额 大佬 没理解 能详细说说吗

我这边发起请求的body和签名的body都是json过后的字符串

$originBody = [
    "appid" => "wx612a655e6dc42689",
    "out_batch_no" => "ML".time(),
    "batch_name" => "商户提现",
    "batch_remark" => "测试",
    "total_amount" => "1",
    "total_num" => "1",
    "transfer_detail_list" => [
        [
        "out_detail_no" =>"MLcash".time().rand(10000,99999),
        "transfer_amount" => "1",
        "transfer_remark" => "商户提现测试",
        "openid" => "o15S37cWeEq1qYy1ySBr3i-dLG3c",
        ]
    ]
];
$body = json_encode($originBody, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
$url = "https://api.mch.weixin.qq.com/v3/transfer/batches";


$params = array( "url" => $url, "method" => "POST", "body" => $body );
# 商户号
$mch_id = "1499339842";


$url_parts = parse_url($url);
$canonical_url = $url_parts["path"] . ((!empty($url_parts["query"]) ? "?" . $url_parts["query"] : ""));


$http_method = $params["method"];
$timestamp = time();


$nonce = random(8);












$message = $http_method . "\n" . $canonical_url . "\n" . $timestamp . "\n" . $nonce . "\n" . $body . "\n";










$mch_private_key = openssl_pkey_get_private(file_get_contents("apiclient_key.pem"));
openssl_sign($message, $raw_sign, $mch_private_key, "sha256WithRSAEncryption");
$sign = base64_encode($raw_sign);






$schema = "WECHATPAY2-SHA256-RSA2048";
$merchant_id = $mch_id;
$serial_no = "76424E3229AEB58C946AE180124547BAE432B8F8";
$token = sprintf("mchid=\"%s\",nonce_str=\"%s\",timestamp=\"%d\",serial_no=\"%s\",signature=\"%s\"", $merchant_id, $nonce, $timestamp, $serial_no, $sign);
$result = $schema . " " . $token;






$header = [
    "Authorization" => $result,
    "Accept" => "application/json",
    "Content-Type" => "application/json",
];






$response = ihttp_request($url, $params, $header);




print_r($response);