Hi all,
This started as an internal discussion for U-Booa and SSL which quickly span out of control, so the mailing list is a better suited place for this discussion.
Akashi-san had an interesting idea. Since we will try to implement StandaloneMM as an OP-TEE TA, why not add payload authentication capabilities on it. Since it's already doing variable authentication on the secure side, the needed changes would be minimal (at least that's what i think, please correct me if i am wrong), since most of the code should already be there.
This means that the payload authentication will be moved to the secure world. Although doing the authentication in secure world won't offer any security enhancements, the common code across firmware implementations is probably nice to have.
The obvious drawback is that you limit the payload authentication capabilities, since running StMM will become obligatory for image that.
Thanks /Ilias