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/OperationalKeystore.h>
      21              : #include <lib/core/CHIPError.h>
      22              : #include <lib/core/CHIPPersistentStorageDelegate.h>
      23              : #include <lib/core/DataModelTypes.h>
      24              : #include <lib/support/CHIPMem.h>
      25              : #include <lib/support/CodeUtils.h>
      26              : 
      27              : namespace chip {
      28              : 
      29              : /**
      30              :  * @brief OperationalKeystore implementation making use of PersistentStorageDelegate
      31              :  *        to load/store keypairs. This is the legacy behavior of `FabricTable` prior
      32              :  *        to refactors to use `OperationalKeystore` and exists as a baseline example
      33              :  *        of how to use the interface.
      34              :  *
      35              :  * WARNING: Ensure that any implementation that uses this one as a starting point
      36              :  *          DOES NOT have the raw key material (in usable form) passed up/down to
      37              :  *          direct storage APIs that may make copies on heap/stack without sanitization.
      38              :  */
      39              : class PersistentStorageOperationalKeystore : public Crypto::OperationalKeystore
      40              : {
      41              : public:
      42              :     PersistentStorageOperationalKeystore() = default;
      43            1 :     virtual ~PersistentStorageOperationalKeystore() { Finish(); }
      44              : 
      45              :     // Non-copyable
      46              :     PersistentStorageOperationalKeystore(PersistentStorageOperationalKeystore const &) = delete;
      47              :     void operator=(PersistentStorageOperationalKeystore const &)                       = delete;
      48              : 
      49              :     /**
      50              :      * @brief Initialize the Operational Keystore to map to a given storage delegate.
      51              :      *
      52              :      * @param storage Pointer to persistent storage delegate to use. Must outlive this instance.
      53              :      * @retval CHIP_NO_ERROR on success
      54              :      * @retval CHIP_ERROR_INCORRECT_STATE if already initialized
      55              :      */
      56              :     CHIP_ERROR Init(PersistentStorageDelegate * storage)
      57              :     {
      58              :         VerifyOrReturnError(mStorage == nullptr, CHIP_ERROR_INCORRECT_STATE);
      59              :         mPendingFabricIndex       = kUndefinedFabricIndex;
      60              :         mIsExternallyOwnedKeypair = false;
      61              :         mStorage                  = storage;
      62              :         mPendingKeypair           = nullptr;
      63              :         mIsPendingKeypairActive   = false;
      64              :         return CHIP_NO_ERROR;
      65              :     }
      66              : 
      67              :     /**
      68              :      * @brief Finalize the keystore, so that subsequent operations fail
      69              :      */
      70            1 :     void Finish()
      71              :     {
      72            1 :         VerifyOrReturn(mStorage != nullptr);
      73              : 
      74            1 :         ResetPendingKey();
      75            1 :         mStorage = nullptr;
      76              :     }
      77              : 
      78           58 :     bool HasPendingOpKeypair() const override { return (mPendingKeypair != nullptr); }
      79              : 
      80              :     bool HasOpKeypairForFabric(FabricIndex fabricIndex) const override;
      81              :     CHIP_ERROR NewOpKeypairForFabric(FabricIndex fabricIndex, MutableByteSpan & outCertificateSigningRequest) override;
      82              :     CHIP_ERROR ActivateOpKeypairForFabric(FabricIndex fabricIndex, const Crypto::P256PublicKey & nocPublicKey) override;
      83              :     CHIP_ERROR CommitOpKeypairForFabric(FabricIndex fabricIndex) override;
      84              :     CHIP_ERROR ExportOpKeypairForFabric(FabricIndex fabricIndex, Crypto::P256SerializedKeypair & outKeypair) override;
      85              :     CHIP_ERROR RemoveOpKeypairForFabric(FabricIndex fabricIndex) override;
      86              :     void RevertPendingKeypair() override;
      87              :     CHIP_ERROR SignWithOpKeypair(FabricIndex fabricIndex, const ByteSpan & message,
      88              :                                  Crypto::P256ECDSASignature & outSignature) const override;
      89              :     Crypto::P256Keypair * AllocateEphemeralKeypairForCASE() override;
      90              :     void ReleaseEphemeralKeypair(Crypto::P256Keypair * keypair) override;
      91              :     CHIP_ERROR MigrateOpKeypairForFabric(FabricIndex fabricIndex, OperationalKeystore & operationalKeystore) const override;
      92              : 
      93              : protected:
      94            1 :     void ResetPendingKey()
      95              :     {
      96            1 :         if (!mIsExternallyOwnedKeypair && (mPendingKeypair != nullptr))
      97              :         {
      98            0 :             Platform::Delete(mPendingKeypair);
      99              :         }
     100            1 :         mPendingKeypair           = nullptr;
     101            1 :         mIsExternallyOwnedKeypair = false;
     102            1 :         mIsPendingKeypairActive   = false;
     103            1 :         mPendingFabricIndex       = kUndefinedFabricIndex;
     104            1 :     }
     105              : 
     106              :     PersistentStorageDelegate * mStorage = nullptr;
     107              : 
     108              :     // This pending fabric index is `kUndefinedFabricIndex` if there isn't a pending keypair override for a given fabric.
     109              :     FabricIndex mPendingFabricIndex       = kUndefinedFabricIndex;
     110              :     Crypto::P256Keypair * mPendingKeypair = nullptr;
     111              :     bool mIsPendingKeypairActive          = false;
     112              : 
     113              :     // If overridding NewOpKeypairForFabric method in a subclass, set this to true in
     114              :     // `NewOpKeypairForFabric` if the mPendingKeypair should not be deleted when no longer in use.
     115              :     bool mIsExternallyOwnedKeypair = false;
     116              : };
     117              : 
     118              : } // namespace chip