Support for ed25519 keys missing in AdminUI

[liftedkilt]

ed25519 keys are accepted by sshd on the headnode/compute nodes, but I'm unable to add the key to my account via AdminUI

[bahamat]

@liftedkilt There's an underlying issue that's preventing this.

Currently we store public keys in UFDS using OpenSSL in x509 format. Because ed25519 is not valid in x509 (you can see progress here: https://datatracker.ietf.org/doc/draft-ietf-curdle-pkix/) we currently can't store those keys.

Once supported has been added to OpenSSL, this will work its way into Triton, and ultimately AdminUI.

Until then, you can still use ed25519 keys with an authorized_keys file.