diff options
Diffstat (limited to 'SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c')
| -rw-r--r-- | SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c b/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c new file mode 100644 index 0000000000..318876d693 --- /dev/null +++ b/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c @@ -0,0 +1,237 @@ +/** @file
+ RNG Driver to produce the UEFI Random Number Generator protocol.
+
+ The driver can use RNDR instruction (through the RngLib and if FEAT_RNG is
+ present) to produce random numbers. It also uses the Arm FW-TRNG interface
+ to implement EFI_RNG_ALGORITHM_RAW.
+
+ 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 - Unsupported
+ - EFI_RNG_ALGORITHM_X9_31_AES_GUID - Unsupported
+
+ Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+ Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
+ (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
+ Copyright (c) 2021 - 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/UefiBootServicesTableLib.h>
+#include <Library/RngLib.h>
+#include <Library/DebugLib.h>
+#include <Library/ArmTrngLib.h>
+#include <Protocol/Rng.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;
+}
+
+/** Free mAvailableAlgoArray.
+**/
+VOID
+EFIAPI
+FreeAvailableAlgorithms (
+ VOID
+ )
+{
+ FreePool (mAvailableAlgoArray);
+ return;
+}
+
+/**
+ Produces and returns an RNG value using either the default or specified RNG algorithm.
+
+ @param[in] This A pointer to the EFI_RNG_PROTOCOL instance.
+ @param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG
+ algorithm to use. May be NULL in which case the function will
+ use its default RNG algorithm.
+ @param[in] RNGValueLength The length in bytes of the memory buffer pointed to by
+ RNGValue. The driver shall return exactly this numbers of bytes.
+ @param[out] RNGValue A caller-allocated memory buffer filled by the driver with the
+ resulting RNG value.
+
+ @retval EFI_SUCCESS The RNG value was returned successfully.
+ @retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by
+ this driver.
+ @retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or
+ firmware error.
+ @retval EFI_NOT_READY There is not enough random data available to satisfy the length
+ requested by RNGValueLength.
+ @retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero.
+
+**/
+EFI_STATUS
+EFIAPI
+RngGetRNG (
+ IN EFI_RNG_PROTOCOL *This,
+ IN EFI_RNG_ALGORITHM *RNGAlgorithm OPTIONAL,
+ IN UINTN RNGValueLength,
+ OUT UINT8 *RNGValue
+ )
+{
+ EFI_STATUS Status;
+ UINTN Index;
+
+ if ((This == NULL) || (RNGValueLength == 0) || (RNGValue == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (RNGAlgorithm == NULL) {
+ //
+ // Use the default RNG algorithm if RNGAlgorithm is NULL.
+ //
+ for (Index = 0; Index < mAvailableAlgoArrayCount; Index++) {
+ if (!IsZeroGuid (&mAvailableAlgoArray[Index])) {
+ RNGAlgorithm = &mAvailableAlgoArray[Index];
+ goto FoundAlgo;
+ }
+ }
+
+ if (Index == mAvailableAlgoArrayCount) {
+ // No algorithm available.
+ ASSERT (Index != mAvailableAlgoArrayCount);
+ return EFI_DEVICE_ERROR;
+ }
+ }
+
+FoundAlgo:
+ if (CompareGuid (RNGAlgorithm, PcdGetPtr (PcdCpuRngSupportedAlgorithm))) {
+ Status = RngGetBytes (RNGValueLength, RNGValue);
+ return Status;
+ }
+
+ // Raw algorithm (Trng)
+ if (CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmRaw)) {
+ return GenerateEntropy (RNGValueLength, RNGValue);
+ }
+
+ //
+ // Other algorithms are unsupported by this driver.
+ //
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ Returns information about the random number generation implementation.
+
+ @param[in] This A pointer to the EFI_RNG_PROTOCOL instance.
+ @param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList.
+ On output with a return code of EFI_SUCCESS, the size
+ in bytes of the data returned in RNGAlgorithmList. On output
+ with a return code of EFI_BUFFER_TOO_SMALL,
+ the size of RNGAlgorithmList required to obtain the list.
+ @param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver
+ with one EFI_RNG_ALGORITHM element for each supported
+ RNG algorithm. The list must not change across multiple
+ calls to the same driver. The first algorithm in the list
+ is the default algorithm for the driver.
+
+ @retval EFI_SUCCESS The RNG algorithm list was returned successfully.
+ @retval EFI_UNSUPPORTED The services is not supported by this driver.
+ @retval EFI_DEVICE_ERROR The list of algorithms could not be retrieved due to a
+ hardware or firmware error.
+ @retval EFI_INVALID_PARAMETER One or more of the parameters are incorrect.
+ @retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result.
+
+**/
+EFI_STATUS
+EFIAPI
+RngGetInfo (
+ IN EFI_RNG_PROTOCOL *This,
+ IN OUT UINTN *RNGAlgorithmListSize,
+ OUT EFI_RNG_ALGORITHM *RNGAlgorithmList
+ )
+{
+ UINTN RequiredSize;
+
+ if ((This == NULL) || (RNGAlgorithmListSize == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ RequiredSize = mAvailableAlgoArrayCount * sizeof (EFI_RNG_ALGORITHM);
+
+ if (RequiredSize == 0) {
+ // No supported algorithms found.
+ return EFI_UNSUPPORTED;
+ }
+
+ if (*RNGAlgorithmListSize < RequiredSize) {
+ *RNGAlgorithmListSize = RequiredSize;
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ if (RNGAlgorithmList == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ // There is no gap in the array, so copy the block.
+ CopyMem (RNGAlgorithmList, mAvailableAlgoArray, RequiredSize);
+ *RNGAlgorithmListSize = RequiredSize;
+ return EFI_SUCCESS;
+}
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