Colin Cogle's Blog

Update (July 30, 2010 at 1:17 am): This blog post is now very obsolete with the release of GPGMail 1.3.0 (and a sharp new Web site), fully Snow Leopard compatible.

GPGMail has been an invaluable tool for users of both GPG and Apple’s Mail application. For those unfamiliar with GPG (and its commercial equivalent, PGP), it uses a set of keys — one public, one secret — to encrypt and/or attach digital signatures to email. (Read the Wikipedia article for more information, as it’s not entirely relevant here.)

Unfortunately, the marriage of GPG to Mail has been a bittersweet relationship. Apple doesn’t publish the internal API‘s of Mail, and has not provided much of a plug-in architecture for it. Therefore, GPGMail had to be developed by using undocumented functions, which Apple had no obligation to maintain between major releases of Mac OS X. Like all other major upgrades, Mac users upgrading to Snow Leopard were left to pick up the pieces. To add to the pain, the sole programmer behind this no longer has time to maintain the software.

While the software is getting a long-overdue rewrite from new hands, two enterprising users found a solution, which I’m reposting to spread the word.

1. Download and install GPGMail and MacGPG.
2. Find Mail in the Applications folder. From the File menu, choose Get Info.
3. Check Run in 32-bit mode. (64-bit support will have to wait until a new version of GPGMail is formally released.)
4. Now, go to ~/Library/Mail/Bundles; right-click on GPGMail.mailbundle and choose Show Package Contents.
5. Add the following lines to Info.plist, depending on which version of Mac OS X that you’re running:
   • Mac OS X 10.6:

     1 2 3 4 5

     <key>SupportedPluginCompatibilityUUIDs</key> <array>     <string>B3F3FC72-315D-4323-BE85-7AB76090224D</string>     <string>225E0A48-2CDB-44A6-8D99-A9BB8AF6BA04</string> </array>

   • Mac OS X 10.6.1:

     1 2 3 4 5

     <key>SupportedPluginCompatibilityUUIDs</key> <array>     <string>2610F061-32C6-4C6B-B90A-7A3102F9B9C8</string>     <string>99BB3782-6C16-4C6F-B910-25ED1C1CB38B</string> </array>

   • Mac OS X 10.6.2 (beta):

     1 2 3 4 5

     <key>SupportedPluginCompatibilityUUIDs</key> <array>     <string>0CB5F2A0-A173-4809-86E3-9317261F1745</string>     <string>2F0CF6F9-35BA-4812-9CB2-155C0FDB9B0F</string> </array>

6. Save the file, and then open Mail.

Everything should be working fine now! Many thanks to detlefschmitt and pretemsteinmetz from the SourceForge.net forums for this solution. If you found this helpful, please thank the original posters, and then urge Apple to do any of the following:

1. Provide native support for GnuPG in Mail, as they do S/MIME.
2. Publish a Mail plugin API, to make development of GPGMail easier.
3. Assign one or more members of the Mail development team to the GPGMail project.

Tags: Apple, email, Mac, PGP

This entry was posted on Monday, October 12th, 2009 at 2:44 am and is filed under Apple, Computers. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.