TP5.1写接口用来加密解密的方法

//对uid进行加密
function think_encrypt($data, $key = '', $expire = 0) {
    $key  = md5(empty($key) ? Env::get('CRYPT_KEY') : "");
    $data = base64_encode($data);
    $x    = 0;
    $len  = strlen($data);
    $l    = strlen($key);
    $char = '';
    for ($i = 0; $i < $len; $i++) {
        if ($x == $l) $x = 0;
        $char .= substr($key, $x, 1);
        $x++;
    }
    $str = sprintf('%010d', $expire ? $expire + time():0);
    for ($i = 0; $i < $len; $i++) {
        $str .= chr(ord(substr($data, $i, 1)) + (ord(substr($char, $i, 1)))%256);
    }
    return str_replace(array('+','/','='),array('-','_',''),base64_encode($str));
}

//对uid解密
function think_decrypt($data, $key = ''){
    $key    = $key  = md5(empty($key) ? Env::get('CRYPT_KEY') : "");
    $data   = str_replace(array('-','_'),array('+','/'),$data);
    $mod4   = strlen($data) % 4;
    if ($mod4) {
       $data .= substr('====', $mod4);
    }
    $data   = base64_decode($data);
    $expire = substr($data,0,10);
    $data   = substr($data,10);
    if($expire > 0 && $expire < time()) {
        return '';
    }
    $x      = 0;
    $len    = strlen($data);
    $l      = strlen($key);
    $char   = $str = '';
    for ($i = 0; $i < $len; $i++) {
        if ($x == $l) $x = 0;
        $char .= substr($key, $x, 1);
        $x++;
    }
    for ($i = 0; $i < $len; $i++) {
        if (ord(substr($data, $i, 1))<ord(substr($char, $i, 1))) {
            $str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1)));
        }else{
            $str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1)));
        }
    }
    return base64_decode($str);
}