签名如下

function generateUserSignatureCorrected($postData, $sessionKey) {

  $signature = hash_hmac('sha256', $postData, $sessionKey);

return $signature;

    }

function generatePaySignCorrected($uri, $postData)

    {

        $message = $uri . '&' . $postData;

        $appKey = $this->config['appkey'];

        $signature = hash_hmac('sha256', $message, $appKey);

         return $signature;

    }

参数如下

$uri='requestCommonPayment',

$postData = [

                "mchid" => $config['mch_id'],

                "out_trade_no" => $order_no,

                "description" => $body,

                "amount" => [

                    "order_amount" => 1000,

                    "currency" => "CNY"

                ],

                "env" => 0

            ];

到底是哪错了？有能帮助下的吗？