RA_FTP agent fails with error "Algorithm negotiation fail"
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RA_FTP agent fails with error "Algorithm negotiation fail"

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Article ID: 138591

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Updated On:

Products

CA Automic Workload Automation - Automation Engine CA Automic One Automation Automic SaaS

Issue/Introduction

RA_FTP SFTP agent jobs fail with error "Algorithm negotiation fail"

Error Message :
Algorithm negotiation fail
com.uc4.ftpjob.DataTransferException: Connection exception.
Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail
at com.jcraft.jsch.Session.receive_kexinit(Session.java:583)

or

java.lang.RuntimeException: java.lang.RuntimeException: com.jcraft.jsch.JSchException: Algorithm negotiation fail



Connecting to an FTP Server that only accepts diffie-hellman-group14-sha1 as the key exchange algorithm fails with the following errors.
 

Algorithm negotiation fail
com.uc4.ftpjob.DataTransferException: Connection exception.
at com.uc4.transfer.CITSFTPImpl.<init>(CITSFTPImpl.java:214)
at com.uc4.ftpjob.connections.ConnectionFactory$1.run(ConnectionFactory.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail
at com.jcraft.jsch.Session.receive_kexinit(Session.java:583)
at com.jcraft.jsch.Session.connect(Session.java:320)
at com.jcraft.jsch.Session.connect(Session.java:183)
at com.uc4.transfer.CITSFTPImpl.<init>(CITSFTPImpl.java:194)
... 2 more
 
Turning on tracing as per below:
  1. In the AWI, go to the Administration perspective
  2. Right-click the agent and choose "Advanced Options"
  3. Change ra to 9 and tcp/ip to 9 and click Apply
  4. Open the job definition in Process Assembly
  5. Go to the Rapid Automation tab and be sure that Write agent log to job report is checked; save the changes
  6. Run the job, reproducing the error
  7. Turn off agent traces by following steps 1 through 3, but changing the ra and tcp/ip settings to 0

shows something like this in the job report:

ciphers that are required on the server side in the job report:

2022-05-17 14:56:23             kex: server: diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
2022-05-17 14:56:23             kex: server: ssh-rsa
2022-05-17 14:56:23             kex: server: aes256-ctr,aes256-cbc,arcfour256
2022-05-17 14:56:23             kex: server: aes256-ctr,aes256-cbc,arcfour256
2022-05-17 14:56:23             kex: server: hmac-sha2-256,hmac-sha2-512,hmac-sha2-512-96,hmac-sha256
2022-05-17 14:56:23             kex: server: hmac-sha256,hmac-sha2-256,hmac-sha2-512,hmac-sha2-512-96

and which are available with the current setup on the RA FTP (client) side:
2022-05-17 14:56:23             kex: client: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
2022-05-17 14:56:23             kex: client: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
2022-05-17 14:56:23             kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc
2022-05-17 14:56:23             kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc
2022-05-17 14:56:23             kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
2022-05-17 14:56:23             kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
2022-05-17 14:56:23             kex: client: [email protected],zlib,none
2022-05-17 14:56:23             kex: client: [email protected],zlib,none

Environment

Release : 3.X, 4.X

Component : RA FTP agent

Resolution

If you are using the RA FTP agent (4.x), upgrade to the latest FTP Integration agent.  This agent will have the newest jsch that has been released with an FTP solution.

Make sure you have Java Cryptography Extension (JCE) installed in order for the agent to run - this can be done by having Java 1.8 build 302 or higher (The latest compatible version of java is always recommended)

Link to Java Cryptography Extension (JCE): http://www.jcraft.com/jsch/

 

NOTE: all of the algorithms listed on the following page are supported: http://www.jcraft.com/jsch/

 

Additional Information

The following are used as of June 2026 with IG FTP version 24.1.5:

2026-06-09 16:32:45             CheckCiphers: [email protected] 
2026-06-09 16:32:45             CheckKexes: [email protected],curve25519-sha256,[email protected],curve448-sha512 
2026-06-09 16:32:45             CheckSignatures: ssh-ed25519,ssh-ed448 
2026-06-09 16:32:45             client proposal: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c,[email protected] 
2026-06-09 16:32:45             client proposal: host key algorithms: ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-512,rsa-sha2-256 
2026-06-09 16:32:45             client proposal: ciphers c2s: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected] 
2026-06-09 16:32:45             client proposal: ciphers s2c: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected] 
2026-06-09 16:32:45             client proposal: MACs c2s: [email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1 
2026-06-09 16:32:45             client proposal: MACs s2c: [email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1 
2026-06-09 16:32:45             client proposal: compression c2s: none 
2026-06-09 16:32:45             client proposal: compression s2c: none

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