blob: 81673cec3a7171b6fa64ffbbee58b1b642965ff5 [file] [log] [blame]
/*
* Copyright 2011 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "p2p/base/dtls_transport.h"
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <memory>
#include <set>
#include <utility>
#include "absl/strings/string_view.h"
#include "api/dtls_transport_interface.h"
#include "p2p/base/fake_ice_transport.h"
#include "p2p/base/packet_transport_internal.h"
#include "rtc_base/checks.h"
#include "rtc_base/crypto_random.h"
#include "rtc_base/dscp.h"
#include "rtc_base/gunit.h"
#include "rtc_base/network/received_packet.h"
#include "rtc_base/rtc_certificate.h"
#include "rtc_base/ssl_adapter.h"
#include "rtc_base/ssl_identity.h"
#include "rtc_base/ssl_stream_adapter.h"
#define MAYBE_SKIP_TEST(feature) \
if (!(rtc::SSLStreamAdapter::feature())) { \
RTC_LOG(LS_INFO) << #feature " feature disabled... skipping"; \
return; \
}
namespace cricket {
static const size_t kPacketNumOffset = 8;
static const size_t kPacketHeaderLen = 12;
static const int kFakePacketId = 0x1234;
static const int kTimeout = 10000;
static bool IsRtpLeadByte(uint8_t b) {
return ((b & 0xC0) == 0x80);
}
// `modify_digest` is used to set modified fingerprints that are meant to fail
// validation.
void SetRemoteFingerprintFromCert(
DtlsTransport* transport,
const rtc::scoped_refptr<rtc::RTCCertificate>& cert,
bool modify_digest = false) {
std::unique_ptr<rtc::SSLFingerprint> fingerprint =
rtc::SSLFingerprint::CreateFromCertificate(*cert);
if (modify_digest) {
++fingerprint->digest.MutableData()[0];
}
// Even if digest is verified to be incorrect, should fail asynchronously.
EXPECT_TRUE(
transport
->SetRemoteParameters(
fingerprint->algorithm,
reinterpret_cast<const uint8_t*>(fingerprint->digest.data()),
fingerprint->digest.size(), std::nullopt)
.ok());
}
class DtlsTestClient : public sigslot::has_slots<> {
public:
explicit DtlsTestClient(absl::string_view name) : name_(name) {}
void CreateCertificate(rtc::KeyType key_type) {
certificate_ =
rtc::RTCCertificate::Create(rtc::SSLIdentity::Create(name_, key_type));
}
const rtc::scoped_refptr<rtc::RTCCertificate>& certificate() {
return certificate_;
}
void SetupMaxProtocolVersion(rtc::SSLProtocolVersion version) {
ssl_max_version_ = version;
}
// Set up fake ICE transport and real DTLS transport under test.
void SetupTransports(IceRole role, int async_delay_ms = 0) {
dtls_transport_ = nullptr;
fake_ice_transport_ = nullptr;
fake_ice_transport_.reset(new FakeIceTransport("fake", 0));
fake_ice_transport_->SetAsync(true);
fake_ice_transport_->SetAsyncDelay(async_delay_ms);
fake_ice_transport_->SetIceRole(role);
// Hook the raw packets so that we can verify they are encrypted.
fake_ice_transport_->RegisterReceivedPacketCallback(
this, [&](rtc::PacketTransportInternal* transport,
const rtc::ReceivedPacket& packet) {
OnFakeIceTransportReadPacket(transport, packet);
});
dtls_transport_ = std::make_unique<DtlsTransport>(
fake_ice_transport_.get(), webrtc::CryptoOptions(),
/*event_log=*/nullptr, ssl_max_version_);
// Note: Certificate may be null here if testing passthrough.
dtls_transport_->SetLocalCertificate(certificate_);
dtls_transport_->SignalWritableState.connect(
this, &DtlsTestClient::OnTransportWritableState);
dtls_transport_->RegisterReceivedPacketCallback(
this, [&](rtc::PacketTransportInternal* transport,
const rtc::ReceivedPacket& packet) {
OnTransportReadPacket(transport, packet);
});
dtls_transport_->SignalSentPacket.connect(
this, &DtlsTestClient::OnTransportSentPacket);
}
FakeIceTransport* fake_ice_transport() {
return static_cast<FakeIceTransport*>(dtls_transport_->ice_transport());
}
DtlsTransport* dtls_transport() { return dtls_transport_.get(); }
// Simulate fake ICE transports connecting.
bool Connect(DtlsTestClient* peer, bool asymmetric) {
fake_ice_transport()->SetDestination(peer->fake_ice_transport(),
asymmetric);
return true;
}
int received_dtls_client_hellos() const {
return received_dtls_client_hellos_;
}
int received_dtls_server_hellos() const {
return received_dtls_server_hellos_;
}
void CheckRole(rtc::SSLRole role) {
if (role == rtc::SSL_CLIENT) {
ASSERT_EQ(0, received_dtls_client_hellos_);
ASSERT_GT(received_dtls_server_hellos_, 0);
} else {
ASSERT_GT(received_dtls_client_hellos_, 0);
ASSERT_EQ(0, received_dtls_server_hellos_);
}
}
void CheckSrtp(int expected_crypto_suite) {
int crypto_suite;
bool rv = dtls_transport_->GetSrtpCryptoSuite(&crypto_suite);
if (dtls_transport_->IsDtlsActive() && expected_crypto_suite) {
ASSERT_TRUE(rv);
ASSERT_EQ(crypto_suite, expected_crypto_suite);
} else {
ASSERT_FALSE(rv);
}
}
void CheckSsl() {
int cipher;
bool rv = dtls_transport_->GetSslCipherSuite(&cipher);
if (dtls_transport_->IsDtlsActive()) {
ASSERT_TRUE(rv);
EXPECT_TRUE(
rtc::SSLStreamAdapter::IsAcceptableCipher(cipher, rtc::KT_DEFAULT));
} else {
ASSERT_FALSE(rv);
}
}
void SendPackets(size_t size, size_t count, bool srtp) {
std::unique_ptr<char[]> packet(new char[size]);
size_t sent = 0;
do {
// Fill the packet with a known value and a sequence number to check
// against, and make sure that it doesn't look like DTLS.
memset(packet.get(), sent & 0xff, size);
packet[0] = (srtp) ? 0x80 : 0x00;
rtc::SetBE32(packet.get() + kPacketNumOffset,
static_cast<uint32_t>(sent));
// Only set the bypass flag if we've activated DTLS.
int flags = (certificate_ && srtp) ? PF_SRTP_BYPASS : 0;
rtc::PacketOptions packet_options;
packet_options.packet_id = kFakePacketId;
int rv = dtls_transport_->SendPacket(packet.get(), size, packet_options,
flags);
ASSERT_GT(rv, 0);
ASSERT_EQ(size, static_cast<size_t>(rv));
++sent;
} while (sent < count);
}
int SendInvalidSrtpPacket(size_t size) {
std::unique_ptr<char[]> packet(new char[size]);
// Fill the packet with 0 to form an invalid SRTP packet.
memset(packet.get(), 0, size);
rtc::PacketOptions packet_options;
return dtls_transport_->SendPacket(packet.get(), size, packet_options,
PF_SRTP_BYPASS);
}
void ExpectPackets(size_t size) {
packet_size_ = size;
received_.clear();
}
size_t NumPacketsReceived() { return received_.size(); }
// Inverse of SendPackets.
bool VerifyPacket(rtc::ArrayView<const uint8_t> payload, uint32_t* out_num) {
const uint8_t* data = payload.data();
size_t size = payload.size();
if (size != packet_size_ || (data[0] != 0 && (data[0]) != 0x80)) {
return false;
}
uint32_t packet_num = rtc::GetBE32(data + kPacketNumOffset);
for (size_t i = kPacketHeaderLen; i < size; ++i) {
if (data[i] != (packet_num & 0xff)) {
return false;
}
}
if (out_num) {
*out_num = packet_num;
}
return true;
}
bool VerifyEncryptedPacket(const uint8_t* data, size_t size) {
// This is an encrypted data packet; let's make sure it's mostly random;
// less than 10% of the bytes should be equal to the cleartext packet.
if (size <= packet_size_) {
return false;
}
uint32_t packet_num = rtc::GetBE32(data + kPacketNumOffset);
int num_matches = 0;
for (size_t i = kPacketNumOffset; i < size; ++i) {
if (data[i] == (packet_num & 0xff)) {
++num_matches;
}
}
return (num_matches < ((static_cast<int>(size) - 5) / 10));
}
// Transport callbacks
void OnTransportWritableState(rtc::PacketTransportInternal* transport) {
RTC_LOG(LS_INFO) << name_ << ": Transport '" << transport->transport_name()
<< "' is writable";
}
void OnTransportReadPacket(rtc::PacketTransportInternal* transport,
const rtc::ReceivedPacket& packet) {
uint32_t packet_num = 0;
ASSERT_TRUE(VerifyPacket(packet.payload(), &packet_num));
received_.insert(packet_num);
switch (packet.decryption_info()) {
case rtc::ReceivedPacket::kSrtpEncrypted:
ASSERT_TRUE(certificate_ && IsRtpLeadByte(packet.payload()[0]));
break;
case rtc::ReceivedPacket::kDtlsDecrypted:
ASSERT_TRUE(certificate_ && !IsRtpLeadByte(packet.payload()[0]));
break;
case rtc::ReceivedPacket::kNotDecrypted:
ASSERT_FALSE(certificate_);
break;
}
}
void OnTransportSentPacket(rtc::PacketTransportInternal* transport,
const rtc::SentPacket& sent_packet) {
sent_packet_ = sent_packet;
}
rtc::SentPacket sent_packet() const { return sent_packet_; }
// Hook into the raw packet stream to make sure DTLS packets are encrypted.
void OnFakeIceTransportReadPacket(rtc::PacketTransportInternal* transport,
const rtc::ReceivedPacket& packet) {
// Packets should not be decrypted on the underlying Transport packets.
ASSERT_EQ(packet.decryption_info(), rtc::ReceivedPacket::kNotDecrypted);
// Look at the handshake packets to see what role we played.
// Check that non-handshake packets are DTLS data or SRTP bypass.
const uint8_t* data = packet.payload().data();
size_t size = packet.payload().size();
if (data[0] == 22 && size > 17) {
if (data[13] == 1) {
++received_dtls_client_hellos_;
} else if (data[13] == 2) {
++received_dtls_server_hellos_;
}
} else if (dtls_transport_->IsDtlsActive() &&
!(data[0] >= 20 && data[0] <= 22)) {
ASSERT_TRUE(data[0] == 23 || IsRtpLeadByte(data[0]));
if (data[0] == 23) {
ASSERT_TRUE(VerifyEncryptedPacket(data, size));
} else if (IsRtpLeadByte(data[0])) {
ASSERT_TRUE(VerifyPacket(packet.payload(), NULL));
}
}
}
private:
std::string name_;
rtc::scoped_refptr<rtc::RTCCertificate> certificate_;
std::unique_ptr<FakeIceTransport> fake_ice_transport_;
std::unique_ptr<DtlsTransport> dtls_transport_;
size_t packet_size_ = 0u;
std::set<int> received_;
rtc::SSLProtocolVersion ssl_max_version_ = rtc::SSL_PROTOCOL_DTLS_12;
int received_dtls_client_hellos_ = 0;
int received_dtls_server_hellos_ = 0;
rtc::SentPacket sent_packet_;
};
// Base class for DtlsTransportTest and DtlsEventOrderingTest, which
// inherit from different variants of ::testing::Test.
//
// Note that this test always uses a FakeClock, due to the `fake_clock_` member
// variable.
class DtlsTransportTestBase {
public:
DtlsTransportTestBase() : client1_("P1"), client2_("P2"), use_dtls_(false) {}
void SetMaxProtocolVersions(rtc::SSLProtocolVersion c1,
rtc::SSLProtocolVersion c2) {
client1_.SetupMaxProtocolVersion(c1);
client2_.SetupMaxProtocolVersion(c2);
}
// If not called, DtlsTransport will be used in SRTP bypass mode.
void PrepareDtls(rtc::KeyType key_type) {
client1_.CreateCertificate(key_type);
client2_.CreateCertificate(key_type);
use_dtls_ = true;
}
// This test negotiates DTLS parameters before the underlying transports are
// writable. DtlsEventOrderingTest is responsible for exercising differerent
// orderings.
bool Connect(bool client1_server = true) {
Negotiate(client1_server);
EXPECT_TRUE(client1_.Connect(&client2_, false));
EXPECT_TRUE_SIMULATED_WAIT(client1_.dtls_transport()->writable() &&
client2_.dtls_transport()->writable(),
kTimeout, fake_clock_);
if (!client1_.dtls_transport()->writable() ||
!client2_.dtls_transport()->writable())
return false;
// Check that we used the right roles.
if (use_dtls_) {
client1_.CheckRole(client1_server ? rtc::SSL_SERVER : rtc::SSL_CLIENT);
client2_.CheckRole(client1_server ? rtc::SSL_CLIENT : rtc::SSL_SERVER);
}
if (use_dtls_) {
// Check that we negotiated the right ciphers. Since GCM ciphers are not
// negotiated by default, we should end up with kSrtpAes128CmSha1_80.
client1_.CheckSrtp(rtc::kSrtpAes128CmSha1_80);
client2_.CheckSrtp(rtc::kSrtpAes128CmSha1_80);
} else {
// If DTLS isn't actually being used, GetSrtpCryptoSuite should return
// false.
client1_.CheckSrtp(rtc::kSrtpInvalidCryptoSuite);
client2_.CheckSrtp(rtc::kSrtpInvalidCryptoSuite);
}
client1_.CheckSsl();
client2_.CheckSsl();
return true;
}
void Negotiate(bool client1_server = true) {
client1_.SetupTransports(ICEROLE_CONTROLLING);
client2_.SetupTransports(ICEROLE_CONTROLLED);
client1_.dtls_transport()->SetDtlsRole(client1_server ? rtc::SSL_SERVER
: rtc::SSL_CLIENT);
client2_.dtls_transport()->SetDtlsRole(client1_server ? rtc::SSL_CLIENT
: rtc::SSL_SERVER);
if (client2_.certificate()) {
SetRemoteFingerprintFromCert(client1_.dtls_transport(),
client2_.certificate());
}
if (client1_.certificate()) {
SetRemoteFingerprintFromCert(client2_.dtls_transport(),
client1_.certificate());
}
}
void TestTransfer(size_t size, size_t count, bool srtp) {
RTC_LOG(LS_INFO) << "Expect packets, size=" << size;
client2_.ExpectPackets(size);
client1_.SendPackets(size, count, srtp);
EXPECT_EQ_SIMULATED_WAIT(count, client2_.NumPacketsReceived(), kTimeout,
fake_clock_);
}
protected:
rtc::AutoThread main_thread_;
rtc::ScopedFakeClock fake_clock_;
DtlsTestClient client1_;
DtlsTestClient client2_;
bool use_dtls_;
rtc::SSLProtocolVersion ssl_expected_version_;
};
class DtlsTransportTest : public DtlsTransportTestBase,
public ::testing::Test {};
// Connect without DTLS, and transfer RTP data.
TEST_F(DtlsTransportTest, TestTransferRtp) {
ASSERT_TRUE(Connect());
TestTransfer(1000, 100, /*srtp=*/false);
}
// Test that the SignalSentPacket signal is wired up.
TEST_F(DtlsTransportTest, TestSignalSentPacket) {
ASSERT_TRUE(Connect());
// Sanity check default value (-1).
ASSERT_EQ(client1_.sent_packet().send_time_ms, -1);
TestTransfer(1000, 100, false);
// Check that we get the expected fake packet ID, and a time of 0 from the
// fake clock.
EXPECT_EQ(kFakePacketId, client1_.sent_packet().packet_id);
EXPECT_GE(client1_.sent_packet().send_time_ms, 0);
}
// Connect without DTLS, and transfer SRTP data.
TEST_F(DtlsTransportTest, TestTransferSrtp) {
ASSERT_TRUE(Connect());
TestTransfer(1000, 100, /*srtp=*/true);
}
// Connect with DTLS, and transfer data over DTLS.
TEST_F(DtlsTransportTest, TestTransferDtls) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
TestTransfer(1000, 100, /*srtp=*/false);
}
// Connect with DTLS, combine multiple DTLS records into one packet.
// Our DTLS implementation doesn't do this, but other implementations may;
// see https://tools.ietf.org/html/rfc6347#section-4.1.1.
// This has caused interoperability problems with ORTCLib in the past.
TEST_F(DtlsTransportTest, TestTransferDtlsCombineRecords) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
// Our DTLS implementation always sends one record per packet, so to simulate
// an endpoint that sends multiple records per packet, we configure the fake
// ICE transport to combine every two consecutive packets into a single
// packet.
FakeIceTransport* transport = client1_.fake_ice_transport();
transport->combine_outgoing_packets(true);
TestTransfer(500, 100, /*srtp=*/false);
}
TEST_F(DtlsTransportTest, KeyingMaterialExporter) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
int crypto_suite;
EXPECT_TRUE(client1_.dtls_transport()->GetSrtpCryptoSuite(&crypto_suite));
int key_len;
int salt_len;
EXPECT_TRUE(rtc::GetSrtpKeyAndSaltLengths(crypto_suite, &key_len, &salt_len));
rtc::ZeroOnFreeBuffer<uint8_t> client1_out(2 * (key_len + salt_len));
rtc::ZeroOnFreeBuffer<uint8_t> client2_out(2 * (key_len + salt_len));
EXPECT_TRUE(client1_.dtls_transport()->ExportSrtpKeyingMaterial(client1_out));
EXPECT_TRUE(client2_.dtls_transport()->ExportSrtpKeyingMaterial(client2_out));
EXPECT_EQ(client1_out, client2_out);
}
class DtlsTransportVersionTest
: public DtlsTransportTestBase,
public ::testing::TestWithParam<
::testing::tuple<rtc::SSLProtocolVersion, rtc::SSLProtocolVersion>> {
};
// Test that an acceptable cipher suite is negotiated when different versions
// of DTLS are supported. Note that it's IsAcceptableCipher that does the actual
// work.
TEST_P(DtlsTransportVersionTest, TestCipherSuiteNegotiation) {
PrepareDtls(rtc::KT_DEFAULT);
SetMaxProtocolVersions(::testing::get<0>(GetParam()),
::testing::get<1>(GetParam()));
ASSERT_TRUE(Connect());
}
// Will test every combination of 1.0/1.2 on the client and server.
INSTANTIATE_TEST_SUITE_P(
TestCipherSuiteNegotiation,
DtlsTransportVersionTest,
::testing::Combine(::testing::Values(rtc::SSL_PROTOCOL_DTLS_10,
rtc::SSL_PROTOCOL_DTLS_12),
::testing::Values(rtc::SSL_PROTOCOL_DTLS_10,
rtc::SSL_PROTOCOL_DTLS_12)));
// Connect with DTLS, negotiating DTLS-SRTP, and transfer SRTP using bypass.
TEST_F(DtlsTransportTest, TestTransferDtlsSrtp) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
TestTransfer(1000, 100, /*srtp=*/true);
}
// Connect with DTLS-SRTP, transfer an invalid SRTP packet, and expects -1
// returned.
TEST_F(DtlsTransportTest, TestTransferDtlsInvalidSrtpPacket) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
EXPECT_EQ(-1, client1_.SendInvalidSrtpPacket(100));
}
// Create a single transport with DTLS, and send normal data and SRTP data on
// it.
TEST_F(DtlsTransportTest, TestTransferDtlsSrtpDemux) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
TestTransfer(1000, 100, /*srtp=*/false);
TestTransfer(1000, 100, /*srtp=*/true);
}
// Test transferring when the "answerer" has the server role.
TEST_F(DtlsTransportTest, TestTransferDtlsSrtpAnswererIsPassive) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect(/*client1_server=*/false));
TestTransfer(1000, 100, /*srtp=*/true);
}
// Test that renegotiation (setting same role and fingerprint again) can be
// started before the clients become connected in the first negotiation.
TEST_F(DtlsTransportTest, TestRenegotiateBeforeConnect) {
PrepareDtls(rtc::KT_DEFAULT);
// Note: This is doing the same thing Connect normally does, minus some
// additional checks not relevant for this test.
Negotiate();
Negotiate();
EXPECT_TRUE(client1_.Connect(&client2_, false));
EXPECT_TRUE_SIMULATED_WAIT(client1_.dtls_transport()->writable() &&
client2_.dtls_transport()->writable(),
kTimeout, fake_clock_);
TestTransfer(1000, 100, true);
}
// Test Certificates state after negotiation but before connection.
TEST_F(DtlsTransportTest, TestCertificatesBeforeConnect) {
PrepareDtls(rtc::KT_DEFAULT);
Negotiate();
// After negotiation, each side has a distinct local certificate, but still no
// remote certificate, because connection has not yet occurred.
auto certificate1 = client1_.dtls_transport()->GetLocalCertificate();
auto certificate2 = client2_.dtls_transport()->GetLocalCertificate();
ASSERT_NE(certificate1->GetSSLCertificate().ToPEMString(),
certificate2->GetSSLCertificate().ToPEMString());
ASSERT_FALSE(client1_.dtls_transport()->GetRemoteSSLCertChain());
ASSERT_FALSE(client2_.dtls_transport()->GetRemoteSSLCertChain());
}
// Test Certificates state after connection.
TEST_F(DtlsTransportTest, TestCertificatesAfterConnect) {
PrepareDtls(rtc::KT_DEFAULT);
ASSERT_TRUE(Connect());
// After connection, each side has a distinct local certificate.
auto certificate1 = client1_.dtls_transport()->GetLocalCertificate();
auto certificate2 = client2_.dtls_transport()->GetLocalCertificate();
ASSERT_NE(certificate1->GetSSLCertificate().ToPEMString(),
certificate2->GetSSLCertificate().ToPEMString());
// Each side's remote certificate is the other side's local certificate.
std::unique_ptr<rtc::SSLCertChain> remote_cert1 =
client1_.dtls_transport()->GetRemoteSSLCertChain();
ASSERT_TRUE(remote_cert1);
ASSERT_EQ(1u, remote_cert1->GetSize());
ASSERT_EQ(remote_cert1->Get(0).ToPEMString(),
certificate2->GetSSLCertificate().ToPEMString());
std::unique_ptr<rtc::SSLCertChain> remote_cert2 =
client2_.dtls_transport()->GetRemoteSSLCertChain();
ASSERT_TRUE(remote_cert2);
ASSERT_EQ(1u, remote_cert2->GetSize());
ASSERT_EQ(remote_cert2->Get(0).ToPEMString(),
certificate1->GetSSLCertificate().ToPEMString());
}
// Test that packets are retransmitted according to the expected schedule.
// Each time a timeout occurs, the retransmission timer should be doubled up to
// 60 seconds. The timer defaults to 1 second, but for WebRTC we should be
// initializing it to 50ms.
TEST_F(DtlsTransportTest, TestRetransmissionSchedule) {
// We can only change the retransmission schedule with a recently-added
// BoringSSL API. Skip the test if not built with BoringSSL.
MAYBE_SKIP_TEST(IsBoringSsl);
PrepareDtls(rtc::KT_DEFAULT);
// Exchange fingerprints and set SSL roles.
Negotiate();
// Make client2_ writable, but not client1_.
// This means client1_ will send DTLS client hellos but get no response.
EXPECT_TRUE(client2_.Connect(&client1_, true));
EXPECT_TRUE_SIMULATED_WAIT(client2_.fake_ice_transport()->writable(),
kTimeout, fake_clock_);
// Wait for the first client hello to be sent.
EXPECT_EQ_WAIT(1, client1_.received_dtls_client_hellos(), kTimeout);
EXPECT_FALSE(client1_.fake_ice_transport()->writable());
static int timeout_schedule_ms[] = {50, 100, 200, 400, 800, 1600,
3200, 6400, 12800, 25600, 51200, 60000};
int expected_hellos = 1;
for (size_t i = 0;
i < (sizeof(timeout_schedule_ms) / sizeof(timeout_schedule_ms[0]));
++i) {
// For each expected retransmission time, advance the fake clock a
// millisecond before the expected time and verify that no unexpected
// retransmissions were sent. Then advance it the final millisecond and
// verify that the expected retransmission was sent.
fake_clock_.AdvanceTime(
webrtc::TimeDelta::Millis(timeout_schedule_ms[i] - 1));
EXPECT_EQ(expected_hellos, client1_.received_dtls_client_hellos());
fake_clock_.AdvanceTime(webrtc::TimeDelta::Millis(1));
EXPECT_EQ(++expected_hellos, client1_.received_dtls_client_hellos());
}
}
// The following events can occur in many different orders:
// 1. Caller receives remote fingerprint.
// 2. Caller is writable.
// 3. Caller receives ClientHello.
// 4. DTLS handshake finishes.
//
// The tests below cover all causally consistent permutations of these events;
// the caller must be writable and receive a ClientHello before the handshake
// finishes, but otherwise any ordering is possible.
//
// For each permutation, the test verifies that a connection is established and
// fingerprint verified without any DTLS packet needing to be retransmitted.
//
// Each permutation is also tested with valid and invalid fingerprints,
// ensuring that the handshake fails with an invalid fingerprint.
enum DtlsTransportEvent {
CALLER_RECEIVES_FINGERPRINT,
CALLER_WRITABLE,
CALLER_RECEIVES_CLIENTHELLO,
HANDSHAKE_FINISHES
};
class DtlsEventOrderingTest
: public DtlsTransportTestBase,
public ::testing::TestWithParam<
::testing::tuple<std::vector<DtlsTransportEvent>, bool>> {
protected:
// If `valid_fingerprint` is false, the caller will receive a fingerprint
// that doesn't match the callee's certificate, so the handshake should fail.
void TestEventOrdering(const std::vector<DtlsTransportEvent>& events,
bool valid_fingerprint) {
// Pre-setup: Set local certificate on both caller and callee, and
// remote fingerprint on callee, but neither is writable and the caller
// doesn't have the callee's fingerprint.
PrepareDtls(rtc::KT_DEFAULT);
// Simulate packets being sent and arriving asynchronously.
// Otherwise the entire DTLS handshake would occur in one clock tick, and
// we couldn't inject method calls in the middle of it.
int simulated_delay_ms = 10;
client1_.SetupTransports(ICEROLE_CONTROLLING, simulated_delay_ms);
client2_.SetupTransports(ICEROLE_CONTROLLED, simulated_delay_ms);
// Similar to how NegotiateOrdering works.
client1_.dtls_transport()->SetDtlsRole(rtc::SSL_SERVER);
client2_.dtls_transport()->SetDtlsRole(rtc::SSL_CLIENT);
SetRemoteFingerprintFromCert(client2_.dtls_transport(),
client1_.certificate());
for (DtlsTransportEvent e : events) {
switch (e) {
case CALLER_RECEIVES_FINGERPRINT:
if (valid_fingerprint) {
SetRemoteFingerprintFromCert(client1_.dtls_transport(),
client2_.certificate());
} else {
SetRemoteFingerprintFromCert(client1_.dtls_transport(),
client2_.certificate(),
true /*modify_digest*/);
}
break;
case CALLER_WRITABLE:
EXPECT_TRUE(client1_.Connect(&client2_, true));
EXPECT_TRUE_SIMULATED_WAIT(client1_.fake_ice_transport()->writable(),
kTimeout, fake_clock_);
break;
case CALLER_RECEIVES_CLIENTHELLO:
// Sanity check that a ClientHello hasn't already been received.
EXPECT_EQ(0, client1_.received_dtls_client_hellos());
// Making client2_ writable will cause it to send the ClientHello.
EXPECT_TRUE(client2_.Connect(&client1_, true));
EXPECT_TRUE_SIMULATED_WAIT(client2_.fake_ice_transport()->writable(),
kTimeout, fake_clock_);
EXPECT_EQ_SIMULATED_WAIT(1, client1_.received_dtls_client_hellos(),
kTimeout, fake_clock_);
break;
case HANDSHAKE_FINISHES:
// Sanity check that the handshake hasn't already finished.
EXPECT_FALSE(client1_.dtls_transport()->IsDtlsConnected() ||
client1_.dtls_transport()->dtls_state() ==
webrtc::DtlsTransportState::kFailed);
EXPECT_TRUE_SIMULATED_WAIT(
client1_.dtls_transport()->IsDtlsConnected() ||
client1_.dtls_transport()->dtls_state() ==
webrtc::DtlsTransportState::kFailed,
kTimeout, fake_clock_);
break;
}
}
webrtc::DtlsTransportState expected_final_state =
valid_fingerprint ? webrtc::DtlsTransportState::kConnected
: webrtc::DtlsTransportState::kFailed;
EXPECT_EQ_SIMULATED_WAIT(expected_final_state,
client1_.dtls_transport()->dtls_state(), kTimeout,
fake_clock_);
EXPECT_EQ_SIMULATED_WAIT(expected_final_state,
client2_.dtls_transport()->dtls_state(), kTimeout,
fake_clock_);
// Transports should be writable iff there was a valid fingerprint.
EXPECT_EQ(valid_fingerprint, client1_.dtls_transport()->writable());
EXPECT_EQ(valid_fingerprint, client2_.dtls_transport()->writable());
// Check that no hello needed to be retransmitted.
EXPECT_EQ(1, client1_.received_dtls_client_hellos());
EXPECT_EQ(1, client2_.received_dtls_server_hellos());
if (valid_fingerprint) {
TestTransfer(1000, 100, false);
}
}
};
TEST_P(DtlsEventOrderingTest, TestEventOrdering) {
TestEventOrdering(::testing::get<0>(GetParam()),
::testing::get<1>(GetParam()));
}
INSTANTIATE_TEST_SUITE_P(
TestEventOrdering,
DtlsEventOrderingTest,
::testing::Combine(
::testing::Values(
std::vector<DtlsTransportEvent>{
CALLER_RECEIVES_FINGERPRINT, CALLER_WRITABLE,
CALLER_RECEIVES_CLIENTHELLO, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{
CALLER_WRITABLE, CALLER_RECEIVES_FINGERPRINT,
CALLER_RECEIVES_CLIENTHELLO, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{
CALLER_WRITABLE, CALLER_RECEIVES_CLIENTHELLO,
CALLER_RECEIVES_FINGERPRINT, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{
CALLER_WRITABLE, CALLER_RECEIVES_CLIENTHELLO,
HANDSHAKE_FINISHES, CALLER_RECEIVES_FINGERPRINT},
std::vector<DtlsTransportEvent>{
CALLER_RECEIVES_FINGERPRINT, CALLER_RECEIVES_CLIENTHELLO,
CALLER_WRITABLE, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{
CALLER_RECEIVES_CLIENTHELLO, CALLER_RECEIVES_FINGERPRINT,
CALLER_WRITABLE, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{
CALLER_RECEIVES_CLIENTHELLO, CALLER_WRITABLE,
CALLER_RECEIVES_FINGERPRINT, HANDSHAKE_FINISHES},
std::vector<DtlsTransportEvent>{CALLER_RECEIVES_CLIENTHELLO,
CALLER_WRITABLE, HANDSHAKE_FINISHES,
CALLER_RECEIVES_FINGERPRINT}),
::testing::Bool()));
} // namespace cricket