    $encrypt_msg = (string) $xml->Encrypt;

    $signature = business_wechat_sha1($token, $timestamp, $nonce, $encrypt_msg);

    if ($signature != $msg_signature) {
        throw new Exception('ValidateSignatureError');
    }

    return business_wechat_prpcrypt_decrypt($encoding_AES_key, $encrypt_msg, $corpid);
}/*}}}*/

function business_wechat_encrypt_message($xml, $timestamp, $nonce)