Gaoming13\WechatPhpSdk\Utils\Pkcs7Encoder::encode PHP Method

    function encode($text)
    {
        $text_length = strlen($text);
        //计算需要填充的位数
        $amount_to_pad = Pkcs7Encoder::$block_size - $text_length % Pkcs7Encoder::$block_size;
        if ($amount_to_pad == 0) {
            $amount_to_pad = Pkcs7Encoder::$block_size;
        }
        //获得补位所用的字符
        $pad_chr = chr($amount_to_pad);
        $tmp = "";
        for ($index = 0; $index < $amount_to_pad; $index++) {
            $tmp .= $pad_chr;
        }
        return $text . $tmp;
    }

 /**
  * 对明文进行加密
  * @param string $text 需要加密的明文
  * @return string 加密后的密文
  */
 public function encrypt($text, $appid)
 {
     try {
         //获得16位随机字符串，填充到明文之前
         $random = $this->getRandomStr();
         $text = $random . pack("N", strlen($text)) . $text . $appid;
         // 网络字节序
         $size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
         $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
         $iv = substr($this->key, 0, 16);
         //使用自定义的填充方式对明文进行补位填充
         $pkc_encoder = new Pkcs7Encoder();
         $text = $pkc_encoder->encode($text);
         mcrypt_generic_init($module, $this->key, $iv);
         //加密
         $encrypted = mcrypt_generic($module, $text);
         mcrypt_generic_deinit($module);
         mcrypt_module_close($module);
         //使用BASE64对加密后的字符串进行编码
         return base64_encode($encrypted);
     } catch (Exception $e) {
         @error_log('Encrypt AES Error: ' . $e->getMessage(), 0);
         return FALSE;
     }
 }