audk/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/AArch64Algo.c

73 lines
1.9 KiB
C

/** @file
Aarch64 specific code.
Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/ArmTrngLib.h>
#include "RngDxeInternals.h"
// Maximum number of Rng algorithms.
#define RNG_AVAILABLE_ALGO_MAX 2
/** Allocate and initialize mAvailableAlgoArray with the available
Rng algorithms. Also update mAvailableAlgoArrayCount.
@retval EFI_SUCCESS The function completed successfully.
@retval EFI_OUT_OF_RESOURCES Could not allocate memory.
**/
EFI_STATUS
EFIAPI
GetAvailableAlgorithms (
VOID
)
{
UINT64 DummyRand;
UINT16 MajorRevision;
UINT16 MinorRevision;
// Rng algorithms 2 times, one for the allocation, one to populate.
mAvailableAlgoArray = AllocateZeroPool (RNG_AVAILABLE_ALGO_MAX);
if (mAvailableAlgoArray == NULL) {
return EFI_OUT_OF_RESOURCES;
}
// Check RngGetBytes() before advertising PcdCpuRngSupportedAlgorithm.
if (!EFI_ERROR (RngGetBytes (sizeof (DummyRand), (UINT8 *)&DummyRand))) {
CopyMem (
&mAvailableAlgoArray[mAvailableAlgoArrayCount],
PcdGetPtr (PcdCpuRngSupportedAlgorithm),
sizeof (EFI_RNG_ALGORITHM)
);
mAvailableAlgoArrayCount++;
DEBUG_CODE_BEGIN ();
if (IsZeroGuid (PcdGetPtr (PcdCpuRngSupportedAlgorithm))) {
DEBUG ((
DEBUG_WARN,
"PcdCpuRngSupportedAlgorithm should be a non-zero GUID\n"
));
}
DEBUG_CODE_END ();
}
// Raw algorithm (Trng)
if (!EFI_ERROR (GetArmTrngVersion (&MajorRevision, &MinorRevision))) {
CopyMem (
&mAvailableAlgoArray[mAvailableAlgoArrayCount],
&gEfiRngAlgorithmRaw,
sizeof (EFI_RNG_ALGORITHM)
);
mAvailableAlgoArrayCount++;
}
return EFI_SUCCESS;
}