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Windows: Add implementation of ChaCha20 based random generator. Use it for driver need of random bytes (currently only wipe bytes but more to come later).

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This commit is contained in:
Mounir IDRASSI
2019-02-08 01:48:12 +01:00
parent e5b9cee868
commit ba5da0946c
17 changed files with 1015 additions and 37 deletions
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60
src/Driver/Ntdriver.c
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@@ -30,6 +30,8 @@
#include "Cache.h"
#include "Volumes.h"
#include "VolumeFilter.h"
#include "cpu.h"
#include "rdrand.h"
#include <tchar.h>
#include <initguid.h>
@@ -143,6 +145,64 @@ ULONG ExDefaultMdlProtection = 0;
PDEVICE_OBJECT VirtualVolumeDeviceObjects[MAX_MOUNTED_VOLUME_DRIVE_NUMBER + 1];
void GetDriverRandomSeed (unsigned char* pbRandSeed, size_t cbRandSeed)
{
LARGE_INTEGER iSeed, iSeed2;
byte digest[WHIRLPOOL_DIGESTSIZE];
WHIRLPOOL_CTX tctx;
size_t count;
#ifndef _WIN64
KFLOATING_SAVE floatingPointState;
NTSTATUS saveStatus = STATUS_INVALID_PARAMETER;
if (HasISSE())
saveStatus = KeSaveFloatingPointState (&floatingPointState);
#endif
while (cbRandSeed)
{
WHIRLPOOL_init (&tctx);
// we hash current content of digest buffer which is initialized the first time
WHIRLPOOL_add (digest, WHIRLPOOL_DIGESTSIZE, &tctx);
// we use various time information as source of entropy
KeQuerySystemTime( &iSeed );
WHIRLPOOL_add ((unsigned char *) &(iSeed.QuadPart), sizeof(iSeed.QuadPart), &tctx);
iSeed = KeQueryPerformanceCounter (&iSeed2);
WHIRLPOOL_add ((unsigned char *) &(iSeed.QuadPart), sizeof(iSeed.QuadPart), &tctx);
WHIRLPOOL_add ((unsigned char *) &(iSeed2.QuadPart), sizeof(iSeed2.QuadPart), &tctx);
iSeed.QuadPart = KeQueryInterruptTime ();
WHIRLPOOL_add ((unsigned char *) &(iSeed.QuadPart), sizeof(iSeed.QuadPart), &tctx);
// use RDSEED or RDRAND from CPU as source of entropy if enabled
if ( IsCpuRngEnabled() &&
( (HasRDSEED() && RDSEED_getBytes (digest, sizeof (digest)))
|| (HasRDRAND() && RDRAND_getBytes (digest, sizeof (digest)))
))
{
WHIRLPOOL_add (digest, sizeof(digest), &tctx);
}
WHIRLPOOL_finalize (&tctx, digest);
count = VC_MIN (cbRandSeed, sizeof (digest));
// copy digest value to seed buffer
memcpy (pbRandSeed, digest, count);
cbRandSeed -= count;
pbRandSeed += count;
}
#if !defined (_WIN64)
if (NT_SUCCESS (saveStatus))
KeRestoreFloatingPointState (&floatingPointState);
#endif
FAST_ERASE64 (digest, sizeof (digest));
FAST_ERASE64 (&iSeed.QuadPart, 8);
FAST_ERASE64 (&iSeed2.QuadPart, 8);
burn (&tctx, sizeof(tctx));
}
NTSTATUS DriverEntry (PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
{