[feat] support to_java protocol for PKey (#250)

Author: kares

src/main/java/org/jruby/ext/openssl/PKey.java

@@ -237,6 +237,25 @@ public ASN1Primitive toASN1PublicInfo() throws IOException {
         return data;
     }
 
+    @Override
+    public Object toJava(final Class target) {
+        if (PrivateKey.class.isAssignableFrom(target)) {
+            final PrivateKey key = getPrivateKey();
+            if (key == null) {
+                throw getRuntime().newRuntimeError("private key not available, to convert to " + target);
+            }
+            if (target.isInstance(key)) return key;
+            throw getRuntime().newTypeError("cannot convert private key of type " + key.getClass() + " to " + target);
+        }
+        if (target.isAssignableFrom(PublicKey.class) || Key.class.isAssignableFrom(target)) {
+            // default is public key, also want to_java() as well as to_java(java.lang.Object) to end up here
+            final PublicKey key = getPublicKey();
+            if (target.isInstance(key)) return key;
+            throw getRuntime().newTypeError("cannot convert public key of type " + key.getClass() + " to " + target);
+        }
+        return super.toJava(target);
+    }
+
     static ByteList sign(final String signAlg, final PrivateKey privateKey, final ByteList data)
         throws NoSuchAlgorithmException, InvalidKeyException, SignatureException {
         Signature signature = SecurityHelper.getSignature(signAlg);

src/test/ruby/rsa/test_rsa.rb

@@ -179,6 +179,22 @@ def test_RSAPublicKey
     assert_equal expected, OpenSSL::Digest::SHA1.hexdigest(key.to_der)
   end if !defined?(JRUBY_VERSION) || JRUBY_VERSION > '9.1' # set_key only since Ruby 2.3
 
+  def test_to_java
+    key_file = File.join(File.dirname(__FILE__), 'private_key.pem')
+    pkey = OpenSSL::PKey::RSA.new(File.read(key_file))
+    assert_kind_of java.security.PublicKey, pkey.to_java
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.PublicKey)
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.interfaces.RSAPublicKey)
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.Key)
+    assert_kind_of java.security.PrivateKey, pkey.to_java(java.security.PrivateKey)
+    assert_kind_of java.security.PrivateKey, pkey.to_java(java.security.interfaces.RSAPrivateKey)
+    priv_key = pkey.to_java(java.security.PrivateKey)
+    if priv_key.is_a? org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPrivateCrtKey
+      assert_kind_of java.security.PrivateKey, pkey.to_java(org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPrivateCrtKey)
+    end
+    assert_raise_kind_of(TypeError) { pkey.to_java(java.security.interfaces.ECPrivateKey) }
+  end if defined?(JRUBY_VERSION)
+
   private
 
   def assert_same_rsa(expected, key)

src/test/ruby/test_pkey.rb

@@ -3,16 +3,30 @@
 
 class TestPKey < TestCase
 
-  def test_pkey_read
-    key = "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArTlm5TxJp3WHMNmWIfo/\nWvkyhJCXc1S78Y9B8lSXxXnkRqX8Twxu5EkdUP0TwgD5gp0TGy7UPm/SgWlQOcqX\nqtdOWq/Hk29Ve9z6k6wTmst7NTefmm/7OqkeYmBhfhoECLCKBADM8ctjoqD63R0e\n3bUW2knq6vCS5YMmD76/5UoU647BzB9CjgDzjuTKEbXL5AvcO5wWDgHSp7CA+2t4\nIFQvQMrPso5mvm2hNvD19vI0VjiY21rKgkJQAXSrLgkJg/fTL2wQiz10d2GnYsmx\nDeJCiBMwC+cmRW2eWePqaCPaWJwr92KsIiry+LgyGb3y01SUVV8kQgQXazutHqfu\ncQIDAQAB\n-----END PUBLIC KEY-----\n"
-
-    # assert OpenSSL::PKey::RSA.new(key).public?
+  KEY = "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArTlm5TxJp3WHMNmWIfo/\nWvkyhJCXc1S78Y9B8lSXxXnkRqX8Twxu5EkdUP0TwgD5gp0TGy7UPm/SgWlQOcqX\nqtdOWq/Hk29Ve9z6k6wTmst7NTefmm/7OqkeYmBhfhoECLCKBADM8ctjoqD63R0e\n3bUW2knq6vCS5YMmD76/5UoU647BzB9CjgDzjuTKEbXL5AvcO5wWDgHSp7CA+2t4\nIFQvQMrPso5mvm2hNvD19vI0VjiY21rKgkJQAXSrLgkJg/fTL2wQiz10d2GnYsmx\nDeJCiBMwC+cmRW2eWePqaCPaWJwr92KsIiry+LgyGb3y01SUVV8kQgQXazutHqfu\ncQIDAQAB\n-----END PUBLIC KEY-----\n"
 
-    pkey = OpenSSL::PKey.read(key)
+  def test_pkey_read
+    pkey = OpenSSL::PKey.read(KEY)
     assert_same OpenSSL::PKey::RSA, pkey.class
-    assert pkey.public?
-    assert_equal OpenSSL::PKey::RSA.new(key).n, pkey.n
-    assert_equal OpenSSL::PKey::RSA.new(key).e, pkey.e
+    assert_true pkey.public?
+    assert_false pkey.private?
+    assert_equal OpenSSL::PKey::RSA.new(KEY).n, pkey.n
+    assert_equal OpenSSL::PKey::RSA.new(KEY).e, pkey.e
   end
 
+  def test_to_java
+    pkey = OpenSSL::PKey.read(KEY)
+    assert_kind_of java.security.PublicKey, pkey.to_java
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.PublicKey)
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.interfaces.RSAPublicKey)
+    assert_kind_of java.security.PublicKey, pkey.to_java(java.security.Key)
+    pub_key = pkey.to_java(java.security.PublicKey)
+    if pub_key.is_a? org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey
+      assert_kind_of java.security.PublicKey, pkey.to_java(org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey)
+    end
+    assert_raise_kind_of(TypeError) { pkey.to_java(java.security.interfaces.ECPublicKey) }
+    # NOTE: won't fail as it's a marker that is neither a PublicKey or PrivateKey (also does not sub-class Key)
+    #assert_raise_kind_of(TypeError) { pkey.to_java(java.security.interfaces.ECKey) }
+  end if defined?(JRUBY_VERSION)
+
 end