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Windows: enhancements to the mechanism preserving file timestamps, especially for keyfiles.

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This commit is contained in:
Mounir IDRASSI 2019-12-08 22:51:49 +01:00
parent 7f1e21e6a1
commit 5e96a5c44c
No known key found for this signature in database
GPG Key ID: 02C30AE90FAE4A6F
8 changed files with 139 additions and 79 deletions
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11
src/Common/Dlgcode.c
View File

@ -11238,10 +11238,8 @@ int OpenVolume (OpenVolumeContext *context, const wchar_t *volumePath, Password
else
StringCbCopyW (szCFDevice, sizeof(szCFDevice), szDiskFile);
if (preserveTimestamps)
write = TRUE;
context->HostFileHandle = CreateFile (szCFDevice, GENERIC_READ | (write ? GENERIC_WRITE : 0), FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
context->HostFileHandle = CreateFile (szCFDevice, GENERIC_READ | (write ? GENERIC_WRITE : (!context->IsDevice && preserveTimestamps? FILE_WRITE_ATTRIBUTES : 0)), FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
if (context->HostFileHandle == INVALID_HANDLE_VALUE)
{
@ -11263,6 +11261,13 @@ int OpenVolume (OpenVolumeContext *context, const wchar_t *volumePath, Password
// Remember the container modification/creation date and time
if (!context->IsDevice && preserveTimestamps)
{
// ensure that Last Access and Last Write timestamps are not modified
FILETIME ftLastAccessTime;
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (context->HostFileHandle, NULL, &ftLastAccessTime, NULL);
if (GetFileTime (context->HostFileHandle, &context->CreationTime, &context->LastAccessTime, &context->LastWriteTime) == 0)
context->TimestampsValid = FALSE;
else

21
src/Common/Format.c
View File

@ -350,6 +350,19 @@ int TCFormatVolume (volatile FORMAT_VOL_PARAMETERS *volParams)
nStatus = ERR_OS_ERROR;
goto error;
}
else if (volParams->hiddenVol && bPreserveTimestamp)
{
// ensure that Last Access and Last Write timestamps are not modified
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (dev, NULL, &ftLastAccessTime, NULL);
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
DisableFileCompression (dev);
@ -380,14 +393,6 @@ int TCFormatVolume (volatile FORMAT_VOL_PARAMETERS *volParams)
}
}
if (volParams->hiddenVol && !volParams->bDevice && bPreserveTimestamp)
{
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
if (volParams->hwndDlg && volParams->bGuiMode) KillTimer (volParams->hwndDlg, TIMER_ID_RANDVIEW);
/* Volume header */

61
src/Common/Keyfiles.c
View File

@ -149,50 +149,41 @@ void KeyFileCloneAll (KeyFile *firstKeyFile, KeyFile **outputKeyFile)
static BOOL KeyFileProcess (unsigned __int8 *keyPool, unsigned __int32 keyPoolSize, KeyFile *keyFile)
{
FILE *f;
unsigned __int8 buffer[64 * 1024];
unsigned __int32 crc = 0xffffffff;
unsigned __int32 writePos = 0;
size_t bytesRead, totalRead = 0;
DWORD bytesRead, totalRead = 0;
int status = TRUE;
HANDLE src;
FILETIME ftCreationTime;
FILETIME ftLastWriteTime;
FILETIME ftLastAccessTime;
BOOL bReadStatus = FALSE;
BOOL bTimeStampValid = FALSE;
/* Remember the last access time of the keyfile. It will be preserved in order to prevent
an adversary from determining which file may have been used as keyfile. */
src = CreateFile (keyFile->FileName,
GENERIC_READ | GENERIC_WRITE,
GENERIC_READ | FILE_WRITE_ATTRIBUTES,
FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
if (src != INVALID_HANDLE_VALUE)
{
if (GetFileTime ((HANDLE) src, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime))
bTimeStampValid = TRUE;
/* We tell Windows not to update the Last Access timestamp in order to prevent
an adversary from determining which file may have been used as keyfile. */
FILETIME ftLastAccessTime;
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (src, NULL, &ftLastAccessTime, NULL);
}
else
{
/* try to open without FILE_WRITE_ATTRIBUTES in case we are in a ReadOnly filesystem (e.g. CD) */
src = CreateFile (keyFile->FileName,
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
if (src == INVALID_HANDLE_VALUE)
return FALSE;
}
finally_do_arg (HANDLE, src,
while ((bReadStatus = ReadFile (src, buffer, sizeof (buffer), &bytesRead, NULL)) && (bytesRead > 0))
{
if (finally_arg != INVALID_HANDLE_VALUE)
CloseHandle (finally_arg);
});
f = _wfopen (keyFile->FileName, L"rb");
if (f == NULL) return FALSE;
while ((bytesRead = fread (buffer, 1, sizeof (buffer), f)) > 0)
{
size_t i;
if (ferror (f))
{
status = FALSE;
goto close;
}
DWORD i;
for (i = 0; i < bytesRead; i++)
{
@ -211,7 +202,7 @@ static BOOL KeyFileProcess (unsigned __int8 *keyPool, unsigned __int32 keyPoolSi
}
}
if (ferror (f))
if (!bReadStatus)
{
status = FALSE;
}
@ -223,13 +214,9 @@ static BOOL KeyFileProcess (unsigned __int8 *keyPool, unsigned __int32 keyPoolSi
close:
DWORD err = GetLastError();
fclose (f);
if (bTimeStampValid && !IsFileOnReadOnlyFilesystem (keyFile->FileName))
{
// Restore the keyfile timestamp
SetFileTime (src, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime);
}
CloseHandle (src);
burn (buffer, sizeof (buffer));
SetLastError (err);
return status;

20
src/Common/Password.c
View File

@ -224,6 +224,19 @@ int ChangePwd (const wchar_t *lpszVolume, Password *oldPassword, int old_pkcs5,
if (dev == INVALID_HANDLE_VALUE)
goto error;
else if (!bDevice && bPreserveTimestamp)
{
// ensure that Last Access and Last Write timestamps are not modified
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (dev, NULL, &ftLastAccessTime, NULL);
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
if (bDevice)
{
@ -313,13 +326,6 @@ int ChangePwd (const wchar_t *lpszVolume, Password *oldPassword, int old_pkcs5,
SetRandomPoolEnrichedByUserStatus (FALSE); /* force the display of the random enriching dialog */
if (!bDevice && bPreserveTimestamp)
{
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
for (volumeType = TC_VOLUME_TYPE_NORMAL; volumeType < TC_VOLUME_TYPE_COUNT; volumeType++)
{

34
src/Driver/Ntvol.c
View File

@ -303,7 +303,7 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
if (mount->bMountReadOnly || ntStatus == STATUS_ACCESS_DENIED)
{
ntStatus = ZwCreateFile (&Extension->hDeviceFile,
GENERIC_READ | SYNCHRONIZE,
GENERIC_READ | (!bRawDevice && mount->bPreserveTimestamp? FILE_WRITE_ATTRIBUTES : 0) | SYNCHRONIZE,
&oaFileAttributes,
&IoStatusBlock,
NULL,
@ -318,6 +318,26 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
NULL,
0);
if (!NT_SUCCESS (ntStatus) && !bRawDevice && mount->bPreserveTimestamp)
{
/* try again without FILE_WRITE_ATTRIBUTES */
ntStatus = ZwCreateFile (&Extension->hDeviceFile,
GENERIC_READ | SYNCHRONIZE,
&oaFileAttributes,
&IoStatusBlock,
NULL,
FILE_ATTRIBUTE_NORMAL |
FILE_ATTRIBUTE_SYSTEM,
exclusiveAccess ? FILE_SHARE_READ : FILE_SHARE_READ | FILE_SHARE_WRITE,
FILE_OPEN,
FILE_RANDOM_ACCESS |
FILE_WRITE_THROUGH |
(disableBuffering ? FILE_NO_INTERMEDIATE_BUFFERING : 0) |
FILE_SYNCHRONOUS_IO_NONALERT,
NULL,
0);
}
if (NT_SUCCESS (ntStatus) && !mount->bMountReadOnly)
mount->VolumeMountedReadOnlyAfterAccessDenied = TRUE;
@ -362,6 +382,18 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
Extension->fileLastWriteTime = FileBasicInfo.LastWriteTime;
Extension->fileLastChangeTime = FileBasicInfo.ChangeTime;
Extension->bTimeStampValid = TRUE;
// we tell the system not to update LastAccessTime, LastWriteTime, and ChangeTime
FileBasicInfo.CreationTime.QuadPart = 0;
FileBasicInfo.LastAccessTime.QuadPart = -1;
FileBasicInfo.LastWriteTime.QuadPart = -1;
FileBasicInfo.ChangeTime.QuadPart = -1;
ZwSetInformationFile (Extension->hDeviceFile,
&IoStatusBlock,
&FileBasicInfo,
sizeof (FileBasicInfo),
FileBasicInformation);
}
ntStatus = ZwQueryInformationFile (Extension->hDeviceFile,

35
src/ExpandVolume/ExpandVolume.c
View File

@ -535,6 +535,27 @@ static int ExpandVolume (HWND hwndDlg, wchar_t *lpszVolume, Password *pVolumePas
if (dev == INVALID_HANDLE_VALUE)
goto error;
else if (!bDevice && bPreserveTimestamp)
{
// ensure that Last Access and Last Time timestamps are not modified
// in order to preserve plausible deniability of hidden volumes (last password change time is stored in the volume header).
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (dev, NULL, &ftLastAccessTime, NULL);
/* Remember the container modification/creation date and time, (used to reset file date and time of
file-hosted volumes after password change (or attempt to), in order to preserve plausible deniability
of hidden volumes (last password change time is stored in the volume header). */
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
{
bTimeStampValid = FALSE;
MessageBoxW (hwndDlg, GetString ("GETFILETIME_FAILED_PW"), lpszTitle, MB_OK | MB_ICONEXCLAMATION);
}
else
bTimeStampValid = TRUE;
}
if (bDevice)
{
@ -628,20 +649,6 @@ static int ExpandVolume (HWND hwndDlg, wchar_t *lpszVolume, Password *pVolumePas
goto error;
}
if (!bDevice && bPreserveTimestamp)
{
/* Remember the container modification/creation date and time, (used to reset file date and time of
file-hosted volumes after password change (or attempt to), in order to preserve plausible deniability
of hidden volumes (last password change time is stored in the volume header). */
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
{
bTimeStampValid = FALSE;
MessageBoxW (hwndDlg, GetString ("GETFILETIME_FAILED_PW"), lpszTitle, MB_OK | MB_ICONEXCLAMATION);
}
else
bTimeStampValid = TRUE;
}
// Seek the volume header
headerOffset.QuadPart = TC_VOLUME_HEADER_OFFSET;

12
src/Format/Tcformat.c
View File

@ -3313,6 +3313,12 @@ BOOL IsSparseFile (HWND hwndDlg)
if (bPreserveTimestamp)
{
FILETIME ftLastAccessTime;
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (hFile, NULL, &ftLastAccessTime, NULL);
if (GetFileTime (hFile, NULL, &ftLastAccessTime, NULL) == 0)
bTimeStampValid = FALSE;
else
@ -3352,6 +3358,12 @@ BOOL GetFileVolSize (HWND hwndDlg, unsigned __int64 *size)
if (bPreserveTimestamp)
{
FILETIME ftLastAccessTime;
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (hFile, NULL, &ftLastAccessTime, NULL);
if (GetFileTime (hFile, NULL, &ftLastAccessTime, NULL) == 0)
bTimeStampValid = FALSE;
else

24
src/Mount/Mount.c
View File

@ -10861,6 +10861,21 @@ int RestoreVolumeHeader (HWND hwndDlg, const wchar_t *lpszVolume)
nStatus = ERR_OS_ERROR;
goto error;
}
else if (!bDevice && bPreserveTimestamp)
{
// ensure that Last Access timestamp is not modified
ftLastAccessTime.dwHighDateTime = 0xFFFFFFFF;
ftLastAccessTime.dwLowDateTime = 0xFFFFFFFF;
SetFileTime (dev, NULL, &ftLastAccessTime, NULL);
/* Remember the container modification/creation date and time. */
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
// Determine volume host size
if (bDevice)
@ -10931,15 +10946,6 @@ int RestoreVolumeHeader (HWND hwndDlg, const wchar_t *lpszVolume)
hostSize = fileSize.QuadPart;
}
if (!bDevice && bPreserveTimestamp)
{
/* Remember the container modification/creation date and time. */
if (GetFileTime ((HANDLE) dev, &ftCreationTime, &ftLastAccessTime, &ftLastWriteTime) == 0)
bTimeStampValid = FALSE;
else
bTimeStampValid = TRUE;
}
/* Read the volume header from the backup file */
char buffer[TC_VOLUME_HEADER_GROUP_SIZE];