From 5e96a5c44c3c78a901d77297517fa4842a297eb9 Mon Sep 17 00:00:00 2001 From: Mounir IDRASSI Date: Sun, 8 Dec 2019 22:51:49 +0100 Subject: Windows: enhancements to the mechanism preserving file timestamps, especially for keyfiles. --- src/Common/Dlgcode.c | 11 +++++++--- src/Common/Format.c | 21 +++++++++++------- src/Common/Keyfiles.c | 59 ++++++++++++++++++++------------------------------- src/Common/Password.c | 20 +++++++++++------ 4 files changed, 57 insertions(+), 54 deletions(-) (limited to 'src/Common') diff --git a/src/Common/Dlgcode.c b/src/Common/Dlgcode.c index 47578b27..5a837865 100644 --- a/src/Common/Dlgcode.c +++ b/src/Common/Dlgcode.c @@ -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 diff --git a/src/Common/Format.c b/src/Common/Format.c index bd33f754..82c4df55 100644 --- a/src/Common/Format.c +++ b/src/Common/Format.c @@ -350,6 +350,19 @@ begin_format: 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 @@ begin_format: } } - 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 */ diff --git a/src/Common/Keyfiles.c b/src/Common/Keyfiles.c index 686f3ca8..174aed92 100644 --- a/src/Common/Keyfiles.c +++ b/src/Common/Keyfiles.c @@ -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 bTimeStampValid = FALSE; + BOOL bReadStatus = 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; - finally_do_arg (HANDLE, src, + SetFileTime (src, NULL, &ftLastAccessTime, NULL); + } + else { - if (finally_arg != INVALID_HANDLE_VALUE) - CloseHandle (finally_arg); - }); - - f = _wfopen (keyFile->FileName, L"rb"); - if (f == NULL) return FALSE; + /* 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; + } - while ((bytesRead = fread (buffer, 1, sizeof (buffer), f)) > 0) + while ((bReadStatus = ReadFile (src, buffer, sizeof (buffer), &bytesRead, NULL)) && (bytesRead > 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; diff --git a/src/Common/Password.c b/src/Common/Password.c index ca0dd468..f2413b6d 100644 --- a/src/Common/Password.c +++ b/src/Common/Password.c @@ -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++) { -- cgit v1.2.3