des加密解密的两个方法

<?php
//$input - stuff to decrypt
    //$key - the secret key to use

    function do_mencrypt($input, $key)
    {
        $input = str_replace("n", "", $input);
        $input = str_replace("t", "", $input);
        $input = str_replace("r", "", $input);
        $key = substr(md5($key), 0, 24);
        $td = mcrypt_module_open('tripledes', '', 'ecb', '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, $key, $iv);
        $encrypted_data = mcrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        return trim(chop(base64_encode($encrypted_data)));
    }

    //$input - stuff to decrypt
    //$key - the secret key to use

    function do_mdecrypt($input, $key)
    {
        $input = str_replace("n", "", $input);
        $input = str_replace("t", "", $input);
        $input = str_replace("r", "", $input);
        $input = trim(chop(base64_decode($input)));
        $td = mcrypt_module_open('tripledes', '', 'ecb', '');
        $key = substr(md5($key), 0, 24);
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, $key, $iv);
        $decrypted_data = mdecrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        return trim(chop($decrypted_data));
     }
?>