Agent fails to connect to an SFTP server and Algorithm Negotiation Fail error is displayed

Document ID : KB000087554
Last Modified Date : 14/04/2018
Show Technical Document Details
Issue:
Error Message :
Algorithm negotiation fail
com.uc4.ftpjob.DataTransferException: Connection exception.
Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail

RA FTP agent fails to connect to an SFTP server due to a missing key negotiation algorithm.

Investigation

In order to determine whether or not this issue is impacting you, look in the RA FTP’s job report for an error similar to this:
 
2016-11-16 21:00:22            Using hosts file = /home/users/uc4/.ssh/known_hosts
Algorithm negotiation fail
com.uc4.ftpjob.DataTransferException: Connection exception.
               at com.uc4.transfer.CITSFTPImpl.<init>(CITSFTPImpl.java:150)
               at com.uc4.ftpjob.connections.ConnectionFactory$1.run(ConnectionFactory.java:61)
               at java.lang.Thread.run(Thread.java:662)
Caused by: 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)
               at com.uc4.transfer.CITSFTPImpl.<init>(CITSFTPImpl.java:137)
               ... 2 more
2016-11-16 21:00:22            Command aborted with error message: Connection exception. Algorithm negotiation fail.

 
Cause:
Cause type:
Defect
Root Cause: RA FTP agent failed to connect to an SFTP server due to a missing key negotiation algorithm.
Resolution:
This field was added on 30/03/2017. This article has not been updated yet. Refer to the "Description" or "Workaround" sections for solution information.

Fix Status: Released

Fix Version(s):
RA FTP 3.1.5 HF1 - Available
Additional Information:
Workaround :
N/ASOLUTIONThe problem was fixed by updating the ssh library JSCH to the latest version 1.53 that supports the missing diffie-hellman-group14 key negotiation algorithm.Upgrade to RA FTP solution version 3.1.5 HF1 and install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files.