Collect a simple PHP reversible encryption function_PHP tutorial

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. Wait for us Decrypt them when you need to use them.

The encryption process is as follows:

// 加密数据并写到cookie里
$cookie_data = $this -> encrypt("bkjia", $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)));   
}   

Decrypt when using:

if( isset($_COOKIE['data']) )
{
	//用cookie给session赋值
	$_SESSION['data'] = decrypt("bkjia", $_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));   
}  

The use of this reversible encryption function is recorded here.

http://www.bkjia.com/PHPjc/752334.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/752334.htmlTechArticleMany times we need to encrypt and decrypt data. For example, some data needs to be saved in cookies, but cannot be used by users. It is easy to get this data, then we need to encrypt these data...