hemall.terabimsoft.com.cn/app/common/services/qcloud/Helper.php

<?php

namespace app\common\services\qcloud;

class Helper {
    /**
    * Build custom post fields for safe multipart POST request for php before 5.5.
    * @param $fields array of key -> value fields to post.
    * @return $boundary and encoded post fields.
    */
    public static function yz_buildCustomPostFields($fields) {
        // invalid characters for "name" and "filename"
        static $disallow = array("\0", "\"", "\r", "\n");

        // initialize body
        $body = array();

        // build normal parameters
        foreach ($fields as $key => $value) {
            $key = str_replace($disallow, "_", $key);
            $body[] = implode("\r\n", array(
                "Content-Disposition: form-data; name=\"{$key}\"",
                '',
                filter_var($value),
            ));
        }

        // generate safe boundary
        do {
            $boundary = "---------------------" . md5(mt_rand() . microtime());
        } while (preg_grep("/{$boundary}/", $body));

        // add boundary for each parameters
        foreach ($body as &$part) {
            $part = "--{$boundary}\r\n{$part}";
        }
        unset($part);

        // add final boundary
        $body[] = "--{$boundary}--";
        $body[] = '';

        return array($boundary, implode("\r\n", $body));
    }
}