Backend Development
PHP Tutorial
PHP encryption extension library Mcrypt installation and examples_PHP tutorial
PHP encryption extension library Mcrypt installation and examples_PHP tutorial
A brief introduction to mcrypt
When PHP programmers write code programs, in addition to ensuring the high performance of the code, there is another very important point, that is, the security of the program. In addition to several of its own encryption functions, PHP also has more comprehensive PHP encryption extension libraries Mcrypt and Mhash.
Among them, the Mcrypt extension library can realize encryption and decryption functions, that is, it can encrypt plain text and restore cipher text.
mcrypt is an important encryption support extension library in PHP. In Linux environment: this library is not enabled by default. In window environment: PHP>=5.3, mcrypt extension is enabled by default.
1. Installation of Mcrypt() library
mcypt is a very powerful encryption algorithm extension library. Mcrypt is not installed during the standard PHP installation process, but the libmcrypt.dll file is included in the PHP home directory, so we only need to remove the semicolon in front of extension=php_mcrypt.dll in this line in the PHP configuration file. , and then restart the server to use this extension library.
Supported algorithms and encryption modes
The Mcrypt library supports more than 20 encryption algorithms and 8 encryption modes, which can be displayed through the functions mcrypt_list_algorithms() and mcrypt_list_modes() [1] Encryption algorithms
Mcrypt supports The algorithms are:
cast-128
gost
rijndael-128
twofish
arcfour
cast-256
loki97
rijndael-192
saferplus
wake
blowfish-compat
des
rijndael-256
serpent
xtea
blowfish
enigma
rc2
tripledes
Encryption mode
Mcrypt The supported encryption modes are:
cbc
cfb
ctr
ecb
ncfb
nofb
ofb
stream
These algorithms and modes should be used in applications. Constants are represented by adding the prefixes MCRYPT_ and MCRYPT_ when writing, as shown in the Mcrypt application below
Example
DES algorithm is represented as MCRYPT_DES;
ECB mode is represented as MCRYPT_MODE_ECB;
$str = "What is my name? I won’t tell most people!"; //Encrypted content
$key = "key:111"; //Key
$cipher = MCRYPT_DES; //Cryptotype
$modes = MCRYPT_MODE_ECB; //Cipher mode
$iv = mcrypt_create_iv(mcrypt_get_iv_size($cipher,$modes),MCRYPT_RAND);//Initialization vector
echo "Encrypted plaintext: ".$str."
";
$str_encrypt = mcrypt_encrypt($cipher,$key,$str,$modes,$iv); //Encryption function
echo "Encrypted ciphertext:" .$str_encrypt."
";
$str_decrypt = mcrypt_decrypt($cipher,$key,$str_encrypt,$modes,$iv); //Decryption function
echo "Restore:".$str_decrypt ;
?>
Running result:
Encrypted plain text: What is my name? I don’t tell most people!
Encrypted ciphertext: 鍍??]??q???L Laugh??"? ?
Restore: My name is? I won’t tell ordinary people!
<1>From the example It can be seen that before using the PHP encryption extension library Mcrypt to encrypt and decrypt data, an initialization vector is first created, referred to as iv. The initialization vector is created as $iv = mcrypt_create_iv(mcrypt_get_iv_size($cipher,$modes),MCRYPT_RAND); Two parameters are required: size specifies the size of iv; source is the source of iv, where the value MCRYPT_RAND is the system random number.
<2> The function mcrypt_get_iv_size($cipher,$modes) returns the initialization vector size, and the parameters cipher and mode refers to the algorithm and encryption mode respectively.
<3> Encryption function $str_encrypt = mcrypt_encrypt($cipher,$key,$str,$modes,$iv); The five parameters of this function are as follows: cipher—— Encryption algorithm, key - key, data (str) - data to be encrypted, mode - algorithm mode, iv - initialization vector
<4> Decryption function mcrypt_decrypt($cipher,$key,$str_encrypt ,$modes,$iv); The parameters of this function are almost the same as those of the encryption function. The only difference is data, which means that data is the data that needs to be decrypted $str_encrypt, not the original data $str.
Note: encryption and. The parameters cipher, key and mode in the decryption function must correspond one to one, otherwise the data cannot be restored
Summary
mcrypt library constants
The Mcrypt library supports more than 20 encryption algorithms and 8 encryption modes. It can be viewed through the functions mcrypt_list_algorithms() and mcrypt_list_modes().
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1670
14
1428
52
1329
25
1273
29
1256
24
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
