DO NOT MERGE SMP: Validate remote elliptic curve points

Fixes: 72377774
Test: net_test_stack_smp (where applicable)
Change-Id: Iefcf97364493467075fadefd77d12716f71cd4f6
(cherry picked from commit 9181ec28da94705a763edbe60bd2a87e5f882beb)
3 files changed