Customize Encryption Desktop drive encryption bootguard screen backgrounds with XPM images

Products

• Drive Encryption
• Encryption Management Server

Issue/Introduction

If you wish to customize the Encryption Desktop bootguard (pre-boot) screen you need to use XPM (X PixMap) format image files.

Encryption Management Server administrators can add XPM format images to the Consumer Policy that applies to Encryption Desktop clients by loading the Desktop policy and navigating to the Drive Encryption tab. A custom Splash Screen and/or Login Screen can be used. At boot time, the Splash Screen is displayed prior to the Login Screen. The user clicks on any key to load the Login Screen.

When the client updates its policy, the Splash Screen is downloaded to the client as "%APPDATA%\PGP Corporation\PGP\pgpstart.xpm" and the Login Screen is downloaded as "%APPDATA%\PGP Corporation\PGP\pgpauth.xpm".

Custom images must meet the following requirements:

• XPM files only.
• Image size of 640 x 480.
• Palette of 15 colors only, including black (one color is reserved for fonts). You do not have to use all 15 colors in the image.
• 8-bit RGB only (cannot be 16-bit RGB). You can verify you are using 8 bit by looking at the XPM header using a text editor: 8-bit values appear as #285A83 (one hex triplet), 16-bit values appear as #28285A5A8383 (two hex triplets).
• The client machines are using legacy BIOS and not UEFI BIOS.

XPM file sizes can be ten times larger than an equivalent file in popular formats such as PNG, JPG or GIF. However, Encryption Management Server compresses the XPM file when you upload it.

Note that XPM files are text files. You can load an XPM file into a text editor and check that the dimensions and color palette is correct. Within the first few lines of an XPM file you will see a line like this which shows that the dimensions are 640x480,14 colors are in the palette and there is 1 character per pixel:

"640 480 14 1",

Environment

• Encryption Desktop and Encryption Management Server 10.5 and above.
• Windows with legacy BIOS.

Resolution

Below are some general guidelines on how to how to create an image with Windows Paint, how to use the ImageMagick convert utility to convert an existing image to XPM format and how to use the GNU Image Manipulation Program (GIMP) or KolourPaint to create a new XPM image.

Creating an image with Microsoft Paint

The Microsoft Paint application is included with Windows. Attached to this article is a 16 color BMP file 1699032480265__grayimage.bmp which you can download and open with Paint. The image is 640x480 and has a similar gray background to the default bootguard screen. It is a useful starting point:

1. Open Paint and from the File menu open the 1699032480265__grayimage.bmp file.
2. If you want to include your company logo in the image, copy and paste it into the image. Add the logo to the top section of the image and keep it small enough so that it will not obscure the User name field on the bootguard screen.
3. When you have made all the changes required, save the image as a 16 Color Bitmap (*.bmp) file. Clearly, with a maximum of 16 colors, the final image will need to be a simple design.

Converting an image with ImageMagick convert

ImageMagick is a free and open source application that can be downloaded here. In a Linux environment, ImageMagick can be installed using the Linux distribution's package manager.

If you have an existing image in a popular format such as PNG, JPEG, GIF or the 16 Color BMP format that Paint can produce, you can convert it using the ImageMagick convert utility. For example, if your source file is image.bmp and you wish to create image.xpm run this command:

convert -depth 8 -colors 16 -resize 640x480 image.bmp image.xpm

Note that the ImageMagick convert utility will not warn if it cannot convert the image correctly. Therefore, load the XPM file into a text editor and check that the dimensions and color palette are correct. ImageMagick adds a comment:

/* columns rows colors chars-per-pixel */
"640 480 14 1",

Creating an image with GIMP

GIMP is a free and open source application that can be downloaded here. In a Linux environment, GIMP can be installed using the Linux distribution's package manager.

1. Open GIMP.
2. Click File/New.
3. Select 640x480 from the Template dropdown and click OK.
4. Click File/Open As Layers, browse to your image file and click Open.
5. Click OK on the Render Scalable Vector Graphics page.
6. Click Image/Mode/Indexed.
7. Change the Maximum number of colors: from 255 to 15 and click the Convert button.
8. Click on Image/Mode/RGB.
9. Click on Image/Merge Visible Layers and click the Merge button.
10. Optionally, click File/Save to save the image in XCF format.
11. Click File/Export As and save the file as an X PixMap image (*.xpm).

Creating an image with KolourPaint

KolourPaint is a paint program included with the KDE Plasma desktop which is available on many Linux distributions. It is as easy to use as Microsoft Paint but unlike Paint it can save files in XPM format:

1. Open KolourPaint and from the File menu open the 1699032480265__grayimage.bmp file.
2. Modify the image by, for example, copying and pasting your logo into it.
3. From the File menu, choose Save As and save the image with a file type of XPM image.
4. Load the XPM file into a text editor to check the dimensions and color palette are correct.