bootmain.cpp

使用visual studio 2005 开发的开源文件、磁盘加密软件。这是6.1a版。加密自己资料的好工具。也是学习的优秀范本。结成了众多加密算法。

	uint64 sectorOffset;
	sectorOffset.LowPart = 0;
	sectorOffset.HighPart = 0;

	int fragmentSectorCount = 0x7f; // Maximum safe value supported by BIOS
	int statCount;

	if (!CheckMemoryRequirements ())
		goto err;

	if (!GetActiveAndFollowingPartition (drive))
		goto err;

	if (PartitionFollowingActive.Drive == TC_INVALID_BIOS_DRIVE)
		TC_THROW_FATAL_EXCEPTION;

	// Check if BIOS can read the last sector of the hidden system
	AcquireSectorBuffer();

	if (ReadSectors (SectorBuffer, PartitionFollowingActive.Drive, PartitionFollowingActive.EndSector - (TC_VOLUME_HEADER_GROUP_SIZE / TC_LB_SIZE - 2), 1) != BiosResultSuccess
		|| (uint16) GetCrc32 (SectorBuffer, sizeof (SectorBuffer)) != OuterVolumeBackupHeaderCrc)
	{
		PrintError ("Your BIOS does not support large drives");
		Print (TC_BOOT_STR_UPGRADE_BIOS);

		ReleaseSectorBuffer();
		goto err;
	}

	ReleaseSectorBuffer();

	if (!MountVolume (drive, exitKey, true, false))
		return false;

	sectorsRemaining = EncryptedVirtualPartition.SectorCount;

	if (!(sectorsRemaining == ActivePartition.SectorCount))
		TC_THROW_FATAL_EXCEPTION;

	InitScreen();
	Print ("\r\nCopying system to hidden volume. To abort, press Esc.\r\n\r\n");

	while (sectorsRemaining.HighPart != 0 || sectorsRemaining.LowPart != 0)
	{
		if (EscKeyPressed())
		{
			Print ("\rIf aborted, copying will have to start from the beginning (if attempted again).\r\n");
			if (AskYesNo ("Abort"))
				break;
		}

		if (sectorsRemaining.HighPart == 0 && sectorsRemaining.LowPart < fragmentSectorCount)
			fragmentSectorCount = sectorsRemaining.LowPart;

		if (ReadWriteSectors (false, TC_BOOT_LOADER_BUFFER_SEGMENT, 0, drive, ActivePartition.StartSector + sectorOffset, fragmentSectorCount, false) != BiosResultSuccess)
		{
			Print ("To fix bad sectors: 1) Terminate 2) Encrypt and decrypt sys partition 3) Retry\r\n");
			crypto_close (BootCryptoInfo);
			goto err;
		}

		AcquireSectorBuffer();

		for (int i = 0; i < fragmentSectorCount; ++i)
		{
			CopyMemory (TC_BOOT_LOADER_BUFFER_SEGMENT, i * TC_LB_SIZE, SectorBuffer, TC_LB_SIZE);

			uint64 s = HiddenVolumeStartUnitNo + sectorOffset + i;
			EncryptDataUnits (SectorBuffer, &s, 1, BootCryptoInfo);

			CopyMemory (SectorBuffer, TC_BOOT_LOADER_BUFFER_SEGMENT, i * TC_LB_SIZE, TC_LB_SIZE);
		} 

		ReleaseSectorBuffer();

		if (ReadWriteSectors (true, TC_BOOT_LOADER_BUFFER_SEGMENT, 0, drive, HiddenVolumeStartSector + sectorOffset, fragmentSectorCount, false) != BiosResultSuccess)
		{
			crypto_close (BootCryptoInfo);
			goto err;
		}

		sectorsRemaining = sectorsRemaining - fragmentSectorCount;
		sectorOffset = sectorOffset + fragmentSectorCount;

		if (!(statCount++ & 0xf))
		{
			Print ("\rRemaining: ");
			PrintSectorCountInMB (sectorsRemaining);
		}
	}

	crypto_close (BootCryptoInfo);

	if (sectorsRemaining.HighPart == 0 && sectorsRemaining.LowPart == 0)
	{
		status = true;
		Print ("\rCopying completed.");
	}

	PrintEndl (2);
	goto ret;

err:
	exitKey = TC_BIOS_KEY_ESC;
	GetKeyboardChar();

ret:
	EraseMemory ((void *) TC_BOOT_LOADER_ARGS_OFFSET, sizeof (BootArguments));
	return status;
}


#else // TC_WINDOWS_BOOT_RESCUE_DISK_MODE


static void DecryptDrive (byte drive)
{
	byte exitKey;
	if (!MountVolume (drive, exitKey, false, true))
		return;

	BootArguments *bootArguments = (BootArguments *) TC_BOOT_LOADER_ARGS_OFFSET;

	bool headerUpdateRequired = false;
	uint64 sectorsRemaining = EncryptedVirtualPartition.EndSector + 1 - EncryptedVirtualPartition.StartSector;
	uint64 sector = EncryptedVirtualPartition.EndSector + 1;

	int fragmentSectorCount = 0x7f; // Maximum safe value supported by BIOS
	int statCount;

	bool skipBadSectors = false;

	Print ("\r\nUse only if Windows cannot start. Decryption under Windows is much faster\r\n"
			"(in TrueCrypt, select 'System' > 'Permanently Decrypt').\r\n\r\n");

	if (!AskYesNo ("Decrypt now"))
	{
		crypto_close (BootCryptoInfo);
		goto ret;
	}

	if (EncryptedVirtualPartition.Drive == TC_INVALID_BIOS_DRIVE)
	{
		// Drive already decrypted
		sectorsRemaining.HighPart = 0;
		sectorsRemaining.LowPart = 0;
	}
	else
	{
		Print ("\r\nTo safely interrupt and defer decryption, press Esc.\r\n"
			"WARNING: You can turn off power only after you press Esc.\r\n\r\n");
	}

	while (sectorsRemaining.HighPart != 0 || sectorsRemaining.LowPart != 0)
	{
		if (EscKeyPressed())
			break;

		if (sectorsRemaining.HighPart == 0 && sectorsRemaining.LowPart < fragmentSectorCount)
			fragmentSectorCount = sectorsRemaining.LowPart;

		sector = sector - fragmentSectorCount;

		if (!(statCount++ & 0xf))
		{
			Print ("\rRemaining: ");
			PrintSectorCountInMB (sectorsRemaining);
		}

		if (ReadWriteSectors (false, TC_BOOT_LOADER_BUFFER_SEGMENT, 0, drive, sector, fragmentSectorCount, skipBadSectors) == BiosResultSuccess)
		{
			AcquireSectorBuffer();

			for (int i = 0; i < fragmentSectorCount; ++i)
			{
				CopyMemory (TC_BOOT_LOADER_BUFFER_SEGMENT, i * TC_LB_SIZE, SectorBuffer, TC_LB_SIZE);

				uint64 s = sector + i;
				DecryptDataUnits (SectorBuffer, &s, 1, BootCryptoInfo);

				CopyMemory (SectorBuffer, TC_BOOT_LOADER_BUFFER_SEGMENT, i * TC_LB_SIZE, TC_LB_SIZE);
			} 

			ReleaseSectorBuffer();

			if (ReadWriteSectors (true, TC_BOOT_LOADER_BUFFER_SEGMENT, 0, drive, sector, fragmentSectorCount, skipBadSectors) != BiosResultSuccess && !skipBadSectors)
				goto askBadSectorSkip;
		}
		else if (!skipBadSectors)
			goto askBadSectorSkip;

		sectorsRemaining = sectorsRemaining - fragmentSectorCount;
		headerUpdateRequired = true;
		continue;

askBadSectorSkip:
		if (!AskYesNo ("Skip all bad sectors"))
			break;

		skipBadSectors = true;
		sector = sector + fragmentSectorCount;
		fragmentSectorCount = 1;
	}

	crypto_close (BootCryptoInfo);

	if (headerUpdateRequired)
	{
		AcquireSectorBuffer();
		uint64 headerSector;
		headerSector.HighPart = 0;
		headerSector.LowPart = TC_BOOT_VOLUME_HEADER_SECTOR;

		// Update encrypted area size in volume header

		CRYPTO_INFO *headerCryptoInfo = crypto_open();
		while (ReadSectors (SectorBuffer, drive, headerSector, 1) != BiosResultSuccess);

		if (ReadVolumeHeader (TRUE, (char *) SectorBuffer, &bootArguments->BootPassword, NULL, headerCryptoInfo) == 0)
		{
			DecryptBuffer (SectorBuffer + HEADER_ENCRYPTED_DATA_OFFSET, HEADER_ENCRYPTED_DATA_SIZE, headerCryptoInfo);

			uint64 encryptedAreaLength = sectorsRemaining << TC_LB_SIZE_BIT_SHIFT_DIVISOR;

			for (int i = 7; i >= 0; --i)
			{
				SectorBuffer[TC_HEADER_OFFSET_ENCRYPTED_AREA_LENGTH + i] = (byte) encryptedAreaLength.LowPart;
				encryptedAreaLength = encryptedAreaLength >> 8;
			}

			uint32 headerCrc32 = GetCrc32 (SectorBuffer + TC_HEADER_OFFSET_MAGIC, TC_HEADER_OFFSET_HEADER_CRC - TC_HEADER_OFFSET_MAGIC);

			for (i = 3; i >= 0; --i)
			{
				SectorBuffer[TC_HEADER_OFFSET_HEADER_CRC + i] = (byte) headerCrc32;
				headerCrc32 >>= 8;
			}

			EncryptBuffer (SectorBuffer + HEADER_ENCRYPTED_DATA_OFFSET, HEADER_ENCRYPTED_DATA_SIZE, headerCryptoInfo);
		}

		crypto_close (headerCryptoInfo);

		while (WriteSectors (SectorBuffer, drive, headerSector, 1) != BiosResultSuccess);
		ReleaseSectorBuffer();
	}

	if (sectorsRemaining.HighPart == 0 && sectorsRemaining.LowPart == 0)
		Print ("\rDrive decrypted.\r\n");
	else
		Print ("\r\nDecryption deferred.\r\n");

	GetKeyboardChar();
ret:
	EraseMemory (bootArguments, sizeof (*bootArguments));
}


static void RepairMenu ()
{
	DriveGeometry bootLoaderDriveGeometry;

	if (GetDriveGeometry (BootLoaderDrive, bootLoaderDriveGeometry, true) != BiosResultSuccess)
	{
		// Some BIOSes may fail to get the geometry of an emulated floppy drive
		bootLoaderDriveGeometry.Cylinders = 80;
		bootLoaderDriveGeometry.Heads = 2;
		bootLoaderDriveGeometry.Sectors = 18;
	}

	while (true)
	{
		InitScreen();
		Print ("Available "); Print ("Repair Options"); Print (":\r\n");
		PrintRepeatedChar ('\xC4', 25);
		PrintEndl();

		enum
		{
			RestoreNone = 0,
			DecryptVolume,
			RestoreTrueCryptLoader,
			RestoreVolumeHeader,
			RestoreOriginalSystemLoader
		};

		static const char *options[] = { "Permanently decrypt system partition/drive", "Restore TrueCrypt Boot Loader", "Restore key data (volume header)", "Restore original system loader" };

		int selection = AskSelection (options,
			(BootSectorFlags & TC_BOOT_CFG_FLAG_RESCUE_DISK_ORIG_SYS_LOADER) ? array_capacity (options) : array_capacity (options) - 1);

		PrintEndl();

		switch (selection)
		{
			case RestoreNone:
				return;

			case DecryptVolume:
				DecryptDrive (BootDrive);
				continue;

			case RestoreOriginalSystemLoader:
				if (!AskYesNo ("Is the system partition/drive decrypted"))
				{
					Print ("Please decrypt it first.\r\n");
					GetKeyboardChar();
					continue;
				}
				break;
		}

		bool writeConfirmed = false;
		BiosResult result;

		uint64 sector;
		sector.HighPart = 0;
		ChsAddress chs;

		byte mbrPartTable[TC_LB_SIZE - TC_MAX_MBR_BOOT_CODE_SIZE];
		AcquireSectorBuffer();

		for (int i = (selection == RestoreVolumeHeader ? TC_BOOT_VOLUME_HEADER_SECTOR : TC_MBR_SECTOR);
			i < TC_BOOT_LOADER_AREA_SECTOR_COUNT; ++i)
		{
			sector.LowPart = i;

			if (selection == RestoreOriginalSystemLoader)
				sector.LowPart += TC_ORIG_BOOT_LOADER_BACKUP_SECTOR;
			else if (selection == RestoreTrueCryptLoader)
				sector.LowPart += TC_BOOT_LOADER_BACKUP_RESCUE_DISK_SECTOR;

			// The backup medium may be a floppy-emulated bootable CD. The emulation may fail if LBA addressing is used.
			// Therefore, only CHS addressing can be used.
			LbaToChs (bootLoaderDriveGeometry, sector, chs);
			sector.LowPart = i;

			if (i == TC_MBR_SECTOR)
			{
				// Read current partition table
				result = ReadSectors (SectorBuffer, TC_FIRST_BIOS_DRIVE, sector, 1);
				if (result != BiosResultSuccess)
					goto err;

				memcpy (mbrPartTable, SectorBuffer + TC_MAX_MBR_BOOT_CODE_SIZE, sizeof (mbrPartTable));
			}

			result = ReadSectors (SectorBuffer, BootLoaderDrive, chs, 1);
			if (result != BiosResultSuccess)
				goto err;

			if (i == TC_MBR_SECTOR)
			{
				// Preserve current partition table
				memcpy (SectorBuffer + TC_MAX_MBR_BOOT_CODE_SIZE, mbrPartTable, sizeof (mbrPartTable));
			}

			// Volume header
			if (i == TC_BOOT_VOLUME_HEADER_SECTOR)
			{
				if (selection == RestoreTrueCryptLoader)
					continue;

				if (selection == RestoreVolumeHeader)
				{
					while (true)
					{
						Password password;
						byte exitKey = AskPassword (password);

						if (exitKey != TC_BIOS_KEY_ENTER)
							goto abort;

						CRYPTO_INFO *cryptoInfo;

						CopyMemory (SectorBuffer, TC_BOOT_LOADER_BUFFER_SEGMENT, 0, TC_LB_SIZE);
						ReleaseSectorBuffer();

						// Restore volume header only if the current one cannot be used
						if (OpenVolume (TC_FIRST_BIOS_DRIVE, password, &cryptoInfo, nullptr, false, true))
						{
							Print ("Original header preserved.\r\n");
							crypto_close (cryptoInfo);
							goto err;
						}

						AcquireSectorBuffer();
						CopyMemory (TC_BOOT_LOADER_BUFFER_SEGMENT, 0, SectorBuffer, TC_LB_SIZE);

						if (ReadVolumeHeader (TRUE, (char *) SectorBuffer, &password, &cryptoInfo, nullptr) == 0)
						{
							crypto_close (cryptoInfo);
							break;
						}

						Print ("Incorrect password.\r\n\r\n");
					}
				}
			}

			if (!writeConfirmed && !AskYesNo ("Modify drive 0"))
				goto abort;
			writeConfirmed = true;

			if (WriteSectors (SectorBuffer, TC_FIRST_BIOS_DRIVE, sector, 1) != BiosResultSuccess)
				goto err;
		}
done:
		switch (selection)
		{
		case RestoreTrueCryptLoader:
			Print ("TrueCrypt Boot Loader");
			break;

		case RestoreVolumeHeader:
			Print ("Header");
			break;

		case RestoreOriginalSystemLoader:
			Print ("System loader");
			break;
		}
		Print (" restored.\r\n");

err:	GetKeyboardChar();
abort:	ReleaseSectorBuffer();
	}
}

#endif // TC_WINDOWS_BOOT_RESCUE_DISK_MODE


#ifndef DEBUG
extern "C" void _acrtused () { }  // Required by linker
#endif


void main ()
{
	__asm mov BootLoaderDrive, dl
	__asm mov BootSectorFlags, dh

#ifdef TC_BOOT_TRACING_ENABLED
	InitDebugPort();
#endif

#ifdef TC_BOOT_STACK_CHECKING_ENABLED
	InitStackChecker();
#endif

#ifndef TC_WINDOWS_BOOT_RESCUE_DISK_MODE
	ReadBootSectorUserConfiguration();
#endif

	InitVideoMode();
	InitScreen();

	// Determine boot drive
	BootDrive = BootLoaderDrive;
	if (BootDrive < TC_FIRST_BIOS_DRIVE)
		BootDrive = TC_FIRST_BIOS_DRIVE;

	// Query boot drive geometry
	if (GetDriveGeometry (BootDrive, BootDriveGeometry, true) != BiosResultSuccess)
	{
		BootDrive = TC_FIRST_BIOS_DRIVE;
		if (GetDriveGeometry (BootDrive, BootDriveGeometry) == BiosResultSuccess)
			BootDriveGeometryValid = TRUE;
	}
	else
		BootDriveGeometryValid = TRUE;


#ifdef TC_WINDOWS_BOOT_RESCUE_DISK_MODE

	// Check whether the user is not using the Rescue Disk to create a hidden system

	if (ReadWriteMBR (false, BootDrive, true) == BiosResultSuccess
		&& *(uint32 *) (SectorBuffer + 6) == 0x65757254
		&& *(uint32 *) (SectorBuffer + 10) == 0x70797243
		&& (SectorBuffer[TC_BOOT_SECTOR_CONFIG_OFFSET] & TC_BOOT_CFG_MASK_HIDDEN_OS_CREATION_PHASE) != TC_HIDDEN_OS_CREATION_PHASE_NONE)
	{
		PrintError ("It appears you are creating a hidden OS.");
		if (AskYesNo ("Is this correct"))
		{
			Print ("Please remove the Rescue Disk from the drive and restart.");
			while (true);
		}
	}

#endif // TC_WINDOWS_BOOT_RESCUE_DISK_MODE


	// Main menu

	while (true)
	{
		byte exitKey;
		InitScreen();

#ifndef TC_WINDOWS_BOOT_RESCUE_DISK_MODE

		// Hidden system setup
		byte hiddenSystemCreationPhase = BootSectorFlags & TC_BOOT_CFG_MASK_HIDDEN_OS_CREATION_PHASE;

		if (hiddenSystemCreationPhase != TC_HIDDEN_OS_CREATION_PHASE_NONE)
		{
			PreventNormalSystemBoot = true;
			PrintMainMenu();

			if (hiddenSystemCreationPhase == TC_HIDDEN_OS_CREATION_PHASE_CLONING)
			{
				if (CopyActivePartitionToHiddenVolume (BootDrive, exitKey))
				{
					BootSectorFlags = (BootSectorFlags & ~TC_BOOT_CFG_MASK_HIDDEN_OS_CREATION_PHASE) | TC_HIDDEN_OS_CREATION_PHASE_WIPING;
					UpdateBootSectorConfiguration (BootLoaderDrive);
				}
				else if (exitKey == TC_BIOS_KEY_ESC)
					goto bootMenu;
				else
					continue;
			}
		}
		else
			PrintMainMenu();

		exitKey = BootEncryptedDrive();

#else // TC_WINDOWS_BOOT_RESCUE_DISK_MODE
		
		PrintMainMenu();
		exitKey = BootEncryptedDrive();

		if (exitKey == TC_MENU_KEY_REPAIR)
		{
			RepairMenu();
			continue;
		}

#endif // TC_WINDOWS_BOOT_RESCUE_DISK_MODE

bootMenu:
		if (!PreventBootMenu)
			BootMenu();
	}
}