Deprecate support for DSA keys
DSA keys have been deprecated due to weakness by OpenSSH, and we should wind down our support for these keys.
Disallow DSA SSH keys by setting the default setting in
Visibility and access controls to disallow these keys (an admin can still override the setting).
@rdavila What do you think if we just drop support for DSA? It's been deprecated and considered unsafe anyway?
I think that makes sense given OpenSSH has deprecated it but this implies a change in our codebase and also we may need to communicate our users about it. cc: @DouweM
@rdavila Hmm, we should definitely have a separate issue to discuss that, so that we can properly time the deprecation etc. I wonder how many keys on GitLab.com that would affect. If you can come up with a query that'll find that information, I can run it on production :)