It's the year 2022, we should support non-RSA (especially elliptic curve) keys for authentication in the project.

The list of associated tasks is generated using as simple git grep 'OpenSSL.*RSA', which might not be complete.

In most cases, the change should be as trivial as:

-      OpenSSL::PKey::RSA.new(File.read(path))
+      OpenSSL::PKey.read(File.read(path))

as that allows OpenSSL to figure out what kind of key it gets, instead of forcing RSA.