static int ApplyMpqPatch(
TMPQFile * hf,
TPatchHeader * pPatchHeader)
{
unsigned char md5_digest[MD5_DIGEST_SIZE];
hash_state md5_state;
int nError = ERROR_SUCCESS;
// Verify the original file before patching
if(pPatchHeader->dwSizeBeforePatch != 0)
{
md5_init(&md5_state);
md5_process(&md5_state, hf->pbFileData, hf->cbFileData);
md5_done(&md5_state, md5_digest);
if(memcmp(pPatchHeader->md5_before_patch, md5_digest, MD5_DIGEST_SIZE))
nError = ERROR_FILE_CORRUPT;
}
// Apply the patch
if(nError == ERROR_SUCCESS)
{
switch(pPatchHeader->dwPatchType)
{
case 0x59504f43: // 'COPY'
nError = ApplyMpqPatch_COPY(hf, pPatchHeader);
break;
case 0x30445342: // 'BSD0'
nError = ApplyMpqPatch_BSD0(hf, pPatchHeader);
break;
default:
nError = ERROR_FILE_CORRUPT;
break;
}
}
// Verify MD5 after patch
if(nError == ERROR_SUCCESS && pPatchHeader->dwSizeAfterPatch != 0)
{
// Verify the patched file
md5_init(&md5_state);
md5_process(&md5_state, hf->pbFileData, hf->cbFileData);
md5_done(&md5_state, md5_digest);
if(memcmp(pPatchHeader->md5_after_patch, md5_digest, MD5_DIGEST_SIZE))
nError = ERROR_FILE_CORRUPT;
}
return nError;
}
static int ApplyMpqPatch(
TMPQFile * hf,
TPatchHeader * pPatchHeader)
{
int nError = ERROR_SUCCESS;
// Verify the original file before patching
if(pPatchHeader->dwSizeBeforePatch != 0)
{
if(!VerifyDataBlockHash(hf->pbFileData, hf->cbFileData, pPatchHeader->md5_before_patch))
nError = ERROR_FILE_CORRUPT;
}
// Apply the patch
if(nError == ERROR_SUCCESS)
{
switch(pPatchHeader->dwPatchType)
{
case 0x59504f43: // 'COPY'
nError = ApplyMpqPatch_COPY(hf, pPatchHeader);
break;
case 0x30445342: // 'BSD0'
nError = ApplyMpqPatch_BSD0(hf, pPatchHeader);
break;
default:
nError = ERROR_FILE_CORRUPT;
break;
}
}
// Verify MD5 after patch
if(nError == ERROR_SUCCESS && pPatchHeader->dwSizeAfterPatch != 0)
{
// Verify the patched file
if(!VerifyDataBlockHash(hf->pbFileData, hf->cbFileData, pPatchHeader->md5_after_patch))
nError = ERROR_FILE_CORRUPT;
}
return nError;
}
