Summary of the use of php encryption extension mcrypt

The php language comes with many encryption and decryption methods and extensions. Today we introduce one of the extensions mcrypt extension. The mcrypt extension 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. This article summarizes how to use the mcrypt extension.

How to use the mcrypt extension

1. PHP encryption extension library—Mcrypt extension library example usage

Before starting the main text of this article, let’s first understand what is the PHP encryption extension library: There are not only several encryption functions (md5, crypt, sha1) in PHP, but also , there are also some encryption extension libraries with relatively comprehensive functions in PHP! Just like PHP does not originally support operating a certain function, but if you want to support it in the new version, you can provide it in an extended way. In this way, when we configure PHP, if we do not use this function, we can prevent PHP from loading. It thus saves server resources and improves its performance.

2. Details introduce the basic use of PHP encryption extension mcrypt

##Mcrypt supports the following four block cipher modes: CBC, OFB , CFB and ECB. If linked with libmcrypt-2.4.x or higher, nOFB packet mode and streaming mode are also

supported. The following are the supported encryption modes and their corresponding predefined constants.

3.

Use apt-get install under ubuntu to install the php extension library mcrypt, curl, gd

Ubuntu software package download and installation tool: apt- get is very easy to use, and Ubuntu's software source provides most commonly used software packages. Therefore, it is very simple to install the PHP extension library mcrypt, curl and gd libraries under Ubuntu. Enter the following command to complete it automatically (installation below The premise is that PHP5 is installed on the system. Search extension=php_mcrypt.dll inside, remove the semicolon ";" in front, and restart apache. It has no effect (note: php.ini is in the dinwos directory in AppServ). 2. Copy libmcrypt.dll in the php directory to the windows/system32 directory, restart IIS, it doesn’t work. 3. Another method is to copy libmcrypt.dll to the bin directory of apache and it will take effect.

##5.

PHP mcrypt reversible encryption algorithm analysis

Data encryption has become more and more important in our lives, especially considering what happens on the Internet Large volumes of transactions and large amounts of data transferred. For information that does not need to be restored to the original data, we can use irreversible encryption algorithms such as MD5 and SHA1 to encrypt the data. However, important information such as transaction information that needs to be restored to the original data must be encrypted using a restoreable encryption algorithm. Of course, you can write a reversible encryption algorithm yourself to perform encryption and decryption calculations. In this article we introduce the use of the mcrypt module for encryption and decryption operations.

6.

phpMyAdmin cannot load the mcrypt extension, please check the PHP configuration solution

The Mysql database is not installed correctly, and there are no Mysql-related services in the system services. Start (please check the correct method to install Mysql)

The libmcrypt.dll file is missing in the system's system32 (C:\windows\system32) directory. The solution is to find libmcrypt.dll in the php directory and replace it Copy libmcrypt.dll to the C:\windows\system32 directory, and then restart the web service.

Related Questions and Answers

1.

Linux installation mcrypt PHP extension encountered the following problems, how to solve it?

2. Enable Mcrypt PHP extension

4. Is it a problem to enable php-mcrypt?

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1. 【php encryption and decryption class library】10 php encryption and decryption class libraries download

2. Free video tutorial on php Chinese website: 《php.cn Dugujiu Cheap (4)-php video tutorial》

3. Summary of encryption usage of php function crypt()

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