75fb0cfc82
On Arm platforms, the number of available RNG algorithms is dynamically detected and can be 0 in the absence of FEAT_RNG and firmware TRNG. In this case, the EFI_RNG_PROTOCOL should not be installed to prevent from installing an empty protocol. Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> [ardb: return EFI_REQUEST_UNLOAD_IMAGE instead of an error] Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
160 lines
4.0 KiB
C
160 lines
4.0 KiB
C
/** @file
|
|
RNG Driver to produce the UEFI Random Number Generator protocol.
|
|
|
|
The driver uses CPU RNG instructions 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
|
|
- 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
|
|
- EFI_RNG_ALGORITHM_X9_31_AES_GUID
|
|
|
|
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
|
|
(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
|
|
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
#include <Library/BaseLib.h>
|
|
#include <Library/BaseMemoryLib.h>
|
|
#include <Library/UefiBootServicesTableLib.h>
|
|
#include <Library/RngLib.h>
|
|
#include <Protocol/Rng.h>
|
|
|
|
#include "RngDxeInternals.h"
|
|
|
|
//
|
|
// Array containing the validated Rng algorithm.
|
|
// The entry with the lowest index will be the default algorithm.
|
|
//
|
|
UINTN mAvailableAlgoArrayCount;
|
|
EFI_RNG_ALGORITHM *mAvailableAlgoArray;
|
|
|
|
//
|
|
// The Random Number Generator (RNG) protocol
|
|
//
|
|
EFI_RNG_PROTOCOL mRngRdRand = {
|
|
RngGetInfo,
|
|
RngGetRNG
|
|
};
|
|
|
|
/**
|
|
The user Entry Point for the Random Number Generator (RNG) driver.
|
|
|
|
@param[in] ImageHandle The firmware allocated handle for the EFI image.
|
|
@param[in] SystemTable A pointer to the EFI System Table.
|
|
|
|
@retval EFI_SUCCESS The entry point is executed successfully.
|
|
@retval EFI_NOT_SUPPORTED Platform does not support RNG.
|
|
@retval Other Some error occurs when executing this entry point.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
RngDriverEntry (
|
|
IN EFI_HANDLE ImageHandle,
|
|
IN EFI_SYSTEM_TABLE *SystemTable
|
|
)
|
|
{
|
|
EFI_STATUS Status;
|
|
EFI_HANDLE Handle;
|
|
|
|
//
|
|
// Get the list of available algorithm.
|
|
//
|
|
Status = GetAvailableAlgorithms ();
|
|
if (EFI_ERROR (Status)) {
|
|
return Status;
|
|
}
|
|
|
|
if (mAvailableAlgoArrayCount == 0) {
|
|
return EFI_REQUEST_UNLOAD_IMAGE;
|
|
}
|
|
|
|
//
|
|
// Install UEFI RNG (Random Number Generator) Protocol
|
|
//
|
|
Handle = NULL;
|
|
Status = gBS->InstallMultipleProtocolInterfaces (
|
|
&Handle,
|
|
&gEfiRngProtocolGuid,
|
|
&mRngRdRand,
|
|
NULL
|
|
);
|
|
if (EFI_ERROR (Status)) {
|
|
FreeAvailableAlgorithms ();
|
|
}
|
|
|
|
return Status;
|
|
}
|
|
|
|
/**
|
|
This is the unload handle for RndgDxe module.
|
|
|
|
Disconnect the driver specified by ImageHandle from all the devices in the handle database.
|
|
Uninstall all the protocols installed in the driver entry point.
|
|
|
|
@param[in] ImageHandle The drivers' driver image.
|
|
|
|
@retval EFI_SUCCESS The image is unloaded.
|
|
@retval Others Failed to unload the image.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
RngDriverUnLoad (
|
|
IN EFI_HANDLE ImageHandle
|
|
)
|
|
{
|
|
//
|
|
// Free the list of available algorithm.
|
|
//
|
|
FreeAvailableAlgorithms ();
|
|
return EFI_SUCCESS;
|
|
}
|
|
|
|
/**
|
|
Runs CPU RNG instruction to fill a buffer of arbitrary size with random bytes.
|
|
|
|
@param[in] Length Size of the buffer, in bytes, to fill with.
|
|
@param[out] RandBuffer Pointer to the buffer to store the random result.
|
|
|
|
@retval EFI_SUCCESS Random bytes generation succeeded.
|
|
@retval EFI_NOT_READY Failed to request random bytes.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
RngGetBytes (
|
|
IN UINTN Length,
|
|
OUT UINT8 *RandBuffer
|
|
)
|
|
{
|
|
BOOLEAN IsRandom;
|
|
UINT64 TempRand[2];
|
|
|
|
while (Length > 0) {
|
|
IsRandom = GetRandomNumber128 (TempRand);
|
|
if (!IsRandom) {
|
|
return EFI_NOT_READY;
|
|
}
|
|
|
|
if (Length >= sizeof (TempRand)) {
|
|
WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[0]);
|
|
RandBuffer += sizeof (UINT64);
|
|
WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[1]);
|
|
RandBuffer += sizeof (UINT64);
|
|
Length -= sizeof (TempRand);
|
|
} else {
|
|
CopyMem (RandBuffer, TempRand, Length);
|
|
Length = 0;
|
|
}
|
|
}
|
|
|
|
return EFI_SUCCESS;
|
|
}
|