NOTE: This page is part of the Ubuntu Specification process. Please check the status and details in Launchpad before editing. If the spec is Approved then you should contact the Assignee, or another knowledgeable person, before making changes.

NOTE: This specification is a mixture of FaceBrowserLogin and UnifiedLoginUnlock and contains much expansive wittering. I have decided to regard this wiki page as superseded in favour of those two other specs. -IanJackson

• Launchpad entry: https://launchpad.net/distros/ubuntu/+spec/consistent-login-screen (now refers to UnifiedLoginUnlock)

• Packages affected: gdm, gnome-screensaver, fast-user-switch-applet

• See also: FaceBrowserLogin aka https://features.launchpad.net/distros/ubuntu/+spec/feisty-login

Summary

Ubuntu has three different login screens for (1) first user login, (2) unlocking the screensaver and (3) login as a new user when another users screen lock is active. This three situations could be handled by one single login screen, similar to Windows, to provide a much more consistent look and feel. Additionally the default login screen requires to enter the user name which could be done much more user friendly by presenting a clickable list of available users.

Rationale

A default Ubuntu system asks for the password after some time of inactivity. This is more or less alright for a single user system but if another user wants to use the system while the first has locked the screen the usability is too much complicated: At the password prompt the user has to press a button to change user, then the user has to select its user name from a list of available users, afterwards he is confronted with the default login screen where the user has to enter its user name a second time and then his/her password. Windows solved this issue much more user friendly: The user is confronted with one login screen only (and not with three different ones) whatever the user wants to log in the first time, unlock the screen saver or log in a second time resp. changing the user.

To have a login screen allowing to select a user from a list would be much more comfortable for the average desktop user because

• she/he has an overview which users are already registered and can choose one,
• she/he can not forget his/her user name,
• it avoids typos, allows to use the system more quickly and
• is more similar to Windows which many users know already.

Those small usability issues are easily to be ignored but I have seen users with several years of experience failing to login into Ubuntu.

The security implications are minor because

• security should depend on the password, not on the user name (Shall I choose a strong user name and not a simple one??!),
• accessing an Ubuntu system with an active screen saver shows me all available users anyway,
• the user name can often be guessed easily and
• usages with high security requirements need to configure Ubuntu anyway but not the average desktop user for who a user list is sufficient secure.

Use cases

• Trent wants to use the computer of his friend. He starts the machine and is confronted with the default login screen of Ubuntu which does not display the registered users. He needs to ask his friend for the username who asked Trent to use "guest" which does not require any password. A login screen displaying the available users would allow Trent to select the guest user easily.

• Latifa is using her computer for a while but then leaving it switched on and logged in. Later on Isaac wants to use the computer and is asked to unlock the screen lock. His first idea is that he can not use the user while Latifa is logged in because he could easily overlook the change user button. In case he got aware of the change user button he (1) has to press it, (2) select his user name from a list of available users, (3) afterwards he is confronted with the default login screen where he has to enter its user name a second time and (4) then his password. He is confused because he has never seen the select user list before and thinks the Ubuntu system is sooo complicated where other commercial systems need two steps for.

• Peter is a computer newbie and just to check his emails where he is starting his computer for. At the login screen he is confused because he does not remember his login name surely. Was it just his name or also his family name which he entered for his personal profile while installing the system some time ago? Additionally he is doing a typo because he uses his computer infrequently. Thus to login is taking him as much time as to check his email with a webbrowser. Maybe next time he is selecting Windows on his dual-boot system.
• Jane is using her Ubuntu computer. She is comming back after a break and needs to unlock the screen lock in order to use the computer. A unlock screen is presented to her which she has never seen before. She may be a little bit confused which would not happen if the default login screen would be shown which she is already familiar with.

Scope

Probably affects gdm (ubuntu-art), gnome-screensaver

Design

1. Change the default Ubuntu login screen to display a list of available users (gnome arts).
2. Modify gdm and gnome-screensafer-dialog to fall back to the default login screen which needs to be able to indicate and handle already logged in users.

Implementation

Volunteers please!

Code

Data preservation and migration

Unresolved issues

BoF agenda and discussion

Launchpad specification

Comments

• DonScorgie: I believe this proposal has been brought up before. There are several things here

  • No way of seeing user list in gdm
    • GDM already has a "face-browser" mode, which displays a list of available users. This is disabled by default in the Ubuntu GDM theme

      • But WHY? AndreRuediger

      • Bug open here. "This is considered a security risk, because it removes the need for people to type in their usernames, thus potentially handing valuable information to hackers" from here

        • We could display the real names instead of the user names although I don't think this security-by-obfuscation thing works. The login names can be guessed easily. If it makes it easier for a hacker to attack the system if he knows the user name we have a problem. AndreRuediger

  • Have to enter username twice when logging in from locked session

    • This could maybe be solved with some code changes to gnome-screensaver / fast-user-switching applet. See this thread for someone asking this exact question.

  • Being unfamiliar with lock screen vs. login screen
    • This (I think) is the real problem being addressed with this proposal.
• The final example given could also work the other way:
  • "Jane is using her Ubuntu computer. She is comming back after a break and needs to unlock the screen lock in order to use the computer." She wiggles the mouse and is presented with a new login screen and panics. She hasn't saved the essay she was working on for 2 hours (bad girl!). What if the computer has eaten it?

    • What about a "Session is active" Text besides her name. Shouldn't be too hard. A consistent Interface for logging (back) in is a good thing IMHO. If only it's not as ugly as the XP one... The current workflow for user switching should be simplified. AndreRuediger

• Just some things to think about

• OlafurArason: GDM can easily switch to a already logged in user so gnome-screensaver should spawn gdmflexiserver -s as soon as you hit switch user. There are some usecases when you are switching often that this can be frustrating but then you just use the applet.

• I don't think the analogy with Windows really works here, since as far as I know "lock screen" on Windows does not start a screensaver at all. This is the main problem I have with the proposed implementation, and the "Jane panics at the login screen" scenario above is why (also I think it would be an ugly way of doing things to switch to the login screen for a few seconds then back). I think the best way to approach this would be to create a unified look for the GDM theme and the screensaver's password dialogue. This wouldn't really work if the user switched themes though, so maybe switching from a fully themed GDM to the GTK interface would be better (although some simplification and beautification of the GTK interface would be needed), then this same GTK window can be added to the screensaver. The advantage to this is that the GTK login screen is a relatively small box in the centre of the screen, rather than a fullscreen image, and the screensaver already has a GTK box in the middle of the screen, so replacing it will not create any more of a panic than may already exist. Obviously the disadvantage is the lack of eye candy, but Ubuntu's default login screen is designed for simplicity anyway, and most of the screen is blank. Would it really make much difference if the Ubuntu name and logo, the "Options" button and the password entry field (because usernames or real names would be listed) is in a box instead? Remember, the GTK login window can still use images in the background (and if you wanted to be really eyecandy then you can use a screensaver hack in the background ). Even if people don't like the look of it, it would be so similar to the current default that those people wouldn't be happy with the current one either, and whilst adding a custom GDM theme it is pretty clear how to switch to the themed mode. Also, this might make a more consistent interface, since I always found it rather strange that the GNOME login screen doesn't actually use the GNOME (GTK) theme by default... -- Warbo

• Warbo introduced an idea which is very promising, I think. It would be great if such a password entry window could be designed including a user list. Lutz3

• Warbo: In case anyone is interested I am trying to implement my idea above, and have some mockup screenshots on my blog here.

---

CategorySpec CategorySpec