Session sharing between php application and xwiki to enable single sign on

Hello Xwikers,
I have one php application and xwiki.Now I can login using user credentials created in LDAP both from php and xwiki, but separately. The php application is main portal.The php application can also be deployed inside tomcat where xwiki is deployed(I did it with JavaBridge).I am using community mysql(not pro version).
Is there simplest way for xwiki to receive session of other application so that xwiki will not require a separate login. I prefer not to use single sign on tools like cas or any third party application.
Thank you in advance and best,
Tadewos