From ba5da0946c3abaa93d1161ca512c3c326cda3736 Mon Sep 17 00:00:00 2001 From: Mounir IDRASSI Date: Fri, 8 Feb 2019 01:48:12 +0100 Subject: 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). --- src/Driver/DriveFilter.c | 42 +++++++++--------------------------------- 1 file changed, 9 insertions(+), 33 deletions(-) (limited to 'src/Driver/DriveFilter.c') diff --git a/src/Driver/DriveFilter.c b/src/Driver/DriveFilter.c index 6228009f..3c7687f8 100644 --- a/src/Driver/DriveFilter.c +++ b/src/Driver/DriveFilter.c @@ -29,6 +29,7 @@ #include "Boot/Windows/BootCommon.h" #include "cpu.h" #include "rdrand.h" +#include "chachaRng.h" static BOOL DeviceFilterActive = FALSE; @@ -1521,42 +1522,17 @@ static VOID SetupThreadProc (PVOID threadArg) // generate real random values for wipeRandChars and // wipeRandCharsUpdate instead of relying on uninitialized stack memory - LARGE_INTEGER iSeed; - byte digest[WHIRLPOOL_DIGESTSIZE]; - WHIRLPOOL_CTX tctx; - -#ifndef _WIN64 - KFLOATING_SAVE floatingPointState; - NTSTATUS saveStatus = STATUS_INVALID_PARAMETER; - if (HasISSE()) - saveStatus = KeSaveFloatingPointState (&floatingPointState); -#endif + ChaCha20RngCtx rngCtx; + byte pbSeed[CHACHA20RNG_KEYSZ + CHACHA20RNG_IVSZ]; - KeQuerySystemTime( &iSeed ); - WHIRLPOOL_init (&tctx); - 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); + GetDriverRandomSeed (pbSeed, sizeof (pbSeed)); + ChaCha20RngInit (&rngCtx, pbSeed, GetDriverRandomSeed, 0); -#if !defined (_WIN64) - if (NT_SUCCESS (saveStatus)) - KeRestoreFloatingPointState (&floatingPointState); -#endif - - memcpy (wipeRandChars, digest, TC_WIPE_RAND_CHAR_COUNT); - memcpy (wipeRandCharsUpdate, &digest[WHIRLPOOL_DIGESTSIZE - TC_WIPE_RAND_CHAR_COUNT], TC_WIPE_RAND_CHAR_COUNT); + ChaCha20RngGetBytes (&rngCtx, wipeRandChars, TC_WIPE_RAND_CHAR_COUNT); + ChaCha20RngGetBytes (&rngCtx, wipeRandCharsUpdate, TC_WIPE_RAND_CHAR_COUNT); - burn (digest, WHIRLPOOL_DIGESTSIZE); - burn (&tctx, sizeof (tctx)); - - burn (&iSeed, sizeof(iSeed)); + burn (&rngCtx, sizeof (rngCtx)); + FAST_ERASE64 (pbSeed, sizeof (pbSeed)); SetupResult = STATUS_UNSUCCESSFUL; -- cgit v1.2.3