The suit is only half way there. A code that is "Clean" wihout access to the source of the encryption is a trade secret of the writer, not the DCMIA. If he wishes to license such code under the GPL he can do so. IANAL but I think that his code is freestanding, so fair game. Using the argument that the court rendered would give SCO the remedy from Linux as they are requesting.
thanx,
bill