Microsoft Smartphone Code Signing and the GPL?

spacemonkey asks: "I am a professional developer, but in my spare time I have been developing games for the Microsoft Smartphone platform. Included in this work is a port of gnuboy a GPL gameboy colour emulator. Where does the GPL stand on the question of codesigning applications where required? Basically gnuboy is available, with full source for smartphone, however there are a large number of users out there who are unable/unwilling to remove the certification requirements from their smartphone devices, so to allow for these users, I need to sign the code. To enter into the code signing program will cost me approximately £500. I am interested in signing the application to make it available to a wider audience, however since I am not running a charity I was wondering whether charging some nominal fee for the code signed version was compatible with the GPL or not. So users would have an option on a signed version for less than £5, or an unsigned version free, which will include the full source code. Am I allowed to charge for GPL software in this way, where the charge is to cover the packaging of the application into a signed form?"

GPL says you can charge whatever you want

[ArmorFiend]

You can charge money for GPL software. You just have to make the source easily available. I think that would be covered by a URL in the about-box.

In fact, the signing works nicely in your favor, since nobody can undercut you on price. Or they can, but they too have to pay the L500, in which case they'd have to either 1) charge as much as you or 2) hate you enough to take an intentional loss. Both are a lot of hassel. Seems to me like you just win.

Source Code is the small charge

[Anonymous Coward]

It's the Source Code you are only allowed to charge the reasonable 'media charge' for. The application itself you can charge anything you want. The idea of this is to prevent you from charging $5 for the Application, and $50,000 for the source... you know, open source and all.

Re:GPL says you can charge whatever you want

[ArmorFiend]

In fact, the signing works nicely in your favor, since nobody can undercut you on price. Or they can, but they too have to pay the L500, ... or purchase a copy from him and then resell it!

DOH!
LoL

Re:GPL says you can charge whatever you want

[SagSaw]

In fact, the signing works nicely in your favor, since nobody can undercut you on price. Or they can, but they too have to pay the L500, in which case they'd have to either 1) charge as much as you or 2) hate you enough to take an intentional loss. Both are a lot of hassel. Seems to me like you just win.

Not quite, unless I compleatly mis-understand the way this instance of code-signing works. Lets say that Bob has a piece of GPL'ed software avaiaible on his website. Bob makes three files availaible for download: a source tarball, a binary distribution, and a signed binary distribution. In order to cover the cost of code-signing, Bob requires a payment of $25 to download the signed version. Joe pays Bob $25 to download the signed binary. Now, as he is allowed to redistrute Bob's work under the GPL, Joe posts Bob's signed binary package on his own website and allows anyone to download it for free. Bob sees no further downloads of the $25 signed version and never re-coups the $500 it cost him to sign the code in the first place.

I can see two possible solutions for Bob:
1. Bob Obtain the software from the software's copyright holders under a licence which would allow Bob to prevent redistribution of the signed binary version.
2. Bob can write his own software and release the source and normal binary under the GPL, but release the signed binary under some other licence.