Install mcrypt, No package php-mcrypt available.
If you get no package is available:
https://www.digitalocean.com/community/questions/how-to-install-mcrypt-php-extension-on-centos-7-0-x64
# install EPEL with yum
yum -y install epel-release
# install php-mcrypt
yum -y install php-mcrypt
reference:
https://www.conetix.com.au/support/article/install-php-mcrypt-centos-6-vps