Thomas
Tanghus

    tanghus@earthling.net

Steffen
Hansen

    stefh@mip.ou.dk

Mike
McBride
2002-02-13
3.00.00
KDE
KControl
KDM configuration
login manager
login

# Login Manager

Using this module, you can configure the &kde; graphical login manager &kdm;. You can change how the login screen looks, who has access using the login manager and who can shutdown the computer.

In order to organize all of these options, this module is divided into five sections: Appearance, Font, Background, Sessions, Users and Convenience.

You can switch between the sections using the tabs at the top of the window.

If you are not currently logged in as a superuser, you will need to click the Administrator Mode Button. You will then be asked for a superuser password. Entering a correct password will allow you to modify the settings of this module.

## Appearance

From this page you can change the visual appearance of &kdm;, &kde;'s graphical login manager.

The greeting string is the title of the login screen. If the string contains the word `HOSTNAME` it will be translated to the domainless name of the machine &kdm; is installed on.

You can then choose to show either the current system time, a logo or nothing special in the login box. Make your choice in the radio buttons labled Logo area. Using the Positions setting, you can choose to either center the content of the logo area or to position it using fixed coordinates.

If you chose Show logo you can now choose a logo:

- Drop an image file on the image button.

- Click on the image button an select a new image from the image chooser dialog.

If you do not specify a logo the default `$`KDEDIR`/share/apps/kdm/pics/kdelogo.xpm` will be displayed.

While &kde;'s style depends on the settings of the user logged in, the style used by &kdm; can be configured using the GUI Style option.

Below that, you have two dropdown boxes to choose the language and the country for your login box.

## Font

From this section of the module you can change the fonts used in the login window.

You can select three different font styles from the drop down box (Greeting, Fail, Standard) When you click on the Change font button a dialog appears from which you can select the new characteristics for the font style..

- The Greeting font is the font used for the title (Greeting String).

- The Fail font is used when a login fails.

- The Standard font is used all other places in the login window.

An example of each font can be seen in the Example Box.

## Background

Here you can change the desktop background which will be displayed when a user logs in. You can have a single color or an image as a background. If you have an image as background and select center the selected background color will be used around the image if it isn't large enough to cover the entire desktop.

The background colors and effects are controlled by the options on the tab labeled Background and you select a background image and its placement from the options on the tab labeled Wallpaper.

To change the default background color(s) simply click either of the color bottons and select a new color.

The dropdown box above the color buttons provides you with several different blend effects. Choose one from the list, and it will be previewed on the small monitor at the top of the window. Your choices are:

Flat

  By choosing this mode, you select one color (using the color button labeled Color 1), and the entire background is covered with this one color.

Pattern

  By choosing this mode, you select two colors (using both color buttons).

  You then select a pattern by clicking Setup. This opens a new dialog window, which gives you the opportunity to Select a pattern. Simply click once on the pattern of your choice, then click on OK, and &kde; will render the pattern you selected using the two colors you selected. For more on patterns, see the section Background: Adding, Removing and Modifying Patterns.

Background Program

  By selecting this option, you can have &kde; use an external program to determine the background. This can be any program of your choosing. For more information on this option, see the section entitled Background: Using an external program.

Horizontal Gradient

  By choosing this mode, you select two colors (using both color buttons). &kde; will then start with the color selected by Color 1 on the left edge of the screen, and slowly transform into the color selected by Color 2 by the time it gets to the right edge of the screen.

Vertical Gradient

  By choosing this mode, you select two colors (using both color buttons). &kde; will then start with the color selected by Color 1 on the top edge of the screen, and slowly transform into the color selected by Color 2 as it moves to the bottom of the screen.

Pyramid Gradient

  By choosing this mode, you select two colors (using both color buttons). &kde; will then start with the color selected by Color 1 in each corner of the screen, and slowly transform into the color selected by Color 2 as it moves to the center of the screen.

Pipecross Gradient

  By choosing this mode, you select two colors (using both color buttons). &kde; will then start with the color selected by Color 1 in each corner of the screen, and slowly transform into the color selected by Color 2 as it moves to the center of the screen. The shape of this gradient is different then the pyramid gradient.

Elliptic Gradient

  By choosing this mode, you select two colors (using both color buttons). &kde; will then start with the color selected by Color 2 in the center of the screen, and slowly transform into the color selected by Color 1 as it moves to the edges, in an elliptical pattern.

The setup button is only needed for if you select Background program or Patterns. In these instances, another window will appear to configure the specifics.

Wallpaper

To select a new background image first, click on the Wallpapers tab, then you can either select an image from the drop-down list labled Wallpaper or select Browse... and select an image file from a file selector.

The image can be displayed in six different ways:

No wallpaper

  No image is displayed. Just the background colors.

Centered

  The image will be centered on the screen. The background colors will be present anywhere the image does not cover.

Tiled

  The image will be duplicated until it fills the entire desktop. The first image will be placed in the upper left corner of the screen, and duplicated downward and to the right.

Center Tiled

  The image will be duplicated until it fills the entire desktop. The first image will be placed in the center of the screen, and duplicated upward, downward to the right, and to the left.

Centered Maxpect

  The image will be placed in the center of the screen. It will be scaled to fit the desktop, but it will not change the aspect ratio of the original image. This will provide you with an image that is not distorted.

Scaled

  The image will be scaled to fit the desktop. It will be streched to fit all four corners.

## Sessions

Allow to shutdown

Use this dropdown box to choose who is allowed to shut down:

- None: No one can shutdown the computer using &kdm;. You must be logged in, and execute a command.

- All: Everyone can shutdown the computer using &kdm;.

- Root only: &kdm; requires that the root password be entered before shutting down the computer.

- Console only: The user must be at this console, to shut down the computer.

Commands

Use these 3 blanks to define the exact shutdown command.

The shutdown command defaults to:

`/sbin/shutdown`

The restart command defaults to:

`/sbin/reboot`

The Console mode (which restarts the computer as a console only terminal) defaults to:

`/sbin/init `3``

When Show boot options is enabled, &kdm; will on reboot offer you options for the lilo boot manager. For this feature to work, you will need to supply the correct paths to your `lilo` command and to lilos map file.

### Session types

Define which session types should be accessable from the login window.

For more information on this subject, look at `/etc/X11/xdm/Xsession` to find your xdm setup files. Also review the xdm man pages, especially under the SESSION PROGRAM section

To add a session, type its name in the blank entitled New types, and click Add new.

To remove a session, select the session from the list and click Remove.

## Users

From here you can change the way users are represented in the login window.

As you look on this window, you will see three lists (All users, selected users, and no-show users). You also see an image box, and a set of options along the right side of the window.

The first thing you must decide, is if you are going to show users or not.

If you choose to show users, then the login window will show images (which you select), of a list of users. When someone is ready to login, they select their user name/image, enter their password, and they are granted access.

If you choose not to show users, then the login window will be more traditional. Users will need to type their username, and password to gain entrance. This is the preferred way if you have many users on this terminal.

### To show (and sort) or not to show users

Along the right edge of the window, are two check boxes:

If Show users is selected, you have chosen to show images of users, instead of making them type their login name.

If Sort users is selected, then the list of users will be sorted alphabetically in the login window. If unchecked, users will be listed in the same order as they are on this page. If Show users is not checked, this has no effect.

### How to determine which users to show and which users to hide

Below the user image box, and above the Show users check box, is a set of two radio buttions:

- Show only selected users: If this option is selected, only the users contained in the list labelled Selected Users, will be displayed in the login window. If Show users is not checked, this has no effect.

- Show all users but no-show users: If this option is selected, all users will be listed, except those users contained in the list entitled No show users. If Show users is not checked, this has no effect.

### Select users

The pages contains three listboxes. The large listbox on the left shows all the users on the system which might be a genuine user.

The top rightmost listbox shows the selected users and the bottom rightmost listbox shows the users we don't want displayed in the login window.

To move a user from one listbox to another you click on the username in the listbox and selects >> to move the user from the leftmost box the the rightmost box or << to move the user from the rightmost box to the leftmost box.

### Images

This section of the manual only applies if Show users is selected. If it is not, this image box has no effect.

Every user on the system can be represented by a image. The image for the user is kept in a file called `$`KDEDIR`/share/apps/kdm/pics/users/$`USER`.xpm.` If the user doesn't have such a file the file `$`KDEDIR`/share/apps/kdm/pics/users/default.xpm` will be used instead.

To assign a new image to a user just select the user in one of the listboxes and either drop an imagefile on the image button to the right or click on the image button and select a new image from the image selector.

If no user is currently selected you will be asked if you want to change the default image.

The replacement is performed by a &konqueror; process so if the imagefile all ready exists you will be prompted by &konqueror; if you want to replace it. If you confirm the image will be replaced - you will NOT have to press the Apply button.

## Convenience

In the convenience tab you can configure some options that make life easier for lazy people, like auto login or disabling passwords.

Please think more than twice before using these options. Every option in the convenience tab is well suited to seriously compromise your system security. Practically, these options are only to be used in a completely non-critical environment, &eg; a private computer at home.

### Automatic Login

Automatic login will give anyone access to a certain account on your system without doing any authentication. You can enable it using the option Enable auto-login.

Automatic login comes in two flavours: truly automatic login acts like you would expect automatic login to, &ie; &kdm; will automatically login without expecting any input from the user. Enable this using the Truly automatic login option. If this option is not enabled, &kdm; will start normally, enabling you to login as any user, and will only perform automatic login if you kill the X server, &eg; by pressing &Ctrl;&Alt;Backspace.

You can choose the account to be used for automatic login in the list below.

### Password-less Login

Using this feature, you can allow certain users to login without having to provide their password. Enable this feature using the Enable password-less logins option.

Below this option you'll see a list of users for which a password is required, as well as a (by default empty) list of users that don't need to provide a password. When Enable password-less logins is enabled, you can move users from one list into the other, by selecting them and then click the >> and << buttons.

Again, this option should only be used in a safe environment. If you enable it on a rather public system you should take care that only users with heavy access restrictions are granted password-less login, &eg; guest.

The Automatically login after X server crash option allows you to skip the authentication procedure when your X server accidentally crashed. Show previous user will show the name of the last login already entered into the login field in &kdm;. Some site administrators would consider even this a possible security weakness, because potential attackers then know at least one valid login.

## Section Author

This section written by:

Mike McBride mpmcbride7@yahoo.com, Thomas Tanghustanghus@earthling.net, and Steffen Hansen stefh@mip.ou.dk. Updated by Jost Schenck jost@schenck.de.