Wednesday, May 27, 2009

Automatic login and file vault in Mac OS X

If you cannot enable "automatic login" for a user in Mac OS X Leopard or Tiger, make sure that user is not using FileVault. Although no documentation seems to indicate this will cause problems, it makes sense that auto-login and FileVault conflict.

The purpose of FileVault is to leave a user's files encrypted so if the laptop is stolen, the contents remain unreadable. To read a FileVault directory, you need the login password. However if auto-login is enable for that user, then the laptop will automatically apply that user's password, offering decrypted access to all the files, hence defeating the purpose of FileVault.

My wife found out the hard way, know as trial and error and lots of internet searching, to figure out why she was not getting the option to enable auto-login on her account on her Leopard laptop. Her login was simply missing from the menu of choices for auto-login. It was only after stumbling upon a web page alluding to this issue for Tiger that she thought to try disabling FileVault. Apparently FileVault and auto login were much closer together in the UI for Tiger than they are in Leopard, where now they are in separate System Preferences.

In any case, mystery solved.

No comments: