While direct ldap or kerboros auth would be ideal, if the auth is cookie based and on the same base domain, can't another app verify your user's auth based on the presence and verification of your cookie? I'm thinking that if instead of sending your potential vbulletin user straight to the vbulletin home page, you send them to an intermediate page that mimics login.php's functionality. First, does the ldap or kerberos auth loop, then makes the same form submittal that login.php makes. The cookie gets written and your user is auth'd. Then, redirect to home page. You would have to alter and automate the account registration steps so that they would be in sync. An un-auth'd user would get a simple message that they need to contact the admin.

Is this possible?

Here too. We'd like to see an LDAP implementation to cut down on the amount of different usernames/passwords our users need to remember and/or change.

I realize this thread is old. But I'm going to post this for the benefit of future customers looking for LDAP authentication.

I know of two LDAP extensions for vBulletin.
https://vborg.vbsupport.ru/showthread.php?p=1391299
https://vborg.vbsupport.ru/showthread.php?t=148573

I prefer the first one listed above, your experience may be different.

would be appropriate to have the "close threads after X days after last reply"... bumping these threads are completely useless, and more, may bring new visitors to think that there is nothing else to discuss here.. lol

Has there been any movement on this?