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             : /**
      19             :  *    @file
      20             :  *      This file defines the CHIP CASE Session object that provides
      21             :  *      APIs for constructing a secure session using a certificate from the device's
      22             :  *      operational credentials.
      23             :  */
      24             : 
      25             : #pragma once
      26             : 
      27             : #include <lib/core/TLV.h>
      28             : #include <lib/support/DefaultStorageKeyAllocator.h>
      29             : #include <protocols/secure_channel/DefaultSessionResumptionStorage.h>
      30             : 
      31             : namespace chip {
      32             : 
      33             : /**
      34             :  * An example SessionResumptionStorage using PersistentStorageDelegate as it backend.
      35             :  */
      36             : class SimpleSessionResumptionStorage : public DefaultSessionResumptionStorage
      37             : {
      38             : public:
      39           0 :     CHIP_ERROR Init(PersistentStorageDelegate * storage)
      40             :     {
      41           0 :         VerifyOrReturnError(storage != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
      42           0 :         mStorage = storage;
      43           0 :         return CHIP_NO_ERROR;
      44             :     }
      45             : 
      46             :     CHIP_ERROR SaveIndex(const SessionIndex & index) override;
      47             :     CHIP_ERROR LoadIndex(SessionIndex & index) override;
      48             : 
      49             :     CHIP_ERROR SaveLink(ConstResumptionIdView resumptionId, const ScopedNodeId & node) override;
      50             :     CHIP_ERROR LoadLink(ConstResumptionIdView resumptionId, ScopedNodeId & node) override;
      51             :     CHIP_ERROR DeleteLink(ConstResumptionIdView resumptionId) override;
      52             : 
      53             :     CHIP_ERROR SaveState(const ScopedNodeId & node, ConstResumptionIdView resumptionId,
      54             :                          const Crypto::P256ECDHDerivedSecret & sharedSecret, const CATValues & peerCATs) override;
      55             :     CHIP_ERROR LoadState(const ScopedNodeId & node, ResumptionIdStorage & resumptionId,
      56             :                          Crypto::P256ECDHDerivedSecret & sharedSecret, CATValues & peerCATs) override;
      57             :     CHIP_ERROR DeleteState(const ScopedNodeId & node) override;
      58             : 
      59             :     static StorageKeyName GetStorageKey(const ScopedNodeId & node);
      60             :     static StorageKeyName GetStorageKey(ConstResumptionIdView resumptionId);
      61             : 
      62             : private:
      63             :     static constexpr size_t MaxScopedNodeIdSize() { return TLV::EstimateStructOverhead(sizeof(NodeId), sizeof(FabricIndex)); }
      64             : 
      65             :     static constexpr size_t MaxIndexSize()
      66             :     {
      67             :         // The max size of the list is (1 byte control + bytes for actual value) times max number of list items
      68             :         return TLV::EstimateStructOverhead((1 + MaxScopedNodeIdSize()) * CHIP_CONFIG_CASE_SESSION_RESUME_CACHE_SIZE);
      69             :     }
      70             : 
      71             :     static constexpr size_t MaxStateSize()
      72             :     {
      73             :         return TLV::EstimateStructOverhead(kResumptionIdSize, Crypto::P256ECDHDerivedSecret::Capacity(),
      74             :                                            CATValues::kSerializedLength);
      75             :     }
      76             : 
      77             :     static constexpr TLV::Tag kFabricIndexTag  = TLV::ContextTag(1);
      78             :     static constexpr TLV::Tag kPeerNodeIdTag   = TLV::ContextTag(2);
      79             :     static constexpr TLV::Tag kResumptionIdTag = TLV::ContextTag(3);
      80             :     static constexpr TLV::Tag kSharedSecretTag = TLV::ContextTag(4);
      81             :     static constexpr TLV::Tag kCATTag          = TLV::ContextTag(5);
      82             : 
      83             :     PersistentStorageDelegate * mStorage;
      84             : };
      85             : 
      86             : } // namespace chip