Aes CBC加密

<?php
namespace app\components;
use yii;
class Aes
{
/**
* This was AES-128 / CBC / PKCS5Padding
* return base64_encode string
* @param string $plaintext
* @param string $key
* @return string
*/
public static function AesEncrypt($plaintext,$key = null)
{
$plaintext = trim($plaintext);
if ($plaintext == '') return '';
$size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); //PKCS5Padding
$padding = $size - strlen($plaintext) % $size;
// 添加Padding
$plaintext .= str_repeat(chr($padding), $padding); $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
$key=self::substr($key, 0, mcrypt_enc_get_key_size($module));
$iv = $key;
// str_repeat($key, $size);
/* Intialize encryption */
mcrypt_generic_init($module, $key, $iv); /* Encrypt data */
$encrypted = mcrypt_generic($module, $plaintext);
/* Terminate encryption handler */
mcrypt_generic_deinit($module);
mcrypt_module_close($module);
return base64_encode($encrypted);
}
/**
* Returns the length of the given string.
* If available uses the multibyte string function mb_strlen.
* @param string $string the string being measured for length
* @return integer the length of the string
*/
private static function strlen($string)
{
return extension_loaded('mbstring') ? mb_strlen($string,'8bit') : strlen($string);
} /**
* Returns the portion of string specified by the start and length parameters.
* If available uses the multibyte string function mb_substr
* @param string $string the input string. Must be one character or longer.
* @param integer $start the starting position
* @param integer $length the desired portion length
* @return string the extracted part of string, or FALSE on failure or an empty string.
*/
private static function substr($string,$start,$length)
{
return extension_loaded('mbstring') ? mb_substr($string,$start,$length,'8bit') : substr($string,$start,$length);
}
/**
* This was AES-128 / CBC / PKCS5Padding
* @param string $encrypted base64_encode encrypted string
* @param string $key
* @throws CException
* @return string
*/
public static function AesDecrypt($encrypted, $key = null)
{
if ($encrypted == '') return '';
$ciphertext_dec = base64_decode($encrypted);
$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
$key=self::substr($key, 0, mcrypt_enc_get_key_size($module));
$iv = $key;
// str_repeat($key, 16); //解密的初始化向量要和加密时一样。
/* Initialize encryption module for decryption */
mcrypt_generic_init($module, $key, $iv); /* Decrypt encrypted string */
$decrypted = mdecrypt_generic($module, $ciphertext_dec); /* Terminate decryption handle and close module */
mcrypt_generic_deinit($module);
mcrypt_module_close($module);
// echo $decrypted;die;
//$a = rtrim($decrypted,"\0");
return rtrim($decrypted,"\0");
}
}