static int RecryptFileData(
TMPQArchive * ha,
DWORD dwSaveBlockIndex,
const char * szFileName,
const char * szNewFileName)
{
LARGE_INTEGER BlockFilePos;
LARGE_INTEGER MpqFilePos;
TMPQBlockEx * pBlockEx = ha->pExtBlockTable + dwSaveBlockIndex;
TMPQBlock * pBlock = ha->pBlockTable + dwSaveBlockIndex;
const char * szPlainName;
LPDWORD pdwBlockPos1 = NULL;
LPDWORD pdwBlockPos2 = NULL;
LPBYTE pbFileBlock = NULL;
DWORD dwTransferred;
DWORD dwOldSeed;
DWORD dwNewSeed;
DWORD dwToRead;
int nBlocks;
int nError = ERROR_SUCCESS;
// The file must be encrypted
assert(pBlock->dwFlags & MPQ_FILE_ENCRYPTED);
// File decryption seed is calculated from the plain name
szPlainName = strrchr(szFileName, '\\');
if(szPlainName != NULL)
szFileName = szPlainName + 1;
szPlainName = strrchr(szNewFileName, '\\');
if(szPlainName != NULL)
szNewFileName = szPlainName + 1;
// Calculate both file seeds
dwOldSeed = DecryptFileSeed(szFileName);
dwNewSeed = DecryptFileSeed(szNewFileName);
if(pBlock->dwFlags & MPQ_FILE_FIXSEED)
{
dwOldSeed = (dwOldSeed + pBlock->dwFilePos) ^ pBlock->dwFSize;
dwNewSeed = (dwNewSeed + pBlock->dwFilePos) ^ pBlock->dwFSize;
}
// Incase the seeds are equal, don't recrypt the file
if(dwNewSeed == dwOldSeed)
return ERROR_SUCCESS;
// Calculate the file position of the archived file
MpqFilePos.LowPart = pBlock->dwFilePos;
MpqFilePos.HighPart = pBlockEx->wFilePosHigh;
MpqFilePos.QuadPart += ha->MpqPos.QuadPart;
// Calculate the number of file blocks
nBlocks = pBlock->dwFSize / ha->dwBlockSize;
if(pBlock->dwFSize % ha->dwBlockSize)
nBlocks++;
// If the file is stored as single unit, we recrypt one block only
if(pBlock->dwFlags & MPQ_FILE_SINGLE_UNIT)
{
// Allocate the block
pbFileBlock = ALLOCMEM(BYTE, pBlock->dwCSize);
if(pbFileBlock == NULL)
return ERROR_NOT_ENOUGH_MEMORY;
SetFilePointer(ha->hFile, MpqFilePos.LowPart, &MpqFilePos.HighPart, FILE_BEGIN);
ReadFile(ha->hFile, pbFileBlock, pBlock->dwCSize, &dwTransferred, NULL);
if(dwTransferred == pBlock->dwCSize)
nError = ERROR_FILE_CORRUPT;
if(nError == ERROR_SUCCESS)
{
// Recrypt the block
DecryptMPQBlock((DWORD *)pbFileBlock, pBlock->dwCSize, dwOldSeed);
EncryptMPQBlock((DWORD *)pbFileBlock, pBlock->dwCSize, dwNewSeed);
// Write it back
SetFilePointer(ha->hFile, MpqFilePos.LowPart, &MpqFilePos.HighPart, FILE_BEGIN);
WriteFile(ha->hFile, pbFileBlock, pBlock->dwCSize, &dwTransferred, NULL);
if(dwTransferred != pBlock->dwCSize)
nError = ERROR_WRITE_FAULT;
}
FREEMEM(pbFileBlock);
return nError;
}
// If the file is compressed, we have to re-crypt block table first,
// then all file blocks
if(pBlock->dwFlags & MPQ_FILE_COMPRESSED)
{
// Allocate buffer for both blocks
pdwBlockPos1 = ALLOCMEM(DWORD, nBlocks + 2);
pdwBlockPos2 = ALLOCMEM(DWORD, nBlocks + 2);
if(pdwBlockPos1 == NULL || pdwBlockPos2 == NULL)
return ERROR_NOT_ENOUGH_MEMORY;
// Calculate number of bytes to be read
dwToRead = (nBlocks + 1) * sizeof(DWORD);
if(pBlock->dwFlags & MPQ_FILE_HAS_EXTRA)
dwToRead += sizeof(DWORD);
// Read the block positions
SetFilePointer(ha->hFile, MpqFilePos.LowPart, &MpqFilePos.HighPart, FILE_BEGIN);
ReadFile(ha->hFile, pdwBlockPos1, dwToRead, &dwTransferred, NULL);
if(dwTransferred != dwToRead)
nError = ERROR_FILE_CORRUPT;
// Recrypt the block table
if(nError == ERROR_SUCCESS)
{
BSWAP_ARRAY32_UNSIGNED(pdwBlockPos1, dwToRead / sizeof(DWORD));
DecryptMPQBlock(pdwBlockPos1, dwToRead, dwOldSeed - 1);
if(pdwBlockPos1[0] != dwToRead)
nError = ERROR_FILE_CORRUPT;
memcpy(pdwBlockPos2, pdwBlockPos1, dwToRead);
EncryptMPQBlock(pdwBlockPos2, dwToRead, dwNewSeed - 1);
BSWAP_ARRAY32_UNSIGNED(pdwBlockPos2, dwToRead / sizeof(DWORD));
}
// Write the recrypted block table back
if(nError == ERROR_SUCCESS)
{
SetFilePointer(ha->hFile, MpqFilePos.LowPart, &MpqFilePos.HighPart, FILE_BEGIN);
WriteFile(ha->hFile, pdwBlockPos2, dwToRead, &dwTransferred, NULL);
if(dwTransferred != dwToRead)
nError = ERROR_WRITE_FAULT;
}
}
// Allocate the transfer buffer
if(nError == ERROR_SUCCESS)
{
pbFileBlock = ALLOCMEM(BYTE, ha->dwBlockSize);
if(pbFileBlock == NULL)
nError = ERROR_NOT_ENOUGH_MEMORY;
}
// Now we have to recrypt all file blocks
if(nError == ERROR_SUCCESS)
{
for(int nBlock = 0; nBlock < nBlocks; nBlock++)
{
// Calc position and length for uncompressed file
BlockFilePos.QuadPart = MpqFilePos.QuadPart + (ha->dwBlockSize * nBlock);
dwToRead = ha->dwBlockSize;
if(nBlock == nBlocks - 1)
dwToRead = pBlock->dwFSize - (ha->dwBlockSize * (nBlocks - 1));
// Fix position and length for compressed file
if(pBlock->dwFlags & MPQ_FILE_COMPRESS)
{
BlockFilePos.QuadPart = MpqFilePos.QuadPart + pdwBlockPos1[nBlock];
dwToRead = pdwBlockPos1[nBlock+1] - pdwBlockPos1[nBlock];
}
// Read the file block
SetFilePointer(ha->hFile, BlockFilePos.LowPart, &BlockFilePos.HighPart, FILE_BEGIN);
ReadFile(ha->hFile, pbFileBlock, dwToRead, &dwTransferred, NULL);
if(dwTransferred != dwToRead)
nError = ERROR_FILE_CORRUPT;
// Recrypt the file block
BSWAP_ARRAY32_UNSIGNED((DWORD *)pbFileBlock, dwToRead/sizeof(DWORD));
DecryptMPQBlock((DWORD *)pbFileBlock, dwToRead, dwOldSeed + nBlock);
EncryptMPQBlock((DWORD *)pbFileBlock, dwToRead, dwNewSeed + nBlock);
BSWAP_ARRAY32_UNSIGNED((DWORD *)pbFileBlock, dwToRead/sizeof(DWORD));
// Write the block back
SetFilePointer(ha->hFile, BlockFilePos.LowPart, &BlockFilePos.HighPart, FILE_BEGIN);
WriteFile(ha->hFile, pbFileBlock, dwToRead, &dwTransferred, NULL);
if(dwTransferred != dwToRead)
nError = ERROR_WRITE_FAULT;
}
}
// Free buffers and exit
if(pbFileBlock != NULL)
FREEMEM(pbFileBlock);
if(pdwBlockPos2 != NULL)
FREEMEM(pdwBlockPos2);
if(pdwBlockPos1 != NULL)
FREEMEM(pdwBlockPos1);
return nError;
}
// Copies all file blocks into another archive.
static int CopyMpqFileBlocks(
HANDLE hFile,
TMPQArchive * ha,
TMPQBlockEx * pBlockEx,
TMPQBlock * pBlock,
DWORD dwSeed)
{
LARGE_INTEGER FilePos = {0};
DWORD * pdwBlockPos2 = NULL; // File block positions to be written to target file
DWORD * pdwBlockPos = NULL; // File block positions (unencrypted)
BYTE * pbBlock = NULL; // Buffer for the file block
DWORD dwTransferred; // Number of bytes transferred
DWORD dwCSize = 0; // Compressed file size
DWORD dwBytes = 0; // Number of bytes
DWORD dwSeed1 = 0; // File seed used for decryption
DWORD dwSeed2 = 0; // File seed used for encryption
DWORD nBlocks = 0; // Number of file blocks
DWORD nBlock = 0; // Currently processed file block
int nError = ERROR_SUCCESS;
// When file length is zero, do nothing
if(pBlock->dwFSize == 0)
return ERROR_SUCCESS;
// Calculate number of blocks in the file
if(nError == ERROR_SUCCESS)
{
nBlocks = pBlock->dwFSize / ha->dwBlockSize;
if(pBlock->dwFSize % ha->dwBlockSize)
nBlocks++;
pbBlock = ALLOCMEM(BYTE, ha->dwBlockSize);
if(pbBlock == NULL)
nError = ERROR_NOT_ENOUGH_MEMORY;
}
// Set the position to the begin of the file within archive
if(nError == ERROR_SUCCESS)
{
FilePos.HighPart = pBlockEx->wFilePosHigh;
FilePos.LowPart = pBlock->dwFilePos;
FilePos.QuadPart += ha->MpqPos.QuadPart;
if(SetFilePointer(ha->hFile, FilePos.LowPart, &FilePos.HighPart, FILE_BEGIN) != FilePos.LowPart)
nError = GetLastError();
}
// Remember the position in the destination file
if(nError == ERROR_SUCCESS)
{
FilePos.HighPart = 0;
FilePos.LowPart = SetFilePointer(hFile, 0, &FilePos.HighPart, FILE_CURRENT);
}
// Resolve decryption seeds. The 'dwSeed' parameter is the decryption
// seed for the file.
if(nError == ERROR_SUCCESS && (pBlock->dwFlags & MPQ_FILE_ENCRYPTED))
{
dwSeed1 = dwSeed;
if(pBlock->dwFlags & MPQ_FILE_FIXSEED)
dwSeed = (dwSeed1 ^ pBlock->dwFSize) - pBlock->dwFilePos;
dwSeed2 = dwSeed;
if(pBlock->dwFlags & MPQ_FILE_FIXSEED)
dwSeed2 = (dwSeed + (DWORD)(FilePos.QuadPart - ha->MpqPos.QuadPart)) ^ pBlock->dwFSize;
}
// Load the file positions from the archive and save it to the target file
// (only if the file is compressed)
if(pBlock->dwFlags & MPQ_FILE_COMPRESSED)
{
// Allocate buffers
if(nError == ERROR_SUCCESS)
{
pdwBlockPos = ALLOCMEM(DWORD, nBlocks + 2);
pdwBlockPos2 = ALLOCMEM(DWORD, nBlocks + 2);
if(pdwBlockPos == NULL || pdwBlockPos2 == NULL)
nError = ERROR_NOT_ENOUGH_MEMORY;
}
// Load the block positions
if(nError == ERROR_SUCCESS)
{
dwBytes = (nBlocks + 1) * sizeof(DWORD);
if(pBlock->dwFlags & MPQ_FILE_HAS_EXTRA)
dwBytes += sizeof(DWORD);
ReadFile(ha->hFile, pdwBlockPos, dwBytes, &dwTransferred, NULL);
if(dwTransferred != dwBytes)
nError = ERROR_FILE_CORRUPT;
}
// Re-encrypt the block table positions
if(nError == ERROR_SUCCESS)
{
BSWAP_ARRAY32_UNSIGNED(pdwBlockPos, dwBytes / sizeof(DWORD));
if(pBlock->dwFlags & MPQ_FILE_ENCRYPTED)
{
DecryptMPQBlock(pdwBlockPos, dwBytes, dwSeed1 - 1);
if(pdwBlockPos[0] != dwBytes)
nError = ERROR_FILE_CORRUPT;
memcpy(pdwBlockPos2, pdwBlockPos, dwBytes);
EncryptMPQBlock(pdwBlockPos2, dwBytes, dwSeed2 - 1);
}
else
{
memcpy(pdwBlockPos2, pdwBlockPos, dwBytes);
}
BSWAP_ARRAY32_UNSIGNED(pdwBlockPos2, dwBytes / sizeof(DWORD));
}
// Write to the target file
if(nError == ERROR_SUCCESS)
{
WriteFile(hFile, pdwBlockPos2, dwBytes, &dwTransferred, NULL);
dwCSize += dwTransferred;
if(dwTransferred != dwBytes)
nError = ERROR_DISK_FULL;
}
}
// Now we have to copy all file blocks. We will do it without
// recompression, because re-compression is not necessary in this case
if(nError == ERROR_SUCCESS)
{
for(nBlock = 0; nBlock < nBlocks; nBlock++)
{
// Fix: The last block must not be exactly the size of one block.
dwBytes = ha->dwBlockSize;
if(nBlock == nBlocks - 1)
{
dwBytes = pBlock->dwFSize - (ha->dwBlockSize * (nBlocks - 1));
}
if(pBlock->dwFlags & MPQ_FILE_COMPRESSED)
dwBytes = pdwBlockPos[nBlock+1] - pdwBlockPos[nBlock];
// Read the file block
ReadFile(ha->hFile, pbBlock, dwBytes, &dwTransferred, NULL);
if(dwTransferred != dwBytes)
{
nError = ERROR_FILE_CORRUPT;
break;
}
// If necessary, re-encrypt the block
// Note: Recompression is not necessary here. Unlike encryption,
// the compression does not depend on the position of the file in MPQ.
if((pBlock->dwFlags & MPQ_FILE_ENCRYPTED) && dwSeed1 != dwSeed2)
{
BSWAP_ARRAY32_UNSIGNED((DWORD *)pbBlock, dwBytes/sizeof(DWORD));
DecryptMPQBlock((DWORD *)pbBlock, dwBytes, dwSeed1 + nBlock);
EncryptMPQBlock((DWORD *)pbBlock, dwBytes, dwSeed2 + nBlock);
BSWAP_ARRAY32_UNSIGNED((DWORD *)pbBlock, dwBytes/sizeof(DWORD));
}
// Now write the block back to the file
WriteFile(hFile, pbBlock, dwBytes, &dwTransferred, NULL);
dwCSize += dwTransferred;
if(dwTransferred != dwBytes)
{
nError = ERROR_DISK_FULL;
break;
}
}
}
// Copy the file extras, if any
// These extras does not seem to be encrypted, and their purpose is unknown
if(nError == ERROR_SUCCESS && (pBlock->dwFlags & MPQ_FILE_HAS_EXTRA))
{
dwBytes = pdwBlockPos[nBlocks + 1] - pdwBlockPos[nBlocks];
if(dwBytes != 0)
{
ReadFile(ha->hFile, pbBlock, dwBytes, &dwTransferred, NULL);
if(dwTransferred == dwBytes)
{
WriteFile(hFile, pbBlock, dwBytes, &dwTransferred, NULL);
dwCSize += dwTransferred;
if(dwTransferred != dwBytes)
nError = ERROR_DISK_FULL;
}
else
{
nError = ERROR_FILE_CORRUPT;
}
}
}
// Update file position in the block table
if(nError == ERROR_SUCCESS)
{
// At this point, number of bytes written should be exactly
// the same like the compressed file size. If it isn't, there's something wrong
// (maybe new archive version ?)
assert(dwCSize == pBlock->dwCSize);
// Update file pos in the block table
FilePos.QuadPart -= ha->MpqPos.QuadPart;
pBlockEx->wFilePosHigh = (USHORT)FilePos.HighPart;
pBlock->dwFilePos = FilePos.LowPart;
}
// Cleanup and return
if(pdwBlockPos2 != NULL)
FREEMEM(pdwBlockPos2);
if(pdwBlockPos != NULL)
FREEMEM(pdwBlockPos);
if(pbBlock != NULL)
FREEMEM(pbBlock);
return nError;
}