Problems with com.jcraft.jsch.Session.connect

Discussion of the Co:Z Co-Processing Toolkit for z/OS
Post Reply
philhardackermann
Posts: 2
Joined: Wed Jul 22, 2015 4:29 am

Problems with com.jcraft.jsch.Session.connect

Post by philhardackermann » Wed Jul 22, 2015 8:09 am

Occasionally our ftp-steps get an RC 11, and the step log looks like this (some information had to be anonymized, sorry):
  • EZA1736I FTP (EXIT
    EZY2640I Using dd:SYSFTPD=/etc/ftpssh.data for local site configuration parameters.
    EZA1450I IBM FTP CS V1R13
    EZA1772I FTP: EXIT has been set.
    EZA1456I Connect to ?
    EZA1736I ftpgwprd
    EZA1554I Connecting to:------------ XX.XX.XX.37 port: 21.
    220 (Co:Z FtpSshProxy)
    EZA1459I NAME (ftpgwprd:SPSYS03):
    EZA1701I >>> USER ftmftp
    331 Please specify the password.
    EZA1789I PASSWORD:
    EZA1701I >>> PASS
    530 verify: false
    EZA1735I Std Return Code = 26530, Error Code = 00011
    EZA1534I *** Control connection with ------------ dies.
The corresponding entries in COZPROXY's log show:
  • 2015-07-21 19:08:45,283 INFO ProxyConnectionÝ/127.0.0.1:14789¨ - proxy negotiated to /XX.XX.XX.37:21
    2015-07-21 19:08:45,285 INFO FtpControlSessionÝ/127.0.0.1:14789¨ - client login accepted for userid "ftmftp"
    2015-07-21 19:08:45,504 WARN FtpControlSessionÝ/127.0.0.1:14789¨ - Exception starting SSH tunnel
    com.jcraft.jsch.JSchException: verify: false
    at com.jcraft.jsch.Session.connect(Session.java:295)
    at com.dovetail.ftpsshproxy.FtpControlSession.startSshTunnel(FtpControlSession.java:232)
    at com.dovetail.ftpsshproxy.FtpControlSession.startConnection(FtpControlSession.java:129)
    at com.dovetail.ftpsshproxy.FtpControlSession.run(FtpControlSession.java:76)
    at com.dovetail.ftpsshproxy.ProxyConnection.runProxySession(ProxyConnection.java:135)
    at com.dovetail.ftpsshproxy.ProxyConnection.doRun(ProxyConnection.java:91)
    at com.dovetail.ftpsshproxy.ProxyConnection.run(ProxyConnection.java:72)
    at java.lang.Thread.run(Thread.java:857)
    2015-07-21 19:08:45,505 INFO FtpControlSessionÝ/127.0.0.1:14789¨ - disconnected SSH
    2015-07-21 19:08:45,505 INFO ProxyConnectionÝ/127.0.0.1:14789¨ - control connection closed
The funny thing is that the problem, albeit reoccuring, is still temporary - just rerun the step in question and everything is fine (AFAIK we've never had a case where the problem hit a job that did a re-run). Thus there shouldn't be an issue with the credentials used since they don't normally change within such a short time frame. Any ideas?

dovetail
Site Admin
Posts: 1848
Joined: Thu Jul 29, 2004 12:12 pm

Re: Problems with com.jcraft.jsch.Session.connect

Post by dovetail » Wed Jul 29, 2015 2:58 pm

This message:

2015-07-21 19:08:45,504 WARN FtpControlSessionÝ/127.0.0.1:14789¨ - Exception starting SSH tunnel
com.jcraft.jsch.JSchException: verify: false

is an exception from JSch that indicates that there was an ssh connection failure during host key exchange. I don't know what SSH server or platform that you are using, but you may want to check the server logs for more failure diagnostics.

philhardackermann
Posts: 2
Joined: Wed Jul 22, 2015 4:29 am

Re: Problems with com.jcraft.jsch.Session.connect

Post by philhardackermann » Tue Aug 04, 2015 7:49 am

OK, thanks for the hint. I don't 'own' those systems, so I'll ask the people in question. AFAIK there's some unix involved on the target side.

Post Reply