Add Certificate Transparency logs auditing

components/certificate_transparency/timestamped_leaf.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_TIMESTAMPED_LEAF_H_
+#define COMPONENTS_CERTIFICATE_TRANSPARENCY_TIMESTAMPED_LEAF_H_
+
+#include "base/optional.h"
+#include "base/time/time.h"
+#include "net/cert/merkle_tree_leaf.h"

[Rob Percival, 2016/06/30 14:15:58]

#include <stdint.h>  // for uint64_t

[Eran Messeri, 2016/06/30 19:58:28]

Done.

+
+class TimestampedLeaf {

[Rob Percival, 2016/06/30 14:15:58]

It might be better to have this inherit from MerkleTreeLeaf (it looks like an
"is-a" relationship).

[Eran Messeri, 2016/06/30 19:58:28]

I'd rather keep it a separate class:
- Detangling inheritance in the codebase is usually painful.
- I'd argue there's only one type of MerkleTreeLeaf - the one in the Merkle
tree. This class contains metadata about a particular MerkleTreeLeaf.
- Inheritance is more meaningful when there are behavioural changes - here we'd
just be overloading it with data fields.

+ public:
+  TimestampedLeaf(const net::ct::MerkleTreeLeaf& leaf,
+                  const base::Time& seen_at);
+  TimestampedLeaf(const TimestampedLeaf& other);
+  ~TimestampedLeaf();
+
+  void SetLeafIndex(uint64_t index);
+  bool HasLeafIndex();
+  uint64_t GetLeafIndex();

[Rob Percival, 2016/06/30 14:15:58]

HasLeafIndex() and GetLeafIndex() should be const.

[Eran Messeri, 2016/06/30 19:58:28]

Done.

+  net::ct::MerkleTreeLeaf GetLeaf();

[Rob Percival, 2016/06/30 14:15:58]

What's the point in having a non-const version of GetLeaf that returns by value?

[Eran Messeri, 2016/06/30 19:58:28]

No point, removed.

+  const net::ct::MerkleTreeLeaf& GetLeaf() const;
+
+ private:
+  // The entire leaf for the certificate.
+  net::ct::MerkleTreeLeaf leaf_;
+  // When the leaf for the particular certificate was first seen.
+  base::Time first_seen_;
+  // The leaf's index in the tree. Only set if the index has been
+  // obtained from the log.
+  base::Optional<uint64_t> leaf_index_;
+};
+
+#endif  // COMPONENTS_CERTIFICATE_TRANSPARENCY_TIMESTAMPED_LEAF_H_