Add convenience constants

[rchekaluk]

Gem net-ssh defines two convenience constants:

• OpenSSL::PKey::EC::CurveNameAlias
• OpenSSL::PKey::EC::CurveNameAliasInv

Because I have needed to duplicate these constants in other gems that depend on ruby/openssl, migrate them upstream to ruby/openssl for convenience.

[ioquatix]

I had a quick look, but what's the point of the Inv suffix list? Would it make sense to just define a canonical name and stick with it? Is there actually a need to map back to the aliases? (assuming it's 1:1 and not 1:N).

[rchekaluk]

I may not understand the question fully, but the reason for both hashes is that there are use cases for both. Specifically, for examples see:

• CurveNameAlias
  • Gem net-ssh openssl.rb
• CurveNameAliasInv
  • Gem net-ssh agent.rb
  • Gem net-ssh openssl.rb
  • Gem sshkey sshkey.rb

Moreover, note that in order to support JRuby, gem sshkey has a use case where there are duplicated values in the analogue of CurveNameAliasInv (which precludes the use of CurveNameAlias.invert). You may want to consider including that additional case in this pull request.

[ioquatix]

Okay, let me clarify.

When I think of an alias, I think of "There is a person Bob", and I can also refer to "Bob" as Rob, Hob, Dob. Those are aliases.

Because of that, the mapping is not 1:1 but 1:N.

What I want to understand is, is this a table of aliases (1:N) or something else (1:1). I think the mental model and how we organise it will be slightly different.

In principle I understand the use case and agree with adding these, I just want to make sure we do it correctly.

cc @headius maybe you have some thoughts.

[rhenium]

It looks like the /nistp.*/ are the curve names used in the SSH protocol (https://www.rfc-editor.org/rfc/rfc5656.html). I think the gems implementing it are the right places for this mapping table to be defined in.