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/*
* Copyright 2017 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 "pc/srtp_transport.h"
#include <string.h>
#include <vector>
#include "call/rtp_demuxer.h"
#include "media/base/fake_rtp.h"
#include "p2p/base/dtls_transport_internal.h"
#include "p2p/base/fake_packet_transport.h"
#include "pc/test/rtp_transport_test_util.h"
#include "pc/test/srtp_test_util.h"
#include "rtc_base/async_packet_socket.h"
#include "rtc_base/byte_order.h"
#include "rtc_base/checks.h"
#include "rtc_base/containers/flat_set.h"
#include "rtc_base/ssl_stream_adapter.h"
#include "rtc_base/third_party/sigslot/sigslot.h"
#include "test/gtest.h"
#include "test/scoped_key_value_config.h"
using rtc::kSrtpAeadAes128Gcm;
using rtc::kTestKey1;
using rtc::kTestKey2;
using rtc::kTestKeyLen;
namespace webrtc {
static const uint8_t kTestKeyGcm128_1[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ12";
static const uint8_t kTestKeyGcm128_2[] = "21ZYXWVUTSRQPONMLKJIHGFEDCBA";
static const int kTestKeyGcm128Len = 28; // 128 bits key + 96 bits salt.
static const uint8_t kTestKeyGcm256_1[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqr";
static const uint8_t kTestKeyGcm256_2[] =
"rqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA";
static const int kTestKeyGcm256Len = 44; // 256 bits key + 96 bits salt.
class SrtpTransportTest : public ::testing::Test, public sigslot::has_slots<> {
protected:
SrtpTransportTest() {
bool rtcp_mux_enabled = true;
rtp_packet_transport1_ =
std::make_unique<rtc::FakePacketTransport>("fake_packet_transport1");
rtp_packet_transport2_ =
std::make_unique<rtc::FakePacketTransport>("fake_packet_transport2");
bool asymmetric = false;
rtp_packet_transport1_->SetDestination(rtp_packet_transport2_.get(),
asymmetric);
srtp_transport1_ =
std::make_unique<SrtpTransport>(rtcp_mux_enabled, field_trials_);
srtp_transport2_ =
std::make_unique<SrtpTransport>(rtcp_mux_enabled, field_trials_);
srtp_transport1_->SetRtpPacketTransport(rtp_packet_transport1_.get());
srtp_transport2_->SetRtpPacketTransport(rtp_packet_transport2_.get());
srtp_transport1_->SubscribeRtcpPacketReceived(
&rtp_sink1_,
[this](rtc::CopyOnWriteBuffer* buffer, int64_t packet_time_ms) {
rtp_sink1_.OnRtcpPacketReceived(buffer, packet_time_ms);
});
srtp_transport2_->SubscribeRtcpPacketReceived(
&rtp_sink2_,
[this](rtc::CopyOnWriteBuffer* buffer, int64_t packet_time_ms) {
rtp_sink2_.OnRtcpPacketReceived(buffer, packet_time_ms);
});
RtpDemuxerCriteria demuxer_criteria;
// 0x00 is the payload type used in kPcmuFrame.
demuxer_criteria.payload_types().insert(0x00);
srtp_transport1_->RegisterRtpDemuxerSink(demuxer_criteria, &rtp_sink1_);
srtp_transport2_->RegisterRtpDemuxerSink(demuxer_criteria, &rtp_sink2_);
}
~SrtpTransportTest() {
if (srtp_transport1_) {
srtp_transport1_->UnregisterRtpDemuxerSink(&rtp_sink1_);
}
if (srtp_transport2_) {
srtp_transport2_->UnregisterRtpDemuxerSink(&rtp_sink2_);
}
}
// With external auth enabled, SRTP doesn't write the auth tag and
// unprotect would fail. Check accessing the information about the
// tag instead, similar to what the actual code would do that relies
// on external auth.
void TestRtpAuthParams(SrtpTransport* transport, int crypto_suite) {
int overhead;
EXPECT_TRUE(transport->GetSrtpOverhead(&overhead));
switch (crypto_suite) {
case rtc::kSrtpAes128CmSha1_32:
EXPECT_EQ(32 / 8, overhead); // 32-bit tag.
break;
case rtc::kSrtpAes128CmSha1_80:
EXPECT_EQ(80 / 8, overhead); // 80-bit tag.
break;
default:
RTC_DCHECK_NOTREACHED();
break;
}
uint8_t* auth_key = nullptr;
int key_len = 0;
int tag_len = 0;
EXPECT_TRUE(transport->GetRtpAuthParams(&auth_key, &key_len, &tag_len));
EXPECT_NE(nullptr, auth_key);
EXPECT_EQ(160 / 8, key_len); // Length of SHA-1 is 160 bits.
EXPECT_EQ(overhead, tag_len);
}
void TestSendRecvRtpPacket(int crypto_suite) {
size_t rtp_len = sizeof(kPcmuFrame);
size_t packet_size = rtp_len + rtc::rtp_auth_tag_len(crypto_suite);
rtc::Buffer rtp_packet_buffer(packet_size);
char* rtp_packet_data = rtp_packet_buffer.data<char>();
memcpy(rtp_packet_data, kPcmuFrame, rtp_len);
// In order to be able to run this test function multiple times we can not
// use the same sequence number twice. Increase the sequence number by one.
rtc::SetBE16(reinterpret_cast<uint8_t*>(rtp_packet_data) + 2,
++sequence_number_);
rtc::CopyOnWriteBuffer rtp_packet1to2(rtp_packet_data, rtp_len,
packet_size);
rtc::CopyOnWriteBuffer rtp_packet2to1(rtp_packet_data, rtp_len,
packet_size);
char original_rtp_data[sizeof(kPcmuFrame)];
memcpy(original_rtp_data, rtp_packet_data, rtp_len);
rtc::PacketOptions options;
// Send a packet from `srtp_transport1_` to `srtp_transport2_` and verify
// that the packet can be successfully received and decrypted.
ASSERT_TRUE(srtp_transport1_->SendRtpPacket(&rtp_packet1to2, options,
cricket::PF_SRTP_BYPASS));
if (srtp_transport1_->IsExternalAuthActive()) {
TestRtpAuthParams(srtp_transport1_.get(), crypto_suite);
} else {
ASSERT_TRUE(rtp_sink2_.last_recv_rtp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink2_.last_recv_rtp_packet().data(),
original_rtp_data, rtp_len));
// Get the encrypted packet from underneath packet transport and verify
// the data is actually encrypted.
auto fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport1_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len));
}
// Do the same thing in the opposite direction;
ASSERT_TRUE(srtp_transport2_->SendRtpPacket(&rtp_packet2to1, options,
cricket::PF_SRTP_BYPASS));
if (srtp_transport2_->IsExternalAuthActive()) {
TestRtpAuthParams(srtp_transport2_.get(), crypto_suite);
} else {
ASSERT_TRUE(rtp_sink1_.last_recv_rtp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink1_.last_recv_rtp_packet().data(),
original_rtp_data, rtp_len));
auto fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len));
}
}
void TestSendRecvRtcpPacket(int crypto_suite) {
size_t rtcp_len = sizeof(::kRtcpReport);
size_t packet_size = rtcp_len + 4 + rtc::rtcp_auth_tag_len(crypto_suite);
rtc::Buffer rtcp_packet_buffer(packet_size);
char* rtcp_packet_data = rtcp_packet_buffer.data<char>();
memcpy(rtcp_packet_data, ::kRtcpReport, rtcp_len);
rtc::CopyOnWriteBuffer rtcp_packet1to2(rtcp_packet_data, rtcp_len,
packet_size);
rtc::CopyOnWriteBuffer rtcp_packet2to1(rtcp_packet_data, rtcp_len,
packet_size);
rtc::PacketOptions options;
// Send a packet from `srtp_transport1_` to `srtp_transport2_` and verify
// that the packet can be successfully received and decrypted.
ASSERT_TRUE(srtp_transport1_->SendRtcpPacket(&rtcp_packet1to2, options,
cricket::PF_SRTP_BYPASS));
ASSERT_TRUE(rtp_sink2_.last_recv_rtcp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink2_.last_recv_rtcp_packet().data(),
rtcp_packet_data, rtcp_len));
// Get the encrypted packet from underneath packet transport and verify the
// data is actually encrypted.
auto fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport1_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
rtcp_packet_data, rtcp_len));
// Do the same thing in the opposite direction;
ASSERT_TRUE(srtp_transport2_->SendRtcpPacket(&rtcp_packet2to1, options,
cricket::PF_SRTP_BYPASS));
ASSERT_TRUE(rtp_sink1_.last_recv_rtcp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink1_.last_recv_rtcp_packet().data(),
rtcp_packet_data, rtcp_len));
fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
rtcp_packet_data, rtcp_len));
}
void TestSendRecvPacket(bool enable_external_auth,
int crypto_suite,
const uint8_t* key1,
int key1_len,
const uint8_t* key2,
int key2_len) {
EXPECT_EQ(key1_len, key2_len);
if (enable_external_auth) {
srtp_transport1_->EnableExternalAuth();
srtp_transport2_->EnableExternalAuth();
}
std::vector<int> extension_ids;
EXPECT_TRUE(srtp_transport1_->SetRtpParams(crypto_suite, key1, key1_len,
extension_ids, crypto_suite,
key2, key2_len, extension_ids));
EXPECT_TRUE(srtp_transport2_->SetRtpParams(crypto_suite, key2, key2_len,
extension_ids, crypto_suite,
key1, key1_len, extension_ids));
EXPECT_TRUE(srtp_transport1_->SetRtcpParams(crypto_suite, key1, key1_len,
extension_ids, crypto_suite,
key2, key2_len, extension_ids));
EXPECT_TRUE(srtp_transport2_->SetRtcpParams(crypto_suite, key2, key2_len,
extension_ids, crypto_suite,
key1, key1_len, extension_ids));
EXPECT_TRUE(srtp_transport1_->IsSrtpActive());
EXPECT_TRUE(srtp_transport2_->IsSrtpActive());
if (rtc::IsGcmCryptoSuite(crypto_suite)) {
EXPECT_FALSE(srtp_transport1_->IsExternalAuthActive());
EXPECT_FALSE(srtp_transport2_->IsExternalAuthActive());
} else if (enable_external_auth) {
EXPECT_TRUE(srtp_transport1_->IsExternalAuthActive());
EXPECT_TRUE(srtp_transport2_->IsExternalAuthActive());
}
TestSendRecvRtpPacket(crypto_suite);
TestSendRecvRtcpPacket(crypto_suite);
}
void TestSendRecvPacketWithEncryptedHeaderExtension(
int crypto_suite,
const std::vector<int>& encrypted_header_ids) {
size_t rtp_len = sizeof(kPcmuFrameWithExtensions);
size_t packet_size = rtp_len + rtc::rtp_auth_tag_len(crypto_suite);
rtc::Buffer rtp_packet_buffer(packet_size);
char* rtp_packet_data = rtp_packet_buffer.data<char>();
memcpy(rtp_packet_data, kPcmuFrameWithExtensions, rtp_len);
// In order to be able to run this test function multiple times we can not
// use the same sequence number twice. Increase the sequence number by one.
rtc::SetBE16(reinterpret_cast<uint8_t*>(rtp_packet_data) + 2,
++sequence_number_);
rtc::CopyOnWriteBuffer rtp_packet1to2(rtp_packet_data, rtp_len,
packet_size);
rtc::CopyOnWriteBuffer rtp_packet2to1(rtp_packet_data, rtp_len,
packet_size);
char original_rtp_data[sizeof(kPcmuFrameWithExtensions)];
memcpy(original_rtp_data, rtp_packet_data, rtp_len);
rtc::PacketOptions options;
// Send a packet from `srtp_transport1_` to `srtp_transport2_` and verify
// that the packet can be successfully received and decrypted.
ASSERT_TRUE(srtp_transport1_->SendRtpPacket(&rtp_packet1to2, options,
cricket::PF_SRTP_BYPASS));
ASSERT_TRUE(rtp_sink2_.last_recv_rtp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink2_.last_recv_rtp_packet().data(),
original_rtp_data, rtp_len));
// Get the encrypted packet from underneath packet transport and verify the
// data and header extension are actually encrypted.
auto fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport1_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len));
CompareHeaderExtensions(
reinterpret_cast<const char*>(
fake_rtp_packet_transport->last_sent_packet()->data()),
fake_rtp_packet_transport->last_sent_packet()->size(),
original_rtp_data, rtp_len, encrypted_header_ids, false);
// Do the same thing in the opposite direction;
ASSERT_TRUE(srtp_transport2_->SendRtpPacket(&rtp_packet2to1, options,
cricket::PF_SRTP_BYPASS));
ASSERT_TRUE(rtp_sink1_.last_recv_rtp_packet().data());
EXPECT_EQ(0, memcmp(rtp_sink1_.last_recv_rtp_packet().data(),
original_rtp_data, rtp_len));
fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_NE(0, memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len));
CompareHeaderExtensions(
reinterpret_cast<const char*>(
fake_rtp_packet_transport->last_sent_packet()->data()),
fake_rtp_packet_transport->last_sent_packet()->size(),
original_rtp_data, rtp_len, encrypted_header_ids, false);
}
void TestSendRecvEncryptedHeaderExtension(int crypto_suite,
const uint8_t* key1,
int key1_len,
const uint8_t* key2,
int key2_len) {
std::vector<int> encrypted_headers;
encrypted_headers.push_back(kHeaderExtensionIDs[0]);
// Don't encrypt header ids 2 and 3.
encrypted_headers.push_back(kHeaderExtensionIDs[1]);
EXPECT_EQ(key1_len, key2_len);
EXPECT_TRUE(srtp_transport1_->SetRtpParams(
crypto_suite, key1, key1_len, encrypted_headers, crypto_suite, key2,
key2_len, encrypted_headers));
EXPECT_TRUE(srtp_transport2_->SetRtpParams(
crypto_suite, key2, key2_len, encrypted_headers, crypto_suite, key1,
key1_len, encrypted_headers));
EXPECT_TRUE(srtp_transport1_->IsSrtpActive());
EXPECT_TRUE(srtp_transport2_->IsSrtpActive());
EXPECT_FALSE(srtp_transport1_->IsExternalAuthActive());
EXPECT_FALSE(srtp_transport2_->IsExternalAuthActive());
TestSendRecvPacketWithEncryptedHeaderExtension(crypto_suite,
encrypted_headers);
}
std::unique_ptr<SrtpTransport> srtp_transport1_;
std::unique_ptr<SrtpTransport> srtp_transport2_;
std::unique_ptr<rtc::FakePacketTransport> rtp_packet_transport1_;
std::unique_ptr<rtc::FakePacketTransport> rtp_packet_transport2_;
TransportObserver rtp_sink1_;
TransportObserver rtp_sink2_;
int sequence_number_ = 0;
test::ScopedKeyValueConfig field_trials_;
};
class SrtpTransportTestWithExternalAuth
: public SrtpTransportTest,
public ::testing::WithParamInterface<bool> {};
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_AES_CM_128_HMAC_SHA1_80) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::kSrtpAes128CmSha1_80, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen);
}
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_AES_CM_128_HMAC_SHA1_80) {
TestSendRecvEncryptedHeaderExtension(rtc::kSrtpAes128CmSha1_80, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen);
}
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_AES_CM_128_HMAC_SHA1_32) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::kSrtpAes128CmSha1_32, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen);
}
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_AES_CM_128_HMAC_SHA1_32) {
TestSendRecvEncryptedHeaderExtension(rtc::kSrtpAes128CmSha1_32, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen);
}
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_kSrtpAeadAes128Gcm) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::kSrtpAeadAes128Gcm,
kTestKeyGcm128_1, kTestKeyGcm128Len, kTestKeyGcm128_2,
kTestKeyGcm128Len);
}
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_kSrtpAeadAes128Gcm) {
TestSendRecvEncryptedHeaderExtension(rtc::kSrtpAeadAes128Gcm,
kTestKeyGcm128_1, kTestKeyGcm128Len,
kTestKeyGcm128_2, kTestKeyGcm128Len);
}
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_kSrtpAeadAes256Gcm) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::kSrtpAeadAes256Gcm,
kTestKeyGcm256_1, kTestKeyGcm256Len, kTestKeyGcm256_2,
kTestKeyGcm256Len);
}
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_kSrtpAeadAes256Gcm) {
TestSendRecvEncryptedHeaderExtension(rtc::kSrtpAeadAes256Gcm,
kTestKeyGcm256_1, kTestKeyGcm256Len,
kTestKeyGcm256_2, kTestKeyGcm256Len);
}
// Run all tests both with and without external auth enabled.
INSTANTIATE_TEST_SUITE_P(ExternalAuth,
SrtpTransportTestWithExternalAuth,
::testing::Values(true, false));
// Test directly setting the params with bogus keys.
TEST_F(SrtpTransportTest, TestSetParamsKeyTooShort) {
std::vector<int> extension_ids;
EXPECT_FALSE(srtp_transport1_->SetRtpParams(
rtc::kSrtpAes128CmSha1_80, kTestKey1, kTestKeyLen - 1, extension_ids,
rtc::kSrtpAes128CmSha1_80, kTestKey1, kTestKeyLen - 1, extension_ids));
EXPECT_FALSE(srtp_transport1_->SetRtcpParams(
rtc::kSrtpAes128CmSha1_80, kTestKey1, kTestKeyLen - 1, extension_ids,
rtc::kSrtpAes128CmSha1_80, kTestKey1, kTestKeyLen - 1, extension_ids));
}
TEST_F(SrtpTransportTest, RemoveSrtpReceiveStream) {
test::ScopedKeyValueConfig field_trials(
"WebRTC-SrtpRemoveReceiveStream/Enabled/");
auto srtp_transport =
std::make_unique<SrtpTransport>(/*rtcp_mux_enabled=*/true, field_trials);
auto rtp_packet_transport = std::make_unique<rtc::FakePacketTransport>(
"fake_packet_transport_loopback");
bool asymmetric = false;
rtp_packet_transport->SetDestination(rtp_packet_transport.get(), asymmetric);
srtp_transport->SetRtpPacketTransport(rtp_packet_transport.get());
TransportObserver rtp_sink;
std::vector<int> extension_ids;
EXPECT_TRUE(srtp_transport->SetRtpParams(
rtc::kSrtpAeadAes128Gcm, kTestKeyGcm128_1, kTestKeyGcm128Len,
extension_ids, rtc::kSrtpAeadAes128Gcm, kTestKeyGcm128_1,
kTestKeyGcm128Len, extension_ids));
RtpDemuxerCriteria demuxer_criteria;
uint32_t ssrc = 0x1; // SSRC of kPcmuFrame
demuxer_criteria.ssrcs().insert(ssrc);
EXPECT_TRUE(
srtp_transport->RegisterRtpDemuxerSink(demuxer_criteria, &rtp_sink));
// Create a packet and try to send it three times.
size_t rtp_len = sizeof(kPcmuFrame);
size_t packet_size = rtp_len + rtc::rtp_auth_tag_len(rtc::kSrtpAeadAes128Gcm);
rtc::Buffer rtp_packet_buffer(packet_size);
char* rtp_packet_data = rtp_packet_buffer.data<char>();
memcpy(rtp_packet_data, kPcmuFrame, rtp_len);
// First attempt will succeed.
rtc::CopyOnWriteBuffer first_try(rtp_packet_data, rtp_len, packet_size);
EXPECT_TRUE(srtp_transport->SendRtpPacket(&first_try, rtc::PacketOptions(),
cricket::PF_SRTP_BYPASS));
EXPECT_EQ(rtp_sink.rtp_count(), 1);
// Second attempt will be rejected by libSRTP as a replay attack
// (srtp_err_status_replay_fail) since the sequence number was already seen.
// Hence the packet never reaches the sink.
rtc::CopyOnWriteBuffer second_try(rtp_packet_data, rtp_len, packet_size);
EXPECT_TRUE(srtp_transport->SendRtpPacket(&second_try, rtc::PacketOptions(),
cricket::PF_SRTP_BYPASS));
EXPECT_EQ(rtp_sink.rtp_count(), 1);
// Reset the sink.
EXPECT_TRUE(srtp_transport->UnregisterRtpDemuxerSink(&rtp_sink));
EXPECT_TRUE(
srtp_transport->RegisterRtpDemuxerSink(demuxer_criteria, &rtp_sink));
// Third attempt will succeed again since libSRTP does not remember seeing
// the sequence number after the reset.
rtc::CopyOnWriteBuffer third_try(rtp_packet_data, rtp_len, packet_size);
EXPECT_TRUE(srtp_transport->SendRtpPacket(&third_try, rtc::PacketOptions(),
cricket::PF_SRTP_BYPASS));
EXPECT_EQ(rtp_sink.rtp_count(), 2);
// Clear the sink to clean up.
srtp_transport->UnregisterRtpDemuxerSink(&rtp_sink);
}
} // namespace webrtc