diff options
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c')
-rw-r--r-- | src/VBox/Devices/EFI/Firmware/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c b/src/VBox/Devices/EFI/Firmware/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c new file mode 100644 index 00000000..0f7b8295 --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c @@ -0,0 +1,128 @@ +/** @file + Support routines for RDRAND instruction access. + +Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR> +(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR> +SPDX-License-Identifier: BSD-2-Clause-Patent + +**/ +#include <Library/RngLib.h> + +#include "AesCore.h" +#include "RdRand.h" +#include "RngDxeInternals.h" + +/** + Creates a 128bit random value that is fully forward and backward prediction resistant, + suitable for seeding a NIST SP800-90 Compliant, FIPS 1402-2 certifiable SW DRBG. + This function takes multiple random numbers through RDRAND without intervening + delays to ensure reseeding and performs AES-CBC-MAC over the data to compute the + seed value. + + @param[out] SeedBuffer Pointer to a 128bit buffer to store the random seed. + + @retval EFI_SUCCESS Random seed generation succeeded. + @retval EFI_NOT_READY Failed to request random bytes. + +**/ +EFI_STATUS +EFIAPI +RdRandGetSeed128 ( + OUT UINT8 *SeedBuffer + ) +{ + EFI_STATUS Status; + UINT8 RandByte[16]; + UINT8 Key[16]; + UINT8 Ffv[16]; + UINT8 Xored[16]; + UINT32 Index; + UINT32 Index2; + + // + // Chose an arbitrary key and zero the feed_forward_value (FFV) + // + for (Index = 0; Index < 16; Index++) { + Key[Index] = (UINT8) Index; + Ffv[Index] = 0; + } + + // + // Perform CBC_MAC over 32 * 128 bit values, with 10us gaps between 128 bit value + // The 10us gaps will ensure multiple reseeds within the HW RNG with a large design margin. + // + for (Index = 0; Index < 32; Index++) { + MicroSecondDelay (10); + Status = RngGetBytes (16, RandByte); + if (EFI_ERROR (Status)) { + return Status; + } + + // + // Perform XOR operations on two 128-bit value. + // + for (Index2 = 0; Index2 < 16; Index2++) { + Xored[Index2] = RandByte[Index2] ^ Ffv[Index2]; + } + + AesEncrypt (Key, Xored, Ffv); + } + + for (Index = 0; Index < 16; Index++) { + SeedBuffer[Index] = Ffv[Index]; + } + + return EFI_SUCCESS; +} + +/** + Generate high-quality entropy source through RDRAND. + + @param[in] Length Size of the buffer, in bytes, to fill with. + @param[out] Entropy Pointer to the buffer to store the entropy data. + + @retval EFI_SUCCESS Entropy generation succeeded. + @retval EFI_NOT_READY Failed to request random data. + +**/ +EFI_STATUS +EFIAPI +RdRandGenerateEntropy ( + IN UINTN Length, + OUT UINT8 *Entropy + ) +{ + EFI_STATUS Status; + UINTN BlockCount; + UINT8 Seed[16]; + UINT8 *Ptr; + + Status = EFI_NOT_READY; + BlockCount = Length / 16; + Ptr = (UINT8 *)Entropy; + + // + // Generate high-quality seed for DRBG Entropy + // + while (BlockCount > 0) { + Status = RdRandGetSeed128 (Seed); + if (EFI_ERROR (Status)) { + return Status; + } + CopyMem (Ptr, Seed, 16); + + BlockCount--; + Ptr = Ptr + 16; + } + + // + // Populate the remained data as request. + // + Status = RdRandGetSeed128 (Seed); + if (EFI_ERROR (Status)) { + return Status; + } + CopyMem (Ptr, Seed, (Length % 16)); + + return Status; +} |