Unfortunately the php 5.2.17 version can no longer be installed from repos, sad but that’s how it is with old versions. Well the only way here is to manually compile php. First make sure you have gcc, make and httpd-devel libxml2-devel bzip2-devel openssl-devel curl-devel gd-devel libc-client-devel libmcrypt-devel libmhash-devel mysql55-devel aspell-devel libxslt-devel installed as these are needed:
Installing ...