Reland: Completed the functionalities of SrtpTransport.

The SrtpTransport takes the SRTP responsibilities from the BaseChannel
and SrtpFilter. SrtpTransport is now responsible for setting the crypto
keys, protecting and unprotecting the packets. SrtpTransport doesn't
know if the keys are from SDES or DTLS handshake.

BaseChannel is now only responsible setting the offer/answer for SDES
or extracting the key from DtlsTransport and configuring the
SrtpTransport.

SrtpFilter is used by BaseChannel as a helper for SDES negotiation.

BUG=webrtc:7013

Change-Id: If61489dfbdf23481a1f1831ad181fbf45eaadb3e
Reviewed-on: https://webrtc-review.googlesource.com/2560
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Commit-Queue: Zhi Huang <zhihuang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19977}
This commit is contained in:
Zhi Huang
2017-09-22 12:12:30 -07:00
committed by Commit Bot
parent fc3a2e3393
commit cf990f53b0
13 changed files with 1107 additions and 905 deletions

View File

@ -10,67 +10,413 @@
#include "pc/srtptransport.h"
#include "media/base/fakertp.h"
#include "p2p/base/dtlstransportinternal.h"
#include "p2p/base/fakepackettransport.h"
#include "pc/rtptransport.h"
#include "pc/rtptransporttestutil.h"
#include "pc/srtptestutil.h"
#include "rtc_base/asyncpacketsocket.h"
#include "rtc_base/gunit.h"
#include "rtc_base/ptr_util.h"
#include "test/gmock.h"
#include "rtc_base/sslstreamadapter.h"
using rtc::kTestKey1;
using rtc::kTestKey2;
using rtc::kTestKeyLen;
using rtc::SRTP_AEAD_AES_128_GCM;
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.
using testing::_;
using testing::Return;
class SrtpTransportTest : public testing::Test, public sigslot::has_slots<> {
protected:
SrtpTransportTest() {
bool rtcp_mux_enabled = true;
auto rtp_transport1 = rtc::MakeUnique<RtpTransport>(rtcp_mux_enabled);
auto rtp_transport2 = rtc::MakeUnique<RtpTransport>(rtcp_mux_enabled);
class MockRtpTransport : public RtpTransport {
public:
MockRtpTransport() : RtpTransport(true) {}
rtp_packet_transport1_ =
rtc::MakeUnique<rtc::FakePacketTransport>("fake_packet_transport1");
rtp_packet_transport2_ =
rtc::MakeUnique<rtc::FakePacketTransport>("fake_packet_transport2");
MOCK_METHOD4(SendPacket,
bool(bool rtcp,
rtc::CopyOnWriteBuffer* packet,
const rtc::PacketOptions& options,
int flags));
bool asymmetric = false;
rtp_packet_transport1_->SetDestination(rtp_packet_transport2_.get(),
asymmetric);
void PretendReceivedPacket() {
bool rtcp = false;
rtc::CopyOnWriteBuffer buffer;
rtc::PacketTime time;
SignalPacketReceived(rtcp, &buffer, time);
rtp_transport1->SetRtpPacketTransport(rtp_packet_transport1_.get());
rtp_transport2->SetRtpPacketTransport(rtp_packet_transport2_.get());
// Add payload type for RTP packet and RTCP packet.
rtp_transport1->AddHandledPayloadType(0x00);
rtp_transport2->AddHandledPayloadType(0x00);
rtp_transport1->AddHandledPayloadType(0xc9);
rtp_transport2->AddHandledPayloadType(0xc9);
srtp_transport1_ =
rtc::MakeUnique<SrtpTransport>(std::move(rtp_transport1), "content");
srtp_transport2_ =
rtc::MakeUnique<SrtpTransport>(std::move(rtp_transport2), "content");
srtp_transport1_->SignalPacketReceived.connect(
this, &SrtpTransportTest::OnPacketReceived1);
srtp_transport2_->SignalPacketReceived.connect(
this, &SrtpTransportTest::OnPacketReceived2);
}
void OnPacketReceived1(bool rtcp,
rtc::CopyOnWriteBuffer* packet,
const rtc::PacketTime& packet_time) {
LOG(LS_INFO) << "SrtpTransport1 Received a packet.";
last_recv_packet1_ = *packet;
}
void OnPacketReceived2(bool rtcp,
rtc::CopyOnWriteBuffer* packet,
const rtc::PacketTime& packet_time) {
LOG(LS_INFO) << "SrtpTransport2 Received a packet.";
last_recv_packet2_ = *packet;
}
// 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, const std::string& cs) {
int overhead;
EXPECT_TRUE(transport->GetSrtpOverhead(&overhead));
switch (rtc::SrtpCryptoSuiteFromName(cs)) {
case rtc::SRTP_AES128_CM_SHA1_32:
EXPECT_EQ(32 / 8, overhead); // 32-bit tag.
break;
case rtc::SRTP_AES128_CM_SHA1_80:
EXPECT_EQ(80 / 8, overhead); // 80-bit tag.
break;
default:
RTC_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(const std::string& cipher_suite_name) {
size_t rtp_len = sizeof(kPcmuFrame);
size_t packet_size = rtp_len + rtc::rtp_auth_tag_len(cipher_suite_name);
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(), cipher_suite_name);
} else {
ASSERT_TRUE(last_recv_packet2_.data());
EXPECT_TRUE(
memcmp(last_recv_packet2_.data(), original_rtp_data, rtp_len) == 0);
// 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_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len) == 0);
}
// 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(), cipher_suite_name);
} else {
ASSERT_TRUE(last_recv_packet1_.data());
EXPECT_TRUE(
memcmp(last_recv_packet1_.data(), original_rtp_data, rtp_len) == 0);
auto fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len) == 0);
}
}
void TestSendRecvRtcpPacket(const std::string& cipher_suite_name) {
size_t rtcp_len = sizeof(kRtcpReport);
size_t packet_size =
rtcp_len + 4 + rtc::rtcp_auth_tag_len(cipher_suite_name);
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(last_recv_packet2_.data());
EXPECT_TRUE(memcmp(last_recv_packet2_.data(), rtcp_packet_data, rtcp_len) ==
0);
// 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_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
rtcp_packet_data, rtcp_len) == 0);
// Do the same thing in the opposite direction;
ASSERT_TRUE(srtp_transport2_->SendRtcpPacket(&rtcp_packet2to1, options,
cricket::PF_SRTP_BYPASS));
ASSERT_TRUE(last_recv_packet1_.data());
EXPECT_TRUE(memcmp(last_recv_packet1_.data(), rtcp_packet_data, rtcp_len) ==
0);
fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
rtcp_packet_data, rtcp_len) == 0);
}
void TestSendRecvPacket(bool enable_external_auth,
int cs,
const uint8_t* key1,
int key1_len,
const uint8_t* key2,
int key2_len,
const std::string& cipher_suite_name) {
EXPECT_EQ(key1_len, key2_len);
EXPECT_EQ(cipher_suite_name, rtc::SrtpCryptoSuiteToName(cs));
if (enable_external_auth) {
srtp_transport1_->EnableExternalAuth();
srtp_transport2_->EnableExternalAuth();
}
EXPECT_TRUE(
srtp_transport1_->SetRtpParams(cs, key1, key1_len, cs, key2, key2_len));
EXPECT_TRUE(
srtp_transport2_->SetRtpParams(cs, key2, key2_len, cs, key1, key1_len));
EXPECT_TRUE(srtp_transport1_->SetRtcpParams(cs, key1, key1_len, cs, key2,
key2_len));
EXPECT_TRUE(srtp_transport2_->SetRtcpParams(cs, key2, key2_len, cs, key1,
key1_len));
EXPECT_TRUE(srtp_transport1_->IsActive());
EXPECT_TRUE(srtp_transport2_->IsActive());
if (rtc::IsGcmCryptoSuite(cs)) {
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(cipher_suite_name);
TestSendRecvRtcpPacket(cipher_suite_name);
}
void TestSendRecvPacketWithEncryptedHeaderExtension(
const std::string& cs,
const std::vector<int>& encrypted_header_ids) {
size_t rtp_len = sizeof(kPcmuFrameWithExtensions);
size_t packet_size = rtp_len + rtc::rtp_auth_tag_len(cs);
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(last_recv_packet2_.data());
EXPECT_TRUE(memcmp(last_recv_packet2_.data(), original_rtp_data, rtp_len) ==
0);
// 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_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len) == 0);
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(last_recv_packet1_.data());
EXPECT_TRUE(memcmp(last_recv_packet1_.data(), original_rtp_data, rtp_len) ==
0);
fake_rtp_packet_transport = static_cast<rtc::FakePacketTransport*>(
srtp_transport2_->rtp_packet_transport());
EXPECT_FALSE(memcmp(fake_rtp_packet_transport->last_sent_packet()->data(),
original_rtp_data, rtp_len) == 0);
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 cs,
const uint8_t* key1,
int key1_len,
const uint8_t* key2,
int key2_len,
const std::string& cs_name) {
std::vector<int> encrypted_headers;
encrypted_headers.push_back(1);
// Don't encrypt header ids 2 and 3.
encrypted_headers.push_back(4);
EXPECT_EQ(key1_len, key2_len);
EXPECT_EQ(cs_name, rtc::SrtpCryptoSuiteToName(cs));
srtp_transport1_->SetEncryptedHeaderExtensionIds(cricket::CS_LOCAL,
encrypted_headers);
srtp_transport1_->SetEncryptedHeaderExtensionIds(cricket::CS_REMOTE,
encrypted_headers);
srtp_transport2_->SetEncryptedHeaderExtensionIds(cricket::CS_LOCAL,
encrypted_headers);
srtp_transport2_->SetEncryptedHeaderExtensionIds(cricket::CS_REMOTE,
encrypted_headers);
EXPECT_TRUE(
srtp_transport1_->SetRtpParams(cs, key1, key1_len, cs, key2, key2_len));
EXPECT_TRUE(
srtp_transport2_->SetRtpParams(cs, key2, key2_len, cs, key1, key1_len));
EXPECT_TRUE(srtp_transport1_->IsActive());
EXPECT_TRUE(srtp_transport2_->IsActive());
EXPECT_FALSE(srtp_transport1_->IsExternalAuthActive());
EXPECT_FALSE(srtp_transport2_->IsExternalAuthActive());
TestSendRecvPacketWithEncryptedHeaderExtension(cs_name, 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_;
rtc::CopyOnWriteBuffer last_recv_packet1_;
rtc::CopyOnWriteBuffer last_recv_packet2_;
int sequence_number_ = 0;
};
TEST(SrtpTransportTest, SendPacket) {
auto rtp_transport = rtc::MakeUnique<MockRtpTransport>();
EXPECT_CALL(*rtp_transport, SendPacket(_, _, _, _)).WillOnce(Return(true));
class SrtpTransportTestWithExternalAuth
: public SrtpTransportTest,
public testing::WithParamInterface<bool> {};
SrtpTransport srtp_transport(std::move(rtp_transport), "a");
const bool rtcp = false;
rtc::CopyOnWriteBuffer packet;
rtc::PacketOptions options;
int flags = 0;
EXPECT_TRUE(srtp_transport.SendPacket(rtcp, &packet, options, flags));
// TODO(zstein): Also verify that the packet received by RtpTransport has been
// protected once SrtpTransport handles that.
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_AES_CM_128_HMAC_SHA1_80) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::SRTP_AES128_CM_SHA1_80,
kTestKey1, kTestKeyLen, kTestKey2, kTestKeyLen,
rtc::CS_AES_CM_128_HMAC_SHA1_80);
}
// Test that SrtpTransport fires SignalPacketReceived when the underlying
// RtpTransport fires SignalPacketReceived.
TEST(SrtpTransportTest, SignalPacketReceived) {
auto rtp_transport = rtc::MakeUnique<MockRtpTransport>();
MockRtpTransport* rtp_transport_raw = rtp_transport.get();
SrtpTransport srtp_transport(std::move(rtp_transport), "a");
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_AES_CM_128_HMAC_SHA1_80) {
TestSendRecvEncryptedHeaderExtension(rtc::SRTP_AES128_CM_SHA1_80, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen,
rtc::CS_AES_CM_128_HMAC_SHA1_80);
}
SignalPacketReceivedCounter counter(&srtp_transport);
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_AES_CM_128_HMAC_SHA1_32) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::SRTP_AES128_CM_SHA1_32,
kTestKey1, kTestKeyLen, kTestKey2, kTestKeyLen,
rtc::CS_AES_CM_128_HMAC_SHA1_32);
}
rtp_transport_raw->PretendReceivedPacket();
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_AES_CM_128_HMAC_SHA1_32) {
TestSendRecvEncryptedHeaderExtension(rtc::SRTP_AES128_CM_SHA1_32, kTestKey1,
kTestKeyLen, kTestKey2, kTestKeyLen,
rtc::CS_AES_CM_128_HMAC_SHA1_32);
}
EXPECT_EQ(1, counter.rtp_count());
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_SRTP_AEAD_AES_128_GCM) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::SRTP_AEAD_AES_128_GCM,
kTestKeyGcm128_1, kTestKeyGcm128Len, kTestKeyGcm128_2,
kTestKeyGcm128Len, rtc::CS_AEAD_AES_128_GCM);
}
// TODO(zstein): Also verify that the packet is unprotected once SrtpTransport
// handles that.
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_SRTP_AEAD_AES_128_GCM) {
TestSendRecvEncryptedHeaderExtension(
rtc::SRTP_AEAD_AES_128_GCM, kTestKeyGcm128_1, kTestKeyGcm128Len,
kTestKeyGcm128_2, kTestKeyGcm128Len, rtc::CS_AEAD_AES_128_GCM);
}
TEST_P(SrtpTransportTestWithExternalAuth,
SendAndRecvPacket_SRTP_AEAD_AES_256_GCM) {
bool enable_external_auth = GetParam();
TestSendRecvPacket(enable_external_auth, rtc::SRTP_AEAD_AES_256_GCM,
kTestKeyGcm256_1, kTestKeyGcm256Len, kTestKeyGcm256_2,
kTestKeyGcm256Len, rtc::CS_AEAD_AES_256_GCM);
}
TEST_F(SrtpTransportTest,
SendAndRecvPacketWithHeaderExtension_SRTP_AEAD_AES_256_GCM) {
TestSendRecvEncryptedHeaderExtension(
rtc::SRTP_AEAD_AES_256_GCM, kTestKeyGcm256_1, kTestKeyGcm256Len,
kTestKeyGcm256_2, kTestKeyGcm256Len, rtc::CS_AEAD_AES_256_GCM);
}
// Run all tests both with and without external auth enabled.
INSTANTIATE_TEST_CASE_P(ExternalAuth,
SrtpTransportTestWithExternalAuth,
::testing::Values(true, false));
// Test directly setting the params with bogus keys.
TEST_F(SrtpTransportTest, TestSetParamsKeyTooShort) {
EXPECT_FALSE(srtp_transport1_->SetRtpParams(
rtc::SRTP_AES128_CM_SHA1_80, kTestKey1, kTestKeyLen - 1,
rtc::SRTP_AES128_CM_SHA1_80, kTestKey1, kTestKeyLen - 1));
EXPECT_FALSE(srtp_transport1_->SetRtcpParams(
rtc::SRTP_AES128_CM_SHA1_80, kTestKey1, kTestKeyLen - 1,
rtc::SRTP_AES128_CM_SHA1_80, kTestKey1, kTestKeyLen - 1));
}
} // namespace webrtc