PHP可逆暗号化・復号化関数サンプルコード

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(&#39;des&#39;, &#39;ecb&#39;); 
$pad = ord($str[($len = strlen($str)) - 1]); 
if ($pad && $pad < $block && preg_match(&#39;/&#39; . chr($pad) . &#39;{&#39; . $pad . &#39;}$/&#39;, $str)) { 
$str = substr($str, 0, strlen($str) - $pad); 
} 
return unserialize($str); 
}

$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);