it works

jwt.go

@@ -63,7 +63,7 @@ func Parse(tokenString string, keyFunc func(*Token)([]byte, error)) (token *Toke
 		}
 		
 		// Perform validation
-		if err = token.Method.Verify(strings.Join(parts[0:1], "."), parts[2], key); err == nil {
+		if err = token.Method.Verify(strings.Join(parts[0:2], "."), parts[2], key); err == nil {
 			token.Valid = true
 		}
 		

rs256.go

@@ -7,7 +7,7 @@ import (
 	"crypto"
 	"crypto/x509"
 	"crypto/rsa"
-	_ "crypto/sha256"
+	"crypto/sha256"
 )
 
 type SigningMethodRS256 struct {}
@@ -35,7 +35,7 @@ func (m *SigningMethodRS256) Verify(signingString, signature string, key []byte)
 			var parsedKey interface{}
 			if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err == nil {
 				if rsaKey, ok := parsedKey.(*rsa.PublicKey); ok {
-					hasher := crypto.SHA256.New()
+					hasher := sha256.New()
 					hasher.Write([]byte(signingString))
 					
 					err = rsa.VerifyPKCS1v15(rsaKey, crypto.SHA256, hasher.Sum(nil), sig)

rs256_test.go

@@ -39,7 +39,7 @@ func TestRS256Verify(t *testing.T) {
 		parts := strings.Split(data.tokenString, ".")
 		
 		method, _ := GetSigningMethod("RS256")
-		err := method.Verify(strings.Join(parts[0:1], "."), parts[2], key)
+		err := method.Verify(strings.Join(parts[0:2], "."), parts[2], key)
 		if data.valid && err != nil {
 			t.Errorf("[%v] Error while verifying key: %v", data.name, err)
 		}