RngDxe.c File Reference

#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/RngLib.h>
#include "RngDxeInternals.h"

Go to the source code of this file.

Macros
#define	RNG_ALGORITHM_COUNT   2

Functions
EFI_STATUS EFIAPI	GetAvailableAlgorithms (VOID)
VOID EFIAPI	FreeAvailableAlgorithms (VOID)
EFI_STATUS EFIAPI	RngGetRNG (IN EFI_RNG_PROTOCOL *This, IN EFI_RNG_ALGORITHM *RNGAlgorithm OPTIONAL, IN UINTN RNGValueLength, OUT UINT8 *RNGValue)
EFI_STATUS EFIAPI	RngGetInfo (IN EFI_RNG_PROTOCOL *This, IN OUT UINTN *RNGAlgorithmListSize, OUT EFI_RNG_ALGORITHM *RNGAlgorithmList)

Detailed Description

RNG Driver to produce the UEFI Random Number Generator protocol.

The driver will use the new RDRAND instruction to produce high-quality, high-performance entropy and random number.

RNG Algorithms defined in UEFI 2.4:

• EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID - Supported (RDRAND implements a hardware NIST SP800-90 AES-CTR-256 based DRBG)
• EFI_RNG_ALGORITHM_RAW - Supported (Structuring RDRAND invocation can be guaranteed as high-quality entropy source)
• EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID - Unsupported
• EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID - Unsupported
• EFI_RNG_ALGORITHM_X9_31_3DES_GUID - Unsupported
• EFI_RNG_ALGORITHM_X9_31_AES_GUID - Unsupported

Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.
(C) Copyright 2015 Hewlett Packard Enterprise Development LP
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file RngDxe.c.

Macro Definition Documentation

RNG_ALGORITHM_COUNT

#define RNG_ALGORITHM_COUNT   2

Definition at line 33 of file RngDxe.c.

Function Documentation

FreeAvailableAlgorithms()

VOID EFIAPI FreeAvailableAlgorithms

(

VOID

)

Free mAvailableAlgoArray.

Definition at line 60 of file RngDxe.c.

GetAvailableAlgorithms()

EFI_STATUS EFIAPI GetAvailableAlgorithms

(

VOID

)

Allocate and initialize mAvailableAlgoArray with the available Rng algorithms. Also update mAvailableAlgoArrayCount.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_OUT_OF_RESOURCES	Could not allocate memory.

Definition at line 43 of file RngDxe.c.

RngGetInfo()

EFI_STATUS EFIAPI RngGetInfo	(	IN EFI_RNG_PROTOCOL *	This,
		IN OUT UINTN *	RNGAlgorithmListSize,
		OUT EFI_RNG_ALGORITHM *	RNGAlgorithmList
	)

Returns information about the random number generation implementation.

Parameters

[in]	This	A pointer to the EFI_RNG_PROTOCOL instance.
[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.
[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.

Return values

EFI_SUCCESS	The RNG algorithm list was returned successfully.
EFI_UNSUPPORTED	No supported algorithms found.
EFI_DEVICE_ERROR	The list of algorithms could not be retrieved due to a hardware or firmware error.
EFI_INVALID_PARAMETER	One or more of the parameters are incorrect.
EFI_BUFFER_TOO_SMALL	The buffer RNGAlgorithmList is too small to hold the result.

Definition at line 160 of file RngDxe.c.

RngGetRNG()

EFI_STATUS EFIAPI RngGetRNG	(	IN EFI_RNG_PROTOCOL *	This,
		IN EFI_RNG_ALGORITHM *RNGAlgorithm	OPTIONAL,
		IN UINTN	RNGValueLength,
		OUT UINT8 *	RNGValue
	)

Produces and returns an RNG value using either the default or specified RNG algorithm.

Parameters

[in]	This	A pointer to the EFI_RNG_PROTOCOL instance.
[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.
[in]	RNGValueLength	The length in bytes of the memory buffer pointed to by RNGValue. The driver shall return exactly this numbers of bytes.
[out]	RNGValue	A caller-allocated memory buffer filled by the driver with the resulting RNG value.

Return values

EFI_SUCCESS	The RNG value was returned successfully.
EFI_UNSUPPORTED	The algorithm specified by RNGAlgorithm is not supported by this driver.
EFI_DEVICE_ERROR	An RNG value could not be retrieved due to a hardware or firmware error.
EFI_NOT_READY	There is not enough random data available to satisfy the length requested by RNGValueLength.
EFI_INVALID_PARAMETER	RNGValue is NULL or RNGValueLength is zero.

Definition at line 92 of file RngDxe.c.