Refactor HSTS cache implementation

The original monstrosity is not needed at all. It was born only to implement
RFC6797's description of the host matching algorithm (starting from superdomains
and moving to subdomains). Actually, it does not really matter how we find
known host - it can be a congruent match first instead, and then we proceed
with superdomains. This way I can use QMap and my tests so far show it actually
works faster (both insertion and lookup), also the code is cleaner now.

Also, introduce the new class QHstsPolicy that essentially allows to mark
a host as known host and conveniently encapsulates host name/expiration date/
subdomains policy.

Add a public API providing access to HSTS policies, so that client code
can pre-set or read back discovered known hosts (to implement persistent
HSTS storage, for example).

We support server-driven HSTS - this means client code is allowed to provide
policies as hints to QNetworkAccessManager, but these policies can be
overridden by HTTP responses with 'Strict-Transport-Security' headers.

Change-Id: I64d250b6dc78bcb01003fadeded5302471d1389e
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 41 insertions, 0 deletions

diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index 7aa8e61d26..19e9ecc265 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -45,6 +45,8 @@
 #include "qnetworkcookie.h"
 #include "qnetworkcookiejar.h"
 #include "qabstractnetworkcache.h"
+#include "qhstspolicy.h"
+#include "qhsts_p.h"
 
 #include "QtNetwork/qnetworksession.h"
 #include "QtNetwork/private/qsharednetworksession_p.h"
@@ -742,6 +744,45 @@ bool QNetworkAccessManager::strictTransportSecurityEnabled() const
 }
 
 /*!
+    \since 5.9
+
+    Adds HTTP Strict Transport Security policies into HSTS cache.
+
+    \note An expired policy will remove a known host from the cache, if previously
+    present.
+
+    \note While processing HTTP responses, QNetworkAccessManager can also update
+    the HSTS cache, removing or updating exitsting policies or introducing new
+    known hosts. The current implementation thus is server-driven, client code
+    can provide QNetworkAccessManager with previously known or discovered
+    policies, but this information can be overridden by "Strict-Transport-Security"
+    response headers.
+
+    \sa addStrictTransportSecurityHosts(), QHstsPolicy
+*/
+
+void QNetworkAccessManager::addStrictTransportSecurityHosts(const QList<QHstsPolicy> &knownHosts)
+{
+    Q_D(QNetworkAccessManager);
+    d->stsCache.updateFromPolicies(knownHosts);
+}
+
+/*!
+    \since 5.9
+
+    Returns the list of HTTP Strict Transport Security policies. This list can
+    differ from what was initially set via addStrictTransportSecurityHosts() if
+    HSTS cache was updated from a "Strict-Transport-Security" response header.
+
+    \sa addStrictTransportSecurityHosts(), QHstsPolicy
+*/
+QList<QHstsPolicy> QNetworkAccessManager::strictTransportSecurityHosts() const
+{
+    Q_D(const QNetworkAccessManager);
+    return d->stsCache.policies();
+}
+
+/*!
     Posts a request to obtain the network headers for \a request
     and returns a new QNetworkReply object which will contain such headers.