1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
// 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.
#include "components/certificate_transparency/single_tree_tracker.h"
#include <string>
#include <utility>
#include "base/strings/string_piece.h"
#include "base/test/histogram_tester.h"
#include "net/cert/ct_log_verifier.h"
#include "net/cert/ct_serialization.h"
#include "net/cert/signed_certificate_timestamp.h"
#include "net/cert/signed_tree_head.h"
#include "net/cert/x509_certificate.h"
#include "net/test/ct_test_util.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace certificate_transparency {
namespace {
const char kCanCheckForInclusionHistogramName[] =
"Net.CertificateTransparency.CanInclusionCheckSCT";
bool GetOldSignedTreeHead(net::ct::SignedTreeHead* sth) {
sth->version = net::ct::SignedTreeHead::V1;
sth->timestamp = base::Time::UnixEpoch() +
base::TimeDelta::FromMilliseconds(INT64_C(1348589665525));
sth->tree_size = 12u;
const uint8_t kOldSTHRootHash[] = {
0x18, 0x04, 0x1b, 0xd4, 0x66, 0x50, 0x83, 0x00, 0x1f, 0xba, 0x8c,
0x54, 0x11, 0xd2, 0xd7, 0x48, 0xe8, 0xab, 0xbf, 0xdc, 0xdf, 0xd9,
0x21, 0x8c, 0xb0, 0x2b, 0x68, 0xa7, 0x8e, 0x7d, 0x4c, 0x23};
memcpy(sth->sha256_root_hash, kOldSTHRootHash, net::ct::kSthRootHashLength);
sth->log_id = net::ct::GetTestPublicKeyId();
const uint8_t kOldSTHSignatureData[] = {
0x04, 0x03, 0x00, 0x47, 0x30, 0x45, 0x02, 0x20, 0x15, 0x7b, 0x23,
0x42, 0xa2, 0x5f, 0x88, 0xc9, 0x0b, 0x30, 0xa6, 0xb4, 0x49, 0x50,
0xb3, 0xab, 0xf5, 0x25, 0xfe, 0x27, 0xf0, 0x3f, 0x9a, 0xbf, 0xc1,
0x16, 0x5a, 0x7a, 0xc0, 0x62, 0x2b, 0xbb, 0x02, 0x21, 0x00, 0xe6,
0x57, 0xa3, 0xfe, 0xfc, 0x5a, 0x82, 0x9b, 0x29, 0x46, 0x15, 0x1d,
0xbc, 0xfd, 0x9e, 0x87, 0x7f, 0xd0, 0x00, 0x5d, 0x62, 0x4f, 0x9a,
0x1a, 0x9f, 0x20, 0x79, 0xd0, 0xc1, 0x34, 0x2e, 0x08};
base::StringPiece sp(reinterpret_cast<const char*>(kOldSTHSignatureData),
sizeof(kOldSTHSignatureData));
return DecodeDigitallySigned(&sp, &(sth->signature)) && sp.empty();
}
} // namespace
class SingleTreeTrackerTest : public ::testing::Test {
void SetUp() override {
log_ =
net::CTLogVerifier::Create(net::ct::GetTestPublicKey(), "testlog",
"https://ct.example.com", "dns.example.com");
ASSERT_TRUE(log_);
ASSERT_EQ(log_->key_id(), net::ct::GetTestPublicKeyId());
tree_tracker_.reset(new SingleTreeTracker(log_));
const std::string der_test_cert(net::ct::GetDerEncodedX509Cert());
chain_ = net::X509Certificate::CreateFromBytes(der_test_cert.data(),
der_test_cert.length());
ASSERT_TRUE(chain_.get());
net::ct::GetX509CertSCT(&cert_sct_);
}
protected:
scoped_refptr<const net::CTLogVerifier> log_;
std::unique_ptr<SingleTreeTracker> tree_tracker_;
scoped_refptr<net::X509Certificate> chain_;
scoped_refptr<net::ct::SignedCertificateTimestamp> cert_sct_;
};
// Test that an SCT is classified as pending for a newer STH if the
// SingleTreeTracker has not seen any STHs so far.
TEST_F(SingleTreeTrackerTest, CorrectlyClassifiesUnobservedSCTNoSTH) {
base::HistogramTester histograms;
// First make sure the SCT has not been observed at all.
EXPECT_EQ(
SingleTreeTracker::SCT_NOT_OBSERVED,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
tree_tracker_->OnSCTVerified(chain_.get(), cert_sct_.get());
// Since no STH was provided to the tree_tracker_ the status should be that
// the SCT is pending a newer STH.
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_NEWER_STH,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
// Expect logging of a value indicating a valid STH is required.
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 1);
histograms.ExpectBucketCount(kCanCheckForInclusionHistogramName, 0, 1);
}
// Test that an SCT is classified as pending an inclusion check if the
// SingleTreeTracker has a fresh-enough STH to check inclusion against.
TEST_F(SingleTreeTrackerTest, CorrectlyClassifiesUnobservedSCTWithRecentSTH) {
base::HistogramTester histograms;
// Provide an STH to the tree_tracker_.
net::ct::SignedTreeHead sth;
net::ct::GetSampleSignedTreeHead(&sth);
tree_tracker_->NewSTHObserved(sth);
// Make sure the SCT status is the same as if there's no STH for
// this log.
EXPECT_EQ(
SingleTreeTracker::SCT_NOT_OBSERVED,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
tree_tracker_->OnSCTVerified(chain_.get(), cert_sct_.get());
// The status for this SCT should be 'pending inclusion check' since the STH
// provided at the beginning of the test is newer than the SCT.
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_INCLUSION_CHECK,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
// Exactly one value should be logged, indicating the SCT can be checked for
// inclusion, as |tree_tracker_| did have a valid STH when it was notified
// of a new SCT.
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 1);
histograms.ExpectBucketCount(kCanCheckForInclusionHistogramName, 2, 1);
}
// Test that the SingleTreeTracker correctly queues verified SCTs for inclusion
// checking such that, upon receiving a fresh STH, it changes the SCT's status
// from pending newer STH to pending inclusion check.
TEST_F(SingleTreeTrackerTest, CorrectlyUpdatesSCTStatusOnNewSTH) {
base::HistogramTester histograms;
// Report an observed SCT and make sure it's in the pending newer STH
// state.
tree_tracker_->OnSCTVerified(chain_.get(), cert_sct_.get());
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_NEWER_STH,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 1);
// Provide with a fresh STH
net::ct::SignedTreeHead sth;
net::ct::GetSampleSignedTreeHead(&sth);
tree_tracker_->NewSTHObserved(sth);
// Test that its status has changed.
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_INCLUSION_CHECK,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
// Check that no additional UMA was logged for this case as the histogram is
// only supposed to measure the state of newly-observed SCTs, not pending
// ones.
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 1);
}
// Test that the SingleTreeTracker does not change an SCT's status if an STH
// from the log it was issued by is observed, but that STH is too old to check
// inclusion against.
TEST_F(SingleTreeTrackerTest, DoesNotUpdatesSCTStatusOnOldSTH) {
// Notify of an SCT and make sure it's in the 'pending newer STH' state.
tree_tracker_->OnSCTVerified(chain_.get(), cert_sct_.get());
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_NEWER_STH,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
// Provide an old STH for the same log.
net::ct::SignedTreeHead sth;
GetOldSignedTreeHead(&sth);
tree_tracker_->NewSTHObserved(sth);
// Make sure the SCT's state hasn't changed.
EXPECT_EQ(
SingleTreeTracker::SCT_PENDING_NEWER_STH,
tree_tracker_->GetLogEntryInclusionStatus(chain_.get(), cert_sct_.get()));
}
// Test that the SingleTreeTracker correctly logs that an SCT is pending a new
// STH, when it has a valid STH, but the observed SCT is not covered by the
// STH.
TEST_F(SingleTreeTrackerTest, LogsUMAForNewSCTAndOldSTH) {
base::HistogramTester histograms;
// Provide an old STH for the same log.
net::ct::SignedTreeHead sth;
GetOldSignedTreeHead(&sth);
tree_tracker_->NewSTHObserved(sth);
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 0);
// Notify of an SCT and make sure it's in the 'pending newer STH' state.
tree_tracker_->OnSCTVerified(chain_.get(), cert_sct_.get());
// Exactly one value should be logged, indicating the SCT cannot be checked
// for inclusion as the STH is too old.
histograms.ExpectTotalCount(kCanCheckForInclusionHistogramName, 1);
histograms.ExpectBucketCount(kCanCheckForInclusionHistogramName, 1, 1);
}
} // namespace certificate_transparency
|
