Line data    Source code

       1             : /*
       2             :  *
       3             :  *    Copyright (c) 2021 Project CHIP Authors
       4             :  *
       5             :  *    Licensed under the Apache License, Version 2.0 (the "License");
       6             :  *    you may not use this file except in compliance with the License.
       7             :  *    You may obtain a copy of the License at
       8             :  *
       9             :  *        http://www.apache.org/licenses/LICENSE-2.0
      10             :  *
      11             :  *    Unless required by applicable law or agreed to in writing, software
      12             :  *    distributed under the License is distributed on an "AS IS" BASIS,
      13             :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14             :  *    See the License for the specific language governing permissions and
      15             :  *    limitations under the License.
      16             :  */
      17             : 
      18             : #pragma once
      19             : 
      20             : #include <credentials/CertificateValidityPolicy.h>
      21             : #include <credentials/GroupDataProvider.h>
      22             : #include <messaging/ExchangeDelegate.h>
      23             : #include <messaging/ExchangeMgr.h>
      24             : #include <protocols/secure_channel/CASESession.h>
      25             : #include <system/SystemClock.h>
      26             : 
      27             : namespace chip {
      28             : 
      29             : class CASEServer : public SessionEstablishmentDelegate,
      30             :                    public Messaging::UnsolicitedMessageHandler,
      31             :                    public Messaging::ExchangeDelegate
      32             : {
      33             : public:
      34           1 :     CASEServer() {}
      35           1 :     ~CASEServer() override { Shutdown(); }
      36             : 
      37             :     /*
      38             :      * This method will shutdown this object, releasing the strong reference to the pinned SecureSession object.
      39             :      * It will also unregister the unsolicited handler and clear out the session object (which will release the weak
      40             :      * reference through the underlying SessionHolder).
      41             :      *
      42             :      */
      43           2 :     void Shutdown()
      44             :     {
      45           2 :         if (mExchangeManager != nullptr)
      46             :         {
      47           1 :             mExchangeManager->UnregisterUnsolicitedMessageHandlerForType(Protocols::SecureChannel::MsgType::CASE_Sigma1);
      48           1 :             mExchangeManager = nullptr;
      49             :         }
      50             : 
      51           2 :         GetSession().Clear();
      52           2 :         mPinnedSecureSession.ClearValue();
      53           2 :     }
      54             : 
      55             :     CHIP_ERROR ListenForSessionEstablishment(Messaging::ExchangeManager * exchangeManager, SessionManager * sessionManager,
      56             :                                              FabricTable * fabrics, SessionResumptionStorage * sessionResumptionStorage,
      57             :                                              Credentials::CertificateValidityPolicy * policy,
      58             :                                              Credentials::GroupDataProvider * responderGroupDataProvider);
      59             : 
      60             :     //////////// SessionEstablishmentDelegate Implementation ///////////////
      61             :     void OnSessionEstablishmentError(CHIP_ERROR error) override;
      62             :     void OnSessionEstablished(const SessionHandle & session) override;
      63             : 
      64             :     //// UnsolicitedMessageHandler Implementation ////
      65             :     CHIP_ERROR OnUnsolicitedMessageReceived(const PayloadHeader & payloadHeader, ExchangeDelegate *& newDelegate) override;
      66             : 
      67             :     //// ExchangeDelegate Implementation ////
      68             :     CHIP_ERROR OnMessageReceived(Messaging::ExchangeContext * ec, const PayloadHeader & payloadHeader,
      69             :                                  System::PacketBufferHandle && payload) override;
      70           0 :     void OnResponseTimeout(Messaging::ExchangeContext * ec) override {}
      71           8 :     Messaging::ExchangeMessageDispatch & GetMessageDispatch() override { return GetSession().GetMessageDispatch(); }
      72             : 
      73           6 :     CASESession & GetSession() { return mPairingSession; }
      74             : 
      75             : private:
      76             :     Messaging::ExchangeManager * mExchangeManager                       = nullptr;
      77             :     SessionResumptionStorage * mSessionResumptionStorage                = nullptr;
      78             :     Credentials::CertificateValidityPolicy * mCertificateValidityPolicy = nullptr;
      79             : 
      80             :     //
      81             :     // When we're in the process of establishing a session, this is used
      82             :     // to maintain an additional, strong reference to the underlying SecureSession.
      83             :     // This is because the existing reference in PairingSession is a weak one
      84             :     // (i.e a SessionHolder) and can lose its reference if the session is evicted
      85             :     // for any reason.
      86             :     //
      87             :     // This initially points to a session that is not yet active. Upon activation, it
      88             :     // transfers ownership of the session to the SecureSessionManager and this reference
      89             :     // is released before simultaneously acquiring ownership of a new SecureSession.
      90             :     //
      91             :     Optional<SessionHandle> mPinnedSecureSession;
      92             : 
      93             :     CASESession mPairingSession;
      94             :     SessionManager * mSessionManager = nullptr;
      95             : 
      96             :     FabricTable * mFabrics                              = nullptr;
      97             :     Credentials::GroupDataProvider * mGroupDataProvider = nullptr;
      98             : 
      99             :     CHIP_ERROR InitCASEHandshake(Messaging::ExchangeContext * ec);
     100             : 
     101             :     /*
     102             :      * This will clean up any state from a previous session establishment
     103             :      * attempt (if any) and setup the machinery to listen for and handle
     104             :      * any session handshakes there-after.
     105             :      *
     106             :      * If a session had previously been established successfully, previouslyEstablishedPeer
     107             :      * should be set to the scoped node-id of the peer associated with that session.
     108             :      *
     109             :      */
     110             :     void PrepareForSessionEstablishment(const ScopedNodeId & previouslyEstablishedPeer = ScopedNodeId());
     111             : 
     112             :     // If we are in the middle of handshake and receive a Sigma1 then respond with Busy status code.
     113             :     // @param[in] ec              Exchange Context
     114             :     // @param[in] minimumWaitTime Minimum wait time reported to client before it can attempt to resend sigma1
     115             :     //
     116             :     // @return CHIP_NO_ERROR on success, error code otherwise
     117             :     CHIP_ERROR SendBusyStatusReport(Messaging::ExchangeContext * ec, System::Clock::Milliseconds16 minimumWaitTime);
     118             : };
     119             : 
     120             : } // namespace chip