search
HomeBackend DevelopmentPHP TutorialPHP mcrypt-based encryption and decryption example, mcrypt encryption and decryption example_PHP tutorial

php mcrypt-based encryption and decryption example, mcrypt encryption and decryption example

The example in this article describes how PHP implements encryption and decryption based on mcrypt. Share it with everyone for your reference. The specific implementation method is as follows:

PHP comes with quite a few encryption methods. Here we take a look at how to use the mcrypt extension. I also need to use this thing to encrypt the value of the user's cookie at work, and I have studied this aspect seriously.

1. Introduction

Mcrypt is an extension of PHP that completes the encapsulation of commonly used encryption algorithms. In fact, this extension is an encapsulation of the mcrypt standard class library. mcrypt has completed quite a few commonly used encryption algorithms, such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST encryption algorithm and provides four block encryption models: CBC, OFB, CFB and ECB.

2. Installation and use

To use this extension, you must first install the mcrypt standard class library, which can be downloaded at http://mcrypt.sourceforge.net. The compilation and installation methods of this extension are the same as those of regular PHP extensions, so they will not be explained in detail.

3. Four block encryption models

Mcrypt supports four block encryption models, a brief description is as follows:

①. MCRYPT_MODE_ECB (electronic codebook) is suitable for encrypting small amounts of random data, such as encrypting user login passwords.

②. MCRYPT_MODE_CBC (cipher block chaining) is suitable for important file types with high encryption security level.

③. MCRYPT_MODE_CFB (cipher feedback) is suitable for situations where every byte of the data stream needs to be encrypted.

④. MCRYPT_MODE_OFB (output feedback, in 8bit) is compatible with CFB mode, but more secure than CFB mode. CFB mode will cause encryption errors to spread. If one byte is wrong, all subsequent bytes will be wrong. OFB mode does not have this problem. However, this mode is not very safe and is not recommended.

⑤. MCRYPT_MODE_NOFB (output feedback, in nbit) is compatible with OFB and has higher security due to the use of block operation algorithm.

⑥. MCRYPT_MODE_STREAM is an additional model provided for stream encryption algorithms such as WAKE or RC4.

NOFB and STREAM are only valid when the version number of mycrypt is greater than or equal to libmcrypt-2.4.x. (Basically all are larger than this version now, and the latest main version of libmcrypt has reached 4)

4. View supported algorithms and models

①. mcrypt_list_modes() lists the models supported by the current environment

②. mcrypt_list_algorithms() lists the algorithms supported by the current environment

Execute from command line:

Copy code The code is as follows:
php -r "var_dump(mcrypt_list_modes()); var_dump(mcrypt_list_algorithms());"

All results will be listed.

5. How to use

Example 1:

Copy code The code is as follows:
$key = "this is a secret key";
$input = "Let us meet at 9 o'clock at the secret place.";
$encrypted_data = mcrypt_ecb (MCRYPT_3DES, $key, $input, MCRYPT_ENCRYPT);
?>

The simplest method is shown in Example 1. This method indicates that $input is encrypted using the 3DES algorithm, and the encryption key is $key. However, the direct call method is no longer officially recommended. It is also recommended Please do not use this method during development. It may not be possible for this method to become unusable one day. When calling this method under PHP5, you will see a warning message, prompting "PHP Warning: attempt to use an empty IV, which is NOT recommend".

The officially recommended usage is shown in Example 2

Example 2:

Copy code The code is as follows:
$key = "this is a secret key";
$input = "Let us meet at 9 o'clock at the secret place.";
// Open mcrypt, or a resource object of mcrypt type, which uses ecb mode and 3des as the encryption algorithm.
$td = mcrypt_module_open('tripledes', '', 'ecb', '');
// Create iv (initialization vector)
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
// Initialize $td based on key and iv, complete memory allocation and other initialization work
mcrypt_generic_init($td, $key, $iv);
// Encrypt
$encrypted_data = mcrypt_generic($td, $input);
//Deinitialize $td, release resources
mcrypt_generic_deinit($td);
//Close the resource object and exit
       mcrypt_module_close($td);
?>

The above process completes the data encryption process. First select the encryption algorithm and encryption mode to create the resource object and IV of mcrypt, then initialize the buffer (memory) required for encryption, release the buffer after encryption, and finally close the resource object.

The decryption process is basically the same as encryption. Just replace mcrypt_generic($td, $input) with mdecrypt_generic($td, $input). The other parts are exactly the same. Of course, for a symmetric encryption algorithm like 3des, the keys used for encryption and decryption must be exactly the same.

6. About IV

Not all models require IV. CFB and OFB must have IV, while CBC and EBC are optional. For the required IV mode, the values ​​of the encrypted and decrypted IV must be exactly the same. CBC and EBC do not have this requirement. It can be the same or different, it doesn't matter.

7. A simple encryption and decryption class

Copy code The code is as follows:
class AMPCrypt {
Private static function getKey(){
          return md5('exampleKey');
}
Public static function encrypt($value){
            $td = mcrypt_module_open('tripledes', '', 'ecb', '');
           $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_DEV_RANDOM);
           $key = substr(self::getKey(), 0, mcrypt_enc_get_key_size($td));
           mcrypt_generic_init($td, $key, $iv);
            $ret = base64_encode(mcrypt_generic($td, $value));
           mcrypt_generic_deinit($td);
           mcrypt_module_close($td);
         return $ret;
}
Public static function dencrypt($value){
            $td = mcrypt_module_open('tripledes', '', 'ecb', '');
            $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_DEV_RANDOM);
           $key = substr(self::getKey(), 0, mcrypt_enc_get_key_size($td));
           $key = substr(self::getKey(), 0, mcrypt_enc_get_key_size($td));
           mcrypt_generic_init($td, $key, $iv);
           $ret = trim(mdecrypt_generic($td, base64_decode($value))) ;
          mcrypt_generic_deinit($td);
           mcrypt_module_close($td);
         return $ret;
}
}

I hope this article will be helpful to everyone’s PHP programming design.

php code decryption

In fact, you can use DES for decryption. There is an extension in php that can support the DES encryption algorithm. It is: extension=php_mcrypt.dll. Open this extension in the configuration file. It cannot be used in the windows environment. You need to add the PHP file. Copy the libmcrypt.dll in the folder to the system32 directory of the system. You can see through phpinfo that mcrypt means that this module can be tried normally.
Let me give you an example:
function do_mdecrypt($input, $key)
{
$input = str_replace(""n", "", $input);
$input = str_replace(""t", "", $input);
$input = str_replace(""r", "", $input);

$input = trim(chop(base64_decode($ input)));
$td = mcrypt_module_open('tripledes', '', 'ecb', '');
$key = substr(md5($key), 0, 24);

$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
mcrypt_generic_init($td, $key, $iv);
$decrypted_data = mdecrypt_generic($td, $input);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
return trim(chop($decrypted_data));

}
Then, you can implement the code using this method Decrypted!

Some questions about PHP encryption algorithm

1. The encryption algorithm is MCRYPT_RIJNDAEL_128. As for whether it is the AES you mentioned, it is hard to say. I personally think it shouldn't be. After all, the two don't look much alike.

2. There is no flaw in the code, but all encryption may be broken. The exhaustive method is just a time-consuming problem.
3. IV is used to initialize the algorithm. It also needs to be kept confidential.

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/901289.htmlTechArticlephp mcrypt-based encryption and decryption examples, mcrypt encryption and decryption examples. This example describes how php implements encryption and decryption based on mcrypt. . Share it with everyone for your reference. The specific implementation methods are as follows...
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
The Continued Use of PHP: Reasons for Its EnduranceThe Continued Use of PHP: Reasons for Its EnduranceApr 19, 2025 am 12:23 AM

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python: Exploring Their Similarities and DifferencesPHP and Python: Exploring Their Similarities and DifferencesApr 19, 2025 am 12:21 AM

PHP and Python are both high-level programming languages ​​that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP and Python: Different Paradigms ExplainedPHP and Python: Different Paradigms ExplainedApr 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 and Python: A Deep Dive into Their HistoryPHP and Python: A Deep Dive into Their HistoryApr 18, 2025 am 12:25 AM

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

Choosing Between PHP and Python: A GuideChoosing Between PHP and Python: A GuideApr 18, 2025 am 12:24 AM

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP and Frameworks: Modernizing the LanguagePHP and Frameworks: Modernizing the LanguageApr 18, 2025 am 12:14 AM

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHP's Impact: Web Development and BeyondPHP's Impact: Web Development and BeyondApr 18, 2025 am 12:10 AM

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

How does PHP type hinting work, including scalar types, return types, union types, and nullable types?How does PHP type hinting work, including scalar types, return types, union types, and nullable types?Apr 17, 2025 am 12:25 AM

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values ​​and handle functions that may return null values.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

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

Hot Tools

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools