The php-mhash installation in php 5.3 is very easy. Please use the following steps to install it
1) Download the latest mhash from http://mhash.sourceforge.net/ and install it as follows,
# tar -xzf mhash-0.9.9.9.tar.gz # ./configure --prefix=/opt/mhash # make # make install
2) Now add it to the loader configuration in /etc/ld.so.conf.d/mhash.conf
/opt/mhash/lib
3) Now edit the file /var/cpanel/easy/apache/rawopts/all_php5 and add the following line
--with-mhash=/opt/mhash
4) Finally compile the php using the following command
# /scripts/easyapache --build
You can test the mhash by creating a phpinfo page in your website document root.