pkey: make PKey#verify check the existence of the public key

Check existence of the public key in the PKey object before starting
verifying a signature.

For RSA keys, EVP_VerifyFinal() internally calls RSA_size(), which
requires the existence of RSA::n. Since we allow instatiating PKey::RSA
without any key materials, calling PKey#verify against an empty
PKey::RSA causes segfault.

Reference: https://bugs.ruby-lang.org/issues/12783

1 files changed, 7 insertions, 0 deletions

diff --git a/test/test_pkey.rb b/test/test_pkey.rb
index 79647c8f..ba61fa26 100644
--- a/test/test_pkey.rb
+++ b/test/test_pkey.rb
@@ -44,6 +44,13 @@ class OpenSSL::TestPKey < OpenSSL::PKeyTestCase
       end
     end
   end
+
+  def test_verify_empty_rsa
+    rsa = OpenSSL::PKey::RSA.new
+    assert_raise(OpenSSL::PKey::PKeyError, "[Bug #12783]") {
+      rsa.verify("SHA1", "a", "b")
+    }
+  end
 end
 
 end