[webgui] strict check for HMAC signature

[linev]

Prevent situation with manipulated packet send without HMAC at all could be accepted

[github-actions[bot]]

Test Results

     9 files       9 suites   1d 17h 47m 8s :stopwatch:  2 634 tests  2 634 :white_check_mark: 0 :zzz: 0 :x: 22 331 runs  22 331 :white_check_mark: 0 :zzz: 0 :x:

Results for commit 7394e0a9.

[linev]

Can we have a test for this?

For the moment we do not have methods to test communication artifacts. One side is JavaScript, other side is ROOT C++.

[linev]

Is there a plan to introduce testing for this part?

There was no concrete plan.

One can try to emulate attack on RWebWindow communication without real http server.