OpenSSL::PKey::RSA.generate always returns a OpenSSL::PKey::RSA, even when sublcassed, on Ruby 3.1/openssl-3.0.0

[postmodern]

I noticed a change in behavior for OpenSSL::PKey::RSA.generate between Ruby 3.0 (openssl-2.x) and ruby 3.1 (openssl-3.0.0). In Ruby 3.1 OpenSSL::PKey::RSA.generate will always return a OpenSSL::PKey::RSA instance, even when the class has been sublcassed.

Steps To Reproduce

require 'openssl'

class MyRSA < OpenSSL::PKey::RSA
end

p MyRSA.generate(1024)

Expected Behavior

#<MyRSA:...>

Actual Behavior

#<OpenSSL::PKey::RSA:...>

Version

• Ruby 3.0 (Works):
  • ruby 3.0.4p208 (2022-04-12 revision 3fa771dded) [x86_64-linux]
  • `openssl (default: 2.2.1)
• Ruby 3.1 (Fails):
  • ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
  • openssl (default: 3.0.0)

This regression seems to have appeared in 3.0.0.

[postmodern]

Also effects OpenSSL::PKey::DSA as well.