Certificate Transparency: Code for unpacking EV cert hashes whitelist

chrome/browser/net/packed_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 "chrome/browser/net/packed_ct_ev_whitelist.h"
+
+#include <algorithm>
+#include <string>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+const uint8_t kFirstHashRaw[] =
+    {0x00, 0x00, 0x03, 0xd7, 0xfc, 0x18, 0x02, 0xcb};
+std::string GetFirstHash() {
+  return std::string(reinterpret_cast<const char*>(kFirstHashRaw), 8);
+}
+
+// Second hash: Diff from first hash is > 2^47
+const uint8_t kSecondHashRaw[] =
+    {0x00, 0x01, 0x05, 0xd2, 0x58, 0x47, 0xa7, 0xbf};
+std::string GetSecondHash() {
+  return std::string(reinterpret_cast<const char*>(kSecondHashRaw), 8);
+}
+
+// Third hash: Diff from 2nd hash is < 2^47
+const uint8_t kThirdHashRaw[] =
+    {0x00, 0x01, 0x48, 0x45, 0x8c, 0x53, 0x03, 0x94};
+std::string GetThirdHash() {
+  return std::string(reinterpret_cast<const char*>(kThirdHashRaw), 8);
+}
+
+const uint8_t kWhitelistData[] = {
+    0x00, 0x00, 0x03, 0xd7, 0xfc, 0x18, 0x02, 0xcb,  // First hash
+    0xc0, 0x7e, 0x97, 0x0b, 0xe9, 0x3d, 0x10, 0x9c,
+    0xcd, 0x02, 0xd6, 0xf5, 0x40,
+};
+
+std::string GetPartialWhitelistData(uint8_t num_bytes) {
+  return std::string(reinterpret_cast<const char*>(kWhitelistData), num_bytes);
+}
+
+std::string GetAllWhitelistData() {
+  return GetPartialWhitelistData(arraysize(kWhitelistData));
+}
+
+}  // namespace
+
+TEST(PackedEVCertsWhitelistTest, UncompressFailsForTooShortList) {
+  // This list does not contain enough bytes even for the first hash.
+  std::vector<std::string> res;
+  EXPECT_FALSE(PackedEVCertsWhitelist::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData), 7), &res));
+}
+
+TEST(PackedEVCertsWhitelistTest, UncompressFailsForTruncatedList) {
+  // This list is missing bits for the second part of the diff.
+  std::vector<std::string> res;
+  EXPECT_FALSE(PackedEVCertsWhitelist::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData), 14), &res));
+}
+
+TEST(PackedEVCertsWhitelistTest, UncompressFailsForInvalidValuesInList) {
+  // A list with an invalid read_prefix value is the number 131072, unary
+  // encoded, after the fist 8 bytes of a valid hash.
+  // That translates to 16385 0xff bytes.
+  // To make the hash otherwise valid, append 6 bytes of r value.
+  const int num_ff_bytes = 16385;
+  const int total_size = 8 + num_ff_bytes + 7;
+  uint8_t* invalid_whitelist = new uint8_t[total_size];
+  invalid_whitelist[total_size - 1] = '\0';
+  // Valid first hash.
+  memcpy(reinterpret_cast<char*>(invalid_whitelist),
+         reinterpret_cast<const char*>(kWhitelistData),
+         8 * sizeof(char));
+  // 0xff 16385 times.
+  for (int i = 0; i < num_ff_bytes; i++) {
+    invalid_whitelist[8 + i] = 0xff;
+  }
+  // Valid r value (any 6 bytes will do).
+  memcpy(reinterpret_cast<char*>(invalid_whitelist + 8 + num_ff_bytes),
+         reinterpret_cast<const char*>(kWhitelistData),
+         6 * sizeof(char));
+
+  std::vector<std::string> res;
+  EXPECT_FALSE(PackedEVCertsWhitelist::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(invalid_whitelist),
+                  total_size - 1),
+      &res));
+  delete[] invalid_whitelist;
+}
+
+TEST(PackedEVCertsWhitelistTest, UncompressesWhitelistCorrectly) {
+  std::vector<std::string> res;
+  ASSERT_TRUE(PackedEVCertsWhitelist::UncompressEVWhitelist(
+      std::string(reinterpret_cast<const char*>(kWhitelistData),
+                  arraysize(kWhitelistData)),
+      &res));
+
+  // Ensure first hash is found
+  EXPECT_TRUE(std::find(res.begin(), res.end(), GetFirstHash()) != res.end());
+  // Ensure second hash is found
+  EXPECT_TRUE(std::find(res.begin(), res.end(), GetSecondHash()) != res.end());
+  // Ensure last hash is found
+  EXPECT_TRUE(std::find(res.begin(), res.end(), GetThirdHash()) != res.end());
+  // Ensure that there are exactly 3 hashes.
+  EXPECT_EQ(3u, res.size());
+}
+
+TEST(PackedEVCertsWhitelistTest, CanFindHashInSetList) {
+  scoped_refptr<PackedEVCertsWhitelist> whitelist(
+      new PackedEVCertsWhitelist(GetAllWhitelistData()));
+
+  EXPECT_TRUE(whitelist->IsValid());
+  EXPECT_TRUE(whitelist->ContainsCertificateHash(GetFirstHash()));
+  EXPECT_TRUE(whitelist->ContainsCertificateHash(GetSecondHash()));
+  EXPECT_TRUE(whitelist->ContainsCertificateHash(GetThirdHash()));
+}
+
+TEST(PackedEVCertsWhitelistTest, CorrectlyIdentifiesEmptyWhitelistIsInvalid) {
+  scoped_refptr<PackedEVCertsWhitelist> whitelist(
+      new PackedEVCertsWhitelist(""));
+
+  EXPECT_FALSE(whitelist->IsValid());
+}
+
+TEST(PackedEVCertsWhitelistTest, CorrectlyIdentifiesPartialWhitelistIsInvalid) {
+  scoped_refptr<PackedEVCertsWhitelist> whitelist(
+      new PackedEVCertsWhitelist(GetPartialWhitelistData(14)));
+
+  EXPECT_FALSE(whitelist->IsValid());
+}
+
+TEST(PackedEVCertsWhitelistTest, CorrectlyIdentifiesWhitelistIsValid) {
+  scoped_refptr<PackedEVCertsWhitelist> whitelist(
+      new PackedEVCertsWhitelist(GetAllWhitelistData()));
+
+  EXPECT_TRUE(whitelist->IsValid());
+}