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Windows: Fix vulnerability inherited from TrueCrypt that allows an attacker to detect with high probability if a hidden volume is present. Vulnerability reported by Ivanov Alexey Mikhailovich.

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This commit is contained in:
Mounir IDRASSI
2016-08-08 00:49:00 +02:00
parent 3fb2eedab8
commit 5b381ce7d7
5 changed files with 286 additions and 30 deletions
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79
src/Format/InPlace.c
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@@ -566,6 +566,8 @@ int EncryptPartitionInPlaceBegin (volatile FORMAT_VOL_PARAMETERS *volParams, vol
// Prepare the backup header
for (int wipePass = 0; wipePass < (wipeAlgorithm == TC_WIPE_NONE ? 1 : PRAND_HEADER_WIPE_PASSES); wipePass++)
{
PCRYPTO_INFO dummyInfo = NULL;
nStatus = CreateVolumeHeaderInMemory (hwndDlg, FALSE,
header,
volParams->ea,
@@ -607,6 +609,47 @@ int EncryptPartitionInPlaceBegin (volatile FORMAT_VOL_PARAMETERS *volParams, vol
if (nStatus != ERR_SUCCESS)
goto closing_seq;
// write fake hidden volume header to protect against attacks that use statistical entropy
// analysis to detect presence of hidden volumes
nStatus = CreateVolumeHeaderInMemory (hwndDlg, FALSE,
header,
volParams->ea,
FIRST_MODE_OF_OPERATION_ID,
NULL,
0,
0,
NULL,
&dummyInfo,
dataAreaSize,
dataAreaSize,
TC_VOLUME_DATA_OFFSET + dataAreaSize, // Start of the encrypted area = the first byte of the backup heeader (encrypting from the end)
dataAreaSize, // No data is encrypted yet
0,
volParams->headerFlags | TC_HEADER_FLAG_NONSYS_INPLACE_ENC,
volParams->sectorSize,
wipeAlgorithm == TC_WIPE_NONE ? FALSE : (wipePass < PRAND_HEADER_WIPE_PASSES - 1));
if (nStatus != ERR_SUCCESS)
goto closing_seq;
crypto_close (dummyInfo);
offset.QuadPart += TC_HIDDEN_VOLUME_HEADER_OFFSET;
if (!SetFilePointerEx (dev, offset, NULL, FILE_BEGIN))
{
nStatus = ERR_OS_ERROR;
goto closing_seq;
}
// Write the fake hidden backup header to the partition
if (!WriteEffectiveVolumeHeader (TRUE, dev, (byte *) header))
{
nStatus = ERR_OS_ERROR;
goto closing_seq;
}
}
@@ -1045,6 +1088,8 @@ inplace_enc_read:
for (int wipePass = 0; wipePass < (wipeAlgorithm == TC_WIPE_NONE ? 1 : PRAND_HEADER_WIPE_PASSES); wipePass++)
{
PCRYPTO_INFO dummyInfo = NULL;
nStatus = CreateVolumeHeaderInMemory (hwndDlg, FALSE,
header,
headerCryptoInfo->ea,
@@ -1081,6 +1126,40 @@ inplace_enc_read:
if (nStatus != ERR_SUCCESS)
goto closing_seq;
// write fake hidden volume header to protect against attacks that use statistical entropy
// analysis to detect presence of hidden volumes
nStatus = CreateVolumeHeaderInMemory (hwndDlg, FALSE,
header,
headerCryptoInfo->ea,
headerCryptoInfo->mode,
NULL,
0,
0,
NULL,
&dummyInfo,
masterCryptoInfo->VolumeSize.Value,
masterCryptoInfo->VolumeSize.Value,
masterCryptoInfo->EncryptedAreaStart.Value,
masterCryptoInfo->EncryptedAreaLength.Value,
masterCryptoInfo->RequiredProgramVersion,
masterCryptoInfo->HeaderFlags | TC_HEADER_FLAG_NONSYS_INPLACE_ENC,
masterCryptoInfo->SectorSize,
wipeAlgorithm == TC_WIPE_NONE ? FALSE : (wipePass < PRAND_HEADER_WIPE_PASSES - 1));
if (nStatus != ERR_SUCCESS)
goto closing_seq;
crypto_close (dummyInfo);
offset.QuadPart += TC_HIDDEN_VOLUME_HEADER_OFFSET;
if (SetFilePointerEx (dev, offset, NULL, FILE_BEGIN) == 0
|| !WriteEffectiveVolumeHeader (TRUE, dev, (byte *) header))
{
nStatus = ERR_OS_ERROR;
goto closing_seq;
}
}
// Update the configuration files