[JENKINS-29168] SSH credential not used by Windows slave

I have a job configured that opens an SSH connection from a slave node to a remote system. This uses the ssh-agent plugin to choose a private key credential stored in Jenkins. The goal is to SSH from a Windows slave configured to use Cygwin for SSH.

The ssh command is simply:

```
ssh -vvv user@​example.com "ls"

```

When run on a Linux slave, the output looks like:

```
authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: user (SSH key for example.com)
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug3: Wrote 368 bytes for a total of 1661
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug2: input_userauth_pk_ok: SHA1 fp ####
debug3: sign_and_send_pubkey: RSA ####
debug3: Wrote 640 bytes for a total of 2301
debug1: Authentication succeeded (publickey).

```

When run on a Windows slave, the output looks like:

```
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/user/.ssh/id_rsa
debug3: no such identity: /home/user/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /home/user/.ssh/id_dsa
debug3: no such identity: /home/user/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/user/.ssh/id_ecdsa
debug3: no such identity: /home/user/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/user/.ssh/id_ed25519
debug3: no such identity: /home/user/.ssh/id_ed25519: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug2: we sent a password packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
Permission denied, please try again.
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug2: we sent a password packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
Permission denied, please try again.
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug2: we sent a password packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey,gssapi-with-mic,password).

```

The difference appears to be that the credential is not sent to the slave to be used as the identity in the SSH connection.

---
Originally reported by moeglewa, imported from: SSH credential not used by Windows slave

• status: Open
  
• priority: Blocker
  
• component(s): ssh-agent-plugin
  
• label(s): credentials, ssh-agent, windows
  
• resolution: Unresolved
  
• votes: 1
  
• watchers: 2
  
• imported: 20260604-211335
  

Raw content of original issue

I have a job configured that opens an SSH connection from a slave node to a remote system.  This uses the ssh-agent plugin to choose a private key credential stored in Jenkins.  The goal is to SSH from a Windows slave configured to use Cygwin for SSH.


The ssh command is simply:



ssh -vvv user@example.com "ls"





When run on a Linux slave, the output looks like:



authmethod_lookup publickey

debug3: remaining preferred: keyboard-interactive,password

debug3: authmethod_is_enabled publickey

debug1: Next authentication method: publickey

debug1: Offering public key: user (SSH key for example.com)

debug3: send_pubkey_test

debug2: we sent a publickey packet, wait for reply

debug3: Wrote 368 bytes for a total of 1661

debug1: Server accepts key: pkalg ssh-rsa blen 277

debug2: input_userauth_pk_ok: SHA1 fp ####

debug3: sign_and_send_pubkey: RSA ####

debug3: Wrote 640 bytes for a total of 2301

debug1: Authentication succeeded (publickey).





When run on a Windows slave, the output looks like:



debug3: authmethod_lookup publickey

debug3: remaining preferred: keyboard-interactive,password

debug3: authmethod_is_enabled publickey

debug1: Next authentication method: publickey

debug1: Trying private key: /home/user/.ssh/id_rsa

debug3: no such identity: /home/user/.ssh/id_rsa: No such file or directory

debug1: Trying private key: /home/user/.ssh/id_dsa

debug3: no such identity: /home/user/.ssh/id_dsa: No such file or directory

debug1: Trying private key: /home/user/.ssh/id_ecdsa

debug3: no such identity: /home/user/.ssh/id_ecdsa: No such file or directory

debug1: Trying private key: /home/user/.ssh/id_ed25519

debug3: no such identity: /home/user/.ssh/id_ed25519: No such file or directory

debug2: we did not send a packet, disable method

debug3: authmethod_lookup password

debug3: remaining preferred: ,password

debug3: authmethod_is_enabled password

debug1: Next authentication method: password

debug1: read_passphrase: can't open /dev/tty: No such device or address

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,gssapi-with-mic,password

Permission denied, please try again.

debug1: read_passphrase: can't open /dev/tty: No such device or address

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,gssapi-with-mic,password

Permission denied, please try again.

debug1: read_passphrase: can't open /dev/tty: No such device or address

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,gssapi-with-mic,password

debug2: we did not send a packet, disable method

debug1: No more authentication methods to try.

Permission denied (publickey,gssapi-with-mic,password).





The difference appears to be that the credential is not sent to the slave to be used as the identity in the SSH connection.

environment

```
Windows Server 2008

Jenkins 1.580.13.1
```