The mcrypt php extension is an interface for mcrypt cryptography library. We will see how to install mcrypt php extension for laravel. Laravel 5.1 and later versions removed the need to use mcrypt. The web enabled extensions can differ from command line enabled extensions. To see if mcrypt is enabled run the below command in your terminal.

php -m

If not listed then run the below command from terminal to see where the command line is loading the php.ini file.

php --ini 

Then enable the extension in php.ini file.

Linux and Mac / OSX users-Open your terminal and enter the below command.

which php 

if it shows /user/bin/ php then enter

sudo nano ~/.bash_profile 

OSX terminal normally points to the native php which is shipped with OSX. You should update your bash profile to include the actual path to PHP

export PATH=/usr/local/php5/bin:$PATH

Ubuntu users-For 14.04 or earlier versions you need to symlink to mods-available.

sudo ln -s /etc/php5/conf.d/mcrypt.ini /etc/php5/mods-available/mcrypt.ini

Once the mod is installed run the following commands

php5enmod
sudo php5enmod mcrypt
sudo service apache2 restart

try the below commands if the above doesnt work.

cd ~
sudo apt-get remove php5-mcrypt
sudo apt-get install php5-mcrypt
sudo php5enmod mcrypt
sudo service apache2 restart

Laravel doesnot use mcrypt extension anymore. Mcrypt is not in use the last update of libmcrypt was in 2007. Laravel 4.2 has no support anymore. The best and safe option is to update your Laravel to laravel 5.2 or above.