Certificate Transparency: Start tracking logs' state

components/certificate_transparency/tree_state_tracker.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_CERTIFICATE_TRANSPARENCY_TREE_STATE_TRACKER_H_
+#define COMPONENTS_CERTIFICATE_TRANSPARENCY_TREE_STATE_TRACKER_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "net/cert/ct_verifier.h"
+#include "net/cert/sth_observer.h"
+
+namespace net {
+class CTLogVerifier;
+class X509Certificate;
+
+namespace ct {
+struct SignedCertificateTimestamp;
+struct SignedTreeHead;
+}  // namespace ct
+
+}  // namespace net
+
+namespace certificate_transparency {
+class SingleTreeTracker;
+
+// This class receives notifications of new Signed Tree Heads (STHs) and
+// verified Signed Certificate Timestamps (SCTs) and delegates them to
+// the SingleTreeTracker tracking the CT log they relate to.
+// TODO(eranm): Export the inclusion check status of SCTs+Certs so it can
+// be used in the DevTools Security panel, for example. See
+// https://crbug.com/506227#c22.
+class TreeStateTracker : public net::CTVerifier::Observer,
+                         public net::ct::STHObserver {
+ public:
+  // Tracks the state of the logs provided in |ct_logs|. An instance of this
+  // class only tracks the logs provided in the constructor. The implementation
+  // is based on the assumption that the list of recognized logs does not change
+  // during the object's life time.
+  // Observed STHs from logs not in this list will be simply ignored.
+  explicit TreeStateTracker(
+      std::vector<scoped_refptr<const net::CTLogVerifier>> ct_logs);
+  ~TreeStateTracker() override;
+
+  // net::ct::CTVerifier::Observer implementation.
+  // Delegates to the tree tracker corresponding to the log that issued the SCT.
+  void OnSCTVerified(net::X509Certificate* cert,
+                     const net::ct::SignedCertificateTimestamp* sct) override;
+
+  // net::ct::STHObserver implementation.
+  // Delegates to the tree tracker corresponding to the log that issued the STH.
+  void NewSTHObserved(const net::ct::SignedTreeHead& sth) override;
+
+ private:
+  // Holds the SingleTreeTracker for each log
+  std::map<std::string, std::unique_ptr<SingleTreeTracker>> tree_trackers_;
+
+  DISALLOW_COPY_AND_ASSIGN(TreeStateTracker);
+};
+
+}  // namespace certificate_transparency
+
+#endif  // COMPONENTS_CERTIFICATE_TRANSPARENCY_TREE_STATE_TRACKER_H_