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| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2019-10-25 13:08:53 +0200 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2019-10-25 14:47:51 +0200 |
| commit | 343d1a95dc711f0eba5d858967e57ad583b5aa0c (patch) | |
| tree | 8155129a1b9c1e439df4c5b3ce06459772a3e6a8 /src/Common/BootEncryption.cpp | |
| parent | faa541f613ffc9ebe3e53a84f448936d033e0a80 (diff) | |
| download | VeraCrypt-343d1a95dc711f0eba5d858967e57ad583b5aa0c.tar.gz VeraCrypt-343d1a95dc711f0eba5d858967e57ad583b5aa0c.zip | |
Windows: only update MBR first 512 bytes if they have changed and don't update full MBR bootload in case of PostOOBE
Diffstat (limited to 'src/Common/BootEncryption.cpp')
| -rw-r--r-- | src/Common/BootEncryption.cpp | 75 |
1 files changed, 45 insertions, 30 deletions
diff --git a/src/Common/BootEncryption.cpp b/src/Common/BootEncryption.cpp index 9a04bb79..16fac487 100644 --- a/src/Common/BootEncryption.cpp +++ b/src/Common/BootEncryption.cpp @@ -3490,50 +3490,65 @@ namespace VeraCrypt } else { - byte bootLoaderBuf[TC_BOOT_LOADER_AREA_SIZE - TC_BOOT_ENCRYPTION_VOLUME_HEADER_SIZE] = {0}; - CreateBootLoaderInMemory (bootLoaderBuf, sizeof (bootLoaderBuf), false, hiddenOSCreation); + try + { + byte bootLoaderBuf[TC_BOOT_LOADER_AREA_SIZE - TC_BOOT_ENCRYPTION_VOLUME_HEADER_SIZE] = {0}; + CreateBootLoaderInMemory (bootLoaderBuf, sizeof (bootLoaderBuf), false, hiddenOSCreation); - // Write MBR - byte mbr[TC_SECTOR_SIZE_BIOS]; + // Write MBR + byte mbr[TC_SECTOR_SIZE_BIOS]; - device.SeekAt (0); - device.Read (mbr, sizeof (mbr)); + device.SeekAt (0); + device.Read (mbr, sizeof (mbr)); - if (preserveUserConfig && BufferContainsString (mbr, sizeof (mbr), TC_APP_NAME)) - { - uint16 version = BE16 (*(uint16 *) (mbr + TC_BOOT_SECTOR_VERSION_OFFSET)); - if (version != 0) + if (preserveUserConfig && BufferContainsString (mbr, sizeof (mbr), TC_APP_NAME)) { - bootLoaderBuf[TC_BOOT_SECTOR_USER_CONFIG_OFFSET] = mbr[TC_BOOT_SECTOR_USER_CONFIG_OFFSET]; - memcpy (bootLoaderBuf + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, mbr + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, TC_BOOT_SECTOR_USER_MESSAGE_MAX_LENGTH); - - if (bootLoaderBuf[TC_BOOT_SECTOR_USER_CONFIG_OFFSET] & TC_BOOT_USER_CFG_FLAG_DISABLE_PIM) + uint16 version = BE16 (*(uint16 *) (mbr + TC_BOOT_SECTOR_VERSION_OFFSET)); + if (version != 0) { - if (pim >= 0) + bootLoaderBuf[TC_BOOT_SECTOR_USER_CONFIG_OFFSET] = mbr[TC_BOOT_SECTOR_USER_CONFIG_OFFSET]; + memcpy (bootLoaderBuf + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, mbr + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, TC_BOOT_SECTOR_USER_MESSAGE_MAX_LENGTH); + + if (bootLoaderBuf[TC_BOOT_SECTOR_USER_CONFIG_OFFSET] & TC_BOOT_USER_CFG_FLAG_DISABLE_PIM) { - memcpy (bootLoaderBuf + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, &pim, TC_BOOT_SECTOR_PIM_VALUE_SIZE); + if (pim >= 0) + { + memcpy (bootLoaderBuf + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, &pim, TC_BOOT_SECTOR_PIM_VALUE_SIZE); + } + else + memcpy (bootLoaderBuf + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, mbr + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, TC_BOOT_SECTOR_PIM_VALUE_SIZE); } - else - memcpy (bootLoaderBuf + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, mbr + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, TC_BOOT_SECTOR_PIM_VALUE_SIZE); } } - } - memcpy (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE); + // perform actual write only if content is different + if (memcmp (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE)) + { + memcpy (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE); - device.SeekAt (0); - device.Write (mbr, sizeof (mbr)); + device.SeekAt (0); + device.Write (mbr, sizeof (mbr)); - byte mbrVerificationBuf[TC_SECTOR_SIZE_BIOS]; - device.SeekAt (0); - device.Read (mbrVerificationBuf, sizeof (mbr)); + byte mbrVerificationBuf[TC_SECTOR_SIZE_BIOS]; + device.SeekAt (0); + device.Read (mbrVerificationBuf, sizeof (mbr)); - if (memcmp (mbr, mbrVerificationBuf, sizeof (mbr)) != 0) - throw ErrorException ("ERROR_MBR_PROTECTED", SRC_POS); + if (memcmp (mbr, mbrVerificationBuf, sizeof (mbr)) != 0) + throw ErrorException ("ERROR_MBR_PROTECTED", SRC_POS); + } - // Write boot loader - device.SeekAt (TC_SECTOR_SIZE_BIOS); - device.Write (bootLoaderBuf + TC_SECTOR_SIZE_BIOS, sizeof (bootLoaderBuf) - TC_SECTOR_SIZE_BIOS); + if (!PostOOBEMode) + { + // Write boot loader + device.SeekAt (TC_SECTOR_SIZE_BIOS); + device.Write (bootLoaderBuf + TC_SECTOR_SIZE_BIOS, sizeof (bootLoaderBuf) - TC_SECTOR_SIZE_BIOS); + } + } + catch (...) + { + if (!PostOOBEMode) + throw; + } } if (!IsAdmin() && IsUacSupported()) |