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