Thanks for reporting the issue!

Adding multiple newlines didn't seem have any adverse effect so Jenkins should probably just add a newline when it writes the keyfile.

Sounds reasonable to me, although probably a newline should only be added if there isn't one already so that resaving the credentials doesn't keep adding newlines. Feel free to submit a pull request to the repository (ideally with a regression test); here is the class that I think would need to be modified.

PR created here: https://github.com/jenkinsci/ssh-credentials-plugin/pull/33

I've tried the adding a new line after the private key to no avail.  I've also tried adding a few lines and a # sign on one line.  I still get the ssh-add error about the passphrase. 

Jenkins 2.164.3, SSH-agent 1.17 SSH-credentials 1.16

After downgrading these plugins, I'm able to use the credentials with the trailing new line.

SSH-agent 1.13  SSH-credentials 1.12

Has anyone been able to use the trailing new line trick with these plugin versions?  SSH-agent 1.17 SSH-credentials 1.16

Fixed in PR https://github.com/jenkinsci/ssh-credentials-plugin/pull/33 which was just merged.

Released in 1.17.1.

jvz I am still experiencing this issue with ssh-credentials-plugin 1.17.2 / Jenkins 2.176.2, can this be re-opened?

When I paste an SSH key without a password and without a newline after ----END OPENSSH PRIVATE KEY----, I am getting this:

[EnvInject] - Loading node environment variables.
Building in workspace /opt/jenkins/workspace/tests/testssh
[ssh-agent] Looking for ssh-agent implementation...
[ssh-agent]   Exec ssh-agent (binary ssh-agent on a remote machine)
$ ssh-agent
SSH_AUTH_SOCK=/tmp/ssh-LjVbJNMcagCy/agent.130927
SSH_AGENT_PID=130929
[ssh-agent] Started.
Running ssh-add (command line suppressed)
Enter passphrase for /opt/jenkins/workspace/tests/testssh@tmp/private_key_4661922093191141579.key: ERROR: Failed to run ssh-add
Finished: FAILURE 

When I update the key and put a newline, it works fine:

Building in workspace /opt/jenkins/workspace/tests/testssh
[ssh-agent] Looking for ssh-agent implementation...
[ssh-agent]   Exec ssh-agent (binary ssh-agent on a remote machine)
$ ssh-agent
SSH_AUTH_SOCK=/tmp/ssh-LHBjsdVD6N7X/agent.130956
SSH_AGENT_PID=130958
[ssh-agent] Started.
Running ssh-add (command line suppressed)
Identity added: /opt/jenkins/workspace/tests/testssh@tmp/private_key_1585458568929474760.key (SSH CI key)
[ssh-agent] Using credentials jenkins (SSH key used for Tomcat restarts)
[testssh] $ /bin/sh -xe /tmp/jenkins2172743275862346783.sh
+ hostname
ci
$ ssh-agent -k
unset SSH_AUTH_SOCK;
unset SSH_AGENT_PID;
echo Agent pid 130958 killed;
[ssh-agent] Stopped.
Finished: SUCCESS

Is that a separate issue? And can you reproduce this with a unit test? See the original PR for example.

OK, I debugged it a little and I think I know what the problem is:
even though I modified the ssh-credentials plugin to save with a newline, it still didn't work for me.
It turns out that the ssh-agent plugin that writes the private key to the file, strips it out of the newline. Then... ssh-add asks for a password. When I add a newline, it adds it to the agent fine. The question is now, what is stripping this newline... I'll continue to debug but any hints appreciated.

I'm having the same issue as initially described (it seems ssh-add prompts for passphrase and fails), but workaround of adding newline in credentials' key does not solve it.

Versions:

• Jenkins 2.190.3
• "ssh agent" plugin 1.17
• "ssh credentials" plugin 1.18

Logs:
[ssh-agent] Using credentials testcreds
[ssh-agent] Looking for ssh-agent implementation...
[ssh-agent] Exec ssh-agent (binary ssh-agent on a remote machine)
$ ssh-agent
SSH_AUTH_SOCK=/tmp/ssh-HmEucFexUrOg/agent.19128
SSH_AGENT_PID=19129
Running ssh-add (command line suppressed)Enter passphrase for /opt/jenkins/workspace/roduct-service-read-build_master@tmp/private_key_1675109103121607963.key: [Pipeline] // sshagent[Pipeline] }[Pipeline] // stage

UPDATE

I'm not having the issue anymore, it was my fault:

• I was using github token as the private key when I created the "SSH Username with private key" credential.
• Instead, an RSA private key should be used (eg: as per https://help.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh ). With this, it works fine.

After upgrading to ssh-agent 1.21 we had a job hang at a git command.

We terminated it after more than 30 minutes. Tried again and again with same result.

After reverting to 1.20 it worked again.

Versions:

• Jenkins 2.280
• ssh-agent 1.21
• ssh-credentials 1.18.1

Log:

...
[Pipeline] sshagent
15:27:55  [ssh-agent] Using credentials jenkins (jenkins ssh key)
15:27:55  [ssh-agent] Looking for ssh-agent implementation...
15:27:55  [ssh-agent]   Exec ssh-agent (binary ssh-agent on a remote machine)
15:27:55  $ docker exec bb2595d46378e3aa4279cba0a20d8e3026f79d84bc9d2f2b5b856bbfba3ab1f5 ssh-agent
15:27:55  [ssh-agent]   Java/JNR ssh-agent
15:27:55  [ssh-agent] Registered BouncyCastle on the remote agent
15:27:55  [ssh-agent] Started.
[Pipeline] {
[Pipeline] sh
15:27:55  + git ls-remote --heads origin