Certificate Transparency: Code for unpacking EV cert hashes whitelist

net/cert/ct_ev_whitelist_unittest.cc

+// 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.
+
+#include "net/cert/ct_ev_whitelist.h"
+
+#include <string>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace ct {
+
+namespace internal {
+
+const uint8 kSomeData[] = {0xd5, 0xe2, 0xaf, 0xe5, 0xbb, 0x10, 0x7c, 0xd1};

[wtc, 2014/09/03 14:29:48]

A solution I used before is to initialize the char array with char constants
specified as hex escape sequences:

const char kSomeData[] = {'\xd5', '\xe2', '\xaf', ...};

[Eran Messeri, 2014/09/03 20:27:09]

Acknowledged - since I only use the data once (to create the string instance)
I'll keep it this way, with the cast, and will use your solution in the next
tests I write.

+
+TEST(BitStreamReaderTest, CanReadSingleByte) {
+  BitStreamReader reader(reinterpret_cast<const char*>(kSomeData), 1);
+  uint64 v(0);
+
+  EXPECT_EQ(8u, reader.BitsLeft());
+  EXPECT_TRUE(reader.ReadBits(8, &v));
+  EXPECT_EQ(UINT64_C(0xd5), v);
+
+  EXPECT_FALSE(reader.ReadBits(1, &v));
+  EXPECT_EQ(0u, reader.BitsLeft());
+}
+
+TEST(BitStreamReaderTest, CanReadSingleBits) {
+  const uint64 expected_bits[] = {1, 1, 0, 1, 0, 1, 0, 1,
+                                  1, 1, 1, 0, 0, 0, 1, 0};
+  BitStreamReader reader(reinterpret_cast<const char*>(kSomeData), 2);
+  EXPECT_EQ(16u, reader.BitsLeft());
+  uint64 v(0);
+
+  for (int i = 0; i < 16; ++i) {
+    EXPECT_TRUE(reader.ReadBits(1, &v));
+    EXPECT_EQ(expected_bits[i], v);
+  }
+  EXPECT_EQ(0u, reader.BitsLeft());
+}
+
+TEST(BitStreamReaderTest, CanReadBitGroups) {
+  BitStreamReader reader(reinterpret_cast<const char*>(kSomeData), 3);
+  EXPECT_EQ(24u, reader.BitsLeft());
+  uint64 v(0);
+  uint64 res(0);
+
+  EXPECT_TRUE(reader.ReadBits(5, &v));
+  res |= v << 19;
+  EXPECT_EQ(19u, reader.BitsLeft());
+  EXPECT_TRUE(reader.ReadBits(13, &v));
+  res |= v << 6;
+  EXPECT_EQ(6u, reader.BitsLeft());
+  EXPECT_TRUE(reader.ReadBits(6, &v));
+  res |= v;
+  EXPECT_EQ(UINT64_C(0xd5e2af), res);
+
+  EXPECT_FALSE(reader.ReadBits(1, &v));
+}
+
+TEST(BitStreamReaderTest, CanRead64Bit) {
+  BitStreamReader reader(reinterpret_cast<const char*>(kSomeData), 8);
+  EXPECT_EQ(64u, reader.BitsLeft());
+  uint64 v(0);
+
+  EXPECT_TRUE(reader.ReadBits(64, &v));
+  EXPECT_EQ(UINT64_C(0xd5e2afe5bb107cd1), v);
+}
+
+TEST(BitStreamReaderTest, CanReadUnaryEncodedNumbers) {
+  BitStreamReader reader(reinterpret_cast<const char*>(kSomeData), 3);
+  const uint64 expected_values[] = {2, 1, 1, 4, 0, 0, 1, 1, 1, 4};
+  uint64 v(0);
+  for (int i = 0; i < 10; ++i) {
+    EXPECT_TRUE(reader.ReadUnaryEncoding(&v));
+    EXPECT_EQ(expected_values[i], v) << "Values differ at position " << i;
+  }
+}
+
+}  // namespace internal
+
+const uint8 kFirstHashRaw[] = {0x00, 0x00, 0x03, 0xd7, 0xfc, 0x18, 0x02, 0xcb};
+const std::string kFirstHash(reinterpret_cast<const char*>(kFirstHashRaw), 8);

[wtc, 2014/09/03 14:29:48]

IMPORTANT: Chromium doesn't allow static objects. It may be OK to make an
exception here because this is just a test file, but it is best to avoid static
objects.

[Eran Messeri, 2014/09/03 20:27:09]

Changed to use getter methods for the string representation of these values.

+
+// Second hash: Diff from first hash is > 2^47
+const uint8 kSecondHashRaw[] = {0x00, 0x01, 0x05, 0xd2, 0x58, 0x47, 0xa7, 0xbf};
+const std::string kSecondHash(reinterpret_cast<const char*>(kSecondHashRaw), 8);
+
+// Third hash: Diff from 2nd hash is < 2^47
+const uint8 kThirdHashRaw[] = {0x00, 0x01, 0x48, 0x45, 0x8c, 0x53, 0x03, 0x94};
+const std::string kThirdHash(reinterpret_cast<const char*>(kThirdHashRaw), 8);
+
+const uint8 kWhitelistData[] = {
+    0x00, 0x00, 0x03, 0xd7, 0xfc, 0x18, 0x02, 0xcb,  // First hash
+    0xc0, 0x7e, 0x97, 0x0b, 0xe9, 0x3d, 0x10, 0x9c,
+    0xcd, 0x02, 0xd6, 0xf5, 0x40,
+};
+
+TEST(CTEVWhitelistTest, UncompressFailsForTooShortList) {
+  // This list does not contain enough bytes even for the first hash.
+  std::set<std::string> res;
+  EXPECT_FALSE(internal::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData), 7), &res));
+}
+
+TEST(CTEVWhitelistTest, UncompressFailsForTruncatedList) {
+  // This list is missing bits for the second part of the diff.
+  std::set<std::string> res;
+  EXPECT_FALSE(internal::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData), 14), &res));
+}
+
+TEST(CTEVWhitelistTest, UncompressesWhitelistCorrectly) {
+  std::set<std::string> res;
+  ASSERT_TRUE(internal::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData),
+                  arraysize(kWhitelistData)),
+      &res));
+
+  // Ensure first hash is found
+  EXPECT_TRUE(res.find(kFirstHash) != res.end());
+  // Ensure second hash is found
+  EXPECT_TRUE(res.find(kSecondHash) != res.end());
+  // Ensure last hash is found
+  EXPECT_TRUE(res.find(kThirdHash) != res.end());
+  // Ensure that there are exactly 3 hashes.
+  EXPECT_EQ(3u, res.size());
+}
+
+TEST(CTEVWhitelistTest, CanFindHashInSetList) {
+  std::set<std::string> whitelist_data;
+  whitelist_data.insert(kFirstHash);

[wtc, 2014/09/03 14:29:48]

IMPORTANT: you also need to fix this test to construct a std::string from
kFirstHash.

[Eran Messeri, 2014/09/03 20:27:09]

Done.

+  internal::SetEVWhitelistData(whitelist_data);
+
+  EXPECT_TRUE(IsCertificateHashInWhitelist(kFirstHash));
+}
+
+TEST(CTEVWhitelistTest, CannotFindOldHashAfterSetList) {
+  std::set<std::string> whitelist_data;
+  whitelist_data.insert(kFirstHash);
+  internal::SetEVWhitelistData(whitelist_data);
+  EXPECT_TRUE(IsCertificateHashInWhitelist(kFirstHash));
+
+  std::set<std::string> new_whitelist_data;
+  new_whitelist_data.insert(kSecondHash);
+  internal::SetEVWhitelistData(new_whitelist_data);
+  EXPECT_TRUE(IsCertificateHashInWhitelist(kSecondHash));
+  EXPECT_FALSE(IsCertificateHashInWhitelist(kFirstHash));
+}
+
+}  // namespace ct
+
+}  // namespace net