src/transport/SecureSessionMgr.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2020-2021 Project CHIP Authors
  *    Copyright (c) 2013-2017 Nest Labs, Inc.
  *    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 implements the CHIP Connection object that maintains a UDP connection.
  *      TODO This class should be extended to support TCP as well...
  *
  */

 #include "SecureSessionMgr.h"

 #include <inttypes.h>
 #include <string.h>

 #include <core/CHIPKeyIds.h>
 #include <platform/CHIPDeviceLayer.h>
 #include <protocols/secure_channel/Constants.h>
 #include <support/CodeUtils.h>
 #include <support/SafeInt.h>
 #include <support/logging/CHIPLogging.h>
 #include <transport/AdminPairingTable.h>
 #include <transport/SecureMessageCodec.h>
 #include <transport/TransportMgr.h>

 #include <inttypes.h>

 namespace chip {

 using System::PacketBufferHandle;
 using Transport::PeerAddress;
 using Transport::PeerConnectionState;

 uint32_t EncryptedPacketBufferHandle::GetMsgId() const
 {
     PacketHeader header;
     uint16_t headerSize = 0;
     CHIP_ERROR err      = header.Decode((*this)->Start(), (*this)->DataLength(), &headerSize);

     if (err == CHIP_NO_ERROR)
     {
         return header.GetMessageId();
     }

     ChipLogError(Inet, "Failed to decode EncryptedPacketBufferHandle header with error: %s", ErrorStr(err));

     return 0;
 }

 SecureSessionMgr::SecureSessionMgr() : mState(State::kNotReady) {}

 SecureSessionMgr::~SecureSessionMgr()
 {
     CancelExpiryTimer();
 }

 CHIP_ERROR SecureSessionMgr::Init(NodeId localNodeId, System::Layer * systemLayer, TransportMgrBase * transportMgr,
                                   Transport::AdminPairingTable * admins)
 {
     VerifyOrReturnError(mState == State::kNotReady, CHIP_ERROR_INCORRECT_STATE);
     VerifyOrReturnError(transportMgr != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

     mState        = State::kInitialized;
     mLocalNodeId  = localNodeId;
     mSystemLayer  = systemLayer;
     mTransportMgr = transportMgr;
     mAdmins       = admins;

     ChipLogProgress(Inet, "local node id is 0x%08" PRIx32 "%08" PRIx32, static_cast<uint32_t>(mLocalNodeId >> 32),
                     static_cast<uint32_t>(mLocalNodeId));

     ScheduleExpiryTimer();

     mTransportMgr->SetSecureSessionMgr(this);

     return CHIP_NO_ERROR;
 }

 void SecureSessionMgr::Shutdown()
 {
     CancelExpiryTimer();

     mState        = State::kNotReady;
     mLocalNodeId  = kUndefinedNodeId;
     mSystemLayer  = nullptr;
     mTransportMgr = nullptr;
     mAdmins       = nullptr;
     mCB           = nullptr;
 }

 Transport::Type SecureSessionMgr::GetTransportType(NodeId peerNodeId)
 {
     PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(peerNodeId, nullptr);

     if (state)
     {
         return state->GetPeerAddress().GetTransportType();
     }

     return Transport::Type::kUndefined;
 }

 CHIP_ERROR SecureSessionMgr::SendMessage(SecureSessionHandle session, PayloadHeader & payloadHeader,
                                          System::PacketBufferHandle && msgBuf, EncryptedPacketBufferHandle * bufferRetainSlot)
 {
     PacketHeader unusedPacketHeader;
     return SendMessage(session, payloadHeader, unusedPacketHeader, std::move(msgBuf), bufferRetainSlot,
                        EncryptionState::kPayloadIsUnencrypted);
 }

 CHIP_ERROR SecureSessionMgr::SendEncryptedMessage(SecureSessionHandle session, EncryptedPacketBufferHandle msgBuf,
                                                   EncryptedPacketBufferHandle * bufferRetainSlot)
 {
     VerifyOrReturnError(!msgBuf.IsNull(), CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(!msgBuf->HasChainedBuffer(), CHIP_ERROR_INVALID_MESSAGE_LENGTH);

     // Advancing the start to encrypted header, since the transport will attach the packet header on top of it
     PacketHeader packetHeader;
     ReturnErrorOnFailure(packetHeader.DecodeAndConsume(msgBuf));

     VerifyOrReturnError(msgBuf->TotalLength() <= kMaxAppMessageLen + packetHeader.EncodeSizeBytes(), CHIP_ERROR_MESSAGE_TOO_LONG);

     PayloadHeader payloadHeader;
     return SendMessage(session, payloadHeader, packetHeader, std::move(msgBuf), bufferRetainSlot,
                        EncryptionState::kPayloadIsEncrypted);
 }

 CHIP_ERROR SecureSessionMgr::SendMessage(SecureSessionHandle session, PayloadHeader & payloadHeader, PacketHeader & packetHeader,
                                          System::PacketBufferHandle msgBuf, EncryptedPacketBufferHandle * bufferRetainSlot,
                                          EncryptionState encryptionState)
 {
     CHIP_ERROR err              = CHIP_NO_ERROR;
     PeerConnectionState * state = nullptr;
     uint8_t * msgStart          = nullptr;
     uint16_t msgLen             = 0;
     uint16_t headerSize         = 0;
     NodeId localNodeId          = mLocalNodeId;

     Transport::AdminPairingInfo * admin = nullptr;

     // Hold the reference to encrypted message in stack variable.
     // In case of any failures, the reference is not returned, and this stack variable
     // will automatically free the reference on returning from the function.
     EncryptedPacketBufferHandle encryptedMsg;

     VerifyOrExit(mState == State::kInitialized, err = CHIP_ERROR_INCORRECT_STATE);

     VerifyOrExit(!msgBuf.IsNull(), err = CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrExit(!msgBuf->HasChainedBuffer(), err = CHIP_ERROR_INVALID_MESSAGE_LENGTH);

     // Find an active connection to the specified peer node
     state = GetPeerConnectionState(session);
     VerifyOrExit(state != nullptr, err = CHIP_ERROR_NOT_CONNECTED);

     // This marks any connection where we send data to as 'active'
     mPeerConnections.MarkConnectionActive(state);
     admin = mAdmins->FindAdmin(state->GetAdminId());
     VerifyOrExit(admin != nullptr, err = CHIP_ERROR_INCORRECT_STATE);
     localNodeId = admin->GetNodeId();

     if (payloadHeader.HasMessageType(Protocols::SecureChannel::MsgType::MsgCounterSyncReq) ||
         payloadHeader.HasMessageType(Protocols::SecureChannel::MsgType::MsgCounterSyncRsp))
     {
         packetHeader.SetSecureSessionControlMsg(true);
     }

     if (encryptionState == EncryptionState::kPayloadIsUnencrypted)
     {
         err = SecureMessageCodec::Encode(localNodeId, state, payloadHeader, packetHeader, msgBuf);
         SuccessOrExit(err);
     }

     // The start of buffer points to the beginning of the encrypted header, and the length of buffer
     // contains both the encrypted header and encrypted data.
     // Locally store the start and length of the retained buffer after accounting for the size of packet header.
     headerSize = packetHeader.EncodeSizeBytes();

     msgStart = static_cast<uint8_t *>(msgBuf->Start() - headerSize);
     msgLen   = static_cast<uint16_t>(msgBuf->DataLength() + headerSize);

     // Retain the packet buffer in case it's needed for retransmissions.
     if (bufferRetainSlot != nullptr)
     {
         encryptedMsg = msgBuf.Retain();
     }

     ChipLogProgress(Inet,
                     "Sending msg from 0x%08" PRIx32 "%08" PRIx32 " to 0x%08" PRIx32 "%08" PRIx32 " at utc time: %" PRId64 " msec",
                     static_cast<uint32_t>(localNodeId >> 32), static_cast<uint32_t>(localNodeId),
                     static_cast<uint32_t>(state->GetPeerNodeId() >> 32), static_cast<uint32_t>(state->GetPeerNodeId()),
                     System::Layer::GetClock_MonotonicMS());

     if (state->GetTransport() != nullptr)
     {
         ChipLogProgress(Inet, "Sending secure msg on connection specific transport");
         err = state->GetTransport()->SendMessage(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
     }
     else
     {
         ChipLogProgress(Inet, "Sending secure msg on generic transport");
         err = mTransportMgr->SendMessage(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
     }
     ChipLogProgress(Inet, "Secure msg send status %s", ErrorStr(err));
     SuccessOrExit(err);

     if (bufferRetainSlot != nullptr)
     {
         // Rewind the start and len of the buffer back to pre-send state for following possible retransmition.
         encryptedMsg->SetStart(msgStart);
         encryptedMsg->SetDataLength(msgLen);

         (*bufferRetainSlot) = std::move(encryptedMsg);
     }

 exit:
     if (!msgBuf.IsNull())
     {
         const char * errStr = ErrorStr(err);
         if (state == nullptr)
         {
             ChipLogError(Inet, "Secure transport could not find a valid PeerConnection: %s", errStr);
         }
     }

     return err;
 }

 CHIP_ERROR SecureSessionMgr::NewPairing(const Optional<Transport::PeerAddress> & peerAddr, NodeId peerNodeId,
                                         PairingSession * pairing, PairingDirection direction, Transport::AdminId admin,
                                         Transport::Base * transport)
 {
     uint16_t peerKeyId          = pairing->GetPeerKeyId();
     uint16_t localKeyId         = pairing->GetLocalKeyId();
     PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(Optional<NodeId>::Value(peerNodeId), peerKeyId, nullptr);

     // Find any existing connection with the same node and key ID
     if (state && (state->GetAdminId() == Transport::kUndefinedAdminId || state->GetAdminId() == admin))
     {
         mPeerConnections.MarkConnectionExpired(
             state, [this](const Transport::PeerConnectionState & state1) { HandleConnectionExpired(state1); });
     }

     ChipLogDetail(Inet, "New pairing for device 0x%08" PRIx32 "%08" PRIx32 ", key %d!!", static_cast<uint32_t>(peerNodeId >> 32),
                   static_cast<uint32_t>(peerNodeId), peerKeyId);
     state = nullptr;
     ReturnErrorOnFailure(
         mPeerConnections.CreateNewPeerConnectionState(Optional<NodeId>::Value(peerNodeId), peerKeyId, localKeyId, &state));

     state->SetAdminId(admin);
     state->SetTransport(transport);

     if (peerAddr.HasValue() && peerAddr.Value().GetIPAddress() != Inet::IPAddress::Any)
     {
         state->SetPeerAddress(peerAddr.Value());
     }
     else if (peerAddr.HasValue() && peerAddr.Value().GetTransportType() == Transport::Type::kBle)
     {
         state->SetPeerAddress(peerAddr.Value());
     }
     else if (peerAddr.HasValue() &&
              (peerAddr.Value().GetTransportType() == Transport::Type::kTcp ||
               peerAddr.Value().GetTransportType() == Transport::Type::kUdp))
     {
         return CHIP_ERROR_INVALID_ARGUMENT;
     }

     if (state != nullptr)
     {
         switch (direction)
         {
         case PairingDirection::kInitiator: {
             const char * i2rInfo = pairing->GetI2RSessionInfo();
             ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(i2rInfo), strlen(i2rInfo),
                                                               state->GetSenderSecureSession()));

             const char * r2iInfo = pairing->GetR2ISessionInfo();
             ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(r2iInfo), strlen(r2iInfo),
                                                               state->GetReceiverSecureSession()));
         }
         break;
         case PairingDirection::kResponder: {
             const char * i2rInfo = pairing->GetR2ISessionInfo();
             ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(i2rInfo), strlen(i2rInfo),
                                                               state->GetSenderSecureSession()));

             const char * r2iInfo = pairing->GetI2RSessionInfo();
             ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(r2iInfo), strlen(r2iInfo),
                                                               state->GetReceiverSecureSession()));
         }
         break;
         default:
             return CHIP_ERROR_INVALID_ARGUMENT;
         };

         if (mCB != nullptr)
         {
             mCB->OnNewConnection({ state->GetPeerNodeId(), state->GetPeerKeyID(), admin }, this);
         }
     }

     return CHIP_NO_ERROR;
 }

 void SecureSessionMgr::ScheduleExpiryTimer()
 {
     CHIP_ERROR err =
         mSystemLayer->StartTimer(CHIP_PEER_CONNECTION_TIMEOUT_CHECK_FREQUENCY_MS, SecureSessionMgr::ExpiryTimerCallback, this);

     VerifyOrDie(err == CHIP_NO_ERROR);
 }

 void SecureSessionMgr::CancelExpiryTimer()
 {
     if (mSystemLayer != nullptr)
     {
         mSystemLayer->CancelTimer(SecureSessionMgr::ExpiryTimerCallback, this);
     }
 }

 void SecureSessionMgr::HandleGroupMessageReceived(const PacketHeader & packetHeader, System::PacketBufferHandle msgBuf)
 {
     PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(packetHeader.GetEncryptionKeyID(), nullptr);
     VerifyOrReturn(state != nullptr, ChipLogError(Inet, "Failed to find the peer connection state"));

     OnMessageReceived(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
 }

 void SecureSessionMgr::OnMessageReceived(const PacketHeader & packetHeader, const PeerAddress & peerAddress,
                                          System::PacketBufferHandle msg)
 {
     if (packetHeader.GetFlags().Has(Header::FlagValues::kSecure))
     {
         SecureMessageDispatch(packetHeader, peerAddress, std::move(msg));
     }
     else
     {
         MessageDispatch(packetHeader, peerAddress, std::move(msg));
     }
 }

 void SecureSessionMgr::MessageDispatch(const PacketHeader & packetHeader, const Transport::PeerAddress & peerAddress,
                                        System::PacketBufferHandle msg)
 {
     if (mCB != nullptr)
     {
         PayloadHeader payloadHeader;
         ReturnOnFailure(payloadHeader.DecodeAndConsume(msg));
         mCB->OnMessageReceived(packetHeader, payloadHeader, SecureSessionHandle(), peerAddress, std::move(msg), this);
     }
 }

 void SecureSessionMgr::SecureMessageDispatch(const PacketHeader & packetHeader, const Transport::PeerAddress & peerAddress,
                                              System::PacketBufferHandle msg)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;

     PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(packetHeader.GetEncryptionKeyID(), nullptr);

     PayloadHeader payloadHeader;

     Transport::AdminPairingInfo * admin = nullptr;

     VerifyOrExit(!msg.IsNull(), ChipLogError(Inet, "Secure transport received NULL packet, discarding"));

     if (state == nullptr)
     {
         ChipLogError(Inet, "Data received on an unknown connection (%d). Dropping it!!", packetHeader.GetEncryptionKeyID());
         ExitNow(err = CHIP_ERROR_KEY_NOT_FOUND_FROM_PEER);
     }

     admin = mAdmins->FindAdmin(state->GetAdminId());
     VerifyOrExit(admin != nullptr,
                  ChipLogError(Inet, "Secure transport received packet for unknown admin (%p, %d) pairing, discarding", state,
                               state->GetAdminId()));
     if (packetHeader.GetDestinationNodeId().HasValue() && admin->GetNodeId() != kUndefinedNodeId)
     {
         VerifyOrExit(
             admin->GetNodeId() == packetHeader.GetDestinationNodeId().Value(),
             ChipLogError(Inet, "Secure transport received message, but destination node ID doesn't match our node ID, discarding"));
     }
     mPeerConnections.MarkConnectionActive(state);

     if (!packetHeader.IsSecureSessionControlMsg() && !state->IsPeerMsgCounterSynced() &&
         ChipKeyId::IsAppGroupKey(packetHeader.GetEncryptionKeyID()))
     {
         // Queue the message as needed for sync with destination node.
         if (mCB != nullptr)
         {
             // We should encode the packetHeader into the buffer before storing the buffer into the queue.
             // The encoded packetHeader needs to be peeled off during re-processing after the peer message
             // counter is synced.
             ReturnOnFailure(packetHeader.EncodeBeforeData(msg));
             err = mCB->QueueReceivedMessageAndSync(state, std::move(msg));
             VerifyOrReturn(err == CHIP_NO_ERROR);
         }

         // After the message that triggers message counter synchronization is stored, and a message counter
         // synchronization exchange is initiated, we need to return immediately and re-process the original message
         // when the synchronization is completed.

         return;
     }

     // Decode the message
     VerifyOrExit(CHIP_NO_ERROR == SecureMessageCodec::Decode(state, payloadHeader, packetHeader, msg),
                  ChipLogError(Inet, "Secure transport received message, but failed to decode it, discarding"));

     if (packetHeader.GetSourceNodeId().HasValue())
     {
         if (state->GetPeerNodeId() == kUndefinedNodeId)
         {
             state->SetPeerNodeId(packetHeader.GetSourceNodeId().Value());
         }
     }

     if (packetHeader.GetDestinationNodeId().HasValue())
     {
         admin->SetNodeId(packetHeader.GetDestinationNodeId().Value());
     }

     // TODO: once mDNS address resolution is available reconsider if this is required
     // This updates the peer address once a packet is received from a new address
     // and serves as a way to auto-detect peer changing IPs.
     if (state->GetPeerAddress() != peerAddress)
     {
         state->SetPeerAddress(peerAddress);
     }

     if (!state->IsPeerMsgCounterSynced())
     {
         // For all control messages, the first authenticated message counter from an unsynchronized peer is trusted
         // and used to seed subsequent message counter based replay protection.
         if (packetHeader.IsSecureSessionControlMsg())
         {
             state->SetPeerMessageIndex(packetHeader.GetMessageId());
         }
     }

     if (mCB != nullptr)
     {
         SecureSessionHandle session(state->GetPeerNodeId(), state->GetPeerKeyID(), state->GetAdminId());
         mCB->OnMessageReceived(packetHeader, payloadHeader, session, peerAddress, std::move(msg), this);
     }

 exit:
     if (err != CHIP_NO_ERROR && mCB != nullptr)
     {
         mCB->OnReceiveError(err, peerAddress, this);
     }
 }

 void SecureSessionMgr::HandleConnectionExpired(const Transport::PeerConnectionState & state)
 {
     char addr[Transport::PeerAddress::kMaxToStringSize];
     state.GetPeerAddress().ToString(addr);

     ChipLogDetail(Inet, "Connection from '%s' expired", addr);

     if (mCB != nullptr)
     {
         mCB->OnConnectionExpired({ state.GetPeerNodeId(), state.GetPeerKeyID(), state.GetAdminId() }, this);
     }

     mTransportMgr->Disconnect(state.GetPeerAddress());
 }

 void SecureSessionMgr::ExpiryTimerCallback(System::Layer * layer, void * param, System::Error error)
 {
     SecureSessionMgr * mgr = reinterpret_cast<SecureSessionMgr *>(param);
 #if CHIP_CONFIG_SESSION_REKEYING
     // TODO(#2279): session expiration is currently disabled until rekeying is supported
     // the #ifdef should be removed after that.
     mgr->mPeerConnections.ExpireInactiveConnections(
         CHIP_PEER_CONNECTION_TIMEOUT_MS,
         [this](const Transport::PeerConnectionState & state1) { HandleConnectionExpired(state1); });
 #endif
     mgr->ScheduleExpiryTimer(); // re-schedule the oneshot timer
 }

 PeerConnectionState * SecureSessionMgr::GetPeerConnectionState(SecureSessionHandle session)
 {
     return mPeerConnections.FindPeerConnectionState(Optional<NodeId>::Value(session.mPeerNodeId), session.mPeerKeyId, nullptr);
 }

 } // namespace chip
	/*
	*
	* Copyright (c) 2020-2021 Project CHIP Authors
	* Copyright (c) 2013-2017 Nest Labs, Inc.
	* 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 implements the CHIP Connection object that maintains a UDP connection.
	* TODO This class should be extended to support TCP as well...
	*
	*/

	#include "SecureSessionMgr.h"

	#include <inttypes.h>
	#include <string.h>

	#include <core/CHIPKeyIds.h>
	#include <platform/CHIPDeviceLayer.h>
	#include <protocols/secure_channel/Constants.h>
	#include <support/CodeUtils.h>
	#include <support/SafeInt.h>
	#include <support/logging/CHIPLogging.h>
	#include <transport/AdminPairingTable.h>
	#include <transport/SecureMessageCodec.h>
	#include <transport/TransportMgr.h>

	#include <inttypes.h>

	namespace chip {

	using System::PacketBufferHandle;
	using Transport::PeerAddress;
	using Transport::PeerConnectionState;

	uint32_t EncryptedPacketBufferHandle::GetMsgId() const
	{
	PacketHeader header;
	uint16_t headerSize = 0;
	CHIP_ERROR err = header.Decode((this)->Start(), (this)->DataLength(), &headerSize);

	if (err == CHIP_NO_ERROR)
	{
	return header.GetMessageId();
	}

	ChipLogError(Inet, "Failed to decode EncryptedPacketBufferHandle header with error: %s", ErrorStr(err));

	return 0;
	}

	SecureSessionMgr::SecureSessionMgr() : mState(State::kNotReady) {}

	SecureSessionMgr::~SecureSessionMgr()
	{
	CancelExpiryTimer();
	}

	CHIP_ERROR SecureSessionMgr::Init(NodeId localNodeId, System::Layer * systemLayer, TransportMgrBase * transportMgr,
	Transport::AdminPairingTable * admins)
	{
	VerifyOrReturnError(mState == State::kNotReady, CHIP_ERROR_INCORRECT_STATE);
	VerifyOrReturnError(transportMgr != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

	mState = State::kInitialized;
	mLocalNodeId = localNodeId;
	mSystemLayer = systemLayer;
	mTransportMgr = transportMgr;
	mAdmins = admins;

	ChipLogProgress(Inet, "local node id is 0x%08" PRIx32 "%08" PRIx32, static_cast<uint32_t>(mLocalNodeId >> 32),
	static_cast<uint32_t>(mLocalNodeId));

	ScheduleExpiryTimer();

	mTransportMgr->SetSecureSessionMgr(this);

	return CHIP_NO_ERROR;
	}

	void SecureSessionMgr::Shutdown()
	{
	CancelExpiryTimer();

	mState = State::kNotReady;
	mLocalNodeId = kUndefinedNodeId;
	mSystemLayer = nullptr;
	mTransportMgr = nullptr;
	mAdmins = nullptr;
	mCB = nullptr;
	}

	Transport::Type SecureSessionMgr::GetTransportType(NodeId peerNodeId)
	{
	PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(peerNodeId, nullptr);

	if (state)
	{
	return state->GetPeerAddress().GetTransportType();
	}

	return Transport::Type::kUndefined;
	}

	CHIP_ERROR SecureSessionMgr::SendMessage(SecureSessionHandle session, PayloadHeader & payloadHeader,
	System::PacketBufferHandle && msgBuf, EncryptedPacketBufferHandle * bufferRetainSlot)
	{
	PacketHeader unusedPacketHeader;
	return SendMessage(session, payloadHeader, unusedPacketHeader, std::move(msgBuf), bufferRetainSlot,
	EncryptionState::kPayloadIsUnencrypted);
	}

	CHIP_ERROR SecureSessionMgr::SendEncryptedMessage(SecureSessionHandle session, EncryptedPacketBufferHandle msgBuf,
	EncryptedPacketBufferHandle * bufferRetainSlot)
	{
	VerifyOrReturnError(!msgBuf.IsNull(), CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(!msgBuf->HasChainedBuffer(), CHIP_ERROR_INVALID_MESSAGE_LENGTH);

	// Advancing the start to encrypted header, since the transport will attach the packet header on top of it
	PacketHeader packetHeader;
	ReturnErrorOnFailure(packetHeader.DecodeAndConsume(msgBuf));

	VerifyOrReturnError(msgBuf->TotalLength() <= kMaxAppMessageLen + packetHeader.EncodeSizeBytes(), CHIP_ERROR_MESSAGE_TOO_LONG);

	PayloadHeader payloadHeader;
	return SendMessage(session, payloadHeader, packetHeader, std::move(msgBuf), bufferRetainSlot,
	EncryptionState::kPayloadIsEncrypted);
	}

	CHIP_ERROR SecureSessionMgr::SendMessage(SecureSessionHandle session, PayloadHeader & payloadHeader, PacketHeader & packetHeader,
	System::PacketBufferHandle msgBuf, EncryptedPacketBufferHandle * bufferRetainSlot,
	EncryptionState encryptionState)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	PeerConnectionState * state = nullptr;
	uint8_t * msgStart = nullptr;
	uint16_t msgLen = 0;
	uint16_t headerSize = 0;
	NodeId localNodeId = mLocalNodeId;

	Transport::AdminPairingInfo * admin = nullptr;

	// Hold the reference to encrypted message in stack variable.
	// In case of any failures, the reference is not returned, and this stack variable
	// will automatically free the reference on returning from the function.
	EncryptedPacketBufferHandle encryptedMsg;

	VerifyOrExit(mState == State::kInitialized, err = CHIP_ERROR_INCORRECT_STATE);

	VerifyOrExit(!msgBuf.IsNull(), err = CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrExit(!msgBuf->HasChainedBuffer(), err = CHIP_ERROR_INVALID_MESSAGE_LENGTH);

	// Find an active connection to the specified peer node
	state = GetPeerConnectionState(session);
	VerifyOrExit(state != nullptr, err = CHIP_ERROR_NOT_CONNECTED);

	// This marks any connection where we send data to as 'active'
	mPeerConnections.MarkConnectionActive(state);
	admin = mAdmins->FindAdmin(state->GetAdminId());
	VerifyOrExit(admin != nullptr, err = CHIP_ERROR_INCORRECT_STATE);
	localNodeId = admin->GetNodeId();

	if (payloadHeader.HasMessageType(Protocols::SecureChannel::MsgType::MsgCounterSyncReq) \|\|
	payloadHeader.HasMessageType(Protocols::SecureChannel::MsgType::MsgCounterSyncRsp))
	{
	packetHeader.SetSecureSessionControlMsg(true);
	}

	if (encryptionState == EncryptionState::kPayloadIsUnencrypted)
	{
	err = SecureMessageCodec::Encode(localNodeId, state, payloadHeader, packetHeader, msgBuf);
	SuccessOrExit(err);
	}

	// The start of buffer points to the beginning of the encrypted header, and the length of buffer
	// contains both the encrypted header and encrypted data.
	// Locally store the start and length of the retained buffer after accounting for the size of packet header.
	headerSize = packetHeader.EncodeSizeBytes();

	msgStart = static_cast<uint8_t *>(msgBuf->Start() - headerSize);
	msgLen = static_cast<uint16_t>(msgBuf->DataLength() + headerSize);

	// Retain the packet buffer in case it's needed for retransmissions.
	if (bufferRetainSlot != nullptr)
	{
	encryptedMsg = msgBuf.Retain();
	}

	ChipLogProgress(Inet,
	"Sending msg from 0x%08" PRIx32 "%08" PRIx32 " to 0x%08" PRIx32 "%08" PRIx32 " at utc time: %" PRId64 " msec",
	static_cast<uint32_t>(localNodeId >> 32), static_cast<uint32_t>(localNodeId),
	static_cast<uint32_t>(state->GetPeerNodeId() >> 32), static_cast<uint32_t>(state->GetPeerNodeId()),
	System::Layer::GetClock_MonotonicMS());

	if (state->GetTransport() != nullptr)
	{
	ChipLogProgress(Inet, "Sending secure msg on connection specific transport");
	err = state->GetTransport()->SendMessage(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
	}
	else
	{
	ChipLogProgress(Inet, "Sending secure msg on generic transport");
	err = mTransportMgr->SendMessage(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
	}
	ChipLogProgress(Inet, "Secure msg send status %s", ErrorStr(err));
	SuccessOrExit(err);

	if (bufferRetainSlot != nullptr)
	{
	// Rewind the start and len of the buffer back to pre-send state for following possible retransmition.
	encryptedMsg->SetStart(msgStart);
	encryptedMsg->SetDataLength(msgLen);

	(*bufferRetainSlot) = std::move(encryptedMsg);
	}

	exit:
	if (!msgBuf.IsNull())
	{
	const char * errStr = ErrorStr(err);
	if (state == nullptr)
	{
	ChipLogError(Inet, "Secure transport could not find a valid PeerConnection: %s", errStr);
	}
	}

	return err;
	}

	CHIP_ERROR SecureSessionMgr::NewPairing(const Optional<Transport::PeerAddress> & peerAddr, NodeId peerNodeId,
	PairingSession * pairing, PairingDirection direction, Transport::AdminId admin,
	Transport::Base * transport)
	{
	uint16_t peerKeyId = pairing->GetPeerKeyId();
	uint16_t localKeyId = pairing->GetLocalKeyId();
	PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(Optional<NodeId>::Value(peerNodeId), peerKeyId, nullptr);

	// Find any existing connection with the same node and key ID
	if (state && (state->GetAdminId() == Transport::kUndefinedAdminId \|\| state->GetAdminId() == admin))
	{
	mPeerConnections.MarkConnectionExpired(
	state, [this](const Transport::PeerConnectionState & state1) { HandleConnectionExpired(state1); });
	}

	ChipLogDetail(Inet, "New pairing for device 0x%08" PRIx32 "%08" PRIx32 ", key %d!!", static_cast<uint32_t>(peerNodeId >> 32),
	static_cast<uint32_t>(peerNodeId), peerKeyId);
	state = nullptr;
	ReturnErrorOnFailure(
	mPeerConnections.CreateNewPeerConnectionState(Optional<NodeId>::Value(peerNodeId), peerKeyId, localKeyId, &state));

	state->SetAdminId(admin);
	state->SetTransport(transport);

	if (peerAddr.HasValue() && peerAddr.Value().GetIPAddress() != Inet::IPAddress::Any)
	{
	state->SetPeerAddress(peerAddr.Value());
	}
	else if (peerAddr.HasValue() && peerAddr.Value().GetTransportType() == Transport::Type::kBle)
	{
	state->SetPeerAddress(peerAddr.Value());
	}
	else if (peerAddr.HasValue() &&
	(peerAddr.Value().GetTransportType() == Transport::Type::kTcp \|\|
	peerAddr.Value().GetTransportType() == Transport::Type::kUdp))
	{
	return CHIP_ERROR_INVALID_ARGUMENT;
	}

	if (state != nullptr)
	{
	switch (direction)
	{
	case PairingDirection::kInitiator: {
	const char * i2rInfo = pairing->GetI2RSessionInfo();
	ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(i2rInfo), strlen(i2rInfo),
	state->GetSenderSecureSession()));

	const char * r2iInfo = pairing->GetR2ISessionInfo();
	ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(r2iInfo), strlen(r2iInfo),
	state->GetReceiverSecureSession()));
	}
	break;
	case PairingDirection::kResponder: {
	const char * i2rInfo = pairing->GetR2ISessionInfo();
	ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(i2rInfo), strlen(i2rInfo),
	state->GetSenderSecureSession()));

	const char * r2iInfo = pairing->GetI2RSessionInfo();
	ReturnErrorOnFailure(pairing->DeriveSecureSession(reinterpret_cast<const uint8_t *>(r2iInfo), strlen(r2iInfo),
	state->GetReceiverSecureSession()));
	}
	break;
	default:
	return CHIP_ERROR_INVALID_ARGUMENT;
	};

	if (mCB != nullptr)
	{
	mCB->OnNewConnection({ state->GetPeerNodeId(), state->GetPeerKeyID(), admin }, this);
	}
	}

	return CHIP_NO_ERROR;
	}

	void SecureSessionMgr::ScheduleExpiryTimer()
	{
	CHIP_ERROR err =
	mSystemLayer->StartTimer(CHIP_PEER_CONNECTION_TIMEOUT_CHECK_FREQUENCY_MS, SecureSessionMgr::ExpiryTimerCallback, this);

	VerifyOrDie(err == CHIP_NO_ERROR);
	}

	void SecureSessionMgr::CancelExpiryTimer()
	{
	if (mSystemLayer != nullptr)
	{
	mSystemLayer->CancelTimer(SecureSessionMgr::ExpiryTimerCallback, this);
	}
	}

	void SecureSessionMgr::HandleGroupMessageReceived(const PacketHeader & packetHeader, System::PacketBufferHandle msgBuf)
	{
	PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(packetHeader.GetEncryptionKeyID(), nullptr);
	VerifyOrReturn(state != nullptr, ChipLogError(Inet, "Failed to find the peer connection state"));

	OnMessageReceived(packetHeader, state->GetPeerAddress(), std::move(msgBuf));
	}

	void SecureSessionMgr::OnMessageReceived(const PacketHeader & packetHeader, const PeerAddress & peerAddress,
	System::PacketBufferHandle msg)
	{
	if (packetHeader.GetFlags().Has(Header::FlagValues::kSecure))
	{
	SecureMessageDispatch(packetHeader, peerAddress, std::move(msg));
	}
	else
	{
	MessageDispatch(packetHeader, peerAddress, std::move(msg));
	}
	}

	void SecureSessionMgr::MessageDispatch(const PacketHeader & packetHeader, const Transport::PeerAddress & peerAddress,
	System::PacketBufferHandle msg)
	{
	if (mCB != nullptr)
	{
	PayloadHeader payloadHeader;
	ReturnOnFailure(payloadHeader.DecodeAndConsume(msg));
	mCB->OnMessageReceived(packetHeader, payloadHeader, SecureSessionHandle(), peerAddress, std::move(msg), this);
	}
	}

	void SecureSessionMgr::SecureMessageDispatch(const PacketHeader & packetHeader, const Transport::PeerAddress & peerAddress,
	System::PacketBufferHandle msg)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;

	PeerConnectionState * state = mPeerConnections.FindPeerConnectionState(packetHeader.GetEncryptionKeyID(), nullptr);

	PayloadHeader payloadHeader;

	Transport::AdminPairingInfo * admin = nullptr;

	VerifyOrExit(!msg.IsNull(), ChipLogError(Inet, "Secure transport received NULL packet, discarding"));

	if (state == nullptr)
	{
	ChipLogError(Inet, "Data received on an unknown connection (%d). Dropping it!!", packetHeader.GetEncryptionKeyID());
	ExitNow(err = CHIP_ERROR_KEY_NOT_FOUND_FROM_PEER);
	}

	admin = mAdmins->FindAdmin(state->GetAdminId());
	VerifyOrExit(admin != nullptr,
	ChipLogError(Inet, "Secure transport received packet for unknown admin (%p, %d) pairing, discarding", state,
	state->GetAdminId()));
	if (packetHeader.GetDestinationNodeId().HasValue() && admin->GetNodeId() != kUndefinedNodeId)
	{
	VerifyOrExit(
	admin->GetNodeId() == packetHeader.GetDestinationNodeId().Value(),
	ChipLogError(Inet, "Secure transport received message, but destination node ID doesn't match our node ID, discarding"));
	}
	mPeerConnections.MarkConnectionActive(state);

	if (!packetHeader.IsSecureSessionControlMsg() && !state->IsPeerMsgCounterSynced() &&
	ChipKeyId::IsAppGroupKey(packetHeader.GetEncryptionKeyID()))
	{
	// Queue the message as needed for sync with destination node.
	if (mCB != nullptr)
	{
	// We should encode the packetHeader into the buffer before storing the buffer into the queue.
	// The encoded packetHeader needs to be peeled off during re-processing after the peer message
	// counter is synced.
	ReturnOnFailure(packetHeader.EncodeBeforeData(msg));
	err = mCB->QueueReceivedMessageAndSync(state, std::move(msg));
	VerifyOrReturn(err == CHIP_NO_ERROR);
	}

	// After the message that triggers message counter synchronization is stored, and a message counter
	// synchronization exchange is initiated, we need to return immediately and re-process the original message
	// when the synchronization is completed.

	return;
	}

	// Decode the message
	VerifyOrExit(CHIP_NO_ERROR == SecureMessageCodec::Decode(state, payloadHeader, packetHeader, msg),
	ChipLogError(Inet, "Secure transport received message, but failed to decode it, discarding"));

	if (packetHeader.GetSourceNodeId().HasValue())
	{
	if (state->GetPeerNodeId() == kUndefinedNodeId)
	{
	state->SetPeerNodeId(packetHeader.GetSourceNodeId().Value());
	}
	}

	if (packetHeader.GetDestinationNodeId().HasValue())
	{
	admin->SetNodeId(packetHeader.GetDestinationNodeId().Value());
	}

	// TODO: once mDNS address resolution is available reconsider if this is required
	// This updates the peer address once a packet is received from a new address
	// and serves as a way to auto-detect peer changing IPs.
	if (state->GetPeerAddress() != peerAddress)
	{
	state->SetPeerAddress(peerAddress);
	}

	if (!state->IsPeerMsgCounterSynced())
	{
	// For all control messages, the first authenticated message counter from an unsynchronized peer is trusted
	// and used to seed subsequent message counter based replay protection.
	if (packetHeader.IsSecureSessionControlMsg())
	{
	state->SetPeerMessageIndex(packetHeader.GetMessageId());
	}
	}

	if (mCB != nullptr)
	{
	SecureSessionHandle session(state->GetPeerNodeId(), state->GetPeerKeyID(), state->GetAdminId());
	mCB->OnMessageReceived(packetHeader, payloadHeader, session, peerAddress, std::move(msg), this);
	}

	exit:
	if (err != CHIP_NO_ERROR && mCB != nullptr)
	{
	mCB->OnReceiveError(err, peerAddress, this);
	}
	}

	void SecureSessionMgr::HandleConnectionExpired(const Transport::PeerConnectionState & state)
	{
	char addr[Transport::PeerAddress::kMaxToStringSize];
	state.GetPeerAddress().ToString(addr);

	ChipLogDetail(Inet, "Connection from '%s' expired", addr);

	if (mCB != nullptr)
	{
	mCB->OnConnectionExpired({ state.GetPeerNodeId(), state.GetPeerKeyID(), state.GetAdminId() }, this);
	}

	mTransportMgr->Disconnect(state.GetPeerAddress());
	}

	void SecureSessionMgr::ExpiryTimerCallback(System::Layer * layer, void * param, System::Error error)
	{
	SecureSessionMgr * mgr = reinterpret_cast<SecureSessionMgr *>(param);
	#if CHIP_CONFIG_SESSION_REKEYING
	// TODO(#2279): session expiration is currently disabled until rekeying is supported
	// the #ifdef should be removed after that.
	mgr->mPeerConnections.ExpireInactiveConnections(
	CHIP_PEER_CONNECTION_TIMEOUT_MS,
	[this](const Transport::PeerConnectionState & state1) { HandleConnectionExpired(state1); });
	#endif
	mgr->ScheduleExpiryTimer(); // re-schedule the oneshot timer
	}

	PeerConnectionState * SecureSessionMgr::GetPeerConnectionState(SecureSessionHandle session)
	{
	return mPeerConnections.FindPeerConnectionState(Optional<NodeId>::Value(session.mPeerNodeId), session.mPeerKeyId, nullptr);
	}

	} // namespace chip