CASE: Send Busy response when we are in the middle of handshake and receives sigma1

[shubhamdp]

Type

Other

Explanation

Once #27226 gets merged, the unsolicited handler for sigma1 will not be unregistered after receiving a sigma1, so we can send the busy response when we receives a sigma1 when we are in the middle of handshake.

Platform

core (please add to version below)

Platform Version(s)

No response

Testing

Manually tested with SDK

(Optional) If manually tested please explain why this is only manually tested

No response

Anything else?

No response

[shubhamdp]

While looking into this I had three options... so though of putting up here.

1. Define a function and do similar stuff what SendStatusReport from PairingSession.h is doing.
2. SendStatusReport() is not dependent on anything from PairingSession and it just requires exchange context which it takes as an argument, so can we make it static?
3. Move SendStatusReport() to ExchangeContext besides SendMessage so that we call it using exchange context. And we stop duplicating Sending status response code.

Thoughts?

[bzbarsky-apple]

@shubhamdp I really like option 3. Presumably this will have SendStatusReport taking const Protocols::SecureChannel::StatusReport & or so? Having that be a single utility on exchanges makes a lot of sense.

[bzbarsky-apple]

I guess another option would be to have a SendOnExchange on SecureChannel::StatusReport, but that seems like a bit of a layering issue.....

[shubhamdp]

1. Going with this... and implemented in the PR CASE: Send busy status report if we receive a sigma1 and we are in the middle of handshake #28153
2. Since SendStatusReport is protected and I did not feel good about making it private, so avoided that path.
3. I see the cyclic dependency issue so, could not get around it

I'll raise an issue to see if I can optimize the SendStatusReport bits to avoid code duplication.

[bzbarsky-apple]

I see the cyclic dependency issue so, could not get around it

@shubhamdp what was the cyclic dependency?

[shubhamdp]

After #28219 got merged, going with option 3, where we add SendStatusReport() API on ExchangeContext.