I have a problem that sounds very common in a web development nowadays, and suppose there is a common solution...
There are two WEB sites: A and B.
The user will log in on the site A. After this, the site A should somehow redirect the user's browser to site B letting him navigate this second site. The redirecting link should contain some parameters (like user ID). The user shouldn't ever be able to enter the site B directly, since the autentification information resides on the site A.
A solution which crossed my mind was to use https both to return redirection info (with user ID parameter) from the site A to the user, and later from browser to connect to site B.
Is there any "common solution" to this problem?