How to install mcrypt on CentOS 7.6?

Hey, @umijs

I managed to get this installed on my droplet using the following commands:

sudo yum install epel-release

sudo yum install libmcrypt-devel

If you are running the default PHP installation you will want to run the following command as well.

sudo yum install php-mcrypt

Also you will need to find which is your main php.ini file and add or uncomment the following line:

extension=mcrypt.so

Let me know how it goes.

Hey @danielzhang,

The mcrypt library was deprecated in PHP 7.1, and it was removed entirely in PHP 7.2. If you’re using PHP 7.3 or a later version, you can’t enable mcrypt in the same way as before. Instead, you’ll need to use a different method.

However, if you still need to use mcrypt due to some legacy code that you can’t update to use a more modern encryption method, there’s a PECL extension available that brings back mcrypt to PHP 7.3 or later versions.

In this example, we’ll be using 8.1

Install prerequisites

Before you install the mcrypt extension, you’ll need to make sure that you have some necessary packages installed on your system.

On Ubuntu:

sudo apt-get update
sudo apt-get install php-pear php8.1-dev gcc make autoconf libc-dev pkg-config libmcrypt-dev php-pear

On CentOS:

sudo yum install php-pear php-devel gcc make autoconf libc-dev pkg-config libmcrypt-devel php-pear

Install mcrypt extension

After you’ve installed these packages, you can install the mcrypt extension itself:

sudo pecl install mcrypt-1.0.3

During the installation, you may be asked for the libmcrypt prefix. If you are, press enter to skip.

Configure PHP to use the mcrypt extension

After the installation is complete, you’ll need to tell PHP to use the mcrypt extension. To do this, you’ll need to modify your php.ini file.

First, you’ll need to find it. You can do this by using the following command:

php --ini

Look for the line that says “Loaded Configuration File”. This will tell you where your php.ini file is located.

Open this file with your favorite text editor (like nano or vim). For example:

sudo nano /etc/php/8.1/cli/php.ini

Add the following line to the file:

extension=mcrypt.so

Restart your web server

Finally, you’ll need to restart your web server for the changes to take effect.