function decrypt($str, $key)
{
    if ($str == '') {
        return '';
    }
    $v = str2long($str, false);
    $k = str2long($key, false);
    if (count($k) < 4) {
        for ($i = count($k); $i < 4; $i++) {
            $k[$i] = 0;
        }
    }
    $n = count($v) - 1;
    $z = $v[$n];
    $y = $v[0];
    $delta = 0x9e3779b9;
    $q = floor(6 + 52 / ($n + 1));
    $sum = int32($q * $delta);
    while ($sum != 0) {
        $e = $sum >> 2 & 3;
        for ($p = $n; $p > 0; $p--) {
            $z = $v[$p - 1];
            $mx = int32(($z >> 5 & 0x7ffffff ^ $y << 2) + ($y >> 3 & 0x1fffffff ^ $z << 4)) ^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
            $y = $v[$p] = int32($v[$p] - $mx);
        }
        $z = $v[$n];
        $mx = int32(($z >> 5 & 0x7ffffff ^ $y << 2) + ($y >> 3 & 0x1fffffff ^ $z << 4)) ^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
        $y = $v[0] = int32($v[0] - $mx);
        $sum = int32($sum - $delta);
    }
    return long2str($v, true);
}

function TEAdecrypt($str, $key = EW_RANDOM_KEY)
{
    $str = ew_UrlDecode($str);
    if ($str == "") {
        return "";
    }
    $v = str2long($str, false);
    $k = str2long($key, false);
    $cntk = count($k);
    if ($cntk < 4) {
        for ($i = $cntk; $i < 4; $i++) {
            $k[$i] = 0;
        }
    }
    $n = count($v) - 1;
    $z = $v[$n];
    $y = $v[0];
    $delta = 0.0;
    $q = floor(6 + 52 / ($n + 1));
    $sum = int32($q * $delta);
    while ($sum != 0) {
        $e = $sum >> 2 & 3;
        for ($p = $n; $p > 0; $p--) {
            $z = $v[$p - 1];
            $mx = int32(($z >> 5 & 0x7ffffff ^ $y << 2) + ($y >> 3 & 0x1fffffff ^ $z << 4)) ^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
            $y = $v[$p] = int32($v[$p] - $mx);
        }
        $z = $v[$n];
        $mx = int32(($z >> 5 & 0x7ffffff ^ $y << 2) + ($y >> 3 & 0x1fffffff ^ $z << 4)) ^ int32(($sum ^ $y) + ($k[$p & 3 ^ $e] ^ $z));
        $y = $v[0] = int32($v[0] - $mx);
        $sum = int32($sum - $delta);
    }
    return long2str($v, true);
}

/** Decipher
* @param string binary cipher
* @param string
* @return string plain-text password
*/
function decrypt_string($str, $key)
{
    if ($str == "") {
        return "";
    }
    if (!$key) {
        return false;
    }
    $key = array_values(unpack("V*", pack("H*", md5($key))));
    $v = str2long($str, false);
    $n = count($v) - 1;
    $z = $v[$n];
    $y = $v[0];
    $q = floor(6 + 52 / ($n + 1));
    $sum = int32($q * 0x9e3779b9);
    while ($sum) {
        $e = $sum >> 2 & 3;
        for ($p = $n; $p > 0; $p--) {
            $z = $v[$p - 1];
            $mx = xxtea_mx($z, $y, $sum, $key[$p & 3 ^ $e]);
            $y = int32($v[$p] - $mx);
            $v[$p] = $y;
        }
        $z = $v[$n];
        $mx = xxtea_mx($z, $y, $sum, $key[$p & 3 ^ $e]);
        $y = int32($v[0] - $mx);
        $v[0] = $y;
        $sum = int32($sum - 0x9e3779b9);
    }
    return long2str($v, true);
}