While running QA tests with https://gitlab.com/gitlab-org/gitlab/-/merge_requests/92150 against a FIPS Omnibus system, I found that ED25519 keys do not work on FIPS systems. This seems to be echoed by other sources: https://superuser.com/a/1567730 In https://gitlab.com/gitlab-org/gitlab/-/blob/709d432864d970cf6bbe88daeee31faf5aef829c/lib/gitlab/fips.rb#L14-16, it seems we allow users to add these keys. We have a few options here: 1. Allow them to be entered into the system, but OpenSSH won't honor them. 2. Drop `ed25519` and `ed25519_sk` from the supported keys list. We might need to consider solving https://gitlab.com/gitlab-org/gitlab/-/issues/358985 if we do this, since it's quite annoying to have to manually adjust these settings. I also wonder whether `ecdsa_sk` works, although I would hope that it does. /cc: @robotmay_gitlab