web/vendor/qiniu/php-sdk/examples/upload_verify_callback.php

<?php
require_once __DIR__ . '/../autoload.php';

use Qiniu\Auth;

$accessKey = getenv('QINIU_ACCESS_KEY');
$secretKey = getenv('QINIU_SECRET_KEY');
$bucket = getenv('QINIU_TEST_BUCKET');

$auth = new Auth($accessKey, $secretKey);

//获取回调的body信息
$callbackBody = file_get_contents('php://input');

//回调的contentType
$contentType = 'application/x-www-form-urlencoded';

//回调的签名信息，可以验证该回调是否来自七牛
$authorization = $_SERVER['HTTP_AUTHORIZATION'];

//七牛回调的url，具体可以参考：http://developer.qiniu.com/docs/v6/api/reference/security/put-policy.html
$url = 'http://172.30.251.210/upload_verify_callback.php';

$isQiniuCallback = $auth->verifyCallback($contentType, $authorization, $url, $callbackBody);

if ($isQiniuCallback) {
    $resp = array('ret' => 'success');
} else {
    $resp = array('ret' => 'failed');
}

echo json_encode($resp);