third_party/hunspell/google/bdict.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "third_party/hunspell/google/bdict.h"
   6
   7 // static
   8 bool hunspell::BDict::Verify(const char* bdict_data, size_t bdict_length) {
   9   if (bdict_length <= sizeof(hunspell::BDict::Header))
  10     return false;
  11
  12   const BDict::Header* header =
  13       reinterpret_cast<const hunspell::BDict::Header*>(bdict_data);
  14   if (header->signature != hunspell::BDict::SIGNATURE ||
  15       header->major_version > hunspell::BDict::MAJOR_VERSION ||
  16       header->dic_offset > bdict_length)
  17     return false;
  18
  19   // Get the affix header, make sure there is enough room for it.
  20   if (header->aff_offset + sizeof(hunspell::BDict::AffHeader) > bdict_length)
  21     return false;
  22
  23   // Make sure there is enough room for the affix group count dword.
  24   const hunspell::BDict::AffHeader* aff_header =
  25       reinterpret_cast<const hunspell::BDict::AffHeader*>(
  26           &bdict_data[header->aff_offset]);
  27   if (aff_header->affix_group_offset + sizeof(uint32) > bdict_length)
  28     return false;
  29
  30   // The new BDICT header has a MD5 digest of the dictionary data. Compare the
  31   // MD5 digest of the data with the one in the BDICT header.
  32   if (header->major_version >= 2) {
  33     base::MD5Digest digest;
  34     base::MD5Sum(aff_header, bdict_length - header->aff_offset, &digest);
  35     if (memcmp(&digest, &header->digest, sizeof(digest)))
  36       return false;
  37   }
  38
  39   return true;
  40 }