Add support for JuiceSSH generated ed25519 keys (#770)

Reported from TeamAmaze/AmazeFileManager#2976, it was found the key uses aes-128-cbc which is currently not supported by sshj. This change adds support for it.

To enable support for this, also eliminated hardcoding byte array size for key and IV, as a result of BCrypt.pbkdf().

src/itest/docker-image/authorized_keys

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

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

@@ -80,6 +80,7 @@ class IntegrationSpec extends Specification {
         "id_ecdsa_opensshv1" | null
         "id_ed25519_opensshv1" | null
         "id_ed25519_opensshv1_aes256cbc.pem" | "foobar"
+        "id_ed25519_opensshv1_aes128cbc.pem" | "sshjtest"
         "id_ed25519_opensshv1_protected" | "sshjtest"
         "id_rsa" | null
         "id_rsa_opensshv1" | null

src/itest/resources/keyfiles/id_ed25519_opensshv1_aes128cbc.pem

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

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

@@ -177,11 +177,11 @@ private void initializeCipher(String kdfName, byte[] kdfOptions, Cipher cipher)
                 Arrays.fill(charBuffer.array(), '\u0000');
                 Arrays.fill(byteBuffer.array(), (byte) 0);
             }
-            byte[] keyiv = new byte[48];
+            byte[] keyiv = new byte[cipher.getIVSize()+ cipher.getBlockSize()];
             new BCrypt().pbkdf(passphrase, opts.readBytes(), opts.readUInt32AsInt(), keyiv);
             Arrays.fill(passphrase, (byte) 0);
-            byte[] key = Arrays.copyOfRange(keyiv, 0, 32);
-            byte[] iv = Arrays.copyOfRange(keyiv, 32, 48);
+            byte[] key = Arrays.copyOfRange(keyiv, 0, cipher.getBlockSize());
+            byte[] iv = Arrays.copyOfRange(keyiv, cipher.getBlockSize(), cipher.getIVSize() + cipher.getBlockSize());
             cipher.init(Cipher.Mode.Decrypt, key, iv);
         } else {
             throw new IllegalStateException("No support for KDF '" + kdfName + "'.");
@@ -193,6 +193,8 @@ private Cipher createCipher(String cipherName) {
             return BlockCiphers.AES256CTR().create();
         } else if (cipherName.equals(BlockCiphers.AES256CBC().getName())) {
             return BlockCiphers.AES256CBC().create();
+        } else if (cipherName.equals(BlockCiphers.AES128CBC().getName())) {
+            return BlockCiphers.AES128CBC().create();
         }
         throw new IllegalStateException("Cipher '" + cipherName + "' not currently implemented for openssh-key-v1 format");
     }

src/test/java/net/schmizz/sshj/keyprovider/OpenSSHKeyFileTest.java

@@ -247,6 +247,12 @@ public void shouldLoadProtectedED25519PrivateKeyAes256CBC() throws IOException {
         checkOpenSSHKeyV1("src/test/resources/keytypes/ed25519_aes256cbc.pem", "foobar", true);
     }
 
+    @Test
+    public void shouldLoadProtectedED25519PrivateKeyAes128CBC() throws IOException {
+        checkOpenSSHKeyV1("src/test/resources/keytypes/ed25519_aes128cbc.pem", "sshjtest", false);
+        checkOpenSSHKeyV1("src/test/resources/keytypes/ed25519_aes128cbc.pem", "sshjtest", true);
+    }
+
     @Test(expected = KeyDecryptionFailedException.class)
     public void shouldFailOnIncorrectPassphraseAfterRetries() throws IOException {
         OpenSSHKeyV1KeyFile keyFile = new OpenSSHKeyV1KeyFile();

src/test/resources/keytypes/ed25519_aes128cbc.pem

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

src/test/resources/keytypes/ed25519_aes128cbc.pem.pub

@@ -0,0 +1 @@
+ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICYfPGSYFOHuSzTJ67H0ynvKJDfgDmwPOj7iJaLGbIBi sshjtest@TranceLove