Yubikey fails on macOS Ventura with "sign_and_send_pubkey: signing failed"

Posted on Feb 24, 2023

$ ssh hambone
sign_and_send_pubkey: signing failed for RSA "cardno:11_9e5_49a" from agent: agent refused operation
user@hambone: Permission denied (publickey).

echo "disable-ccid" >> ~/.gnupg/scdaemon.conf

After adding that line to scdaemon.conf, I just restarted the GPG daemon and I was finally able to use my Yubikey again.

pkill gpg-agent; gpg-agent --homedir $HOME/.gnupg --daemon

Other causes

I have also found that this error can be caused by having an incorrect pinentry-program in ~/.gnupg/gpg-agent.conf. In my case, I had this in my config:

pinentry-program /opt/homebrew/bin/pinentry-mac

But somewhere along the line, pinentry-mac was removed. You can verify if it does/doesn’t exist by running /opt/homebrew/bin/pinentry-mac in your shell. I ran brew install pinentry-mac and it resolved the issue for me.