Line data    Source code

       1              : /**
       2              :  *
       3              :  *    Copyright (c) 2021 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              : /**
      19              :  *    @file
      20              :  *      This file provides a utility to generate Additional Data payload and its members
      21              :  *      (e.g. rotating device id)
      22              :  *
      23              :  */
      24              : 
      25              : #pragma once
      26              : 
      27              : #if CHIP_HAVE_CONFIG_H
      28              : #include <setup_payload/CHIPAdditionalDataPayloadBuildConfig.h>
      29              : #endif
      30              : 
      31              : #include <lib/core/CHIPError.h>
      32              : #include <lib/support/BitFlags.h>
      33              : #include <system/TLVPacketBufferBackingStore.h>
      34              : 
      35              : namespace chip {
      36              : namespace RotatingDeviceId {
      37              : static constexpr unsigned kLifetimeCounterSize = 2;
      38              : static constexpr unsigned kHashSuffixLength    = 16;
      39              : static constexpr unsigned kMaxLength           = kLifetimeCounterSize + kHashSuffixLength;
      40              : static constexpr unsigned kHexMaxLength        = kMaxLength * 2 + 1;
      41              : } // namespace RotatingDeviceId
      42              : 
      43              : enum class AdditionalDataFields : int8_t
      44              : {
      45              :     NotSpecified     = 0x00,
      46              :     RotatingDeviceId = 0x01
      47              : };
      48              : 
      49              : struct AdditionalDataPayloadGeneratorParams
      50              : {
      51              : #if CHIP_ENABLE_ROTATING_DEVICE_ID
      52              :     uint16_t rotatingDeviceIdLifetimeCounter;
      53              :     ByteSpan rotatingDeviceIdUniqueId;
      54              : #endif
      55              : };
      56              : 
      57              : class AdditionalDataPayloadGenerator
      58              : {
      59              : 
      60              : public:
      61            1 :     AdditionalDataPayloadGenerator() {}
      62              : 
      63              :     /**
      64              :      * Generate additional data payload (i.e. TLV encoded).
      65              :      *
      66              :      * @param params parameters needed to generate additional data payload
      67              :      * @param bufferHandle output buffer handle
      68              :      * @param additionalDataFields bitfield for what fields should be generated in the additional data
      69              :      *
      70              :      * @retval #CHIP_ERROR_INVALID_TLV_TAG
      71              :      *                              If the specified tag value is invalid or inappropriate in the context
      72              :      *                              in which the value is being written.
      73              :      * @retval #CHIP_ERROR_BUFFER_TOO_SMALL
      74              :      *                              If writing the value would exceed the limit on the maximum number of
      75              :      *                              bytes specified when the writer was initialized.
      76              :      * @retval #CHIP_ERROR_NO_MEMORY
      77              :      *                              If an attempt to allocate an output buffer failed due to lack of
      78              :      *                              memory.
      79              :      * @retval other                Other CHIP or platform-specific errors returned by the configured
      80              :      *                              TLVBackingStore
      81              :      *
      82              :      */
      83              :     CHIP_ERROR generateAdditionalDataPayload(AdditionalDataPayloadGeneratorParams & params,
      84              :                                              chip::System::PacketBufferHandle & bufferHandle,
      85              :                                              BitFlags<AdditionalDataFields> additionalDataFields);
      86              : 
      87              : #if CHIP_ENABLE_ROTATING_DEVICE_ID
      88              :     /**
      89              :      * Generate Rotating Device ID in Binary Format
      90              :      *
      91              :      * @param params parameters needed to generate additional data payload
      92              :      * @param [in,out] rotatingDeviceIdBuffer as input, the buffer to use for
      93              :      *                 the binary data.  As output, will have its size set to
      94              :      *                 the actual size used upon successful generation
      95              :      */
      96              :     CHIP_ERROR generateRotatingDeviceIdAsBinary(AdditionalDataPayloadGeneratorParams & params,
      97              :                                                 MutableByteSpan & rotatingDeviceIdBuffer);
      98              : 
      99              :     /**
     100              :      * Generate Device Rotating ID in String Format
     101              :      *
     102              :      * @param params parameters needed to generate additional data payload
     103              :      * @param rotatingDeviceIdBuffer rotating device id buffer
     104              :      * @param rotatingDeviceIdBufferSize the current size of the supplied buffer
     105              :      * @param rotatingDeviceIdValueOutputSize the number of chars making up the actual value of the returned rotating device id
     106              :      * excluding the null terminator
     107              :      *
     108              :      * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise.
     109              :      *
     110              :      */
     111              :     CHIP_ERROR generateRotatingDeviceIdAsHexString(AdditionalDataPayloadGeneratorParams & params, char * rotatingDeviceIdBuffer,
     112              :                                                    size_t rotatingDeviceIdBufferSize, size_t & rotatingDeviceIdValueOutputSize);
     113              : #endif
     114              : };
     115              : 
     116              : } // namespace chip