format.c

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/*
 Legal Notice: Some portions of the source code contained in this file were
 derived from the source code of Encryption for the Masses 2.02a, which is
 Copyright (c) 1998-2000 Paul Le Roux and which is governed by the 'License
 Agreement for Encryption for the Masses'. Modifications and additions to
 the original source code (contained in this file) and all other portions of
 this file are Copyright (c) 2003-2008 TrueCrypt Foundation and are governed
 by the TrueCrypt License 2.6 the full text of which is contained in the
 file License.txt included in TrueCrypt binary and source code distribution
 packages. */

#include <stdlib.h>
#include <string.h>

#include "Tcdefs.h"

#include "Common.h"
#include "Crypto.h"
#include "Fat.h"
#include "Format.h"
#include "Random.h"
#include "Volumes.h"

#include "Apidrvr.h"
#include "Dlgcode.h"
#include "Language.h"
#include "Progress.h"
#include "Resource.h"
#include "Format/FormatCom.h"
#include "Format/Tcformat.h"


uint64 GetVolumeDataAreaSize (BOOL hiddenVolume, uint64 volumeSize)
{
	uint64 reservedSize;

	if (hiddenVolume)
	{
		// Reserve free space at the end of the host filesystem
		if (volumeSize < TC_VOLUME_SMALL_SIZE_THRESHOLD)
			reservedSize = TC_HIDDEN_VOLUME_HOST_FS_RESERVED_END_AREA_SIZE;
		else
			reservedSize = TC_HIDDEN_VOLUME_HOST_FS_RESERVED_END_AREA_SIZE_HIGH; // Ensure size of a hidden volume larger than TC_VOLUME_SMALL_SIZE_THRESHOLD is a multiple of the maximum supported sector size
	}
	else
	{
		reservedSize = TC_TOTAL_VOLUME_HEADERS_SIZE;
	}

	if (volumeSize < reservedSize)
		return 0;

	return volumeSize - reservedSize;
}


int TCFormatVolume (volatile FORMAT_VOL_PARAMETERS *volParams)
{
	int nStatus;
	PCRYPTO_INFO cryptoInfo = NULL;
	HANDLE dev = INVALID_HANDLE_VALUE;
	DWORD dwError;
	char header[TC_VOLUME_HEADER_EFFECTIVE_SIZE];
	unsigned __int64 num_sectors, startSector;
	fatparams ft;
	FILETIME ftCreationTime;
	FILETIME ftLastWriteTime;
	FILETIME ftLastAccessTime;
	BOOL bTimeStampValid = FALSE;
	BOOL bInstantRetryOtherFilesys = FALSE;
	char dosDev[TC_MAX_PATH] = { 0 };
	char devName[MAX_PATH] = { 0 };
	int driveLetter = -1;
	WCHAR deviceName[MAX_PATH];
	uint64 dataOffset, dataAreaSize;
	LARGE_INTEGER offset;
	BOOL bFailedRequiredDASD = FALSE;


	/* WARNING: Note that if Windows fails to format the volume as NTFS and the volume size is
	less than TC_MAX_FAT_FS_SIZE, the user is asked within this function whether he wants to instantly
	retry FAT format instead (to avoid having to re-create the whole container again). If the user
	answers yes, some of the input parameters are modified, the code below 'begin_format' is re-executed 
	and some destructive operations that were performed during the first attempt must be (and are) skipped. 
	Therefore, whenever adding or modifying any potentially destructive operations below 'begin_format',
	determine whether they (or their portions) need to be skipped during such a second attempt; if so, 
	use the 'bInstantRetryOtherFilesys' flag to skip them. */

	if (volParams->hiddenVol)
	{
		dataOffset = volParams->hiddenVolHostSize - TC_VOLUME_HEADER_GROUP_SIZE - volParams->size;
	}
	else
	{
		if (volParams->size <= TC_TOTAL_VOLUME_HEADERS_SIZE)
			return ERR_VOL_SIZE_WRONG;

		dataOffset = TC_VOLUME_DATA_OFFSET;
	}

	dataAreaSize = GetVolumeDataAreaSize (volParams->hiddenVol, volParams->size);

	num_sectors = dataAreaSize / SECTOR_SIZE;

	if (volParams->bDevice)
	{
		strcpy ((char *)deviceName, volParams->volumePath);
		ToUNICODE ((char *)deviceName);

		driveLetter = GetDiskDeviceDriveLetter (deviceName);
	}

	VirtualLock (header, sizeof (header));

	nStatus = CreateVolumeHeaderInMemory (FALSE,
				     header,
				     volParams->ea,
					 FIRST_MODE_OF_OPERATION_ID,
				     volParams->password,
				     volParams->pkcs5,
					 NULL,
				     &cryptoInfo,
					 dataAreaSize,
					 volParams->hiddenVol ? dataAreaSize : 0,
					 dataOffset,
					 dataAreaSize,
					 0,
					 volParams->headerFlags,
					 FALSE);

	if (nStatus != 0)
	{
		burn (header, sizeof (header));
		VirtualUnlock (header, sizeof (header));
		return nStatus;
	}

begin_format:

	if (volParams->bDevice)
	{
		/* Device-hosted volume */

		DWORD dwResult;
		int nPass;

		if (FakeDosNameForDevice (volParams->volumePath, dosDev, devName, FALSE) != 0)
			return ERR_OS_ERROR;

		if (IsDeviceMounted (devName))
		{
			if ((dev = DismountDrive (devName, volParams->volumePath)) == INVALID_HANDLE_VALUE)
			{
				Error ("FORMAT_CANT_DISMOUNT_FILESYS");
				nStatus = ERR_DONT_REPORT; 
				goto error;
			}

			/* Gain "raw" access to the partition (it contains a live filesystem and the filesystem driver 
			would otherwise prevent us from writing to hidden sectors). */

			if (!DeviceIoControl (dev,
				FSCTL_ALLOW_EXTENDED_DASD_IO,
				NULL,
				0,   
				NULL,
				0,
				&dwResult,
				NULL))
			{
				bFailedRequiredDASD = TRUE;
			}
		}
		else if (nCurrentOS == WIN_VISTA_OR_LATER && driveLetter == -1)
		{
			// Windows Vista doesn't allow overwriting sectors belonging to an unformatted partition 
			// to which no drive letter has been assigned under the system. This problem can be worked
			// around by assigning a drive letter to the partition temporarily.

			char szDriveLetter[] = { 'A', ':', 0 };
			char rootPath[] = { 'A', ':', '\\', 0 };
			char uniqVolName[MAX_PATH+1] = { 0 };
			int tmpDriveLetter = -1;
			BOOL bResult = FALSE;

			tmpDriveLetter = GetFirstAvailableDrive ();
 
			if (tmpDriveLetter != -1)
			{
				rootPath[0] += tmpDriveLetter;
				szDriveLetter[0] += tmpDriveLetter;

				if (DefineDosDevice (DDD_RAW_TARGET_PATH, szDriveLetter, volParams->volumePath))
				{
					bResult = GetVolumeNameForVolumeMountPoint (rootPath, uniqVolName, MAX_PATH);

					DefineDosDevice (DDD_RAW_TARGET_PATH|DDD_REMOVE_DEFINITION|DDD_EXACT_MATCH_ON_REMOVE,
						szDriveLetter,
						volParams->volumePath);

					if (bResult 
						&& SetVolumeMountPoint (rootPath, uniqVolName))
					{
						// The drive letter can be removed now
						DeleteVolumeMountPoint (rootPath);
					}
				}
			}
		}

		// For extra safety, we will try to gain "raw" access to the partition. Note that this should actually be
		// redundant because if the filesystem was mounted, we already tried to obtain DASD above. If we failed,
		// bFailedRequiredDASD was set to TRUE and therefore we will perform pseudo "quick format" below. However, 
		// for extra safety, in case IsDeviceMounted() failed to detect a live filesystem, we will blindly
		// send FSCTL_ALLOW_EXTENDED_DASD_IO (possibly for a second time) without checking the result.

		DeviceIoControl (dev,
			FSCTL_ALLOW_EXTENDED_DASD_IO,
			NULL,
			0,   
			NULL,
			0,
			&dwResult,
			NULL);


		// If DASD is needed but we failed to obtain it, perform open - 'quick format' - close - open 
		// so that the filesystem driver does not prevent us from formatting hidden sectors.
		for (nPass = (bFailedRequiredDASD ? 0 : 1); nPass < 2; nPass++)
		{
			int retryCount;

			retryCount = 0;

			// Try exclusive access mode first
			// Note that when exclusive access is denied, it is worth retrying (usually succeeds after a few tries).
			while (dev == INVALID_HANDLE_VALUE && retryCount++ < EXCL_ACCESS_MAX_AUTO_RETRIES)
			{
				dev = CreateFile (devName, GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);

				if (retryCount > 1)
					Sleep (EXCL_ACCESS_AUTO_RETRY_DELAY);
			}

			if (dev == INVALID_HANDLE_VALUE)
			{
				// Exclusive access denied -- retry in shared mode
				dev = CreateFile (devName, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
				if (dev != INVALID_HANDLE_VALUE)
				{
					if (IDNO == MessageBoxW (volParams->hwndDlg, GetString ("DEVICE_IN_USE_FORMAT"), lpszTitle, MB_YESNO|MB_ICONWARNING|MB_DEFBUTTON2))
					{
						nStatus = ERR_DONT_REPORT; 
						goto error;
					}
				}
				else
				{
					handleWin32Error (volParams->hwndDlg);
					Error ("CANT_ACCESS_VOL");
					nStatus = ERR_DONT_REPORT; 
					goto error;
				}
			}

			if (volParams->hiddenVol || bInstantRetryOtherFilesys)
				break;	// The following "quick format" operation would damage the outer volume

			if (nPass == 0)
			{
				char buf [2 * TC_MAX_VOLUME_SECTOR_SIZE];
				DWORD bw;

				// Perform pseudo "quick format" so that the filesystem driver does not prevent us from 
				// formatting hidden sectors
				memset (buf, 0, sizeof (buf));

				if (!WriteFile (dev, buf, sizeof (buf), &bw, NULL))
				{
					nStatus = ERR_OS_ERROR; 
					goto error;
				}

				FlushFileBuffers (dev);
				CloseHandle (dev);
				dev = INVALID_HANDLE_VALUE;
			}
		}

		if (DeviceIoControl (dev, FSCTL_IS_VOLUME_MOUNTED, NULL, 0, NULL, 0, &dwResult, NULL))
		{
			Error ("FORMAT_CANT_DISMOUNT_FILESYS");
			nStatus = ERR_DONT_REPORT; 
			goto error;
		}
	}
	else
	{
		/* File-hosted volume */

		// We could support FILE_ATTRIBUTE_HIDDEN as an option
		// (Now if the container has hidden or system file attribute, the OS will not allow
		// overwritting it; so the user will have to delete it manually).
		dev = CreateFile (volParams->volumePath, GENERIC_WRITE,
			(volParams->hiddenVol || bInstantRetryOtherFilesys) ? (FILE_SHARE_READ | FILE_SHARE_WRITE) : 0,
			NULL, (volParams->hiddenVol || bInstantRetryOtherFilesys) ? OPEN_EXISTING : CREATE_ALWAYS, 0, NULL);

		if (dev == INVALID_HANDLE_VALUE)
		{
			nStatus = ERR_OS_ERROR; 
			goto error;
		}

		if (!volParams->hiddenVol && !bInstantRetryOtherFilesys)
		{
			LARGE_INTEGER volumeSize;
			volumeSize.QuadPart = dataAreaSize + TC_VOLUME_HEADER_GROUP_SIZE;

			if (volParams->sparseFileSwitch && volParams->quickFormat)
			{
				// Create as sparse file container
				DWORD tmp;
				if (!DeviceIoControl (dev, FSCTL_SET_SPARSE, NULL, 0, NULL, 0, &tmp, NULL))
				{
					nStatus = ERR_OS_ERROR; 
					goto error;
				}
			}

			// Preallocate the file
			if (!SetFilePointerEx (dev, volumeSize, NULL, FILE_BEGIN)
				|| !SetEndOfFile (dev)
				|| SetFilePointer (dev, 0, NULL, FILE_BEGIN) != 0)
			{
				nStatus = ERR_OS_ERROR;
				goto error;
			}
		}
	}

	if (volParams->hiddenVol && !volParams->bDevice && bPreserveTimestamp)
	{
		/* Remember the container timestamp (used to reset file date and time of file-hosted
		containers to preserve plausible deniability of hidden volume)  */
		if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
		{
			bTimeStampValid = FALSE;
			MessageBoxW (volParams->hwndDlg, GetString ("GETFILETIME_FAILED_IMPLANT"), lpszTitle, MB_OK | MB_ICONEXCLAMATION);
		}
		else
			bTimeStampValid = TRUE;
	}

	KillTimer (volParams->hwndDlg, TIMER_ID_RANDVIEW);

	/* Volume header */

	// Hidden volume setup
	if (volParams->hiddenVol)
	{
		LARGE_INTEGER headerOffset;

		// Check hidden volume size
		if (volParams->hiddenVolHostSize < TC_MIN_HIDDEN_VOLUME_HOST_SIZE || volParams->hiddenVolHostSize > TC_MAX_HIDDEN_VOLUME_HOST_SIZE)
		{		
			nStatus = ERR_VOL_SIZE_WRONG;
			goto error;
		}

		// Seek to hidden volume header location
		
		headerOffset.QuadPart = TC_HIDDEN_VOLUME_HEADER_OFFSET;

		if (!SetFilePointerEx ((HANDLE) dev, headerOffset, NULL, FILE_BEGIN))
		{
			nStatus = ERR_OS_ERROR;
			goto error;
		}
	}
	else if (bInstantRetryOtherFilesys)
	{
		// The previous file system format failed and the user wants to try again with a different file system.
		// The volume header had been written successfully so we need to seek to the byte after the header.

		LARGE_INTEGER offset;
		offset.QuadPart = TC_VOLUME_DATA_OFFSET;
		if (!SetFilePointerEx ((HANDLE) dev, offset, NULL, FILE_BEGIN))
		{
			nStatus = ERR_OS_ERROR;
			goto error;
		}
	}

	if (!bInstantRetryOtherFilesys)
	{
		// Write the volume header
		if (_lwrite ((HFILE) dev, header, TC_VOLUME_HEADER_EFFECTIVE_SIZE) == HFILE_ERROR)
		{
			nStatus = ERR_OS_ERROR;
			goto error;
		}

		// To prevent fragmentation, write zeroes to reserved header sectors which are going to be filled with random data
		if (!volParams->hiddenVol)
		{
			byte buf[TC_VOLUME_HEADER_GROUP_SIZE - TC_VOLUME_HEADER_EFFECTIVE_SIZE];
			ZeroMemory (buf, sizeof (buf));
			if (_lwrite ((HFILE) dev, buf, sizeof (buf)) == HFILE_ERROR)
			{
				nStatus = ERR_OS_ERROR;
				goto error;
			}
		}
	}

	if (volParams->hiddenVol)
	{
		// Calculate data area position of hidden volume
		cryptoInfo->hiddenVolumeOffset = dataOffset;

		// Validate the offset
		if (dataOffset % SECTOR_SIZE != 0)
		{
			nStatus = ERR_VOL_SIZE_WRONG; 
			goto error;
		}

		volParams->quickFormat = TRUE;		// To entirely format a hidden volume would be redundant
	}

	/* Data area */
	startSector = dataOffset / SECTOR_SIZE;

	// Format filesystem

	switch (volParams->fileSystem)
	{
	case FILESYS_NONE:
	case FILESYS_NTFS:

		if (volParams->bDevice && !StartFormatWriteThread())
		{
			nStatus = ERR_OS_ERROR; 
			goto error;
		}

		nStatus = FormatNoFs (startSector, num_sectors, dev, cryptoInfo, volParams->quickFormat);

		if (volParams->bDevice)
			StopFormatWriteThread();

		break;
		
	case FILESYS_FAT:
		if (num_sectors > 0xFFFFffff)
		{
			nStatus = ERR_VOL_SIZE_WRONG; 
			goto error;
		}

		// Calculate the fats, root dir etc
		ft.num_sectors = (unsigned int) (num_sectors);
		ft.cluster_size = volParams->clusterSize;
		memcpy (ft.volume_name, "NO NAME    ", 11);
		GetFatParams (&ft); 
		*(volParams->realClusterSize) = ft.cluster_size * SECTOR_SIZE;

		if (volParams->bDevice && !StartFormatWriteThread())
		{
			nStatus = ERR_OS_ERROR; 
			goto error;
		}

		nStatus = FormatFat (startSector, &ft, (void *) dev, cryptoInfo, volParams->quickFormat);

		if (volParams->bDevice)
			StopFormatWriteThread();

		break;

	default:
		nStatus = ERR_PARAMETER_INCORRECT; 
		goto error;
	}

	if (nStatus != ERR_SUCCESS)
		goto error;