| /* |
| * Copyright 2009 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. |
| */ |
| |
| #ifndef PC_SRTP_FILTER_H_ |
| #define PC_SRTP_FILTER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <list> |
| #include <map> |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "absl/types/optional.h" |
| #include "api/array_view.h" |
| #include "api/crypto_params.h" |
| #include "api/jsep.h" |
| #include "api/sequence_checker.h" |
| #include "pc/session_description.h" |
| #include "rtc_base/buffer.h" |
| #include "rtc_base/constructor_magic.h" |
| #include "rtc_base/ssl_stream_adapter.h" |
| |
| // Forward declaration to avoid pulling in libsrtp headers here |
| struct srtp_event_data_t; |
| struct srtp_ctx_t_; |
| |
| namespace cricket { |
| |
| // A helper class used to negotiate SDES crypto params. |
| // TODO(zhihuang): Find a better name for this class, like "SdesNegotiator". |
| class SrtpFilter { |
| public: |
| enum Mode { PROTECT, UNPROTECT }; |
| enum Error { |
| ERROR_NONE, |
| ERROR_FAIL, |
| ERROR_AUTH, |
| ERROR_REPLAY, |
| }; |
| |
| SrtpFilter(); |
| ~SrtpFilter(); |
| |
| // Whether the filter is active (i.e. crypto has been properly negotiated). |
| bool IsActive() const; |
| |
| // Handle the offer/answer negotiation of the crypto parameters internally. |
| // TODO(zhihuang): Make SetOffer/ProvisionalAnswer/Answer private as helper |
| // methods once start using Process. |
| bool Process(const std::vector<CryptoParams>& cryptos, |
| webrtc::SdpType type, |
| ContentSource source); |
| |
| // Indicates which crypto algorithms and keys were contained in the offer. |
| // offer_params should contain a list of available parameters to use, or none, |
| // if crypto is not desired. This must be called before SetAnswer. |
| bool SetOffer(const std::vector<CryptoParams>& offer_params, |
| ContentSource source); |
| // Same as SetAnwer. But multiple calls are allowed to SetProvisionalAnswer |
| // after a call to SetOffer. |
| bool SetProvisionalAnswer(const std::vector<CryptoParams>& answer_params, |
| ContentSource source); |
| // Indicates which crypto algorithms and keys were contained in the answer. |
| // answer_params should contain the negotiated parameters, which may be none, |
| // if crypto was not desired or could not be negotiated (and not required). |
| // This must be called after SetOffer. If crypto negotiation completes |
| // successfully, this will advance the filter to the active state. |
| bool SetAnswer(const std::vector<CryptoParams>& answer_params, |
| ContentSource source); |
| |
| bool ResetParams(); |
| |
| static bool ParseKeyParams(const std::string& params, |
| uint8_t* key, |
| size_t len); |
| |
| absl::optional<int> send_cipher_suite() { return send_cipher_suite_; } |
| absl::optional<int> recv_cipher_suite() { return recv_cipher_suite_; } |
| |
| rtc::ArrayView<const uint8_t> send_key() { return send_key_; } |
| rtc::ArrayView<const uint8_t> recv_key() { return recv_key_; } |
| |
| protected: |
| bool ExpectOffer(ContentSource source); |
| |
| bool StoreParams(const std::vector<CryptoParams>& params, |
| ContentSource source); |
| |
| bool ExpectAnswer(ContentSource source); |
| |
| bool DoSetAnswer(const std::vector<CryptoParams>& answer_params, |
| ContentSource source, |
| bool final); |
| |
| bool NegotiateParams(const std::vector<CryptoParams>& answer_params, |
| CryptoParams* selected_params); |
| |
| private: |
| bool ApplySendParams(const CryptoParams& send_params); |
| |
| bool ApplyRecvParams(const CryptoParams& recv_params); |
| |
| enum State { |
| ST_INIT, // SRTP filter unused. |
| ST_SENTOFFER, // Offer with SRTP parameters sent. |
| ST_RECEIVEDOFFER, // Offer with SRTP parameters received. |
| ST_SENTPRANSWER_NO_CRYPTO, // Sent provisional answer without crypto. |
| // Received provisional answer without crypto. |
| ST_RECEIVEDPRANSWER_NO_CRYPTO, |
| ST_ACTIVE, // Offer and answer set. |
| // SRTP filter is active but new parameters are offered. |
| // When the answer is set, the state transitions to ST_ACTIVE or ST_INIT. |
| ST_SENTUPDATEDOFFER, |
| // SRTP filter is active but new parameters are received. |
| // When the answer is set, the state transitions back to ST_ACTIVE. |
| ST_RECEIVEDUPDATEDOFFER, |
| // SRTP filter is active but the sent answer is only provisional. |
| // When the final answer is set, the state transitions to ST_ACTIVE or |
| // ST_INIT. |
| ST_SENTPRANSWER, |
| // SRTP filter is active but the received answer is only provisional. |
| // When the final answer is set, the state transitions to ST_ACTIVE or |
| // ST_INIT. |
| ST_RECEIVEDPRANSWER |
| }; |
| State state_ = ST_INIT; |
| std::vector<CryptoParams> offer_params_; |
| CryptoParams applied_send_params_; |
| CryptoParams applied_recv_params_; |
| absl::optional<int> send_cipher_suite_; |
| absl::optional<int> recv_cipher_suite_; |
| rtc::ZeroOnFreeBuffer<uint8_t> send_key_; |
| rtc::ZeroOnFreeBuffer<uint8_t> recv_key_; |
| }; |
| |
| } // namespace cricket |
| |
| #endif // PC_SRTP_FILTER_H_ |