Certificate Transparency: Code for unpacking EV cert hashes whitelist

chrome/browser/net/packed_ct_ev_whitelist.h

+// Copyright 2014 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 CHROME_BROWSER_NET_PACKED_CT_EV_WHITELIST_H_
+#define CHROME_BROWSER_NET_PACKED_CT_EV_WHITELIST_H_
+
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/string_piece.h"
+#include "net/cert/ct_ev_whitelist.h"
+
+namespace base {
+class FilePath;
+}
+
+class PackedEVCertsWhitelist : public net::ct::EVCertsWhitelist {

[Ryan Sleevi, 2014/10/20 19:18:25]

Document

[Eran Messeri, 2014/10/21 14:59:59]

Done.

+ public:
+  explicit PackedEVCertsWhitelist(const std::string& compressed_whitelist);

[Ryan Sleevi, 2014/10/20 19:18:25]

Document

[Eran Messeri, 2014/10/21 14:59:59]

Done.

+
+  // Returns true if the |certificate_hash| appears in the EV certificate hashes
+  // whitelist.
+  virtual bool ContainsCertificateHash(
+      const std::string& certificate_hash) const OVERRIDE;
+
+  // Returns true if the global EV certificate hashes whitelist is non-empty,
+  // false otherwise.
+  virtual bool IsValid() const OVERRIDE;
+
+ protected:
+  virtual ~PackedEVCertsWhitelist();
+  // Given a Golomb-coded list of hashes in |compressed_whitelist|, unpack into
+  // |uncompressed_list|. Returns true if the format of the compressed whitelist
+  // is valid, false otherwise.
+  static bool UncompressEVWhitelist(
+      const std::string& compressed_whitelist,
+      std::vector<std::string>* uncompressed_list);

[Ryan Sleevi, 2014/10/20 19:18:25]

Why is this protected+static?

Private+static plus friend (potentially using a test fixture & "friend class
PackedEVCertsWhitelistTest")

[Eran Messeri, 2014/10/21 14:59:59]

Done.

+
+  FRIEND_TEST_ALL_PREFIXES(PackedEVCertsWhitelistTest,
+                           UncompressFailsForTooShortList);
+  FRIEND_TEST_ALL_PREFIXES(PackedEVCertsWhitelistTest,
+                           UncompressFailsForTruncatedList);
+  FRIEND_TEST_ALL_PREFIXES(PackedEVCertsWhitelistTest,
+                           UncompressesWhitelistCorrectly);
+
+ private:
+  friend class base::RefCountedThreadSafe<net::ct::EVCertsWhitelist>;

[Ryan Sleevi, 2014/10/20 19:18:25]

This isn't necessary - the base class must already friend this.

[Eran Messeri, 2014/10/21 14:59:59]

Done.

+
+  bool is_whitelist_valid_;
+  // The whitelist is an array containing certificate hashes (truncated
+  // to a fixed size of 8 bytes), sorted.
+  // Binary search is used to locate hashes in the the array.
+  // Benchmarking bsearch vs std::set (with 120K entries, doing 1.2M lookups)
+  // shows that bsearch is about twice as fast as std::set lookups (and std::set
+  // has additional memory overhead).
+  char* whitelist_;
+  uint32_t whitelist_size_;
+};
+
+// Sets the EV certificate hashes whitelist from |compressed_whitelist_file|
+// in |ssl_config_service|, after uncompressing it.
+// If the data in |compressed_whitelist_file| is not a valid compressed
+// whitelist, does nothing.
+void SetEVWhitelistFromFile(const base::FilePath& compressed_whitelist_file);
+
+#endif  // CHROME_BROWSER_NET_PACKED_CT_EV_WHITELIST_H_