VeraCrypt
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authorMounir IDRASSI <mounir.idrassi@idrix.fr>2019-10-25 13:08:53 +0200
committerMounir IDRASSI <mounir.idrassi@idrix.fr>2019-10-25 14:47:51 +0200
commit343d1a95dc711f0eba5d858967e57ad583b5aa0c (patch)
tree8155129a1b9c1e439df4c5b3ce06459772a3e6a8 /src/Common/BootEncryption.cpp
parentfaa541f613ffc9ebe3e53a84f448936d033e0a80 (diff)
downloadVeraCrypt-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.cpp75
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())