How to solve "sign_and_send_pubkey: signing failed: agent refused operation"?

Question

Run ssh-add on the client machine, that will add the SSH key to the agent.

Confirm with ssh-add -l (again on the client) that it was indeed added.

After upgrading Fedora 26 to 28 I faced same issue. And following logs were missing

/var/log/secure
/var/log/messages

ISSUE:

antop@localmachine  ~  ssh [email protected]
sign_and_send_pubkey: signing failed: agent refused operation
[email protected]'s password:

error message is not pointing actual issue. Issue resolved by

chmod 700 ~/.ssh
chmod 600 ~/.ssh/*

I was having the same problem in Linux Ubuntu 18. After the update from Ubuntu 17.10, every git command would show that message.

The way to solve it is to make sure that you have the correct permission on the id_rsa and id_rsa.pub.

Check the current chmod number by using stat --format '%a' <file>. It should be 600 for id_rsa and 644 for id_rsa.pub.

To change the permission on the files use

chmod 600 id_rsa
chmod 644 id_rsa.pub

That solved my issue with the update.

Run the below command to resolve this issue.

It worked for me.

chmod 600 ~/.ssh/id_rsa

I had the error when using gpg-agent as my ssh-agent and using a gpg subkey as my ssh key https://wiki.archlinux.org/index.php/GnuPG#gpg-agent.

I suspect that the problem was caused by having an invalid pin entry tty for gpg caused by my sleep+lock command used in my sway config

bindsym $mod+Shift+l exec "sh -c 'gpg-connect-agent reloadagent /bye>/dev/null; systemctl suspend; swaylock'"

or just the sleep/suspend

Reset the pin entry tty to fix the problem

gpg-connect-agent updatestartuptty /bye > /dev/null

and the fix for my sway sleep+lock command:

bindsym $mod+Shift+l exec "sh -c 'gpg-connect-agent reloadagent /bye>/dev/null; systemctl suspend; swaylock; gpg-connect-agent updatestartuptty /bye > /dev/null'"