I am trying to connect to remote sftp server over ssh with JSch (0.1.44-1) but during "session.connect();" I am getting this exception:
com.jcraft.jsch.JSchException: Algorithm negotiation fail
Logs from JSch:
INFO: Connecting to xx.xx.xx.xxport 22
INFO: Connection established
INFO: Remote version string: SSH-2.0-WeOnlyDo 2.0.6
INFO: Local version string: SSH-2.0-JSCH-0.1.44
INFO: CheckCiphers: aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
INFO: aes256-ctr is not available.
INFO: aes192-ctr is not available.
INFO: aes256-cbc is not available.
INFO: aes192-cbc is not available.
INFO: arcfour256 is not available.
INFO: SSH_MSG_KEXINIT sent
INFO: SSH_MSG_KEXINIT received
INFO: Disconnecting from xx.xx.xx.xx port 22
I am able to log in to remote server with linux sftp command. I was trying to find any kind of clue in the internet but I failed. Any help would be greatly appreciated.
Debug output from sftp console:
OpenSSH_5.5p1-DAM_1.2, OpenSSL 0.9.8r 8 Feb 2011
debug1: Reading configuration data /etc/DAM/ssh/ssh_config
debug1: Applying options for *
debug1: Applying options for *.*
debug1: Connecting to xx.xx.xx.xx port 22.
debug1: Connection established.
debug1: identity file /**/spv_id_rsa.key type -1
debug1: identity file /**/spv_id_rsa.key-cert type -1
debug1: Remote protocol version 2.0, remote software version WeOnlyDo 2.0.6
debug1: no match: WeOnlyDo 2.0.6
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.5p1-DAM_1.2
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes256-cbc hmac-md5 none
debug1: kex: client->server aes256-cbc hmac-md5 none
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug1: Host 'xx.xx.xx.xx' is known and matches the RSA host key.
debug1: Found key in ~/.ssh/known_hosts:8
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /**/spv_id_rsa.key
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
debug1: channel 0: new
debug1: Entering interactive session.
debug1: Sending subsystem: sftp
Connected to xx.xx.xx.xx.
Ok the problem is solved, I have found that I the remote server had only these encryption options: .
To enable aes256-cbc I had to apply "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files" as it was written in http://www.jcraft.com/jsch/README.
After this I can connect to remote server without problems.