I'm creating a job in Jenkins 2.152 running on Windows Server 2016 which needs to pull from a git repo hosted on bitbucket.org.
I tested the ssh key through git-bash so I know it works and there is no passphrase.
When I try to use the very same private key with Jenkins I get an error message.

```
Failed to connect to repository : Command "git.exe ls-remote -h 
git@bitbucket.org:mygroup/myrepo HEAD" returned status code 128:
stdout: 
stderr: Load key 
"C:\\Users\\JE~1\\AppData\\Local\\Temp\\ssh2142299850576289882.key": invalid format 
git@bitbucket.org: Permission denied (publickey). 
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

```

The Credentials are set up as

```
 scope: Global
 user: git
 Private Key -> Enter Directly -> copy and past - generated by ssh-keygen -t rsa in gitbash
 Passphrase: empty
 ID: empty
 description: bitbucket.org

```

I noticed that on another Windows Jenkins server the private key has a different number of characters per line

Does anybody know what is the expected format of Private Key in Jenkins Credentials? Or maybe there is something else that I could check.

Any help is greatly appreciated.