Home  >  Article  >  php教程  >  A concise PHP reversible encryption function

A concise PHP reversible encryption function

大家讲道理
大家讲道理Original
2016-11-11 10:26:041539browse

Many times we need to encrypt and decrypt data. For example, some data needs to be saved in cookies, but the data cannot be easily obtained by users. At this time, we need to encrypt the data and save it in cookies until we need to use them. Decrypt again.

// 加密数据并写到cookie里
$cookie_data = $this -> encrypt("nowamagic", $data);
                  
$cookie = array(
    'name'   => '$data',
    'value'  => $cookie_data,
    'expire' => $user_expire,
    'domain' => '',
    'path'   => '/',
    'prefix' => ''
);
$this->input->set_cookie($cookie);
  
// 加密
public function encrypt($key, $plain_text) {  
    $plain_text = trim($plain_text);  
    $iv = substr(md5($key), 0,mcrypt_get_iv_size (MCRYPT_CAST_256,MCRYPT_MODE_CFB));  
    $c_t = mcrypt_cfb (MCRYPT_CAST_256, $key, $plain_text, MCRYPT_ENCRYPT, $iv);  
    return trim(chop(base64_encode($c_t)));  
}  
 
使用的时候再解密:
if( isset($_COOKIE['data']) )
{
    //用cookie给session赋值
    $_SESSION['data'] = decrypt("nowamagic", $_COOKIE['data']);
}
  
function decrypt($key, $c_t) {  
    $c_t = trim(chop(base64_decode($c_t)));  
    $iv = substr(md5($key), 0,mcrypt_get_iv_size (MCRYPT_CAST_256,MCRYPT_MODE_CFB));  
    $p_t = mcrypt_cfb (MCRYPT_CAST_256, $key, $c_t, MCRYPT_DECRYPT, $iv);  
    return trim(chop($p_t));  
}
Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn