To enable SSO using HTTP headers, where can I get the HTTP header for user’s identifier?

[#1]

I am working on SSO using HTTP headers, but I do not know how to get the user's identifier. I have use some the labels obtain by synchronization to Windows Active Directory, but I have not been able to make it work.  Thank you.

[#2 · Accepted solution]

Read Justins comments here: How does SSO work in CQ