php写的AES加密解密类分享

 params['encryptKey'] : $key, 0, mcrypt_enc_get_key_size($module)); /* Create the IV and determine the keysize length, use MCRYPT_RAND * on Windows instead */ $iv = substr(md5($key),0,mcrypt_enc_get_iv_size($module)); /* Intialize encryption */ mcrypt_generic_init($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); } /** * This was AES-128 / CBC / NoPadding decrypted. * @author Terry * @param string $encrypted		base64_encode encrypted string * @param string $key * @throws CException * @return string */ public static function AesDecrypt($encrypted, $key = null) { if ($encrypted == '') return ''; if(!extension_loaded('mcrypt')) throw new CException(Yii::t('yii','AesDecrypt requires PHP mcrypt extension to be loaded in order to use data encryption feature.')); $ciphertext_dec = base64_decode($encrypted); $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); $key=self::substr($key===null ? Yii::app()->params['encryptKey'] : $key, 0, mcrypt_enc_get_key_size($module)); $iv = substr(md5($key),0,mcrypt_enc_get_iv_size($module)); /* Initialize encryption module for decryption */ mcrypt_generic_init($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($module); return rtrim($decrypted,"\0"); } /** * 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); } }