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1 /* | 1 /* |
2 * Copyright 2017 The WebRTC project authors. All Rights Reserved. | 2 * Copyright 2017 The WebRTC project authors. All Rights Reserved. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license | 4 * Use of this source code is governed by a BSD-style license |
5 * that can be found in the LICENSE file in the root of the source | 5 * that can be found in the LICENSE file in the root of the source |
6 * tree. An additional intellectual property rights grant can be found | 6 * tree. An additional intellectual property rights grant can be found |
7 * in the file PATENTS. All contributing project authors may | 7 * in the file PATENTS. All contributing project authors may |
8 * be found in the AUTHORS file in the root of the source tree. | 8 * be found in the AUTHORS file in the root of the source tree. |
9 */ | 9 */ |
10 | 10 |
11 #include "webrtc/pc/srtptransport.h" | 11 #include "webrtc/pc/srtptransport.h" |
12 | 12 |
13 #include <string> | 13 #include <string> |
14 | 14 |
15 #include "webrtc/media/base/rtputils.h" | 15 #include "webrtc/media/base/rtputils.h" |
16 #include "webrtc/pc/rtptransport.h" | 16 #include "webrtc/pc/rtptransport.h" |
17 #include "webrtc/pc/srtpsession.h" | 17 #include "webrtc/pc/srtpsession.h" |
18 #include "webrtc/rtc_base/asyncpacketsocket.h" | 18 #include "webrtc/rtc_base/asyncpacketsocket.h" |
| 19 #include "webrtc/rtc_base/base64.h" |
19 #include "webrtc/rtc_base/copyonwritebuffer.h" | 20 #include "webrtc/rtc_base/copyonwritebuffer.h" |
20 #include "webrtc/rtc_base/ptr_util.h" | 21 #include "webrtc/rtc_base/ptr_util.h" |
21 #include "webrtc/rtc_base/trace_event.h" | 22 #include "webrtc/rtc_base/trace_event.h" |
22 | 23 |
23 namespace webrtc { | 24 namespace webrtc { |
24 | 25 |
25 SrtpTransport::SrtpTransport(bool rtcp_mux_enabled, | 26 SrtpTransport::SrtpTransport(bool rtcp_mux_enabled, |
26 const std::string& content_name) | 27 const std::string& content_name) |
27 : content_name_(content_name), | 28 : content_name_(content_name), |
28 rtp_transport_(rtc::MakeUnique<RtpTransport>(rtcp_mux_enabled)) { | 29 rtp_transport_(rtc::MakeUnique<RtpTransport>(rtcp_mux_enabled)) { |
29 ConnectToRtpTransport(); | 30 ConnectToRtpTransport(); |
30 } | 31 } |
31 | 32 |
32 SrtpTransport::SrtpTransport(std::unique_ptr<RtpTransportInternal> transport, | 33 SrtpTransport::SrtpTransport(std::unique_ptr<RtpTransportInternal> transport, |
33 const std::string& content_name) | 34 const std::string& content_name) |
34 : content_name_(content_name), rtp_transport_(std::move(transport)) { | 35 : content_name_(content_name), rtp_transport_(std::move(transport)) { |
35 ConnectToRtpTransport(); | 36 ConnectToRtpTransport(); |
36 } | 37 } |
37 | 38 |
38 void SrtpTransport::ConnectToRtpTransport() { | 39 void SrtpTransport::ConnectToRtpTransport() { |
39 rtp_transport_->SignalPacketReceived.connect( | 40 rtp_transport_->SignalPacketReceived.connect( |
40 this, &SrtpTransport::OnPacketReceived); | 41 this, &SrtpTransport::OnPacketReceived); |
41 rtp_transport_->SignalReadyToSend.connect(this, | 42 rtp_transport_->SignalReadyToSend.connect(this, |
42 &SrtpTransport::OnReadyToSend); | 43 &SrtpTransport::OnReadyToSend); |
43 } | 44 } |
44 | 45 |
| 46 bool SrtpTransport::SendRtpPacket(rtc::CopyOnWriteBuffer* packet, |
| 47 const rtc::PacketOptions& options, |
| 48 int flags) { |
| 49 return SendPacket(false, packet, options, flags); |
| 50 } |
| 51 |
| 52 bool SrtpTransport::SendRtcpPacket(rtc::CopyOnWriteBuffer* packet, |
| 53 const rtc::PacketOptions& options, |
| 54 int flags) { |
| 55 return SendPacket(true, packet, options, flags); |
| 56 } |
| 57 |
45 bool SrtpTransport::SendPacket(bool rtcp, | 58 bool SrtpTransport::SendPacket(bool rtcp, |
46 rtc::CopyOnWriteBuffer* packet, | 59 rtc::CopyOnWriteBuffer* packet, |
47 const rtc::PacketOptions& options, | 60 const rtc::PacketOptions& options, |
48 int flags) { | 61 int flags) { |
49 // TODO(zstein): Protect packet. | 62 if (!IsActive()) { |
50 | 63 LOG(LS_ERROR) |
51 return rtp_transport_->SendPacket(rtcp, packet, options, flags); | 64 << "Failed to send the packet because SRTP transport is inactive."; |
| 65 return false; |
| 66 } |
| 67 |
| 68 rtc::PacketOptions updated_options = options; |
| 69 rtc::CopyOnWriteBuffer cp = *packet; |
| 70 TRACE_EVENT0("webrtc", "SRTP Encode"); |
| 71 bool res; |
| 72 uint8_t* data = packet->data(); |
| 73 int len = static_cast<int>(packet->size()); |
| 74 if (!rtcp) { |
| 75 // If ENABLE_EXTERNAL_AUTH flag is on then packet authentication is not done |
| 76 // inside libsrtp for a RTP packet. A external HMAC module will be writing |
| 77 // a fake HMAC value. This is ONLY done for a RTP packet. |
| 78 // Socket layer will update rtp sendtime extension header if present in |
| 79 // packet with current time before updating the HMAC. |
| 80 #if !defined(ENABLE_EXTERNAL_AUTH) |
| 81 res = ProtectRtp(data, len, static_cast<int>(packet->capacity()), &len); |
| 82 #else |
| 83 if (!IsExternalAuthActive()) { |
| 84 res = ProtectRtp(data, len, static_cast<int>(packet->capacity()), &len); |
| 85 } else { |
| 86 updated_options.packet_time_params.rtp_sendtime_extension_id = |
| 87 rtp_abs_sendtime_extn_id_; |
| 88 res = ProtectRtp(data, len, static_cast<int>(packet->capacity()), &len, |
| 89 &updated_options.packet_time_params.srtp_packet_index); |
| 90 // If protection succeeds, let's get auth params from srtp. |
| 91 if (res) { |
| 92 uint8_t* auth_key = NULL; |
| 93 int key_len; |
| 94 res = GetRtpAuthParams( |
| 95 &auth_key, &key_len, |
| 96 &updated_options.packet_time_params.srtp_auth_tag_len); |
| 97 if (res) { |
| 98 updated_options.packet_time_params.srtp_auth_key.resize(key_len); |
| 99 updated_options.packet_time_params.srtp_auth_key.assign( |
| 100 auth_key, auth_key + key_len); |
| 101 } |
| 102 } |
| 103 } |
| 104 #endif |
| 105 if (!res) { |
| 106 int seq_num = -1; |
| 107 uint32_t ssrc = 0; |
| 108 cricket::GetRtpSeqNum(data, len, &seq_num); |
| 109 cricket::GetRtpSsrc(data, len, &ssrc); |
| 110 LOG(LS_ERROR) << "Failed to protect " << content_name_ |
| 111 << " RTP packet: size=" << len << ", seqnum=" << seq_num |
| 112 << ", SSRC=" << ssrc; |
| 113 return false; |
| 114 } |
| 115 } else { |
| 116 res = ProtectRtcp(data, len, static_cast<int>(packet->capacity()), &len); |
| 117 if (!res) { |
| 118 int type = -1; |
| 119 cricket::GetRtcpType(data, len, &type); |
| 120 LOG(LS_ERROR) << "Failed to protect " << content_name_ |
| 121 << " RTCP packet: size=" << len << ", type=" << type; |
| 122 return false; |
| 123 } |
| 124 } |
| 125 |
| 126 // Update the length of the packet now that we've added the auth tag. |
| 127 packet->SetSize(len); |
| 128 return rtcp ? rtp_transport_->SendRtcpPacket(packet, updated_options, flags) |
| 129 : rtp_transport_->SendRtpPacket(packet, updated_options, flags); |
52 } | 130 } |
53 | 131 |
54 void SrtpTransport::OnPacketReceived(bool rtcp, | 132 void SrtpTransport::OnPacketReceived(bool rtcp, |
55 rtc::CopyOnWriteBuffer* packet, | 133 rtc::CopyOnWriteBuffer* packet, |
56 const rtc::PacketTime& packet_time) { | 134 const rtc::PacketTime& packet_time) { |
57 // TODO(zstein): Unprotect packet. | 135 if (!IsActive()) { |
58 | 136 LOG(LS_WARNING) << "Inactive SRTP transport received a packet. Drop it."; |
| 137 return; |
| 138 } |
| 139 |
| 140 TRACE_EVENT0("webrtc", "SRTP Decode"); |
| 141 char* data = packet->data<char>(); |
| 142 int len = static_cast<int>(packet->size()); |
| 143 bool res; |
| 144 if (!rtcp) { |
| 145 res = UnprotectRtp(data, len, &len); |
| 146 if (!res) { |
| 147 int seq_num = -1; |
| 148 uint32_t ssrc = 0; |
| 149 cricket::GetRtpSeqNum(data, len, &seq_num); |
| 150 cricket::GetRtpSsrc(data, len, &ssrc); |
| 151 LOG(LS_ERROR) << "Failed to unprotect " << content_name_ |
| 152 << " RTP packet: size=" << len << ", seqnum=" << seq_num |
| 153 << ", SSRC=" << ssrc; |
| 154 return; |
| 155 } |
| 156 } else { |
| 157 res = UnprotectRtcp(data, len, &len); |
| 158 if (!res) { |
| 159 int type = -1; |
| 160 cricket::GetRtcpType(data, len, &type); |
| 161 LOG(LS_ERROR) << "Failed to unprotect " << content_name_ |
| 162 << " RTCP packet: size=" << len << ", type=" << type; |
| 163 return; |
| 164 } |
| 165 } |
| 166 |
| 167 packet->SetSize(len); |
59 SignalPacketReceived(rtcp, packet, packet_time); | 168 SignalPacketReceived(rtcp, packet, packet_time); |
60 } | 169 } |
61 | 170 |
| 171 bool SrtpTransport::SetRtpParams(int send_cs, |
| 172 const uint8_t* send_key, |
| 173 int send_key_len, |
| 174 int recv_cs, |
| 175 const uint8_t* recv_key, |
| 176 int recv_key_len) { |
| 177 CreateSrtpSessions(); |
| 178 send_session_->SetEncryptedHeaderExtensionIds( |
| 179 send_encrypted_header_extension_ids_); |
| 180 if (external_auth_enabled_) { |
| 181 send_session_->EnableExternalAuth(); |
| 182 } |
| 183 if (!send_session_->SetSend(send_cs, send_key, send_key_len)) { |
| 184 ResetParams(); |
| 185 return false; |
| 186 } |
| 187 |
| 188 recv_session_->SetEncryptedHeaderExtensionIds( |
| 189 recv_encrypted_header_extension_ids_); |
| 190 if (!recv_session_->SetRecv(recv_cs, recv_key, recv_key_len)) { |
| 191 ResetParams(); |
| 192 return false; |
| 193 } |
| 194 |
| 195 LOG(LS_INFO) << "SRTP activated with negotiated parameters:" |
| 196 << " send cipher_suite " << send_cs << " recv cipher_suite " |
| 197 << recv_cs; |
| 198 return true; |
| 199 } |
| 200 |
| 201 bool SrtpTransport::SetRtcpParams(int send_cs, |
| 202 const uint8_t* send_key, |
| 203 int send_key_len, |
| 204 int recv_cs, |
| 205 const uint8_t* recv_key, |
| 206 int recv_key_len) { |
| 207 // This can only be called once, but can be safely called after |
| 208 // SetRtpParams |
| 209 if (send_rtcp_session_ || recv_rtcp_session_) { |
| 210 LOG(LS_ERROR) << "Tried to set SRTCP Params when filter already active"; |
| 211 return false; |
| 212 } |
| 213 |
| 214 send_rtcp_session_.reset(new cricket::SrtpSession()); |
| 215 if (!send_rtcp_session_->SetRecv(send_cs, send_key, send_key_len)) { |
| 216 return false; |
| 217 } |
| 218 |
| 219 recv_rtcp_session_.reset(new cricket::SrtpSession()); |
| 220 if (!recv_rtcp_session_->SetRecv(recv_cs, recv_key, recv_key_len)) { |
| 221 return false; |
| 222 } |
| 223 |
| 224 LOG(LS_INFO) << "SRTCP activated with negotiated parameters:" |
| 225 << " send cipher_suite " << send_cs << " recv cipher_suite " |
| 226 << recv_cs; |
| 227 |
| 228 return true; |
| 229 } |
| 230 |
| 231 bool SrtpTransport::IsActive() const { |
| 232 return send_session_ && recv_session_; |
| 233 } |
| 234 |
| 235 void SrtpTransport::ResetParams() { |
| 236 send_session_ = nullptr; |
| 237 recv_session_ = nullptr; |
| 238 send_rtcp_session_ = nullptr; |
| 239 recv_rtcp_session_ = nullptr; |
| 240 LOG(LS_INFO) << "The params in SRTP transport are reset."; |
| 241 } |
| 242 |
| 243 void SrtpTransport::SetEncryptedHeaderExtensionIds( |
| 244 cricket::ContentSource source, |
| 245 const std::vector<int>& extension_ids) { |
| 246 if (source == cricket::CS_LOCAL) { |
| 247 recv_encrypted_header_extension_ids_ = extension_ids; |
| 248 } else { |
| 249 send_encrypted_header_extension_ids_ = extension_ids; |
| 250 } |
| 251 } |
| 252 |
| 253 void SrtpTransport::CreateSrtpSessions() { |
| 254 send_session_.reset(new cricket::SrtpSession()); |
| 255 recv_session_.reset(new cricket::SrtpSession()); |
| 256 |
| 257 if (external_auth_enabled_) { |
| 258 send_session_->EnableExternalAuth(); |
| 259 } |
| 260 } |
| 261 |
| 262 bool SrtpTransport::ProtectRtp(void* p, int in_len, int max_len, int* out_len) { |
| 263 if (!IsActive()) { |
| 264 LOG(LS_WARNING) << "Failed to ProtectRtp: SRTP not active"; |
| 265 return false; |
| 266 } |
| 267 RTC_CHECK(send_session_); |
| 268 return send_session_->ProtectRtp(p, in_len, max_len, out_len); |
| 269 } |
| 270 |
| 271 bool SrtpTransport::ProtectRtp(void* p, |
| 272 int in_len, |
| 273 int max_len, |
| 274 int* out_len, |
| 275 int64_t* index) { |
| 276 if (!IsActive()) { |
| 277 LOG(LS_WARNING) << "Failed to ProtectRtp: SRTP not active"; |
| 278 return false; |
| 279 } |
| 280 RTC_CHECK(send_session_); |
| 281 return send_session_->ProtectRtp(p, in_len, max_len, out_len, index); |
| 282 } |
| 283 |
| 284 bool SrtpTransport::ProtectRtcp(void* p, |
| 285 int in_len, |
| 286 int max_len, |
| 287 int* out_len) { |
| 288 if (!IsActive()) { |
| 289 LOG(LS_WARNING) << "Failed to ProtectRtcp: SRTP not active"; |
| 290 return false; |
| 291 } |
| 292 if (send_rtcp_session_) { |
| 293 return send_rtcp_session_->ProtectRtcp(p, in_len, max_len, out_len); |
| 294 } else { |
| 295 RTC_CHECK(send_session_); |
| 296 return send_session_->ProtectRtcp(p, in_len, max_len, out_len); |
| 297 } |
| 298 } |
| 299 |
| 300 bool SrtpTransport::UnprotectRtp(void* p, int in_len, int* out_len) { |
| 301 if (!IsActive()) { |
| 302 LOG(LS_WARNING) << "Failed to UnprotectRtp: SRTP not active"; |
| 303 return false; |
| 304 } |
| 305 RTC_CHECK(recv_session_); |
| 306 return recv_session_->UnprotectRtp(p, in_len, out_len); |
| 307 } |
| 308 |
| 309 bool SrtpTransport::UnprotectRtcp(void* p, int in_len, int* out_len) { |
| 310 if (!IsActive()) { |
| 311 LOG(LS_WARNING) << "Failed to UnprotectRtcp: SRTP not active"; |
| 312 return false; |
| 313 } |
| 314 if (recv_rtcp_session_) { |
| 315 return recv_rtcp_session_->UnprotectRtcp(p, in_len, out_len); |
| 316 } else { |
| 317 RTC_CHECK(recv_session_); |
| 318 return recv_session_->UnprotectRtcp(p, in_len, out_len); |
| 319 } |
| 320 } |
| 321 |
| 322 bool SrtpTransport::GetRtpAuthParams(uint8_t** key, |
| 323 int* key_len, |
| 324 int* tag_len) { |
| 325 if (!IsActive()) { |
| 326 LOG(LS_WARNING) << "Failed to GetRtpAuthParams: SRTP not active"; |
| 327 return false; |
| 328 } |
| 329 |
| 330 RTC_CHECK(send_session_); |
| 331 return send_session_->GetRtpAuthParams(key, key_len, tag_len); |
| 332 } |
| 333 |
| 334 bool SrtpTransport::GetSrtpOverhead(int* srtp_overhead) const { |
| 335 if (!IsActive()) { |
| 336 LOG(LS_WARNING) << "Failed to GetSrtpOverhead: SRTP not active"; |
| 337 return false; |
| 338 } |
| 339 |
| 340 RTC_CHECK(send_session_); |
| 341 *srtp_overhead = send_session_->GetSrtpOverhead(); |
| 342 return true; |
| 343 } |
| 344 |
| 345 void SrtpTransport::EnableExternalAuth() { |
| 346 RTC_DCHECK(!IsActive()); |
| 347 external_auth_enabled_ = true; |
| 348 } |
| 349 |
| 350 bool SrtpTransport::IsExternalAuthEnabled() const { |
| 351 return external_auth_enabled_; |
| 352 } |
| 353 |
| 354 bool SrtpTransport::IsExternalAuthActive() const { |
| 355 if (!IsActive()) { |
| 356 LOG(LS_WARNING) << "Failed to check IsExternalAuthActive: SRTP not active"; |
| 357 return false; |
| 358 } |
| 359 |
| 360 RTC_CHECK(send_session_); |
| 361 return send_session_->IsExternalAuthActive(); |
| 362 } |
| 363 |
62 } // namespace webrtc | 364 } // namespace webrtc |
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