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, 7 insertions, 0 deletions

diff --git a/test/openssl/test_pkey_dh.rb b/test/openssl/test_pkey_dh.rb
index a0eca53c48..bca40ee202 100644
--- a/test/openssl/test_pkey_dh.rb
+++ b/test/openssl/test_pkey_dh.rb
@@ -68,6 +68,13 @@ YoaOffgTf5qxiwkjnlVZQc3whgnEt9FpVMvQ9eknyeGB5KHfayAc3+hUAvI3/Cr3
     assert_equal(dh.to_pem, public_key.to_pem)
   end
 
+  def test_public_pkey
+    dh = OpenSSL::TestUtils::TEST_KEY_DH1024
+    dh_test = dh.public_pkey
+    assert(!dh_test.private?)
+    assert(dh_test.public?)
+  end
+
   def test_generate_key
     dh = OpenSSL::TestUtils::TEST_KEY_DH1024.public_key # creates a copy
     assert_no_key(dh)