4b3e9d80be
RngGetBytes() relies on the RngLib. The RngLib might use the RNDR instruction if the FEAT_RNG feature is present. RngGetInfo and RngGetRNG both must check that RngGetBytes() is working before advertising/using it. To do so, allocate an array storing the available algorithms. The Rng algorithm at the lowest index will be the default Rng algorithm. The array is shared between RngGetInfo and RngGetRNG. This array is allocated when the driver is loaded, and freed when unloaded. This patch also prevents from having PcdCpuRngSupportedAlgorithm let to a zero GUID, but let the possibility to have no valid Rng algorithm in such case. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Acked-by: Jiewen Yao <jiewen.yao@intel.com>
151 lines
3.8 KiB
C
151 lines
3.8 KiB
C
/** @file
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RNG Driver to produce the UEFI Random Number Generator protocol.
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The driver uses CPU RNG instructions to produce high-quality,
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high-performance entropy and random number.
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RNG Algorithms defined in UEFI 2.4:
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- EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID
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- EFI_RNG_ALGORITHM_RAW
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- EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID
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- EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID
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- EFI_RNG_ALGORITHM_X9_31_3DES_GUID
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- EFI_RNG_ALGORITHM_X9_31_AES_GUID
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Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
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(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include <Library/BaseLib.h>
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#include <Library/BaseMemoryLib.h>
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#include <Library/UefiBootServicesTableLib.h>
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#include <Library/RngLib.h>
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#include <Protocol/Rng.h>
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#include "RngDxeInternals.h"
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//
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// Array containing the validated Rng algorithm.
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// The entry with the lowest index will be the default algorithm.
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//
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UINTN mAvailableAlgoArrayCount;
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EFI_RNG_ALGORITHM *mAvailableAlgoArray;
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//
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// The Random Number Generator (RNG) protocol
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//
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EFI_RNG_PROTOCOL mRngRdRand = {
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RngGetInfo,
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RngGetRNG
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};
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/**
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The user Entry Point for the Random Number Generator (RNG) driver.
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@param[in] ImageHandle The firmware allocated handle for the EFI image.
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@param[in] SystemTable A pointer to the EFI System Table.
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@retval EFI_SUCCESS The entry point is executed successfully.
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@retval EFI_NOT_SUPPORTED Platform does not support RNG.
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@retval Other Some error occurs when executing this entry point.
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**/
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EFI_STATUS
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EFIAPI
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RngDriverEntry (
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IN EFI_HANDLE ImageHandle,
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IN EFI_SYSTEM_TABLE *SystemTable
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)
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{
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EFI_STATUS Status;
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EFI_HANDLE Handle;
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//
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// Install UEFI RNG (Random Number Generator) Protocol
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//
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Handle = NULL;
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Status = gBS->InstallMultipleProtocolInterfaces (
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&Handle,
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&gEfiRngProtocolGuid,
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&mRngRdRand,
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NULL
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);
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if (EFI_ERROR (Status)) {
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return Status;
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}
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//
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// Get the list of available algorithm.
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//
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return GetAvailableAlgorithms ();
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}
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/**
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This is the unload handle for RndgDxe module.
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Disconnect the driver specified by ImageHandle from all the devices in the handle database.
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Uninstall all the protocols installed in the driver entry point.
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@param[in] ImageHandle The drivers' driver image.
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@retval EFI_SUCCESS The image is unloaded.
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@retval Others Failed to unload the image.
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**/
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EFI_STATUS
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EFIAPI
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RngDriverUnLoad (
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IN EFI_HANDLE ImageHandle
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)
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{
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//
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// Free the list of available algorithm.
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//
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FreeAvailableAlgorithms ();
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return EFI_SUCCESS;
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}
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/**
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Runs CPU RNG instruction to fill a buffer of arbitrary size with random bytes.
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@param[in] Length Size of the buffer, in bytes, to fill with.
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@param[out] RandBuffer Pointer to the buffer to store the random result.
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@retval EFI_SUCCESS Random bytes generation succeeded.
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@retval EFI_NOT_READY Failed to request random bytes.
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**/
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EFI_STATUS
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EFIAPI
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RngGetBytes (
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IN UINTN Length,
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OUT UINT8 *RandBuffer
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)
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{
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BOOLEAN IsRandom;
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UINT64 TempRand[2];
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while (Length > 0) {
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IsRandom = GetRandomNumber128 (TempRand);
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if (!IsRandom) {
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return EFI_NOT_READY;
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}
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if (Length >= sizeof (TempRand)) {
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WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[0]);
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RandBuffer += sizeof (UINT64);
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WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[1]);
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RandBuffer += sizeof (UINT64);
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Length -= sizeof (TempRand);
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} else {
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CopyMem (RandBuffer, TempRand, Length);
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Length = 0;
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}
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}
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return EFI_SUCCESS;
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}
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