Function MpqeStream_DetectFileKey

3rdParty/StormLib/src/FileStream.cpp:2027–2065

}

static bool MpqeStream_DetectFileKey(TEncryptedStream * pStream)
{
    ULONGLONG ByteOffset = 0;
    BYTE EncryptedHeader[MPQE_CHUNK_SIZE];
    BYTE FileHeader[MPQE_CHUNK_SIZE];

    // Read the first file chunk
    if(pStream->BaseRead(pStream, &ByteOffset, EncryptedHeader, sizeof(EncryptedHeader)))
    {
        // We just try all known keys one by one
        for(int i = 0; AuthCodeArray[i] != NULL; i++)
        {
            // Prepare they decryption key from game serial number
            CreateKeyFromAuthCode(pStream->Key, AuthCodeArray[i]);

            // Try to decrypt with the given key 
            memcpy(FileHeader, EncryptedHeader, MPQE_CHUNK_SIZE);
            DecryptFileChunk((LPDWORD)FileHeader, pStream->Key, ByteOffset, MPQE_CHUNK_SIZE);

            // We check the decrypted data
            // All known encrypted MPQs have header at the begin of the file,
            // so we check for MPQ signature there.
            if(FileHeader[0] == 'M' && FileHeader[1] == 'P' && FileHeader[2] == 'Q')
            {
                // Update the stream size
                pStream->StreamSize = pStream->Base.File.FileSize;

                // Fill the block information
                pStream->BlockSize  = MPQE_CHUNK_SIZE;
                pStream->BlockCount = (DWORD)(pStream->Base.File.FileSize + MPQE_CHUNK_SIZE - 1) / MPQE_CHUNK_SIZE;
                pStream->IsComplete = 1;
                return true;
            }
        }
    }

    // Key not found, sorry
    return false;
}

static bool MpqeStream_BlockRead(
    TEncryptedStream * pStream,