From ac53e293d4c6ac06e1376c28cb8b96efb844bc75 Mon Sep 17 00:00:00 2001 From: kavsrf Date: Sat, 10 Dec 2016 15:07:56 +0300 Subject: comments and better cleanup Signed-off-by: kavsrf --- src/Driver/DriveFilter.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) (limited to 'src/Driver') diff --git a/src/Driver/DriveFilter.c b/src/Driver/DriveFilter.c index b8aad224..47a592dd 100644 --- a/src/Driver/DriveFilter.c +++ b/src/Driver/DriveFilter.c @@ -135,6 +135,7 @@ NTSTATUS LoadBootArguments () burn (BootLoaderFingerprint, sizeof (BootLoaderFingerprint)); MmUnmapIoSpace (mappedBootArgs, sizeof (BootArguments)); + // Extra parameters? (pkcs5, hash) if (BootArgs.CryptoInfoLength > 0) { PHYSICAL_ADDRESS cryptoInfoAddress; @@ -146,11 +147,12 @@ NTSTATUS LoadBootArguments () { /* Get the parameters used for booting to speed up driver startup and avoid testing irrelevant PRFs */ BOOT_CRYPTO_HEADER* pBootCryptoInfo = (BOOT_CRYPTO_HEADER*) mappedCryptoInfo; - BootPkcs5 = pBootCryptoInfo->pkcs5; + BootPkcs5 = pBootCryptoInfo->pkcs5; // save hash to speed up boot. BootSecRegionData = NULL; BootSecRegionSize = 0; + // SecRegion data? if(BootArgs.CryptoInfoLength > (sizeof(BOOT_CRYPTO_HEADER) + sizeof(SECREGION_BOOT_PARAMS)) ) { uint32 crc; PHYSICAL_ADDRESS SecRegionAddress; @@ -159,25 +161,27 @@ NTSTATUS LoadBootArguments () SecRegionAddress.QuadPart = SecRegionParams->Ptr; Dump ("SecRegion memory 0x%x %d\n", SecRegionAddress.LowPart, SecRegionParams->Size); - + // SecRegion correct? if( (SecRegionParams->Ptr != 0) && (SecRegionParams->Size > 0)) { crc = GetCrc32((byte*)SecRegionParams, 12); if(crc == SecRegionParams->Crc) { Dump ("SecRegion crc ok\n"); secRegionData = MmMapIoSpace (SecRegionAddress, SecRegionParams->Size, MmCached); - BootSecRegionData = TCalloc (SecRegionParams->Size); - if(BootSecRegionData != NULL) { - BootSecRegionSize = SecRegionParams->Size; - memcpy(BootSecRegionData, secRegionData, SecRegionParams->Size); + if(secRegionData) { + BootSecRegionData = TCalloc (SecRegionParams->Size); + if(BootSecRegionData != NULL) { + BootSecRegionSize = SecRegionParams->Size; + memcpy(BootSecRegionData, secRegionData, SecRegionParams->Size); + } + burn (secRegionData, SecRegionParams->Size); + MmUnmapIoSpace (secRegionData, SecRegionParams->Size); } - burn (secRegionData, SecRegionParams->Size); - MmUnmapIoSpace (secRegionData, SecRegionParams->Size); } - // Erase boot loader scheduled keys - burn (mappedCryptoInfo, BootArgs.CryptoInfoLength); - MmUnmapIoSpace (mappedCryptoInfo, BootArgs.CryptoInfoLength); } } + // Erase boot loader scheduled keys + burn (mappedCryptoInfo, BootArgs.CryptoInfoLength); + MmUnmapIoSpace (mappedCryptoInfo, BootArgs.CryptoInfoLength); } } status = STATUS_SUCCESS; @@ -371,6 +375,7 @@ static NTSTATUS MountDrive (DriveFilterExtension *Extension, Password *password, Dump ("MountDrive pdo=%p\n", Extension->Pdo); ASSERT (KeGetCurrentIrql() == PASSIVE_LEVEL); + // Check disk MBR id and GPT ID if BootSecRegion is available to detect boot drive if (BootSecRegionData != NULL && BootSecRegionSize >= 1024) { byte mbr[TC_SECTOR_SIZE_BIOS]; DCS_DISK_ENTRY_LIST* DeList = (DCS_DISK_ENTRY_LIST*)(BootSecRegionData + 512); @@ -388,8 +393,10 @@ static NTSTATUS MountDrive (DriveFilterExtension *Extension, Password *password, header = TCalloc (TC_BOOT_ENCRYPTION_VOLUME_HEADER_SIZE); if (!header) return STATUS_INSUFFICIENT_RESOURCES; + // Copy header from SecRegion instead of read from disk memcpy(header, BootSecRegionData, 512); - // Set extra data for the disk + + // Set SecRegion data for the disk (sectors to substitute to hide GPT table) Extension->Queue.SecRegionData = BootSecRegionData; Extension->Queue.SecRegionSize = BootSecRegionSize; } else { @@ -538,6 +545,7 @@ static NTSTATUS MountDrive (DriveFilterExtension *Extension, Password *password, BootDriveFound = Extension->BootDrive = Extension->DriveMounted = Extension->VolumeHeaderPresent = TRUE; BootDriveFilterExtension->MagicNumber = TC_BOOT_DRIVE_FILTER_EXTENSION_MAGIC_NUMBER; + // Try to load password cached if saved in SecRegion if (BootSecRegionData != NULL && BootSecRegionSize > 1024) { DCS_DISK_ENTRY_LIST* DeList = (DCS_DISK_ENTRY_LIST*)(BootSecRegionData + 512); uint32 crc; -- cgit v1.2.3