1 /* 2 * Copyright 2018 The WebRTC project authors. All Rights Reserved. 3 * 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 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef API_CRYPTO_FRAME_ENCRYPTOR_INTERFACE_H_ 12 #define API_CRYPTO_FRAME_ENCRYPTOR_INTERFACE_H_ 13 14 #include "api/array_view.h" 15 #include "api/media_types.h" 16 #include "rtc_base/ref_count.h" 17 18 namespace webrtc { 19 20 // FrameEncryptorInterface allows users to provide a custom encryption 21 // implementation to encrypt all outgoing audio and video frames. The user must 22 // also provide a FrameDecryptorInterface to be able to decrypt the frames on 23 // the receiving device. Note this is an additional layer of encryption in 24 // addition to the standard SRTP mechanism and is not intended to be used 25 // without it. Implementations of this interface will have the same lifetime as 26 // the RTPSenders it is attached to. Additional data may be null. 27 class FrameEncryptorInterface : public rtc::RefCountInterface { 28 public: ~FrameEncryptorInterface()29 ~FrameEncryptorInterface() override {} 30 31 // Attempts to encrypt the provided frame. You may assume the encrypted_frame 32 // will match the size returned by GetMaxCiphertextByteSize for a give frame. 33 // You may assume that the frames will arrive in order if SRTP is enabled. 34 // The ssrc will simply identify which stream the frame is travelling on. You 35 // must set bytes_written to the number of bytes you wrote in the 36 // encrypted_frame. 0 must be returned if successful all other numbers can be 37 // selected by the implementer to represent error codes. 38 virtual int Encrypt(cricket::MediaType media_type, 39 uint32_t ssrc, 40 rtc::ArrayView<const uint8_t> additional_data, 41 rtc::ArrayView<const uint8_t> frame, 42 rtc::ArrayView<uint8_t> encrypted_frame, 43 size_t* bytes_written) = 0; 44 45 // Returns the total required length in bytes for the output of the 46 // encryption. This can be larger than the actual number of bytes you need but 47 // must never be smaller as it informs the size of the encrypted_frame buffer. 48 virtual size_t GetMaxCiphertextByteSize(cricket::MediaType media_type, 49 size_t frame_size) = 0; 50 }; 51 52 } // namespace webrtc 53 54 #endif // API_CRYPTO_FRAME_ENCRYPTOR_INTERFACE_H_ 55