mirror of https://github.com/acidanthera/audk.git
131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
/** @file
|
|
Random number generator services that uses RdRand instruction access
|
|
to provide high-quality random numbers.
|
|
|
|
Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
|
|
Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
|
|
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
#include <Uefi.h>
|
|
#include <Library/BaseLib.h>
|
|
#include <Library/DebugLib.h>
|
|
|
|
#include "BaseRngLibInternals.h"
|
|
|
|
//
|
|
// Bit mask used to determine if RdRand instruction is supported.
|
|
//
|
|
#define RDRAND_MASK BIT30
|
|
|
|
STATIC BOOLEAN mRdRandSupported;
|
|
|
|
/**
|
|
The constructor function checks whether or not RDRAND instruction is supported
|
|
by the host hardware.
|
|
|
|
The constructor function checks whether or not RDRAND instruction is supported.
|
|
It will ASSERT() if RDRAND instruction is not supported.
|
|
It will always return EFI_SUCCESS.
|
|
|
|
@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
BaseRngLibConstructor (
|
|
VOID
|
|
)
|
|
{
|
|
UINT32 RegEcx;
|
|
|
|
//
|
|
// Determine RDRAND support by examining bit 30 of the ECX register returned by
|
|
// CPUID. A value of 1 indicates that processor support RDRAND instruction.
|
|
//
|
|
AsmCpuid (1, 0, 0, &RegEcx, 0);
|
|
ASSERT ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
|
|
|
|
mRdRandSupported = ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
|
|
|
|
return EFI_SUCCESS;
|
|
}
|
|
|
|
/**
|
|
Generates a 16-bit random number.
|
|
|
|
@param[out] Rand Buffer pointer to store the 16-bit random value.
|
|
|
|
@retval TRUE Random number generated successfully.
|
|
@retval FALSE Failed to generate the random number.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
ArchGetRandomNumber16 (
|
|
OUT UINT16 *Rand
|
|
)
|
|
{
|
|
return AsmRdRand16 (Rand);
|
|
}
|
|
|
|
/**
|
|
Generates a 32-bit random number.
|
|
|
|
@param[out] Rand Buffer pointer to store the 32-bit random value.
|
|
|
|
@retval TRUE Random number generated successfully.
|
|
@retval FALSE Failed to generate the random number.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
ArchGetRandomNumber32 (
|
|
OUT UINT32 *Rand
|
|
)
|
|
{
|
|
return AsmRdRand32 (Rand);
|
|
}
|
|
|
|
/**
|
|
Generates a 64-bit random number.
|
|
|
|
@param[out] Rand Buffer pointer to store the 64-bit random value.
|
|
|
|
@retval TRUE Random number generated successfully.
|
|
@retval FALSE Failed to generate the random number.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
ArchGetRandomNumber64 (
|
|
OUT UINT64 *Rand
|
|
)
|
|
{
|
|
return AsmRdRand64 (Rand);
|
|
}
|
|
|
|
/**
|
|
Checks whether RDRAND is supported.
|
|
|
|
@retval TRUE RDRAND is supported.
|
|
@retval FALSE RDRAND is not supported.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
ArchIsRngSupported (
|
|
VOID
|
|
)
|
|
{
|
|
/*
|
|
Existing software depends on this always returning TRUE, so for
|
|
now hard-code it.
|
|
|
|
return mRdRandSupported;
|
|
*/
|
|
return TRUE;
|
|
}
|