HTTP Strict Transport Security (HSTS) is a web security policy that
allows a web server to declare that user agents should only interact
with it using secure HTTPS connections. HSTS is described by RFC6797.
This patch introduces a new API in Network Access Manager to enable
this policy or disable it (default - STS is disabled).
We also implement QHstsCache which caches known HTTS hosts, does
host name lookup and domain name matching; QHstsHeaderParser to
parse HSTS headers with HSTS policies.
A new autotest added to test the caching, host name matching
and headers parsing.
[ChangeLog][QtNetwork] Added HTTP Strict Transport Security to QNAM
Task-number: QTPM-238
Change-Id: Iabb5920344bf204a0d3036284f0d60675c29315c
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
