VeraCrypt
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authorMounir IDRASSI <mounir.idrassi@idrix.fr>2016-08-08 00:49:00 +0200
committerMounir IDRASSI <mounir.idrassi@idrix.fr>2016-08-15 01:09:05 +0200
commit5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40 (patch)
tree49f9cc8a5cc65386b021566e9b7d7ec631923b79 /src/Common/Format.c
parent3fb2eedab8ef586cd2686efba0b668a5070fd0af (diff)
downloadVeraCrypt-5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40.tar.gz
VeraCrypt-5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40.zip
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/Common/Format.c')
-rw-r--r--src/Common/Format.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/src/Common/Format.c b/src/Common/Format.c
index f3114e5e..7d6f3edb 100644
--- a/src/Common/Format.c
+++ b/src/Common/Format.c
@@ -566,10 +566,63 @@ begin_format:
// Fill reserved header sectors (including the backup header area) with random data
if (!volParams->hiddenVol)
{
+ BOOL bUpdateBackup = FALSE;
+
nStatus = WriteRandomDataToReservedHeaderAreas (hwndDlg, dev, cryptoInfo, dataAreaSize, FALSE, FALSE);
if (nStatus != ERR_SUCCESS)
goto error;
+
+ // write fake hidden volume header to protect against attacks that use statistical entropy
+ // analysis to detect presence of hidden volumes.
+
+ while (TRUE)
+ {
+ PCRYPTO_INFO dummyInfo = NULL;
+ LARGE_INTEGER hiddenOffset;
+
+ hiddenOffset.QuadPart = bUpdateBackup ? dataAreaSize + TC_VOLUME_HEADER_GROUP_SIZE + TC_HIDDEN_VOLUME_HEADER_OFFSET: TC_HIDDEN_VOLUME_HEADER_OFFSET;
+
+ nStatus = CreateVolumeHeaderInMemory (hwndDlg, FALSE,
+ header,
+ volParams->ea,
+ FIRST_MODE_OF_OPERATION_ID,
+ NULL,
+ 0,
+ 0,
+ NULL,
+ &dummyInfo,
+ dataAreaSize,
+ dataAreaSize,
+ dataOffset,
+ dataAreaSize,
+ 0,
+ volParams->headerFlags,
+ FormatSectorSize,
+ FALSE);
+
+ if (nStatus != ERR_SUCCESS)
+ goto error;
+
+ crypto_close (dummyInfo);
+
+ if (!SetFilePointerEx ((HANDLE) dev, hiddenOffset, NULL, FILE_BEGIN))
+ {
+ nStatus = ERR_OS_ERROR;
+ goto error;
+ }
+
+ if (!WriteEffectiveVolumeHeader (volParams->bDevice, dev, header))
+ {
+ nStatus = ERR_OS_ERROR;
+ goto error;
+ }
+
+ if (bUpdateBackup)
+ break;
+
+ bUpdateBackup = TRUE;
+ }
}
#ifndef DEBUG