Ubuntu 16.04 ssh: sign_and_send_pubkey: signing failed: agent refused operation
Looks like an ssh-agent is running already but it can not find any keys attached. To solve this add the private key identities to the authentication agent like so:
ssh-add
Then you can ssh into your server.
in addition, you can see the list of fingerprints of all identities currently added by:
ssh-add -l
Simple Solution
I had the same problem at Ubuntu 18.04. That's all about client-side private key permissions.
$ ssh [email protected]
sign_and_send_pubkey: signing failed: agent refused operation
The file permissions were too open (0644).
The following command solved it:
chmod 600 ~/.ssh/id_rsa
I had the same problem (same symptoms)
sam@xxxxx:~/.ssh$ ssh [email protected]
sign_and_send_pubkey: signing failed: agent refused operation
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
... but the solution was different.
The problem was coming from the use of GNOME-KEYRING. The post referring to the solution may be read here.
In short:
- Detect the problem by adding SSH_AUTH_SOCK=0 in front of the ssh command. sam@xxxxx:~/.ssh$ SSH_AUTH_SOCK=0 ssh [email protected]
- In case it succeed to connect. Open the application StartUp Application (by using the search function of the Desktop for example) and disable the use of gnome-keyring.
- Reboot
The page provide other details in case of similar problem with different solution.