Revert "update jwt-go to v3.0.0-4-g01aeca5"

vendor/github.com/dgrijalva/jwt-go/rsa.go

@@ -44,7 +44,8 @@ func (m *SigningMethodRSA) Alg() string {
 }
 
 // Implements the Verify method from SigningMethod
-// For this signing method, must be an rsa.PublicKey structure.
+// For this signing method, must be either a PEM encoded PKCS1 or PKCS8 RSA public key as
+// []byte, or an rsa.PublicKey structure.
 func (m *SigningMethodRSA) Verify(signingString, signature string, key interface{}) error {
 	var err error
 
@@ -55,10 +56,16 @@ func (m *SigningMethodRSA) Verify(signingString, signature string, key interface
 	}
 
 	var rsaKey *rsa.PublicKey
-	var ok bool
 
-	if rsaKey, ok = key.(*rsa.PublicKey); !ok {
-		return ErrInvalidKeyType
+	switch k := key.(type) {
+	case []byte:
+		if rsaKey, err = ParseRSAPublicKeyFromPEM(k); err != nil {
+			return err
+		}
+	case *rsa.PublicKey:
+		rsaKey = k
+	default:
+		return ErrInvalidKey
 	}
 
 	// Create hasher
@@ -73,13 +80,20 @@ func (m *SigningMethodRSA) Verify(signingString, signature string, key interface
 }
 
 // Implements the Sign method from SigningMethod
-// For this signing method, must be an rsa.PrivateKey structure.
+// 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
 	var rsaKey *rsa.PrivateKey
-	var ok bool
 
-	// Validate type of key
-	if rsaKey, ok = key.(*rsa.PrivateKey); !ok {
+	switch k := key.(type) {
+	case []byte:
+		if rsaKey, err = ParseRSAPrivateKeyFromPEM(k); err != nil {
+			return "", err
+		}
+	case *rsa.PrivateKey:
+		rsaKey = k
+	default:
 		return "", ErrInvalidKey
 	}