Cannot login-without-password when home folder is encrypted

[Jeroen]

Users of whom the home folder is encrypted using the CLI (unfortunately there is no GUI option for this, see https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1279766), and for which the 'login without password' is set, cannot login.

Steps to reproduce:
1. Using an Administrator account, create a new user in System Settings > User Accounts and set a password.
2. Open a shell and encrypt the newly created user folder by 'sudo ecryptfs-migrate-home -u <username>'
3. Login into the new account: successful
4. Logout and login into the Administrator account and select 'Login without password' for the newly created user.
5. Login into the new account: cannot login (the password field for this users now displays 'Log in' but trying to login results in a flickering screen and back to the login screen.

Ubuntu 14.04 x64 (reproducable on two different machines)

[Seth Arnold (seth-arnold)]

This sounds like expected behaviour to me -- the login password is used to encrypt the filesystem key. Without a login password at login time, the files should be unavailable, and thus there's no home directory to contain anything of value for the user.

There might be a better way to tell the user that a password is required for encrypted home directories though.

[Marc Deslauriers (mdeslaur)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.