can now pass a PrivateKey to SigningMethodRSA.Sign

Conflicts:
	rsa.go

rsa.go

@@ -71,17 +71,22 @@ func (m *SigningMethodRSA) Verify(signingString, signature string, key interface
 }
 
 // Implements the Sign method from SigningMethod
-// For this signing method, must be PEM encoded PKCS1 or PKCS8 RSA private key
+// For this signing method, must be either a PEM encoded PKCS1 or PKCS8 RSA private key as
+// []byte, or an rsa.PrivateKey structure.
 func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string, error) {
 	var err error
-
-	if keyBytes, ok := key.([]byte); ok {
-		// Key
 	var rsaKey *rsa.PrivateKey
-		if rsaKey, err = m.parsePrivateKey(keyBytes); err != nil {
+
+	switch k := key.(type) {
+	case []byte:
+		if rsaKey, err = m.parsePrivateKey(k); err != nil {
 			return "", err
 		}
-
+	case *rsa.PrivateKey:
+		rsaKey = k
+	default:
+		return "", ErrInvalidKey
+	}
 	// Create the hasher
 	hasher := m.Hash.New()
 	hasher.Write([]byte(signingString))
@@ -94,9 +99,6 @@ func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string,
 	}
 }
 
-	return "", ErrInvalidKey
-}
-
 // Parse PEM encoded PKCS1 or PKCS8 public key
 func (m *SigningMethodRSA) parsePublicKey(key []byte) (*rsa.PublicKey, error) {
 	var err error

rsa_test.go

@@ -78,6 +78,24 @@ func TestRSASign(t *testing.T) {
 	}
 }
 
+func TestRSAWithPreParsedPrivateKey(t *testing.T) {
+	key, _ := ioutil.ReadFile("test/sample_key")
+	method := GetSigningMethod("RS256").(*SigningMethodRSA)
+	parsedKey, err := method.parsePrivateKey(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	testData := rsaTestData[0]
+	parts := strings.Split(testData.tokenString, ".")
+	sig, err := method.Sign(strings.Join(parts[0:2], "."), parsedKey)
+	if err != nil {
+		t.Errorf("[%v] Error signing token: %v", testData.name, err)
+	}
+	if sig != parts[2] {
+		t.Errorf("[%v] Incorrect signature.\nwas:\n%v\nexpecting:\n%v", testData.name, sig, parts[2])
+	}
+}
+
 func TestRSAKeyParsing(t *testing.T) {
 	key, _ := ioutil.ReadFile("test/sample_key")
 	pubKey, _ := ioutil.ReadFile("test/sample_key.pub")