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| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2016-04-20 00:30:28 +0200 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2016-04-20 00:48:20 +0200 |
| commit | 1396269d573256248bece97e1e291ef0c08e513f (patch) | |
| tree | e43c8e0a26d2d6ce0b84caa5200df585ab4d9a72 /src/Common/BootEncryption.cpp | |
| parent | bd9105794b1103e814e983e15e35ce139e6c2371 (diff) | |
| download | VeraCrypt-1396269d573256248bece97e1e291ef0c08e513f.tar.gz VeraCrypt-1396269d573256248bece97e1e291ef0c08e513f.zip | |
Windows: Add option to avoid PIM prompt in pre-boot authentication by storing PIM value unencrypted in MBR.
Diffstat (limited to 'src/Common/BootEncryption.cpp')
| -rw-r--r-- | src/Common/BootEncryption.cpp | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/src/Common/BootEncryption.cpp b/src/Common/BootEncryption.cpp index 07eb9a99..851d7622 100644 --- a/src/Common/BootEncryption.cpp +++ b/src/Common/BootEncryption.cpp @@ -1300,7 +1300,7 @@ namespace VeraCrypt }
- void BootEncryption::WriteBootSectorUserConfig (byte userConfig, const string &customUserMessage)
+ void BootEncryption::WriteBootSectorUserConfig (byte userConfig, const string &customUserMessage, int pim)
{
Device device (GetSystemDriveConfiguration().DevicePath);
device.CheckOpened (SRC_POS);
@@ -1326,6 +1326,15 @@ namespace VeraCrypt memcpy (mbr + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, customUserMessage.c_str(), customUserMessage.size());
}
+
+ if (userConfig & TC_BOOT_USER_CFG_FLAG_DISABLE_PIM)
+ {
+ // PIM for pre-boot authentication can be encoded on two bytes since its maximum
+ // value is 65535 (0xFFFF)
+ memcpy (mbr + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, &pim, TC_BOOT_SECTOR_PIM_VALUE_SIZE);
+ }
+ else
+ memset (mbr + TC_BOOT_SECTOR_PIM_VALUE_OFFSET, 0, TC_BOOT_SECTOR_PIM_VALUE_SIZE);
device.SeekAt (0);
device.Write (mbr, sizeof (mbr));
@@ -1494,7 +1503,7 @@ namespace VeraCrypt InstallBootLoader (device, preserveUserConfig, hiddenOSCreation);
}
- void BootEncryption::InstallBootLoader (Device& device, bool preserveUserConfig, bool hiddenOSCreation)
+ void BootEncryption::InstallBootLoader (Device& device, bool preserveUserConfig, bool hiddenOSCreation, int pim)
{
byte bootLoaderBuf[TC_BOOT_LOADER_AREA_SIZE - TC_BOOT_ENCRYPTION_VOLUME_HEADER_SIZE] = {0};
CreateBootLoaderInMemory (bootLoaderBuf, sizeof (bootLoaderBuf), false, hiddenOSCreation);
@@ -1512,6 +1521,16 @@ namespace VeraCrypt {
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)
+ {
+ 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);
+ }
}
}
@@ -2499,17 +2518,32 @@ namespace VeraCrypt if (headerUpdated)
{
+ bool storedPimUpdateNeeded = false;
ReopenBootVolumeHeaderRequest reopenRequest;
reopenRequest.VolumePassword = *newPassword;
reopenRequest.pkcs5_prf = cryptoInfo->pkcs5;
reopenRequest.pim = pim;
finally_do_arg (ReopenBootVolumeHeaderRequest*, &reopenRequest, { burn (finally_arg, sizeof (*finally_arg)); });
+ if (old_pim != pim)
+ {
+ try
+ {
+ // check if PIM is stored in MBR
+ byte userConfig;
+ ReadBootSectorConfig (nullptr, 0, &userConfig);
+ if (userConfig & TC_BOOT_USER_CFG_FLAG_DISABLE_PIM)
+ storedPimUpdateNeeded = true;
+ }
+ catch (...)
+ {}
+ }
+
try
{
- // force update of bootloader if fingerprint doesn't match
- if (!CheckBootloaderFingerprint (true))
- InstallBootLoader (device, true);
+ // force update of bootloader if fingerprint doesn't match or if the stored PIM changed
+ if (storedPimUpdateNeeded || !CheckBootloaderFingerprint (true))
+ InstallBootLoader (device, true, false, pim);
}
catch (...)
{}
|