(), "id_rsa");
+        File folder = new File(temporaryFolder, "keys");
+        assertTrue(folder.mkdir());
+        File corruptedPrivateKey = new File(folder, "id_rsa");
         File corruptedPublicKey = new File(corruptedPrivateKey.getParent(), "id_rsa.pub");
 
         BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(initialPrivateKey)));
@@ -449,10 +445,10 @@ public class OpenSSHKeyFileTest {
         FileKeyProvider keyProvider = new OpenSSHKeyV1KeyFile();
         keyProvider.init(new StringReader(""));
 
-        assertThrows("This key is not in 'openssh-key-v1' format", IOException.class, keyProvider::getPrivate);
+        assertThrows(IOException.class, keyProvider::getPrivate, "This key is not in 'openssh-key-v1' format");
     }
 
-    @Before
+    @BeforeEach
     public void checkBCRegistration() {
         if (!SecurityUtils.isBouncyCastleRegistered()) {
             throw new AssertionError("bouncy castle needed");
diff --git a/src/test/java/net/schmizz/sshj/keyprovider/PKCS8KeyFileTest.java b/src/test/java/net/schmizz/sshj/keyprovider/PKCS8KeyFileTest.java
index 7a54d3ca..48a03de1 100644
--- a/src/test/java/net/schmizz/sshj/keyprovider/PKCS8KeyFileTest.java
+++ b/src/test/java/net/schmizz/sshj/keyprovider/PKCS8KeyFileTest.java
@@ -23,15 +23,15 @@ import net.schmizz.sshj.userauth.password.PasswordFinder;
 import net.schmizz.sshj.userauth.password.PasswordUtils;
 import net.schmizz.sshj.userauth.password.Resource;
 import net.schmizz.sshj.util.KeyUtil;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.File;
 import java.io.IOException;
 import java.net.URL;
 import java.security.GeneralSecurityException;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class PKCS8KeyFileTest {
 
diff --git a/src/test/java/net/schmizz/sshj/keyprovider/PuTTYKeyFileTest.java b/src/test/java/net/schmizz/sshj/keyprovider/PuTTYKeyFileTest.java
index a80ce653..cfed5537 100644
--- a/src/test/java/net/schmizz/sshj/keyprovider/PuTTYKeyFileTest.java
+++ b/src/test/java/net/schmizz/sshj/keyprovider/PuTTYKeyFileTest.java
@@ -19,7 +19,7 @@ import com.hierynomus.sshj.userauth.keyprovider.OpenSSHKeyV1KeyFile;
 import net.schmizz.sshj.userauth.keyprovider.PKCS8KeyFile;
 import net.schmizz.sshj.userauth.keyprovider.PuTTYKeyFile;
 import net.schmizz.sshj.util.UnitTestPasswordFinder;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.File;
 import java.io.IOException;
@@ -27,9 +27,7 @@ import java.io.StringReader;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class PuTTYKeyFileTest {
 
@@ -530,13 +528,15 @@ public class PuTTYKeyFileTest {
         assertNotNull(key.getPublic());
     }
 
-    @Test(expected = IOException.class)
+    @Test
     public void testWrongPassphraseRsa() throws Exception {
-        PuTTYKeyFile key = new PuTTYKeyFile();
-        key.init(new StringReader(ppk1024_passphrase),
-                new UnitTestPasswordFinder("egfsdgdfgsdfsdfasfs523534dgdsgdfa"));
-        assertNotNull(key.getPublic());
-        assertNull(key.getPrivate());
+        assertThrows(IOException.class, () -> {
+            PuTTYKeyFile key = new PuTTYKeyFile();
+            key.init(new StringReader(ppk1024_passphrase),
+                    new UnitTestPasswordFinder("egfsdgdfgsdfsdfasfs523534dgdsgdfa"));
+            assertNotNull(key.getPublic());
+            assertNull(key.getPrivate());
+        });
     }
 
     @Test
@@ -548,12 +548,14 @@ public class PuTTYKeyFileTest {
         assertNotNull(key.getPublic());
     }
 
-    @Test(expected = IOException.class)
+    @Test
     public void testWrongPassphraseDsa() throws Exception {
-        PuTTYKeyFile key = new PuTTYKeyFile();
-        key.init(new StringReader(ppkdsa_passphrase),
-                new UnitTestPasswordFinder("egfsdgdfgsdfsdfasfs523534dgdsgdfa"));
-        assertNotNull(key.getPublic());
-        assertNull(key.getPrivate());
+        assertThrows(IOException.class, () -> {
+            PuTTYKeyFile key = new PuTTYKeyFile();
+            key.init(new StringReader(ppkdsa_passphrase),
+                    new UnitTestPasswordFinder("egfsdgdfgsdfsdfasfs523534dgdsgdfa"));
+            assertNotNull(key.getPublic());
+            assertNull(key.getPrivate());
+        });
     }
 }
diff --git a/src/test/java/net/schmizz/sshj/sftp/FileModeTest.java b/src/test/java/net/schmizz/sshj/sftp/FileModeTest.java
index 861a9f41..7bf03338 100644
--- a/src/test/java/net/schmizz/sshj/sftp/FileModeTest.java
+++ b/src/test/java/net/schmizz/sshj/sftp/FileModeTest.java
@@ -15,10 +15,10 @@
  */
 package net.schmizz.sshj.sftp;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.junit.Assert.assertThat;
 
 public class FileModeTest {
 
diff --git a/src/test/java/net/schmizz/sshj/sftp/PacketReaderTest.java b/src/test/java/net/schmizz/sshj/sftp/PacketReaderTest.java
index 63b12819..3d666e76 100644
--- a/src/test/java/net/schmizz/sshj/sftp/PacketReaderTest.java
+++ b/src/test/java/net/schmizz/sshj/sftp/PacketReaderTest.java
@@ -18,8 +18,8 @@ package net.schmizz.sshj.sftp;
 import net.schmizz.sshj.common.LoggerFactory;
 import net.schmizz.sshj.common.SSHException;
 import net.schmizz.sshj.connection.channel.direct.Session.Subsystem;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 import java.io.DataOutputStream;
@@ -27,14 +27,14 @@ import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
 import java.util.Arrays;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
 public class PacketReaderTest {
 
     private DataOutputStream dataout;
     private PacketReader reader;
 
-    @Before
+    @BeforeEach
     public void setUp() throws Exception {
         PipedOutputStream pipedout = new PipedOutputStream();
         PipedInputStream pipedin = new PipedInputStream(pipedout);
@@ -59,7 +59,7 @@ public class PacketReaderTest {
 
         SFTPPacket<Response> packet = reader.readPacket();
         assertEquals(packet.available(), 10);
-        assertTrue("actual=" + Arrays.toString(packet.array()), Arrays.equals(bytes, subArray(packet.array(), 0, 10)));
+        assertTrue(Arrays.equals(bytes, subArray(packet.array(), 0, 10)), "actual=" + Arrays.toString(packet.array()));
     }
 
     @Test
diff --git a/src/test/java/net/schmizz/sshj/sftp/SFTPClientTest.java b/src/test/java/net/schmizz/sshj/sftp/SFTPClientTest.java
index 7e932558..3f48ef9f 100644
--- a/src/test/java/net/schmizz/sshj/sftp/SFTPClientTest.java
+++ b/src/test/java/net/schmizz/sshj/sftp/SFTPClientTest.java
@@ -16,8 +16,8 @@
 package net.schmizz.sshj.sftp;
 
 import net.schmizz.sshj.common.LoggerFactory;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
 
@@ -27,7 +27,7 @@ import static org.mockito.Mockito.*;
 public class SFTPClientTest {
     private final SFTPEngine sftpEngine = mock(SFTPEngine.class);
 
-    @Before
+    @BeforeEach
     public void setPathHelper() throws Exception {
         PathHelper helper = new PathHelper(new PathHelper.Canonicalizer() {
             /**
@@ -48,7 +48,7 @@ public class SFTPClientTest {
         when(sftpEngine.getLoggerFactory()).thenReturn(LoggerFactory.DEFAULT);
     }
 
-    @Before
+    @BeforeEach
     public void setRemoteWorkingDirectory() throws IOException {
         FileAttributes isADirectory = new FileAttributes.Builder().withType(FileMode.Type.DIRECTORY).build();
         when(sftpEngine.stat("/workingdirectory")).thenReturn(isADirectory);
diff --git a/src/test/java/net/schmizz/sshj/sftp/SFTPFileTransferTest.java b/src/test/java/net/schmizz/sshj/sftp/SFTPFileTransferTest.java
index 0c467d24..44b61627 100644
--- a/src/test/java/net/schmizz/sshj/sftp/SFTPFileTransferTest.java
+++ b/src/test/java/net/schmizz/sshj/sftp/SFTPFileTransferTest.java
@@ -15,71 +15,74 @@
  */
 package net.schmizz.sshj.sftp;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import com.hierynomus.sshj.test.util.FileUtil;
-import java.io.File;
-import java.io.IOException;
 import net.schmizz.sshj.SSHClient;
 import net.schmizz.sshj.common.StreamCopier;
 import net.schmizz.sshj.xfer.TransferListener;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class SFTPFileTransferTest {
-    
+
     public static final String TARGET_FILE_NAME = "target.txt";
-    
+
     File targetDir;
     File targetFile;
     File sourceFile;
-    
+
     File partialFile;
-    
+
     SSHClient sshClient;
     SFTPFileTransfer xfer;
     ByteCounter listener;
-    
-    @Rule
-    public SshFixture fixture = new SshFixture();
 
-    @Rule
-    public TemporaryFolder tempFolder = new TemporaryFolder();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Before
+    @TempDir
+    public File tempFolder;
+
+    @BeforeEach
     public void init() throws IOException {
-        targetDir   = tempFolder.newFolder();
+        targetDir   = new File(tempFolder, "targetDir");
+        assertTrue(targetDir.mkdir());
         targetFile  = new File(targetDir, TARGET_FILE_NAME);
         sourceFile  = new File("src/test/resources/files/test_file_full.txt");
-        
+
         partialFile = new File("src/test/resources/files/test_file_partial.txt");
-        
+
         sshClient   = fixture.setupConnectedDefaultClient();
         sshClient.authPassword("test", "test");
         xfer = sshClient.newSFTPClient().getFileTransfer();
         xfer.setTransferListener(listener = new ByteCounter());
     }
-    
-    @After
+
+    @AfterEach
     public void cleanup() {
         if (targetFile.exists()) {
             targetFile.delete();
         }
-        
+
         if (targetDir.exists()) {
             targetDir.delete();
         }
     }
-    
+
     private void performDownload(long byteOffset) throws IOException {
         assertTrue(listener.getBytesTransferred() == 0);
-        
+
         long expectedBytes = 0;
-        
+
         // Using the resume param this way to call the different entry points into the FileTransfer interface
         if (byteOffset > 0) {
             expectedBytes = sourceFile.length() - targetFile.length(); // only the difference between what is there and what should be
@@ -88,16 +91,16 @@ public class SFTPFileTransferTest {
             expectedBytes = sourceFile.length(); // the entire source file should be transferred
             xfer.download(sourceFile.getAbsolutePath(), targetFile.getAbsolutePath());
         }
-        
+
         assertTrue(FileUtil.compareFileContents(sourceFile, targetFile));
         assertTrue(listener.getBytesTransferred() == expectedBytes);
     }
-    
+
     private void performUpload(long byteOffset) throws IOException {
         assertTrue(listener.getBytesTransferred() == 0);
-        
+
         long expectedBytes = 0;
-        
+
         // Using the resume param this way to call the different entry points into the FileTransfer interface
         if (byteOffset > 0) {
             expectedBytes = sourceFile.length() - targetFile.length(); // only the difference between what is there and what should be
@@ -109,64 +112,64 @@ public class SFTPFileTransferTest {
         assertTrue(FileUtil.compareFileContents(sourceFile, targetFile));
         assertTrue(listener.getBytesTransferred() == expectedBytes);
     }
-    
+
     @Test
     public void testDownload() throws IOException {
         performDownload(0);
     }
-    
+
     @Test
     public void testDownloadResumePartial() throws IOException {
         FileUtil.writeToFile(targetFile, FileUtil.readFromFile(partialFile));
         assertFalse(FileUtil.compareFileContents(sourceFile, targetFile));
         performDownload(targetFile.length());
     }
-    
+
     @Test
     public void testDownloadResumeNothing() throws IOException {
         assertFalse(targetFile.exists());
         performDownload(targetFile.length());
     }
-    
+
     @Test
     public void testDownloadResumePreviouslyCompleted() throws IOException {
         FileUtil.writeToFile(targetFile, FileUtil.readFromFile(sourceFile));
         assertTrue(FileUtil.compareFileContents(sourceFile, targetFile));
         performDownload(targetFile.length());
     }
-    
+
     @Test
     public void testUpload() throws IOException {
         performUpload(0);
     }
-    
+
     @Test
     public void testUploadResumePartial() throws IOException {
         FileUtil.writeToFile(targetFile, FileUtil.readFromFile(partialFile));
         assertFalse(FileUtil.compareFileContents(sourceFile, targetFile));
         performUpload(targetFile.length());
     }
-    
+
     @Test
     public void testUploadResumeNothing() throws IOException {
         assertFalse(targetFile.exists());
         performUpload(targetFile.length());
     }
-    
+
     @Test
     public void testUploadResumePreviouslyCompleted() throws IOException {
         FileUtil.writeToFile(targetFile, FileUtil.readFromFile(sourceFile));
         assertTrue(FileUtil.compareFileContents(sourceFile, targetFile));
         performUpload(targetFile.length());
     }
-    
+
     public class ByteCounter implements TransferListener, StreamCopier.Listener {
         long bytesTransferred;
 
         public long getBytesTransferred() {
             return bytesTransferred;
         }
-        
+
         @Override
         public TransferListener directory(String name) {
             return this;
diff --git a/src/test/java/net/schmizz/sshj/signature/SignatureDSATest.java b/src/test/java/net/schmizz/sshj/signature/SignatureDSATest.java
index 37c7bfd4..758dcdba 100644
--- a/src/test/java/net/schmizz/sshj/signature/SignatureDSATest.java
+++ b/src/test/java/net/schmizz/sshj/signature/SignatureDSATest.java
@@ -15,6 +15,12 @@
  */
 package net.schmizz.sshj.signature;
 
+import com.hierynomus.sshj.common.KeyAlgorithm;
+import net.schmizz.sshj.common.Buffer;
+import net.schmizz.sshj.common.IOUtils;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
 import java.math.BigInteger;
 import java.security.KeyFactory;
 import java.security.NoSuchAlgorithmException;
@@ -22,19 +28,13 @@ import java.security.spec.DSAPrivateKeySpec;
 import java.security.spec.DSAPublicKeySpec;
 import java.util.Arrays;
 
-import com.hierynomus.sshj.common.KeyAlgorithm;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-import net.schmizz.sshj.common.Buffer;
-import net.schmizz.sshj.common.IOUtils;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class SignatureDSATest {
 
     private KeyFactory keyFactory;
 
-    @Before
+    @BeforeEach
     public void setUp() throws NoSuchAlgorithmException {
         keyFactory = KeyFactory.getInstance(KeyAlgorithm.DSA);
     }
@@ -61,9 +61,9 @@ public class SignatureDSATest {
         SignatureDSA signatureForVerifying = new SignatureDSA();
         signatureForVerifying.initVerify(keyFactory.generatePublic(new DSAPublicKeySpec(y, p, q, g)));
         signatureForVerifying.update(data);
-        Assert.assertTrue("Failed to verify signature: " + Arrays.toString(sigFull), signatureForVerifying.verify(sigFull));
+        assertTrue(signatureForVerifying.verify(sigFull), "Failed to verify signature: " + Arrays.toString(sigFull));
         signatureForVerifying.update(data);
-        Assert.assertTrue("Failed to verify signature: " + Arrays.toString(dataSig), signatureForVerifying.verify(dataSig));
+        assertTrue(signatureForVerifying.verify(dataSig), "Failed to verify signature: " + Arrays.toString(dataSig));
     }
 
 }
diff --git a/src/test/java/net/schmizz/sshj/signature/SignatureECDSATest.java b/src/test/java/net/schmizz/sshj/signature/SignatureECDSATest.java
index 2ed767c9..c0bb2f47 100644
--- a/src/test/java/net/schmizz/sshj/signature/SignatureECDSATest.java
+++ b/src/test/java/net/schmizz/sshj/signature/SignatureECDSATest.java
@@ -17,11 +17,12 @@ package net.schmizz.sshj.signature;
 
 import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.Buffer.BufferException;
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.security.PublicKey;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 public class SignatureECDSATest {
 
     @Test
@@ -35,10 +36,10 @@ public class SignatureECDSATest {
         Signature signature = new SignatureECDSA.Factory256().create();
         signature.initVerify(hostKey);
         signature.update(H, 0, H.length);
-        
-        Assert.assertTrue("ECDSA256 signature verifies", signature.verify(sig));
+
+        assertTrue(signature.verify(sig), "ECDSA256 signature verifies");
     }
-    
+
     @Test
     public void testECDSA384Verifies() throws BufferException {
         byte[] K_S = fromString("0, 0, 0, 19, 101, 99, 100, 115, 97, 45, 115, 104, 97, 50, 45, 110, 105, 115, 116, 112, 51, 56, 52, 0, 0, 0, 8, 110, 105, 115, 116, 112, 51, 56, 52, 0, 0, 0, 97, 4, 105, 52, -67, 89, 21, 53, -125, -26, -23, -125, 48, 119, -63, -66, 30, -46, -110, 21, 14, -96, -28, 40, -108, 60, 120, 110, 58, 30, -56, 37, 6, -17, -25, 109, 84, 67, -19, 0, -30, -33, 54, 94, -121, 49, 68, -66, 14, 6, 76, -51, 102, -123, 59, -24, -34, 79, -51, 64, -48, -45, 21, -42, -96, -123, -27, -21, 15, 56, -96, -12, 73, -10, 113, -20, -22, 38, 100, 38, -85, -113, 46, 36, 17, -30, 89, 40, 16, 104, 123, 50, 8, 122, 49, -41, -97, 95");
@@ -50,10 +51,10 @@ public class SignatureECDSATest {
         Signature signature = new SignatureECDSA.Factory384().create();
         signature.initVerify(hostKey);
         signature.update(H, 0, H.length);
-        
-        Assert.assertTrue("ECDSA384 signature verifies", signature.verify(sig));
+
+        assertTrue(signature.verify(sig), "ECDSA384 signature verifies");
     }
-    
+
     @Test
     public void testECDSA521Verifies() throws BufferException {
         byte[] K_S = fromString("0, 0, 0, 19, 101, 99, 100, 115, 97, 45, 115, 104, 97, 50, 45, 110, 105, 115, 116, 112, 53, 50, 49, 0, 0, 0, 8, 110, 105, 115, 116, 112, 53, 50, 49, 0, 0, 0, -123, 4, 1, -56, 55, 64, -73, -109, 95, 94, -107, -116, -46, -16, 119, -66, -68, 41, -103, -66, 102, -123, -69, 59, -8, 106, 72, 75, 7, 56, -79, 109, -88, 77, 12, -97, -109, -32, -60, 64, -75, -48, 50, -51, -68, -81, 75, 110, -7, -79, -32, -36, -73, -7, -65, -24, 40, -74, 58, 43, -26, -5, -55, 125, -32, -89, -54, -111, 0, 81, 37, -73, 60, 69, 107, -108, 115, 60, -61, 22, 6, -128, -69, -28, 122, -26, -37, -117, 121, -106, -126, 23, -90, 127, 73, -58, -113, -61, 105, 68, 116, 85, -115, -47, 90, 122, 109, -21, 127, 39, -75, -58, -109, 73, -82, -122, -11, -44, -87, 85, -100, -4, -123, -31, 126, -94, 127, 96, 9, -30, 70, -113, -42, 28");
@@ -65,17 +66,17 @@ public class SignatureECDSATest {
         Signature signature = new SignatureECDSA.Factory521().create();
         signature.initVerify(hostKey);
         signature.update(H, 0, H.length);
-        
-        Assert.assertTrue("ECDSA521 signature verifies", signature.verify(sig));
+
+        assertTrue(signature.verify(sig), "ECDSA521 signature verifies");
     }
 
     private byte[] fromString(String string) {
         String[] split = string.split(", ");
         byte[] res = new byte[split.length];
-        
+
         for (int i = 0; i < split.length; i++)
             res[i] = Byte.parseByte(split[i]);
-        
+
         return res;
     }
 }
diff --git a/src/test/java/net/schmizz/sshj/signature/SignatureRSATest.java b/src/test/java/net/schmizz/sshj/signature/SignatureRSATest.java
index f031c277..8839218e 100644
--- a/src/test/java/net/schmizz/sshj/signature/SignatureRSATest.java
+++ b/src/test/java/net/schmizz/sshj/signature/SignatureRSATest.java
@@ -16,11 +16,12 @@
 package net.schmizz.sshj.signature;
 
 import net.schmizz.sshj.common.Buffer;
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.security.PublicKey;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 
 public class SignatureRSATest {
 
@@ -36,7 +37,7 @@ public class SignatureRSATest {
         signature.initVerify(hostKey);
         signature.update(msg, 0, msg.length);
 
-        Assert.assertTrue("RSACERT signature verifies", signature.verify(sig));
+        assertTrue(signature.verify(sig), "RSACERT signature verifies");
     }
 
     private byte[] fromString(String string) {
diff --git a/src/test/java/net/schmizz/sshj/transport/DecoderDecryptGcmCipherSshPacketTest.java b/src/test/java/net/schmizz/sshj/transport/DecoderDecryptGcmCipherSshPacketTest.java
index 6387e4d4..c1c6a0f6 100644
--- a/src/test/java/net/schmizz/sshj/transport/DecoderDecryptGcmCipherSshPacketTest.java
+++ b/src/test/java/net/schmizz/sshj/transport/DecoderDecryptGcmCipherSshPacketTest.java
@@ -23,13 +23,13 @@ import net.schmizz.sshj.common.SSHException;
 import net.schmizz.sshj.common.SSHPacket;
 import net.schmizz.sshj.transport.cipher.Cipher;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.security.SecureRandom;
 import java.security.Security;
 
-import static org.junit.Assert.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.*;
 
@@ -47,7 +47,7 @@ public class DecoderDecryptGcmCipherSshPacketTest {
 
     private Decoder decoder;
 
-    @Before
+    @BeforeEach
     public void setUp() throws Exception {
         Security.addProvider(new BouncyCastleProvider());
         ClassLoader classLoader = DecoderDecryptGcmCipherSshPacketTest.class.getClassLoader();
diff --git a/src/test/java/net/schmizz/sshj/transport/kex/Curve25519DHTest.java b/src/test/java/net/schmizz/sshj/transport/kex/Curve25519DHTest.java
index b2a00c04..3e2e2b3b 100644
--- a/src/test/java/net/schmizz/sshj/transport/kex/Curve25519DHTest.java
+++ b/src/test/java/net/schmizz/sshj/transport/kex/Curve25519DHTest.java
@@ -16,13 +16,13 @@
 package net.schmizz.sshj.transport.kex;
 
 import net.schmizz.sshj.transport.random.JCERandom;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 public class Curve25519DHTest {
 
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/BaseMacTest.java b/src/test/java/net/schmizz/sshj/transport/mac/BaseMacTest.java
index 6ebab0b9..2989624c 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/BaseMacTest.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/BaseMacTest.java
@@ -15,17 +15,17 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.fail;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class BaseMacTest {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
@@ -41,11 +41,13 @@ public class BaseMacTest {
         assertThat(Hex.toHexString(hmac.doFinal()),  is(EXPECTED_HMAC));
     }
 
-    @Test(expected = SSHRuntimeException.class)
+    @Test
     public void testUnknownAlgorithm() {
-        BaseMAC hmac = new BaseMAC("AlgorithmThatDoesNotExist", 20, 20, false);
-        hmac.init((KEY + "foo").getBytes(CHARSET));
-        fail("Should not initialize a non-existent MAC");
+        assertThrows(SSHRuntimeException.class, () -> {
+            BaseMAC hmac = new BaseMAC("AlgorithmThatDoesNotExist", 20, 20, false);
+            hmac.init((KEY + "foo").getBytes(CHARSET));
+            fail("Should not initialize a non-existent MAC");
+        });
     }
 
     @Test
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACMD596Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACMD596Test.java
index 492deaee..4d87fcab 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACMD596Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACMD596Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACMD596Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACMD5Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACMD5Test.java
index c9ef60c4..0179eea6 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACMD5Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACMD5Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACMD5Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA196Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA196Test.java
index 507735d3..b45913de 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA196Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA196Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACSHA196Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA1Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA1Test.java
index 0204b052..ac1d4bc2 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA1Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA1Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACSHA1Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2256Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2256Test.java
index dca3a7a9..de7f43cd 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2256Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2256Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACSHA2256Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2512Test.java b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2512Test.java
index ce47fa06..2e0c7d8a 100644
--- a/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2512Test.java
+++ b/src/test/java/net/schmizz/sshj/transport/mac/HMACSHA2512Test.java
@@ -15,15 +15,14 @@
  */
 package net.schmizz.sshj.transport.mac;
 
+import com.hierynomus.sshj.transport.mac.Macs;
 import org.bouncycastle.util.encoders.Hex;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.nio.charset.Charset;
 
-import com.hierynomus.sshj.transport.mac.Macs;
-
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class HMACSHA2512Test {
     private static final Charset CHARSET = Charset.forName("US-ASCII");
diff --git a/src/test/java/net/schmizz/sshj/userauth/password/TestConsolePasswordFinder.java b/src/test/java/net/schmizz/sshj/userauth/password/TestConsolePasswordFinder.java
index f0bc3d17..0d084da4 100644
--- a/src/test/java/net/schmizz/sshj/userauth/password/TestConsolePasswordFinder.java
+++ b/src/test/java/net/schmizz/sshj/userauth/password/TestConsolePasswordFinder.java
@@ -15,12 +15,13 @@
  */
 package net.schmizz.sshj.userauth.password;
 
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 import java.io.Console;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 public class TestConsolePasswordFinder {
 
     private static final String FORMAT = "%s";
@@ -36,8 +37,7 @@ public class TestConsolePasswordFinder {
         Resource resource = Mockito.mock(Resource.class);
         char[] password = new ConsolePasswordFinder(console).reqPassword(resource);
 
-        Assert.assertArrayEquals("Password should match mocked return value",
-                expectedPassword, password);
+        assertArrayEquals(expectedPassword, password, "Password should match mocked return value");
         Mockito.verifyNoMoreInteractions(resource);
     }
 
@@ -46,7 +46,7 @@ public class TestConsolePasswordFinder {
         Resource<?> resource = Mockito.mock(Resource.class);
         char[] password = new ConsolePasswordFinder(null, FORMAT, 1).reqPassword(resource);
 
-        Assert.assertNull("Password should be null with null console", password);
+        assertNull(password, "Password should be null with null console");
         Mockito.verifyNoMoreInteractions(resource);
     }
 
@@ -54,30 +54,28 @@ public class TestConsolePasswordFinder {
     public void testShouldRetry() {
         Resource<String> resource = new PrivateKeyStringResource("");
         ConsolePasswordFinder finder = new ConsolePasswordFinder(null, FORMAT, 1);
-        Assert.assertTrue("Should allow a retry at first", finder.shouldRetry(resource));
+        assertTrue(finder.shouldRetry(resource), "Should allow a retry at first");
 
         finder.reqPassword(resource);
-        Assert.assertFalse("Should stop allowing retries after one interaction", finder.shouldRetry(resource));
+        assertFalse(finder.shouldRetry(resource), "Should stop allowing retries after one interaction");
     }
 
     @Test
     public void testPromptFormat() {
-        Assert.assertNotNull(
-                "Empty format should create valid ConsolePasswordFinder",
-                new ConsolePasswordFinder(null, "", 1));
-        Assert.assertNotNull(
-                "Single-string format should create valid ConsolePasswordFinder",
-                new ConsolePasswordFinder(null, FORMAT, 1));
+        assertNotNull(
+                new ConsolePasswordFinder(null, "", 1), "Empty format should create valid ConsolePasswordFinder");
+        assertNotNull(
+                new ConsolePasswordFinder(null, FORMAT, 1), "Single-string format should create valid ConsolePasswordFinder");
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void testPromptFormatTooManyMarkers() {
-        new ConsolePasswordFinder(null, "%s%s", 1);
+        assertThrows(IllegalArgumentException.class, () -> new ConsolePasswordFinder(null, "%s%s", 1));
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void testPromptFormatWrongMarkerType() {
-        new ConsolePasswordFinder(null, "%d", 1);
+        assertThrows(IllegalArgumentException.class, () -> new ConsolePasswordFinder(null, "%d", 1));
     }
 
 }
diff --git a/src/test/java/net/schmizz/sshj/util/BufferTest.java b/src/test/java/net/schmizz/sshj/util/BufferTest.java
index 39dce85f..9b9b2de1 100644
--- a/src/test/java/net/schmizz/sshj/util/BufferTest.java
+++ b/src/test/java/net/schmizz/sshj/util/BufferTest.java
@@ -32,15 +32,14 @@ package net.schmizz.sshj.util;
 
 import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.IOUtils;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.io.UnsupportedEncodingException;
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
 
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
 
 /** Tests {@link Buffer} functionality */
 public class BufferTest {
@@ -48,7 +47,7 @@ public class BufferTest {
     private Buffer.PlainBuffer posBuf;
     private Buffer.PlainBuffer handyBuf;
 
-    @Before
+    @BeforeEach
     public void setUp()
             throws UnsupportedEncodingException, GeneralSecurityException {
         // for position test
@@ -113,14 +112,15 @@ public class BufferTest {
         // TODO stub
     }
 
-    @Test(expected = Buffer.BufferException.class)
-    public void testUnderflow()
-            throws Buffer.BufferException {
-        // exhaust the buffer
-        for (int i = 0; i < 5; ++i)
+    @Test
+    public void testUnderflow() throws Buffer.BufferException {
+        assertThrows(Buffer.BufferException.class, () -> {
+            // exhaust the buffer
+            for (int i = 0; i < 5; ++i)
+                posBuf.readByte();
+            // underflow
             posBuf.readByte();
-        // underflow
-        posBuf.readByte();
+        });
     }
 
 }
diff --git a/src/test/java/net/schmizz/sshj/xfer/scp/SCPFileTransferTest.java b/src/test/java/net/schmizz/sshj/xfer/scp/SCPFileTransferTest.java
index 77bdcd0a..e8119fa0 100644
--- a/src/test/java/net/schmizz/sshj/xfer/scp/SCPFileTransferTest.java
+++ b/src/test/java/net/schmizz/sshj/xfer/scp/SCPFileTransferTest.java
@@ -15,97 +15,103 @@
  */
 package net.schmizz.sshj.xfer.scp;
 
-import com.hierynomus.sshj.test.SshFixture;
+import com.hierynomus.sshj.test.SshServerExtension;
 import com.hierynomus.sshj.test.util.FileUtil;
 import net.schmizz.sshj.SSHClient;
 import org.hamcrest.CoreMatchers;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.io.TempDir;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class SCPFileTransferTest {
 
     public static final String DEFAULT_FILE_NAME = "my_file.txt";
-    File targetDir;
-    File sourceFile;
-    File targetFile;
+    Path targetDir;
+    Path sourceFile;
+    Path targetFile;
     SSHClient sshClient;
 
-    @Rule
-    public SshFixture fixture = new SshFixture();
+    @RegisterExtension
+    public SshServerExtension fixture = new SshServerExtension();
 
-    @Rule
-    public TemporaryFolder tempFolder = new TemporaryFolder();
+    @TempDir
+    public File tempFolder;
 
-    @Before
+    @BeforeEach
     public void init() throws IOException {
-        sourceFile = tempFolder.newFile(DEFAULT_FILE_NAME);
-        FileUtil.writeToFile(sourceFile, "This is my file");
-        targetDir = tempFolder.newFolder();
-        targetFile = new File(targetDir, DEFAULT_FILE_NAME);
+        sourceFile = Files.createFile(tempFolder.toPath().resolve(DEFAULT_FILE_NAME));
+        FileUtil.writeToFile(sourceFile.toFile(), "This is my file");
+        targetDir = Files.createDirectory(tempFolder.toPath().resolve("folder"));
+        targetFile = targetDir.resolve(DEFAULT_FILE_NAME);
         sshClient = fixture.setupConnectedDefaultClient();
         sshClient.authPassword("test", "test");
     }
 
-    @After
+    @AfterEach
     public void cleanup() {
-        if (targetFile.exists()) {
-            targetFile.delete();
+        if (Files.exists(targetFile)) {
+            try {
+                Files.delete(targetFile);
+            } catch (IOException ioe) {
+                // ok
+            }
         }
     }
 
     @Test
     public void shouldSCPUploadFile() throws IOException {
         SCPFileTransfer scpFileTransfer = sshClient.newSCPFileTransfer();
-        assertFalse(targetFile.exists());
-        assertTrue(targetDir.exists());
-        scpFileTransfer.upload(sourceFile.getAbsolutePath(), targetDir.getAbsolutePath());
-        assertTrue(targetFile.exists());
+        assertFalse(Files.exists(targetFile));
+        assertTrue(Files.exists(targetDir));
+        scpFileTransfer.upload(sourceFile.toAbsolutePath().toString(), targetDir.toAbsolutePath().toString());
+        assertTrue(Files.exists(targetFile));
     }
 
     @Test
     public void shouldSCPUploadFileWithBandwidthLimit() throws IOException {
         // Limit upload transfer at 2Mo/s
         SCPFileTransfer scpFileTransfer = sshClient.newSCPFileTransfer().bandwidthLimit(16000);
-        assertFalse(targetFile.exists());
-        scpFileTransfer.upload(sourceFile.getAbsolutePath(), targetDir.getAbsolutePath());
-        assertTrue(targetFile.exists());
+        assertFalse(Files.exists(targetFile));
+        scpFileTransfer.upload(sourceFile.toAbsolutePath().toString(), targetDir.toAbsolutePath().toString());
+        assertTrue(Files.exists(targetFile));
     }
 
     @Test
     public void shouldSCPDownloadFile() throws IOException {
         SCPFileTransfer scpFileTransfer = sshClient.newSCPFileTransfer();
-        assertFalse(targetFile.exists());
-        scpFileTransfer.download(sourceFile.getAbsolutePath(), targetDir.getAbsolutePath());
-        assertTrue(targetFile.exists());
+        assertFalse(Files.exists(targetFile));
+        scpFileTransfer.download(sourceFile.toAbsolutePath().toString(), targetDir.toAbsolutePath().toString());
+        assertTrue(Files.exists(targetFile));
     }
 
     @Test
     public void shouldSCPDownloadFileWithBandwidthLimit() throws IOException {
         // Limit download transfer at 128Ko/s
         SCPFileTransfer scpFileTransfer = sshClient.newSCPFileTransfer().bandwidthLimit(1024);
-        assertFalse(targetFile.exists());
-        scpFileTransfer.download(sourceFile.getAbsolutePath(), targetDir.getAbsolutePath());
-        assertTrue(targetFile.exists());
+        assertFalse(Files.exists(targetFile));
+        scpFileTransfer.download(sourceFile.toAbsolutePath().toString(), targetDir.toAbsolutePath().toString());
+        assertTrue(Files.exists(targetFile));
     }
 
     @Test
     public void shouldSCPDownloadFileWithoutPathEscaping() throws IOException {
         SCPFileTransfer scpFileTransfer = sshClient.newSCPFileTransfer();
-        assertFalse(targetFile.exists());
-        File file = tempFolder.newFile("new file.txt");
-        FileUtil.writeToFile(file, "Some content");
-        scpFileTransfer.download(tempFolder.getRoot().getAbsolutePath() + "/new file.txt", targetFile.getAbsolutePath());
-        assertTrue(targetFile.exists());
-        assertThat(FileUtil.readFromFile(targetFile), CoreMatchers.containsString("Some content"));
+        assertFalse(Files.exists(targetFile));
+        Path file = tempFolder.toPath().resolve("new file.txt");
+        FileUtil.writeToFile(file.toFile(), "Some content");
+        scpFileTransfer.download(tempFolder.toPath().toAbsolutePath() + "/new file.txt", targetFile.toAbsolutePath().toString());
+        assertTrue(Files.exists(targetFile));
+        assertThat(FileUtil.readFromFile(targetFile.toFile()), CoreMatchers.containsString("Some content"));
     }
 }