I'm using MS Cloud SharePoint solution and one of the disadvantages is that it requires all tenants to use the exact same login page (no custom branding allowed). I found some links using pass through authentication solutions (i.e., Claims-Based Authentication):
I basically would have my own login page and pass credentials through to SP for authentication.
Has anyone tried doing this to any success? Before I put forth the effort, I just wanted to know whether this was a lost cause or not.