php 加密解密类

class ScoreEncrypt {
   
    public static function Jiami($txt, $key = null) {
        empty($key) && $key = SECURE_CODE;
        //有mcrypt扩展时
        if(function_exists('mcrypt_module_open')){
            return self::encrypt($txt, $key);
        }
        //无mcrypt扩展时
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-=_";
        $nh = rand(0, 64);
        $ch = $chars[$nh];
        $mdKey = md5($key.$ch);
        $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
        $txt = base64_encode($txt);
        $tmp = '';
        $i = 0;
        $j = 0;
        $k = 0;
        for($i = 0; $i < strlen($txt); $i++) {
            $k = $k == strlen($mdKey) ? 0 : $k;
            $j = ($nh + strpos($chars, $txt [$i]) + ord($mdKey[$k++])) % 64;
            $tmp .= $chars[$j];
        }
        return $ch.$tmp;
    }

   
    public static function Jiemi($txt, $key = null) {
        empty($key) && $key = SECURE_CODE;
        //有mcrypt扩展时
        if(function_exists('mcrypt_module_open')){
            return self::decrypt($txt, $key);
        }
        //无mcrypt扩展时
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-=_";
        $ch = $txt[0];
        $nh = strpos($chars, $ch);
        $mdKey = md5($key.$ch);
        $mdKey = substr($mdKey, $nh % 8, $nh % 8 + 7);
        $txt = substr($txt, 1);
        $tmp = '';
        $i = 0;
        $j = 0;
        $k = 0;
        for($i = 0; $i < strlen($txt); $i++) {
            $k = $k == strlen($mdKey) ? 0 : $k;
            $j = strpos($chars, $txt[$i]) - $nh - ord($mdKey[$k++]);
            while($j < 0) {
                $j += 64;
            }
            $tmp .= $chars[$j];
        }
        return base64_decode($tmp);
    }

   
    static public function encrypt($input, $key) {
        $size = mcrypt_get_block_size('des', 'ecb');
        $input = self::pkcs5_pad($input, $size);
        $key = $key;
        $td = mcrypt_module_open('des', '', 'ecb', '');
        $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        @mcrypt_generic_init($td, $key, $iv);
        $data = mcrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        $data = base64_encode($data);
        return $data;
    }
   
    static public function decrypt($encrypted, $key) {
        $encrypted = base64_decode($encrypted);
        $key = $key;
        $td = mcrypt_module_open('des','','ecb','');
        //使用MCRYPT_DES算法,cbc模式
        $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        $ks = mcrypt_enc_get_key_size($td);
        @mcrypt_generic_init($td, $key, $iv);
        //初始处理
        $decrypted = mdecrypt_generic($td, $encrypted);
        //解密
        mcrypt_generic_deinit($td);
        //结束
        mcrypt_module_close($td);
        $y= self::pkcs5_unpad($decrypted);
        return $y;
    }

    static private function pkcs5_pad ($text, $blocksize) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }
    static private function pkcs5_unpad($text) {
        $pad = ord($text{strlen($text)-1});
        if ($pad > strlen($text))
            return false;
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad)
            return false;
        return substr($text, 0, -1 * $pad);
    }
}