/** @file | |
Random number generator services that uses CPU RNG instructions to | |
provide 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 <Library/BaseLib.h> | |
#include <Library/DebugLib.h> | |
#include "BaseRngLibInternals.h" | |
// | |
// Limited retry number when valid random data is returned. | |
// Uses the recommended value defined in Section 7.3.17 of "Intel 64 and IA-32 | |
// Architectures Software Developer's Manual". | |
// | |
#define GETRANDOM_RETRY_LIMIT 10 | |
/** | |
Generates a 16-bit random number. | |
if Rand is NULL, then ASSERT(). | |
@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 | |
GetRandomNumber16 ( | |
OUT UINT16 *Rand | |
) | |
{ | |
UINT32 Index; | |
ASSERT (Rand != NULL); | |
if (Rand == NULL) { | |
return FALSE; | |
} | |
if (!ArchIsRngSupported ()) { | |
return FALSE; | |
} | |
// | |
// A loop to fetch a 16 bit random value with a retry count limit. | |
// | |
for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) { | |
if (ArchGetRandomNumber16 (Rand)) { | |
return TRUE; | |
} | |
} | |
return FALSE; | |
} | |
/** | |
Generates a 32-bit random number. | |
if Rand is NULL, then ASSERT(). | |
@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 | |
GetRandomNumber32 ( | |
OUT UINT32 *Rand | |
) | |
{ | |
UINT32 Index; | |
ASSERT (Rand != NULL); | |
if (Rand == NULL) { | |
return FALSE; | |
} | |
if (!ArchIsRngSupported ()) { | |
return FALSE; | |
} | |
// | |
// A loop to fetch a 32 bit random value with a retry count limit. | |
// | |
for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) { | |
if (ArchGetRandomNumber32 (Rand)) { | |
return TRUE; | |
} | |
} | |
return FALSE; | |
} | |
/** | |
Generates a 64-bit random number. | |
if Rand is NULL, then ASSERT(). | |
@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 | |
GetRandomNumber64 ( | |
OUT UINT64 *Rand | |
) | |
{ | |
UINT32 Index; | |
ASSERT (Rand != NULL); | |
if (Rand == NULL) { | |
return FALSE; | |
} | |
if (!ArchIsRngSupported ()) { | |
return FALSE; | |
} | |
// | |
// A loop to fetch a 64 bit random value with a retry count limit. | |
// | |
for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) { | |
if (ArchGetRandomNumber64 (Rand)) { | |
return TRUE; | |
} | |
} | |
return FALSE; | |
} | |
/** | |
Generates a 128-bit random number. | |
if Rand is NULL, then ASSERT(). | |
@param[out] Rand Buffer pointer to store the 128-bit random value. | |
@retval TRUE Random number generated successfully. | |
@retval FALSE Failed to generate the random number. | |
**/ | |
BOOLEAN | |
EFIAPI | |
GetRandomNumber128 ( | |
OUT UINT64 *Rand | |
) | |
{ | |
ASSERT (Rand != NULL); | |
if (Rand == NULL) { | |
return FALSE; | |
} | |
if (!ArchIsRngSupported ()) { | |
return FALSE; | |
} | |
// | |
// Read first 64 bits | |
// | |
if (!GetRandomNumber64 (Rand)) { | |
return FALSE; | |
} | |
// | |
// Read second 64 bits | |
// | |
return GetRandomNumber64 (++Rand); | |
} |