/usr/lib/ is in ruby-certificate-authority 0.2.0~6dd483bf-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/certificate_authority/
/usr/lib/ruby/vendor_ruby/certificate_authority/certificate.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/certificate_revocation_list.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/core_extensions.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/distinguished_name.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/extensions.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/key_material.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/ocsp_handler.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/pkcs11_key_material.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/revocable.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/serial_number.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/signing_entity.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/signing_request.rb
/usr/lib/ruby/vendor_ruby/certificate_authority/validations.rb
/usr/lib/ruby/vendor_ruby/certificate_authority.rb