Advanced Encryption Standard (English: Advanced Encryption Standard, abbreviation: AES), also known as Rijndael encryption method in cryptography, is a block encryption standard adopted by the U.S. federal government. This standard is used to replace the original DES. It has been analyzed by many parties and is widely used around the world. After a five-year selection process, the Advanced Encryption Standard was published by the National Institute of Standards and Technology (NIST) in FIPS PUB 197 on November 26, 2001, and became an effective standard on May 26, 2002. In 2006, Advanced Encryption Standard has become one of the most popular algorithms for symmetric key encryption. This article mainly introduces PHP's AES encryption algorithm, and analyzes PHP's AES encryption algorithm class and its specific usage in the form of a complete example. It has certain reference value. Friends in need can refer to it
<?php class MCrypt { private $hex_iv = '00000000000000000000000000000000'; # converted JAVA byte code in to HEX and placed it here private $key = 'U1MjU1M0FDOUZ.Qz'; #Same as in JAVA function construct() { $this->key = hash('sha256', $this->key, true); //echo $this->key.'<br/>'; } function encrypt($str) { $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv)); $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); $pad = $block - (strlen($str) % $block); $str .= str_repeat(chr($pad), $pad); $encrypted = mcrypt_generic($td, $str); mcrypt_generic_deinit($td); mcrypt_module_close($td); return base64_encode($encrypted); } function decrypt($code) { $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv)); $str = mdecrypt_generic($td, base64_decode($code)); $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); mcrypt_generic_deinit($td); mcrypt_module_close($td); return $this->strippadding($str); } /* For PKCS7 padding */ private function addpadding($string, $blocksize = 16) { $len = strlen($string); $pad = $blocksize - ($len % $blocksize); $string .= str_repeat(chr($pad), $pad); return $string; } private function strippadding($string) { $slast = ord(substr($string, -1)); $slastc = chr($slast); $pcheck = substr($string, -$slast); if (preg_match("/$slastc{" . $slast . "}/", $string)) { $string = substr($string, 0, strlen($string) - $slast); return $string; } else { return false; } } function hexToStr($hex) { $string=''; for ($i=0; $i < strlen($hex)-1; $i+=2) { $string .= chr(hexdec($hex[$i].$hex[$i+1])); } return $string; } } $encryption = new MCrypt(); echo $encryption->encrypt('123456') . "<br/>"; echo $encryption->decrypt('tpyxISJ83dqEs3uw8bN/+w=='); ?>
The above is the detailed content of Complete example code of AES encryption algorithm in php. For more information, please follow other related articles on the PHP Chinese website!

Effective methods to prevent session fixed attacks include: 1. Regenerate the session ID after the user logs in; 2. Use a secure session ID generation algorithm; 3. Implement the session timeout mechanism; 4. Encrypt session data using HTTPS. These measures can ensure that the application is indestructible when facing session fixed attacks.

Implementing session-free authentication can be achieved by using JSONWebTokens (JWT), a token-based authentication system where all necessary information is stored in the token without server-side session storage. 1) Use JWT to generate and verify tokens, 2) Ensure that HTTPS is used to prevent tokens from being intercepted, 3) Securely store tokens on the client side, 4) Verify tokens on the server side to prevent tampering, 5) Implement token revocation mechanisms, such as using short-term access tokens and long-term refresh tokens.

The security risks of PHP sessions mainly include session hijacking, session fixation, session prediction and session poisoning. 1. Session hijacking can be prevented by using HTTPS and protecting cookies. 2. Session fixation can be avoided by regenerating the session ID before the user logs in. 3. Session prediction needs to ensure the randomness and unpredictability of session IDs. 4. Session poisoning can be prevented by verifying and filtering session data.

To destroy a PHP session, you need to start the session first, then clear the data and destroy the session file. 1. Use session_start() to start the session. 2. Use session_unset() to clear the session data. 3. Finally, use session_destroy() to destroy the session file to ensure data security and resource release.

How to change the default session saving path of PHP? It can be achieved through the following steps: use session_save_path('/var/www/sessions');session_start(); in PHP scripts to set the session saving path. Set session.save_path="/var/www/sessions" in the php.ini file to change the session saving path globally. Use Memcached or Redis to store session data, such as ini_set('session.save_handler','memcached'); ini_set(

TomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe

Arrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.

PHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SublimeText3 English version
Recommended: Win version, supports code prompts!

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Chinese version
Chinese version, very easy to use

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
