static int ApplyFilePatch(
TMPQFile * hfBase, // The file in the base MPQ
TMPQFile * hfPrev, // The file in the previous MPQ
TMPQFile * hf)
{
TPatchHeader * pPatchHeader = hf->pPatchHeader;
TMPQFile * hfFrom = NULL;
int nError = ERROR_SUCCESS;
// Sanity checks
assert(hf->pbFileData == NULL);
// Either take the base version or the previous version
if(!memcmp(hfBase->FileDataMD5, pPatchHeader->md5_before_patch, MD5_DIGEST_SIZE))
hfFrom = hfBase;
if(!memcmp(hfPrev->FileDataMD5, pPatchHeader->md5_before_patch, MD5_DIGEST_SIZE))
hfFrom = hfPrev;
if(hfFrom == NULL)
return ERROR_FILE_CORRUPT;
// Allocate the buffer for patched file content
hf->pbFileData = STORM_ALLOC(BYTE, pPatchHeader->dwSizeAfterPatch);
hf->cbFileData = pPatchHeader->dwSizeAfterPatch;
if(hf->pbFileData == NULL)
return ERROR_NOT_ENOUGH_MEMORY;
// Apply the patch
if(nError == ERROR_SUCCESS)
{
switch(pPatchHeader->dwPatchType)
{
case 0x59504f43: // 'COPY'
nError = ApplyFilePatch_COPY(hfFrom, hf, pPatchHeader);
break;
case 0x30445342: // 'BSD0'
nError = ApplyFilePatch_BSD0(hfFrom, 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;
// Copy the MD5 of the new block
memcpy(hf->FileDataMD5, pPatchHeader->md5_after_patch, MD5_DIGEST_SIZE);
}
return nError;
}
static int ApplyFilePatch(
TMPQPatcher * pPatcher,
PMPQ_PATCH_HEADER pFullPatch)
{
LPBYTE pbSource = (pPatcher->nCounter & 0x1) ? pPatcher->pbFileData2 : pPatcher->pbFileData1;
LPBYTE pbTarget = (pPatcher->nCounter & 0x1) ? pPatcher->pbFileData1 : pPatcher->pbFileData2;
int nError;
// Sanity checks
assert(pFullPatch->dwSizeAfterPatch <= pPatcher->cbMaxFileData);
// Apply the patch according to the type
switch(pFullPatch->dwPatchType)
{
case 0x59504f43: // 'COPY'
nError = ApplyFilePatch_COPY(pPatcher, pFullPatch, pbTarget, pbSource);
break;
case 0x30445342: // 'BSD0'
nError = ApplyFilePatch_BSD0(pPatcher, pFullPatch, pbTarget, pbSource);
break;
default:
nError = ERROR_FILE_CORRUPT;
break;
}
// Verify MD5 after patch
if(nError == ERROR_SUCCESS && pFullPatch->dwSizeAfterPatch != 0)
{
// Verify the patched file
if(!VerifyDataBlockHash(pbTarget, pFullPatch->dwSizeAfterPatch, pFullPatch->md5_after_patch))
nError = ERROR_FILE_CORRUPT;
// Copy the MD5 of the new block
memcpy(pPatcher->this_md5, pFullPatch->md5_after_patch, MD5_DIGEST_SIZE);
}
return nError;
}
