php可逆加密解密

函数：

function encrypt($data, $key) { 
    $prep_code = serialize($data); 
    $block = mcrypt_get_block_size('des', 'ecb'); 
        if (($pad = $block - (strlen($prep_code) % $block)) < $block) { 
            $prep_code .= str_repeat(chr($pad), $pad); 
        } 
        $encrypt = mcrypt_encrypt(MCRYPT_DES, $key, $prep_code, MCRYPT_MODE_ECB); 
        return base64_encode($encrypt); 
    } 
    function decrypt($str, $key) { 
    $str = base64_decode($str); 
    $str = mcrypt_decrypt(MCRYPT_DES, $key, $str, MCRYPT_MODE_ECB); 
        $block = mcrypt_get_block_size('des', 'ecb'); 
        $pad = ord($str[($len = strlen($str)) - 1]); 
        if ($pad && $pad < $block && preg_match('/' . chr($pad) . '{' . $pad . '}$/', $str)) { 
            $str = substr($str, 0, strlen($str) - $pad); 
        } 
        return unserialize($str); 
} 

调用：

$key = 'okyo.cn'; 
$data = array('id' => 100, 'username' => 'customer', 'password' => 'e10adc3949ba59abbe56e057f20f883e'); 
$snarr = serialize($data); 
$en = encrypt($data, $key); 
$de = decrypt($en, $key); 
echo "加密原型："; 
print_r($data); 
echo " 
密钥：$key 
加密结果：$en 
解密结果："; 
print_r($de);