/** @file
Pseudorandom Number Generator Wrapper Implementation over MbedTLS.
Copyright (c) 2024, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "InternalCryptLib.h"
#include
/**
Sets up the seed value for the pseudorandom number generator.
This function sets up the seed value for the pseudorandom number generator.
If Seed is not NULL, then the seed passed in is used.
If Seed is NULL, then default seed is used.
@param[in] Seed Pointer to seed value.
If NULL, default seed is used.
@param[in] SeedSize Size of seed value.
If Seed is NULL, this parameter is ignored.
@retval TRUE Pseudorandom number generator has enough entropy for random generation.
@retval FALSE Pseudorandom number generator does not have enough entropy for random generation.
**/
BOOLEAN
EFIAPI
RandomSeed (
IN CONST UINT8 *Seed OPTIONAL,
IN UINTN SeedSize
)
{
return TRUE;
}
/**
Generates a pseudorandom byte stream of the specified size.
If Output is NULL, then return FALSE.
@param[out] Output Pointer to buffer to receive random value.
@param[in] Size Size of random bytes to generate.
@retval TRUE Pseudorandom byte stream generated successfully.
@retval FALSE Pseudorandom number generator fails to generate due to lack of entropy.
**/
BOOLEAN
EFIAPI
RandomBytes (
OUT UINT8 *Output,
IN UINTN Size
)
{
BOOLEAN Ret;
volatile UINT64 TempRand;
//
// Check input parameters.
//
if ((Output == NULL) || (Size > INT_MAX)) {
return FALSE;
}
Ret = FALSE;
while (Size > 0) {
// Use RngLib to get random number
Ret = GetRandomNumber64 ((UINT64 *)&TempRand);
if (!Ret) {
TempRand = 0;
return Ret;
}
if (Size >= sizeof (TempRand)) {
*((UINT64 *)Output) = TempRand;
Output += sizeof (UINT64);
Size -= sizeof (TempRand);
} else {
CopyMem (Output, (VOID *)&TempRand, Size);
Size = 0;
}
}
TempRand = 0;
return Ret;
}
/**
The MbedTLS function f_rng, which MbedtlsRand implements.
@param[in] RngState Not used, just for compatibility with mbedtls.
@param[out] Output Pointer to buffer to receive random value.
@param[in] Len Size of random bytes to generate.
@retval 0 Pseudorandom byte stream generated successfully.
@retval Non-0 Pseudorandom number generator fails to generate due to lack of entropy.
**/
INT32
MbedtlsRand (
VOID *RngState,
UINT8 *Output,
UINTN Len
)
{
BOOLEAN Result;
Result = RandomBytes (Output, Len);
return Result ? 0 : -1;
}