How To Install PHP-mCrypt On CentOS 7

Method 1:

# yum install epel-release

Method 2:

# cd /tmp/ && wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm
# sudo yum install epel-release-7-2.noarch.rpm
# sudo yum install php-mcrypt
# sudo systemctl restart httpd.service

https://fedoraproject.org/wiki/EPEL
http://wiki.centos.org/AdditionalResources/Repositories
http://www.rackspace.com/knowledge_center/article/install-epel-and-additional-repositories-on-centos-and-red-hat