/** @file | |
RNG Driver to produce the UEFI Random Number Generator protocol. | |
The driver uses CPU RNG instructions to produce high-quality, | |
high-performance entropy and random number. | |
RNG Algorithms defined in UEFI 2.4: | |
- EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID | |
- EFI_RNG_ALGORITHM_RAW | |
- EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID | |
- EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID | |
- EFI_RNG_ALGORITHM_X9_31_3DES_GUID | |
- EFI_RNG_ALGORITHM_X9_31_AES_GUID | |
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/BaseLib.h> | |
#include <Library/BaseMemoryLib.h> | |
#include <Library/UefiBootServicesTableLib.h> | |
#include <Library/RngLib.h> | |
#include <Protocol/Rng.h> | |
#include "RngDxeInternals.h" | |
// | |
// Array containing the validated Rng algorithm. | |
// The entry with the lowest index will be the default algorithm. | |
// | |
UINTN mAvailableAlgoArrayCount; | |
EFI_RNG_ALGORITHM *mAvailableAlgoArray; | |
// | |
// The Random Number Generator (RNG) protocol | |
// | |
EFI_RNG_PROTOCOL mRngRdRand = { | |
RngGetInfo, | |
RngGetRNG | |
}; | |
/** | |
The user Entry Point for the Random Number Generator (RNG) driver. | |
@param[in] ImageHandle The firmware allocated handle for the EFI image. | |
@param[in] SystemTable A pointer to the EFI System Table. | |
@retval EFI_SUCCESS The entry point is executed successfully. | |
@retval EFI_NOT_SUPPORTED Platform does not support RNG. | |
@retval Other Some error occurs when executing this entry point. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
RngDriverEntry ( | |
IN EFI_HANDLE ImageHandle, | |
IN EFI_SYSTEM_TABLE *SystemTable | |
) | |
{ | |
EFI_STATUS Status; | |
EFI_HANDLE Handle; | |
// | |
// Get the list of available algorithm. | |
// | |
Status = GetAvailableAlgorithms (); | |
if (EFI_ERROR (Status)) { | |
return Status; | |
} | |
if (mAvailableAlgoArrayCount == 0) { | |
return EFI_REQUEST_UNLOAD_IMAGE; | |
} | |
// | |
// Install UEFI RNG (Random Number Generator) Protocol | |
// | |
Handle = NULL; | |
Status = gBS->InstallMultipleProtocolInterfaces ( | |
&Handle, | |
&gEfiRngProtocolGuid, | |
&mRngRdRand, | |
NULL | |
); | |
if (EFI_ERROR (Status)) { | |
FreeAvailableAlgorithms (); | |
} | |
return Status; | |
} | |
/** | |
This is the unload handle for RndgDxe module. | |
Disconnect the driver specified by ImageHandle from all the devices in the handle database. | |
Uninstall all the protocols installed in the driver entry point. | |
@param[in] ImageHandle The drivers' driver image. | |
@retval EFI_SUCCESS The image is unloaded. | |
@retval Others Failed to unload the image. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
RngDriverUnLoad ( | |
IN EFI_HANDLE ImageHandle | |
) | |
{ | |
// | |
// Free the list of available algorithm. | |
// | |
FreeAvailableAlgorithms (); | |
return EFI_SUCCESS; | |
} | |
/** | |
Runs CPU RNG instruction to fill a buffer of arbitrary size with random bytes. | |
@param[in] Length Size of the buffer, in bytes, to fill with. | |
@param[out] RandBuffer Pointer to the buffer to store the random result. | |
@retval EFI_SUCCESS Random bytes generation succeeded. | |
@retval EFI_NOT_READY Failed to request random bytes. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
RngGetBytes ( | |
IN UINTN Length, | |
OUT UINT8 *RandBuffer | |
) | |
{ | |
BOOLEAN IsRandom; | |
UINT64 TempRand[2]; | |
while (Length > 0) { | |
IsRandom = GetRandomNumber128 (TempRand); | |
if (!IsRandom) { | |
return EFI_NOT_READY; | |
} | |
if (Length >= sizeof (TempRand)) { | |
WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[0]); | |
RandBuffer += sizeof (UINT64); | |
WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[1]); | |
RandBuffer += sizeof (UINT64); | |
Length -= sizeof (TempRand); | |
} else { | |
CopyMem (RandBuffer, TempRand, Length); | |
Length = 0; | |
} | |
} | |
return EFI_SUCCESS; | |
} |