Line data    Source code

       1              : /*
       2              :  *
       3              :  *    Copyright (c) 2022 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              : #include <stdint.h>
      19              : 
      20              : #include <credentials/FabricTable.h>
      21              : #include <credentials/GroupDataProvider.h>
      22              : #include <lib/core/CHIPError.h>
      23              : #include <lib/support/BufferWriter.h>
      24              : #include <lib/support/Span.h>
      25              : 
      26              : #include "CASEDestinationId.h"
      27              : 
      28              : namespace chip {
      29              : 
      30              : using namespace chip::Crypto;
      31              : 
      32           23 : CHIP_ERROR GenerateCaseDestinationId(const ByteSpan & ipk, const ByteSpan & initiatorRandom, const ByteSpan & rootPubKey,
      33              :                                      FabricId fabricId, NodeId nodeId, MutableByteSpan & outDestinationId)
      34              : {
      35           23 :     VerifyOrReturnError(ipk.size() == kIPKSize, CHIP_ERROR_INVALID_ARGUMENT);
      36           23 :     VerifyOrReturnError(initiatorRandom.size() == kSigmaParamRandomNumberSize, CHIP_ERROR_INVALID_ARGUMENT);
      37           23 :     VerifyOrReturnError(rootPubKey.size() == kP256_PublicKey_Length, CHIP_ERROR_INVALID_ARGUMENT);
      38           23 :     VerifyOrReturnError(outDestinationId.size() >= kSHA256_Hash_Length, CHIP_ERROR_INVALID_ARGUMENT);
      39              : 
      40           23 :     constexpr size_t kDestinationMessageLen =
      41              :         kSigmaParamRandomNumberSize + kP256_PublicKey_Length + sizeof(FabricId) + sizeof(NodeId);
      42              :     uint8_t destinationMessage[kDestinationMessageLen];
      43              : 
      44           23 :     Encoding::LittleEndian::BufferWriter bbuf(destinationMessage, sizeof(destinationMessage));
      45           23 :     bbuf.Put(initiatorRandom.data(), initiatorRandom.size());
      46           23 :     bbuf.Put(rootPubKey.data(), rootPubKey.size());
      47           23 :     bbuf.Put64(fabricId);
      48           23 :     bbuf.Put64(nodeId);
      49              : 
      50           23 :     size_t written = 0;
      51           23 :     VerifyOrReturnError(bbuf.Fit(written), CHIP_ERROR_BUFFER_TOO_SMALL);
      52              : 
      53           23 :     HMAC_sha hmac;
      54              :     CHIP_ERROR err =
      55           23 :         hmac.HMAC_SHA256(ipk.data(), ipk.size(), bbuf.Buffer(), written, outDestinationId.data(), outDestinationId.size());
      56              : 
      57           23 :     if (err == CHIP_NO_ERROR)
      58              :     {
      59           23 :         outDestinationId.reduce_size(kSHA256_Hash_Length);
      60              :     }
      61              : 
      62           23 :     return err;
      63           23 : }
      64              : 
      65              : } // namespace chip