Improving logging for KeyExchanger (#458)

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

@@ -26,7 +26,6 @@ import net.schmizz.sshj.common.Base64;
 import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.common.SecurityUtils;
-import net.schmizz.sshj.transport.verification.HostKeyVerifier;
 
 public class FingerprintVerifier implements HostKeyVerifier {
     private static final Pattern MD5_FINGERPRINT_PATTERN = Pattern.compile("[0-9a-f]{2}+(:[0-9a-f]{2}+){15}+");
@@ -121,4 +120,8 @@ public class FingerprintVerifier implements HostKeyVerifier {
         return Arrays.equals(fingerprintData, digestData);
     }
 
+    @Override
+    public String toString() {
+        return "FingerprintVerifier{digestAlgorithm='" + digestAlgorithm + "'}";
+    }
 }

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

@@ -440,4 +440,10 @@ public class OpenSSHKnownHosts
             return null;
         }
     }
+
+    @Override
+    public String toString() {
+        return "OpenSSHKnownHosts{khFile='" + khFile + "'}";
+    }
+
 }

src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy

@@ -132,6 +132,18 @@ host1 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBL
         h << ["schmizz.net", "69.163.155.180"]
     }
 
+    def "should produce meaningful toString()"() {
+        given:
+        def f = knownHosts("schmizz.net,69.163.155.180 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6P9Hlwdahh250jGZYKg2snRq2j2lFJVdKSHyxqbJiVy9VX9gTkN3K2MD48qyrYLYOyGs3vTttyUk+cK++JMzURWsrP4piby7LpeOT+3Iq8CQNj4gXZdcH9w15Vuk2qS11at6IsQPVHpKD9HGg9//EFUccI/4w06k4XXLm/IxOGUwj6I2AeWmEOL3aDi+fe07TTosSdLUD6INtR0cyKsg0zC7Da24ixoShT8Oy3x2MpR7CY3PQ1pUVmvPkr79VeA+4qV9F1JM09WdboAMZgWQZ+XrbtuBlGsyhpUHSCQOya+kOJ+bYryS+U7A+6nmTW3C9FX4FgFqTF89UHOC7V0zZQ==")
+
+        when:
+        def knownhosts = new OpenSSHKnownHosts(f)
+
+        def toStringValue = knownhosts.toString()
+        then:
+        toStringValue == "OpenSSHKnownHosts{khFile='" + f + "'}"
+    }
+
     def knownHosts(String s) {
         def f = temp.newFile("known_hosts")
         f.write(s)

src/test/groovy/net/schmizz/sshj/transport/verification/FingerprintVerifierSpec.groovy

@@ -49,6 +49,16 @@ class FingerprintVerifierSpec extends Specification {
 
     }
 
+    def "should produce meaningful toString()"() {
+        given:
+        def verifier = FingerprintVerifier.getInstance("SHA1:2Fo8c/96zv32xc8GZWbOGYOlRak")
+
+        when:
+        def toStringValue = verifier.toString()
+
+        then:
+        toStringValue == "FingerprintVerifier{digestAlgorithm='SHA-1'}"
+    }
 
     def getPublicKey() {
         def lines = new File("src/test/resources/keytypes/test_ed25519.pub").readLines()