/**
    对小程序的api请求进行加密处理，得到加密后的请求对象
    
    @param array $req 请求的对象
    @param string $url_path 加密的api请求url地址(不包含url参数)
    @return object 返回加密后的请求对象
    **/
    public static function makeEncryptReq($req, $url_path)
    {
        $local_ts = floor(time());
        $nonce = str_replace("=", "",base64_encode(random_bytes(16)));
        $reqex = array(
            "_n" => $nonce,
            "_appid" => self::miniAppID,
            "_timestamp" =>$local_ts
        );        
        $real_req = array_merge($req, $reqex);
        ksort($real_req);
        $plaintext = json_encode($real_req, 320);
        //$url_path = self::getExpressAPiUrl()['addorder'];
        $aad = $url_path.'|'.self::miniAppID.'|'.$local_ts.'|'.self::apiAES256['sn'];
        $real_key = base64_encode(self::apiAES256['key']);
        $real_iv = random_bytes(12);
        $real_aad = utf8_encode($aad);
        $real_plaintext = utf8_encode($plaintext);
        $real_ciphertext = openssl_encrypt($plaintext, 'aes-256-gcm', $real_key, OPENSSL_RAW_DATA, $real_iv, $tag, $real_aad, 16);
        
        $iv = base64_encode($real_iv);
        $data = base64_encode($real_ciphertext);
        $authtag = base64_encode($tag);
        $req_data = array(
                "iv" => $iv,
                "data" => $data,
                "authtag" => $authtag
            );
        $new_req = array(
                "req_ts" => $local_ts,
                "req_data" => json_encode($req_data)
            );
        return json_decode(json_encode($new_req)); //返回加密后的对象
    }
    
    
        /**
    对小程序的api请求进行签名，返回base64加密后的签名
    
    @param array $new_req 经过加密后的请求对象
    @param string $url_path 签名的api请求url地址(不包含url参数)
    @return string 返回加base64加密后的签名
    **/
    public static function sign($new_req, $url_path)
    {
        $signature = '';
        $access_token = MiniBase::getMiniAccessToken();
        $appid = MiniBase::miniAppID;
        $timestamp = $new_req->req_ts;
        $postdata = $new_req->req_data;
        $signStr = "$url_path\n $appid\n $timestamp\n $postdata";
        $api_private_key = openssl_pkey_get_private(self::apiRSA256['private_key']);
        $api_public_key = openssl_pkey_get_public(self::apiRSA256['public_key']);
        $postdataUtf8 = utf8_encode($postdata);
        openssl_sign($postdataUtf8, $signature, $api_private_key, OPENSSL_ALGO_SHA256);
        $signature = base64_encode($signature);
        $plainSignature = base64_decode($signature);
        $ok = openssl_verify($postdata, $plainSignature, $api_public_key, OPENSSL_ALGO_SHA256); //验签
        if ($ok == 1){
            //echo $ok;
            return $signature;
        }
    }

不行，函数不一样，我照着一句句写的，自己加密解密，签名验签都通过，但是发送到接口就是签名失败