SSH Agent fails for RSA 3072 key #294
Description
I have two keys registered in bitwarden, one new ed25519 key, and a legacy RSA-3072 key for hosts too old for that. If I try to log into one of the latter, I get sign_and_send_pubkey: signing failed for RSA "~/.ssh/id_rsa" from agent: agent refused operation from SSH and a very unhelpful Error handling message: Other(Encoding(Length)) from rbw.
ssh-add reports both keys:
> ssh-add -l
3072 SHA256:… (RSA)
256 SHA256:… (ED25519)
> ssh-add -L
ssh-rsa AAAA…
ssh-ed25519 AAAA…
Most other ssh-agent implementations (keepassxc, keychain, etc.) can handle the key, so the key itself is fine.
Bitwarden Desktop also fails, but with a different error message, and I think bitwarden/clients#16681 / bitwarden/bitwarden-russh#14 are unrelated to rbw's agent implementation, and don't affect how the key is stored?