VeraCrypt
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authorMounir IDRASSI <mounir.idrassi@idrix.fr>2016-08-07 22:49:00 (GMT)
committerMounir IDRASSI <mounir.idrassi@idrix.fr>2016-08-14 23:09:05 (GMT)
commit5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40 (patch)
tree49f9cc8a5cc65386b021566e9b7d7ec631923b79 /src/Format
parent3fb2eedab8ef586cd2686efba0b668a5070fd0af (diff)
downloadVeraCrypt-5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40.zip
VeraCrypt-5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40.tar.gz
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.
Diffstat (limited to 'src/Format')
-rw-r--r--src/Format/InPlace.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/src/Format/InPlace.c b/src/Format/InPlace.c
index d3b3212..f37cb8b 100644
--- a/src/Format/InPlace.c
+++ b/src/Format/InPlace.c
@@ -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