ext/openssl: implement OpenSSL::PKey::{DSA,RSA,EC}#public_pkeytopic/openssl-pkey-ec

Add OpenSSL::PKey::{DSA,RSA,EC}#public_pkey. They return a new instance
of itself, which contains only parameters and public information.

The old methods, {DSA,RSA}#public_key, are now deprecated.

There are 3 types of PKey#public_key: 1) EC#public_key, which returns
the actual public key (EC::Point). 2) RSA/DSA#public_key, which returns
a new instance of PKey with no private information. 3) DH#public_key,
which returns a new instance of DH which contains only DH params. This
doesn't even contain 'private key'. This is very confusing. The new
methods are intend to replace the 2).

1 files changed, 5 insertions, 0 deletions

diff --git a/test/openssl/test_pkey_dsa.rb b/test/openssl/test_pkey_dsa.rb
index eb3e4f1c65..3537738aa9 100644
--- a/test/openssl/test_pkey_dsa.rb
+++ b/test/openssl/test_pkey_dsa.rb
@@ -228,6 +228,11 @@ YNMbNw==
     assert(pem)
   end
 
+  def test_public_pkey
+    key = OpenSSL::TestUtils::TEST_KEY_DSA256
+    assert_equal(key.public_key.to_der, key.public_pkey.to_der)
+  end
+
   private
 
   def check_sign_verify(digest)