Save VerifiedTicket

[LoganSchmalz]

TPM policy authorization (policy_authorize) can be optimized by caching the VerifiedTicket (so it does not need to be reverified). I am imagining a solution similar to SavedTpmContext with marshall/unmarshall or serde. If somebody can suggest how it should be organized in the file structure, I would be happy to implement it myself and make a PR.

I think I have a pretty simple implementation that converts the tag and hierarchy to integers, and to deserialize takes the SavedVerifiedTicket to a TPMT_TK_VERIFIED. I'm not sure this is the cleanest implementation.

[ionut-arm]

Hi! Apologies for the long delay. It does sound like a good idea to add (de)serialization for VerifiedTicket, but I think hand-rolling something isn't necessary. We already have the required traits and bindings to just serialize it in a TPM-native way.

If you'd like to throw together a PR using this approach you can have a look at the Marshall / UnMarshall traits in traits.rs, and the way they're used and derived for existing types (via the macros we defined).