PHP签名的字符串无法用go验证成功？

PHP签名代码： ```php // sign begin. $private_key_resource = openssl_get_privatekey($rsa_private_key_string); $private_key_details = openssl_pkey_get_details($private_key_resource); if (!isset($private_key_details['key']) || $private_key_details['type'] !== OPENSSL_KEYTYPE_RSA) { throw new InvalidArgumentException('This key is not compatible with RSA signatures'); } $signature = ''; openssl_sign($string_to_sign, $signature, $private_key_resource, OPENSSL_ALGO_SHA256); // free the key from memory openssl_free_key($private_key_resource); $base64url_encode_signature = $this->base64url_encode($signature); $request_header['App-Signature'] = $base64url_encode_signature.'.'.$string_to_sign; private function base64url_encode($data) { return rtrim(strtr(base64_encode($data), '+/', '-_'), '='); } ``` go验证代码： ```go publicKey := LoadRSAPublicKeyFromDisk() digest := sha256.New() //digest.Write(bodyByte) digest.Write([]byte("")) hashed := digest.Sum(nil) tt1 := strings.Replace(elementArray[0], "-", "+", -1) tt2 := strings.Replace(tt1, "_", "/", -1) repeatChar := strings.Repeat("=", 4 - len(tt2) % 4) tt2 += repeatChar ttt,_ := base64.StdEncoding.DecodeString(tt2) //ttt,_ := base64.StdEncoding.DecodeString(elementArray[0]) logger.AccessLog("ttt1=%X, elementArray[0]=%v, tt2=%v", ttt, elementArray[0]) err4 := rsa.VerifyPKCS1v15(publicKey, crypto.SHA256, hashed, ttt) ``` PHP签名的字符串无法用go验证成功？ 大家有没有人遇到过这种问题？