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| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2016-08-08 00:49:00 +0200 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2016-08-15 01:09:05 +0200 |
| commit | 5b381ce7d7ec45e02765b4a180f9aa1ee8aeee40 (patch) | |
| tree | 49f9cc8a5cc65386b021566e9b7d7ec631923b79 /src/Common/Format.c | |
| parent | 3fb2eedab8ef586cd2686efba0b668a5070fd0af (diff) | |
| download | VeraCrypt-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.c | 53 |
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 |