[JSch-users] Algorithm negotiation fail issue

[Nick M. <nmo...@ya...>]

Hello,

I am running into a problem connecting to a server with JSCH.  This worked until recently when the server was upgraded to more stringent security policies.

The issue appears to be that aes256-ctr is required by the server, and JSCH is not reporting it as available during negotiation?  I have installed the "JCE Unlimited Strength Jurisdiction Policy" from Oracle correctly into my JVM, and it does appear to have access to all the ciphers.

Here is the log output from Jsch:

INFO: Connecting to node0 port 22
INFO: Connection established
INFO: Remote version string: SSH-2.0-OpenSSH_4.3
INFO: Local version string: SSH-2.0-JSCH-0.1.48
INFO: CheckCiphers: aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
INFO: CheckKexes: diffie-hellman-group14-sha1
INFO: diffie-hellman-group14-sha1 is not available.
INFO: SSH_MSG_KEXINIT sent
INFO: SSH_MSG_KEXINIT received
INFO: kex: server: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
INFO: kex: server: ssh-rsa,ssh-dss
INFO: kex: server: aes256-ctr
INFO: kex: server: aes256-ctr
INFO: kex: server: hmac-sha1
INFO: kex: server: hmac-sha1
INFO: kex: server: none,zl...@op...
INFO: kex: server: none,zl...@op...
INFO: kex: server: 
INFO: kex: server: 
INFO: kex: client: diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1
INFO: kex: client: ssh-rsa,ssh-dss
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-cbc,aes256-cbc
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-cbc,aes256-cbc
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha1-96,hmac-md5-96
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha1-96,hmac-md5-96
INFO: kex: client: none
INFO: kex: client: none
INFO: kex: client: 
INFO: kex: client: 
INFO: Disconnecting from node0 port 22
com.jcraft.jsch.JSchException: Algorithm negotiation fail
        at com.jcraft.jsch.Session.receive_kexinit(Session.java:552)
        at com.jcraft.jsch.Session.connect(Session.java:299)
        at com.jcraft.jsch.Session.connect(Session.java:162)


Thanks for your assistance!

- nick