src/liblzma/common/stream_flags_common.c

   1 // SPDX-License-Identifier: 0BSD
   2
   3 ///////////////////////////////////////////////////////////////////////////////
   4 //
   5 /// \file       stream_flags_common.c
   6 /// \brief      Common stuff for Stream flags coders
   7 //
   8 //  Author:     Lasse Collin
   9 //
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #include "stream_flags_common.h"
  13
  14
  15 const uint8_t lzma_header_magic[6] = { 0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00 };
  16 const uint8_t lzma_footer_magic[2] = { 0x59, 0x5A };
  17
  18
  19 extern LZMA_API(lzma_ret)
  20 lzma_stream_flags_compare(
  21                 const lzma_stream_flags *a, const lzma_stream_flags *b)
  22 {
  23         // We can compare only version 0 structures.
  24         if (a->version != 0 || b->version != 0)
  25                 return LZMA_OPTIONS_ERROR;
  26
  27         // Check type
  28         if ((unsigned int)(a->check) > LZMA_CHECK_ID_MAX
  29                         || (unsigned int)(b->check) > LZMA_CHECK_ID_MAX)
  30                 return LZMA_PROG_ERROR;
  31
  32         if (a->check != b->check)
  33                 return LZMA_DATA_ERROR;
  34
  35         // Backward Sizes are compared only if they are known in both.
  36         if (a->backward_size != LZMA_VLI_UNKNOWN
  37                         && b->backward_size != LZMA_VLI_UNKNOWN) {
  38                 if (!is_backward_size_valid(a) || !is_backward_size_valid(b))
  39                         return LZMA_PROG_ERROR;
  40
  41                 if (a->backward_size != b->backward_size)
  42                         return LZMA_DATA_ERROR;
  43         }
  44
  45         return LZMA_OK;
  46 }