Line data    Source code

       1              : /*
       2              :  *    Copyright (c) 2022 Project CHIP Authors
       3              :  *    All rights reserved.
       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 <crypto/CHIPCryptoPAL.h>
      21              : #include <lib/core/CASEAuthTag.h>
      22              : #include <lib/core/ScopedNodeId.h>
      23              : 
      24              : namespace chip {
      25              : 
      26              : /**
      27              :  * @brief Interface to store and recover assets for session resumption. The
      28              :  *   resumption data are indexed by 2 parameters: ScopedNodeId and
      29              :  *   ResumptionId. The index on ScopedNodeId is used when initiating a CASE
      30              :  *   session.  It allows the caller to query storage to check whether there is a
      31              :  *   previous session with the given peer for which session resumption may be
      32              :  *   attempted.  The index on ResumptionId is used when receiving a Sigma1 with
      33              :  *   ResumptionId.
      34              :  *
      35              :  */
      36              : class SessionResumptionStorage
      37              : {
      38              : public:
      39              :     static constexpr size_t kResumptionIdSize = 16;
      40              :     using ResumptionIdStorage                 = std::array<uint8_t, kResumptionIdSize>;
      41              :     using ConstResumptionIdView               = FixedSpan<const uint8_t, kResumptionIdSize>;
      42              : 
      43            1 :     virtual ~SessionResumptionStorage(){};
      44              : 
      45              :     /**
      46              :      * Recover session resumption ID, shared secret and CAT values for a given
      47              :      * fabric-scoped node identity.
      48              :      *
      49              :      * @param node the node for which to recover session resumption information
      50              :      * @param resumptionId (out) recovered session resumption ID
      51              :      * @param sharedSecret (out) recovered session shared secret
      52              :      * @param peerCATs (out) recovered CATs for the session peer
      53              :      * @return CHIP_NO_ERROR on success, CHIP_ERROR_KEY_NOT_FOUND if no session resumption information can be found, else an
      54              :      * appropriate CHIP error on failure
      55              :      */
      56              :     virtual CHIP_ERROR FindByScopedNodeId(const ScopedNodeId & node, ResumptionIdStorage & resumptionId,
      57              :                                           Crypto::P256ECDHDerivedSecret & sharedSecret, CATValues & peerCATs) = 0;
      58              :     /**
      59              :      * Recover session shared secret, fabric-scoped node identity and CAT values
      60              :      * for a given session resumption ID.
      61              :      *
      62              :      * @param resumptionId the session resumption ID for which to recover session resumption information
      63              :      * @param node (out) the peer node associated with the session resumption ID
      64              :      * @param sharedSecret (out) recovered session shared secret
      65              :      * @param peerCATs (out) recovered CATs for the session peer
      66              :      * @return CHIP_NO_ERROR on success, CHIP_ERROR_KEY_NOT_FOUND if no session resumption information can be found, else an
      67              :      * appropriate CHIP error on failure
      68              :      */
      69              :     virtual CHIP_ERROR FindByResumptionId(ConstResumptionIdView resumptionId, ScopedNodeId & node,
      70              :                                           Crypto::P256ECDHDerivedSecret & sharedSecret, CATValues & peerCATs) = 0;
      71              :     /**
      72              :      * Save session resumption information to storage.
      73              :      *
      74              :      * @param resumptionId the session resumption ID for the current session
      75              :      * @param node the peer node for the session
      76              :      * @param sharedSecret the session shared secret
      77              :      * @param peerCATs the CATs of the session peer
      78              :      * @return CHIP_NO_ERROR on success, else an appropriate CHIP error on failure
      79              :      */
      80              :     virtual CHIP_ERROR Save(const ScopedNodeId & node, ConstResumptionIdView resumptionId,
      81              :                             const Crypto::P256ECDHDerivedSecret & sharedSecret, const CATValues & peerCATs) = 0;
      82              : 
      83              :     /**
      84              :      * Remove all session resumption information associated with the specified
      85              :      * fabric index.  If no entries for the fabric index exist, this is a no-op
      86              :      * and is considered successful.
      87              :      *
      88              :      * @param fabricIndex the index of the fabric for which to remove session resumption information
      89              :      * @return CHIP_NO_ERROR on success, else an appropriate CHIP error on failure
      90              :      */
      91              :     virtual CHIP_ERROR DeleteAll(FabricIndex fabricIndex) = 0;
      92              : };
      93              : 
      94              : } // namespace chip