Two PHP apps single sign-on

I have a silghtly modified phpbb2 forum at the root of my domain. I will provide the source code for this forum, and a test installation. I also have a Ning community at my subdomain that I need to integrate with the rest of my site. 1. All user management and authentication should happen at Ning's site, meaning all phpbb2 login, forgot pass, other user management pages and user profiles should redirect to corresponding Ning pages 2. Once the user is logged on to Ning, if they click on my forum link in the community menu, they would go to my phpbb2 part of the site 3. Phpbb2 should be able to recognize that the user is logged on to Ning and has a valid username 4. If this is the very first visit of this user to my forum, phpbb2 should recognize it and create his account in phpbb2 database (MySQL) transparently 5. The user should log on only once, to Ning. Phpbb2 should pick up his username either via a cookie from Ning, or some other approach (see the links) Similar discussion and code samples that could be re-used: * [Example: SSO integration with Wordpress][1] * [A possible SSO approach][2] * [How to determine if a user is logged on to Ning to avoid logging in twice][3] ## Deliverables 1. A running Ning community (originally provided by the Byer) modified as necessary to allow single sign-on with a phpbb2-based forum 2. A running Phpbb2-based forum (originally provided by the Byer, with access to the Byer's server for installation and work), modified for single sign-on with the Ning community 3. A user should be able to register for this modified Ning community, navigate to the modified forum and get transparently logged on to the forum without entering credentials the second time 4. All source code required for all work done 5. Deliverables must be in ready-to-run condition, as follows: For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. 6. All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc., except the original Phpbb2-based code supplied by the Buyer and Ning APIs required for the task). ## Platform Linux, Apache, PHP, MySQL, PhpBB2, Ning