monkeying around bitrot

One of the servers to which I SSH ratcheted up its public key requirements and thus the Monkeysphere key I've been using for 15 years stopped working.

Unfortunately, monkeysphere gen-subkey hardcodes RSA keys and if I'm going to be forced to use a new subkey I want mine to be of the 25519 variety. Therefore, to add a subkey by hand:

gpg --expert --edit-key $KEYID

Follow roughly what's in /usr/share/monkeysphere/m/gen_subkey, but change the key type to 11 (ECC (set your own capabilities)), don't bother with Encrypt capability, and pick Curve25519.

monkeysphere subkey-to-ssh-agent and agent-transfer will be all happy with the "ed25519" subkey without any code modifications, and you won't need to rewrite monkeysphere from scratch to use Sequoia for the next 15 years.