src/transport/SecureMessageCodec.h

/*
 *
 *    Copyright (c) 2021 Project CHIP Authors
 *    All rights reserved.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

/**
 *    @file
 *      This file defines functions for encoding and decoding CHIP messages.
 *      The encoded messages contain CHIP packet header, encrypted payload
 *      header, encrypted payload and message authentication code, as per
 *      CHIP specifications.
 *
 */

#pragma once

#include <transport/PeerConnectionState.h>

namespace chip {

namespace SecureMessageCodec {

/**
 * @brief
 *  Attach payload header to the message and encrypt the message buffer using
 *  key from the connection state.
 *
 * @param localNodeId   Node Id of local node
 * @param state         The connection state with peer node
 * @param payloadHeader Reference to the payload header that should be inserted in
 *                      the message
 * @param packetHeader  Reference to the packet header that contains unencrypted
 *                      portion of the message header
 * @param msgBuf        The message buffer that contains the unencrypted message. If
 *                      the operation is successuful, this buffer will contain the
 *                      encrypted message.
 * @ return CHIP_ERROR  The result of the encode operation
 */
CHIP_ERROR Encode(NodeId localNodeId, Transport::PeerConnectionState * state, PayloadHeader & payloadHeader,
                  PacketHeader & packetHeader, System::PacketBufferHandle & msgBuf);

/**
 * @brief
 *  Decrypt the message, perform message integrity check, and decode the payload header.
 *
 * @param state         The connection state with peer node
 * @param payloadHeader Reference to the payload header that should be inserted in
 *                      the message
 * @param packetHeader  Reference to the packet header that contains unencrypted
 *                      portion of the message header
 * @param msgBuf        The message buffer that contains the encrypted message. If
 *                      the operation is successuful, this buffer will contain the
 *                      unencrypted message.
 * @ return CHIP_ERROR  The result of the decode operation
 */
CHIP_ERROR Decode(Transport::PeerConnectionState * state, PayloadHeader & payloadHeader, const PacketHeader & packetHeader,
                  System::PacketBufferHandle & msgBuf);
} // namespace SecureMessageCodec

} // namespace chip