Freshness + challenge-response nonce sizes

[setrofim]

Document Veraison approach to handling evidence freshness and update challenge-response docs with nonce size restriction.

[thomas-fossati]

awesome. A few typos fixed inline.

[yogeshbdeshpande]

@setrofim. thank you for the change, I will review the rest a bit later today

[yogeshbdeshpande]

LGTM! Thanks for very well formed draft.

I have made few comments, please do check and take it, if you agree! Otherwise good to go!

[yogeshbdeshpande]

@setrofim All looks good and we are fine to merge. Just one quick question:

In the sequence diagram, for comparison diamond, we depict session == evidence. I know due to space constraint it is done like that, was just curious shall we say something like
s-nonce == ev-nonce

and qualify somewhere below:
s-nonce implies nonce received in session

and
ev-nonce is the nonce decoded in the token.

WDYT?

[SimonFrost-Arm]

LGTM

[setrofim]

@setrofim All looks good and we are fine to merge. Just one quick question:

In the sequence diagram, for comparison diamond, we depict session == evidence. I know due to space constraint it is done like that, was just curious shall we say something like s-nonce == ev-nonce

and qualify somewhere below: s-nonce implies nonce received in session

and ev-nonce is the nonce decoded in the token.

WDYT?

IMO that would make it more confusing as it's not obvious what "s" and "ev" decode to. Conversely, the entire diagram is about the nonce/challenge -- the inputs going into comparison are nonces.

[yogeshbdeshpande]

LGTM!