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| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2017-06-01 01:53:03 +0200 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2017-06-01 01:56:13 +0200 |
| commit | 55aa098295567868af26ca753e33cd9907d3b33d (patch) | |
| tree | 1c1ea675b52bed065611d57bac76638ea22293ff /src/Driver | |
| parent | 029341a7474ab7aa858a9f427c4c5c34713ecff0 (diff) | |
| download | VeraCrypt-55aa098295567868af26ca753e33cd9907d3b33d.tar.gz VeraCrypt-55aa098295567868af26ca753e33cd9907d3b33d.zip | |
Windows: fix high CPU usage when a favorite is configured to mount using VolumeID when its host device is connected to the machine.
Diffstat (limited to 'src/Driver')
| -rw-r--r-- | src/Driver/Ntdriver.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/src/Driver/Ntdriver.c b/src/Driver/Ntdriver.c index 3505826b..a84ada37 100644 --- a/src/Driver/Ntdriver.c +++ b/src/Driver/Ntdriver.c @@ -203,6 +203,16 @@ void DumpMemory (void *mem, int size) } } +BOOL IsAllZeroes (unsigned char* pbData, DWORD dwDataLen) +{ + while (dwDataLen--) + { + if (*pbData) + return FALSE; + pbData++; + } + return TRUE; +} BOOL ValidateIOBufferSize (PIRP irp, size_t requiredBufferSize, ValidateIOBufferSizeType type) { @@ -1293,7 +1303,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex InitializeObjectAttributes (&ObjectAttributes, &FullFileName, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL); - if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bMatchVolumeID) + if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bComputeVolumeIDs) access |= FILE_READ_DATA; ntStatus = ZwCreateFile (&NtFileHandle, @@ -1304,9 +1314,10 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex { opentest->TCBootLoaderDetected = FALSE; opentest->FilesystemDetected = FALSE; - opentest->VolumeIDMatched = FALSE; + memset (opentest->VolumeIDComputed, 0, sizeof (opentest->VolumeIDComputed)); + memset (opentest->volumeIDs, 0, sizeof (opentest->volumeIDs)); - if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bMatchVolumeID) + if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bComputeVolumeIDs) { byte *readBuffer = TCalloc (TC_MAX_VOLUME_SECTOR_SIZE); if (!readBuffer) @@ -1352,27 +1363,30 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex { switch (BE64 (*(uint64 *) readBuffer)) { - case 0xEB52904E54465320: // NTFS - case 0xEB3C904D53444F53: // FAT16/FAT32 - case 0xEB58904D53444F53: // FAT32 - case 0xEB76904558464154: // exFAT - case 0x0000005265465300: // ReFS - case 0xEB58906D6B66732E: // FAT32 mkfs.fat - case 0xEB58906D6B646F73: // FAT32 mkfs.vfat/mkdosfs - case 0xEB3C906D6B66732E: // FAT16/FAT12 mkfs.fat - case 0xEB3C906D6B646F73: // FAT16/FAT12 mkfs.vfat/mkdosfs + case 0xEB52904E54465320ULL: // NTFS + case 0xEB3C904D53444F53ULL: // FAT16/FAT32 + case 0xEB58904D53444F53ULL: // FAT32 + case 0xEB76904558464154ULL: // exFAT + case 0x0000005265465300ULL: // ReFS + case 0xEB58906D6B66732EULL: // FAT32 mkfs.fat + case 0xEB58906D6B646F73ULL: // FAT32 mkfs.vfat/mkdosfs + case 0xEB3C906D6B66732EULL: // FAT16/FAT12 mkfs.fat + case 0xEB3C906D6B646F73ULL: // FAT16/FAT12 mkfs.vfat/mkdosfs opentest->FilesystemDetected = TRUE; break; + case 0x0000000000000000ULL: + // all 512 bytes are zeroes => unencrypted filesystem like Microsoft reserved partition + if (IsAllZeroes (readBuffer + 8, TC_VOLUME_HEADER_EFFECTIVE_SIZE - 8)) + opentest->FilesystemDetected = TRUE; + break; } } } } - if (opentest->bMatchVolumeID) + if (opentest->bComputeVolumeIDs && (!opentest->DetectFilesystem || !opentest->FilesystemDetected)) { int volumeType; - BYTE volumeID[VOLUME_ID_SIZE]; - // Go through all volume types (e.g., normal, hidden) for (volumeType = TC_VOLUME_TYPE_NORMAL; volumeType < TC_VOLUME_TYPE_COUNT; @@ -1404,13 +1418,8 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex if (NT_SUCCESS (ntStatus)) { /* compute the ID of this volume: SHA-256 of the effective header */ - sha256 (volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE); - - if (0 == memcmp (volumeID, opentest->volumeID, VOLUME_ID_SIZE)) - { - opentest->VolumeIDMatched = TRUE; - break; - } + sha256 (opentest->volumeIDs[volumeType], readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE); + opentest->VolumeIDComputed[volumeType] = TRUE; } } } |