[ruby/openssl] pkey: implement {DH,DSA,RSA}#public_key in Ruby

The low-level API that is used to implement #public_key is deprecated
in OpenSSL 3.0. It is actually very simple to implement in another way,
using existing methods only, in much shorter code. Let's do it.

While we are at it, the documentation is updated to recommend against
using #public_key. Now that OpenSSL::PKey::PKey implements public_to_der
method, there is no real use case for #public_key in newly written Ruby
programs.

https://github.com/ruby/openssl/commit/48a6c391ef

1 files changed, 18 insertions, 19 deletions

diff --git a/test/openssl/test_pkey_rsa.rb b/test/openssl/test_pkey_rsa.rb
index d1e68dbc9f..5f8d04e754 100644
--- a/test/openssl/test_pkey_rsa.rb
+++ b/test/openssl/test_pkey_rsa.rb
@@ -69,29 +69,28 @@ class OpenSSL::TestPKeyRSA < OpenSSL::PKeyTestCase
   end
 
   def test_new
-    key = OpenSSL::PKey::RSA.new 512
-    pem  = key.public_key.to_pem
-    OpenSSL::PKey::RSA.new pem
-    assert_equal([], OpenSSL.errors)
-  end
+    key = OpenSSL::PKey::RSA.new(512)
+    assert_equal 512, key.n.num_bits
+    assert_equal 65537, key.e
+    assert_not_nil key.d
 
-  def test_new_exponent_default
-    assert_equal(65537, OpenSSL::PKey::RSA.new(512).e)
+    # Specify public exponent
+    key2 = OpenSSL::PKey::RSA.new(512, 3)
+    assert_equal 512, key2.n.num_bits
+    assert_equal 3, key2.e
+    assert_not_nil key2.d
   end
 
-  def test_new_with_exponent
-    1.upto(30) do |idx|
-      e = (2 ** idx) + 1
-      key = OpenSSL::PKey::RSA.new(512, e)
-      assert_equal(e, key.e)
-    end
-  end
+  def test_s_generate
+    key1 = OpenSSL::PKey::RSA.generate(512)
+    assert_equal 512, key1.n.num_bits
+    assert_equal 65537, key1.e
 
-  def test_generate
-    key = OpenSSL::PKey::RSA.generate(512, 17)
-    assert_equal 512, key.n.num_bits
-    assert_equal 17, key.e
-    assert_not_nil key.d
+    # Specify public exponent
+    key2 = OpenSSL::PKey::RSA.generate(512, 3)
+    assert_equal 512, key2.n.num_bits
+    assert_equal 3, key2.e
+    assert_not_nil key2.d
   end
 
   def test_new_break