How to Install mcrypt PHP Module on Ubuntu 24.04

Install PHP

First, ensure PHP is installed on your system. If you haven’t done this already, our guide ‘How to install PHP on Ubuntu’ will walk you through the process. Once PHP is set up, you can proceed with the next steps.

How to install PHP on Ubuntu

Once PHP is set up, continue below.

Install recommended packages

Several important packages are needed before you can install the mcrypt PHP module on Ubuntu 24.04. This includes development tools like gcc and make, along with libraries and PHP's package managers, pear and pecl. Running the command `sudo apt install gcc make autoconf libc-dev pkg-config libmcrypt-dev php-pear php-dev` prepares your system.

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

Next, add and update the channel for PEAR and PECL using the command below.

sudo pecl channel-update pecl.php.net
sudo pecl update-channels

After that, run the command below to build and install mcrypt.

sudo pecl install mcrypt

Enable the mcrypt module

Once you've installed the mcrypt PHP module on Ubuntu, enabling it is necessary for your web server or PHP applications. This involves adding a specific line to your PHP configuration files. The specific file to edit varies depending on your web server setup: if you're using Apache, look for paths like `/etc/php/8.3/apache2/`; for Nginx with PHP-FPM, it will be closer to `/etc/php/8.3/fpm/`.

For Apache:Run:

sudo -s
echo extension=mcrypt.so > /etc/php/8.3/apache2/php.ini
echo extension=mcrypt.so > /etc/php/8.3/cli/php.ini

For Nginx:Run:

sudo -s
echo extension=mcrypt.so > /etc/php/8.3/fpm/php.ini
echo extension=mcrypt.so > /etc/php/8.3/cli/php.ini

After adding the module to the PHP configuration file, restart the web server and PHP.

Test PHP

To test if the mcrypt PHP module is working correctly on Ubuntu after installation and enabling, a simple terminal command suffices. Type `php -m | grep mcrypt` and press Enter. If the module is active, you'll see `mcrypt` displayed on your screen, confirming it's ready.

php -m | grep mcrypt

It should output mcrypt.

Or use the web.

That should do it!

Conclusion:

To wrap up, installing the mcrypt PHP module on Ubuntu is a process that can be essential for supporting legacy applications. Here are the key takeaways:

• Understanding mcrypt: mcrypt provides essential encryption and decryption functions for PHP developers but is deprecated in newer PHP versions.
• Installation Prerequisites: Ensure PHP is installed before installing the mcrypt module.
• Recommended Packages: Install necessary packages such as gcc, make, and libmcrypt-dev to successfully build the mcrypt module.
• Enabling mcrypt: After installation, update the PHP configuration files for Apache and Nginx to enable the mcrypt extension.
• Testing the Installation: Verify that mcrypt is active using the command line or checking through a web interface.

By following these installation steps, you ensure the mcrypt library integrates with your older PHP applications, allowing them to use encryption functions that mcrypt provides.