go-libwebp

Experimental translation from libwebp to Go source.
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huffman_fuzzer.cc (2696B)

      1 // Copyright 2023 Google Inc.
      2 //
      3 // Licensed under the Apache License, Version 2.0 (the "License");
      4 // you may not use this file except in compliance with the License.
      5 // You may obtain a copy of the License at
      6 //
      7 //      http://www.apache.org/licenses/LICENSE-2.0
      8 //
      9 // Unless required by applicable law or agreed to in writing, software
     10 // distributed under the License is distributed on an "AS IS" BASIS,
     11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 // See the License for the specific language governing permissions and
     13 // limitations under the License.
     14 //
     15 ////////////////////////////////////////////////////////////////////////////////
     16 
     17 #include <cstddef>
     18 #include <cstdint>
     19 #include <cstring>
     20 #include <string_view>
     21 
     22 #include "./fuzz_utils.h"
     23 #include "src/dec/vp8li_dec.h"
     24 #include "src/utils/bit_reader_utils.h"
     25 #include "src/utils/huffman_utils.h"
     26 #include "src/utils/utils.h"
     27 #include "src/webp/format_constants.h"
     28 
     29 namespace {
     30 
     31 void HuffmanTest(std::string_view blob) {
     32   const uint8_t* const data = reinterpret_cast<const uint8_t*>(blob.data());
     33   const size_t size = blob.size();
     34 
     35   // Number of bits to initialize data.
     36   static const int kColorCacheBitsBits = 4;
     37   // 'num_htree_groups' is contained in the RG channel, hence 16 bits.
     38   static const int kNumHtreeGroupsBits = 16;
     39   if (size * sizeof(*data) < kColorCacheBitsBits + kNumHtreeGroupsBits) {
     40     return;
     41   }
     42 
     43   // A non-NULL mapping brings minor changes that are tested by the normal
     44   // fuzzer.
     45   int* const mapping = NULL;
     46   HuffmanTables huffman_tables;
     47   memset(&huffman_tables, 0, sizeof(huffman_tables));
     48   HTreeGroup* htree_groups = NULL;
     49 
     50   int num_htree_groups, num_htree_groups_max, color_cache_bits;
     51   VP8LBitReader* br;
     52   VP8LDecoder* dec = VP8LNew();
     53   if (dec == NULL) goto Error;
     54   br = &dec->br;
     55   VP8LInitBitReader(br, data, size);
     56 
     57   color_cache_bits = VP8LReadBits(br, kColorCacheBitsBits);
     58   if (color_cache_bits < 1 || color_cache_bits > MAX_CACHE_BITS) goto Error;
     59 
     60   num_htree_groups = VP8LReadBits(br, kNumHtreeGroupsBits);
     61   // 'num_htree_groups' cannot be 0 as it is built from a non-empty image.
     62   if (num_htree_groups == 0) goto Error;
     63   // This variable is only useful when mapping is not NULL.
     64   num_htree_groups_max = num_htree_groups;
     65   (void)ReadHuffmanCodesHelper(color_cache_bits, num_htree_groups,
     66                                num_htree_groups_max, mapping, dec,
     67                                &huffman_tables, &htree_groups);
     68 
     69 Error:
     70   WebPSafeFree(mapping);
     71   VP8LHtreeGroupsFree(htree_groups);
     72   VP8LHuffmanTablesDeallocate(&huffman_tables);
     73   VP8LDelete(dec);
     74 }
     75 
     76 }  // namespace
     77 
     78 FUZZ_TEST(Huffman, HuffmanTest).WithDomains(fuzztest::String());