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MdePkg: Add PeiRngLib
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Adds a new PEI library instance for RngLib that uses the RNG services
provided by the RNG PPI.

This library instance will add a DEPEX on gEfiRngPpiGuid on modules
it links against. It can be used to allow PEIMs to get RNG support
over a dynamic interface.

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
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makubacki committed Jun 5, 2024
1 parent 58a2bca commit fc52e41
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230 changes: 230 additions & 0 deletions MdePkg/Library/PeiRngLib/PeiRngLib.c
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/** @file
RNG library instance that uses the Random Number Generator (RNG) PPI to provide
random numbers.
Copyright (c) Microsoft Corporation.
SPDX-License-Identifier: BSD-2-Clause-Patent
MU_CHANGE: WHOLE FILE
**/
#include <PiPei.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/PeiServicesLib.h>
#include <Ppi/Rng.h>

/**
Generates a random number via the NIST 800-9A algorithm. Refer to
http://csrc.nist.gov/groups/STM/cavp/documents/drbg/DRBGVS.pdf for more information.
@param[out] Buffer Buffer to receive the random number.
@param[in] BufferSize Number of bytes in Buffer.
@retval EFI_SUCCESS or underlying failure code.
**/
STATIC
EFI_STATUS
GenerateRandomNumberViaNist800Algorithm (
OUT UINT8 *Buffer,
IN UINTN BufferSize
)
{
EFI_STATUS Status;
EFI_RNG_PPI *RngPpi;

RngPpi = NULL;

if (Buffer == NULL) {
DEBUG ((DEBUG_ERROR, "%a: Buffer == NULL.\n", __func__));
return EFI_INVALID_PARAMETER;
}

Status = PeiServicesLocatePpi (&gEfiRngPpiGuid, 0, NULL, (VOID **)&RngPpi);
if (EFI_ERROR (Status) || (RngPpi == NULL)) {
DEBUG ((DEBUG_ERROR, "%a: Could not locate RNG PPI, Status = %r\n", __func__, Status));
return Status;
}

Status = RngPpi->GetRNG (RngPpi, &gEfiRngAlgorithmSp80090Ctr256Guid, BufferSize, Buffer);
DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm CTR-256 - Status = %r\n", __func__, Status));
if (!EFI_ERROR (Status)) {
return Status;
}

Status = RngPpi->GetRNG (RngPpi, &gEfiRngAlgorithmSp80090Hmac256Guid, BufferSize, Buffer);
DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm HMAC-256 - Status = %r\n", __func__, Status));
if (!EFI_ERROR (Status)) {
return Status;
}

Status = RngPpi->GetRNG (RngPpi, &gEfiRngAlgorithmSp80090Hash256Guid, BufferSize, Buffer);
DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __func__, Status));
if (!EFI_ERROR (Status)) {
return Status;
}

Status = RngPpi->GetRNG (RngPpi, &gEfiRngAlgorithmRaw, BufferSize, Buffer);
DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm Raw - Status = %r\n", __func__, Status));
if (!EFI_ERROR (Status)) {
return Status;
}

// If all the other methods have failed, use the default method from the RngPpi
Status = RngPpi->GetRNG (RngPpi, NULL, BufferSize, Buffer);
DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm default - Status = %r\n", __func__, Status));
if (!EFI_ERROR (Status)) {
return Status;
}

// If we get to this point, we have failed
DEBUG ((DEBUG_ERROR, "%a: GetRNG() failed, staus = %r\n", __func__, Status));

return Status;
}// GenerateRandomNumberViaNist800Algorithm()

/**
Generates a 16-bit random number.
if Rand is NULL, return FALSE.
@param[out] Rand Buffer pointer to store the 16-bit random value.
@retval TRUE Random number generated successfully.
@retval FALSE Failed to generate the random number.
**/
BOOLEAN
EFIAPI
GetRandomNumber16 (
OUT UINT16 *Rand
)
{
EFI_STATUS Status;

if (Rand == NULL) {
return FALSE;
}

Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT16));
if (EFI_ERROR (Status)) {
return FALSE;
}

return TRUE;
}

/**
Generates a 32-bit random number.
if Rand is NULL, return FALSE.
@param[out] Rand Buffer pointer to store the 32-bit random value.
@retval TRUE Random number generated successfully.
@retval FALSE Failed to generate the random number.
**/
BOOLEAN
EFIAPI
GetRandomNumber32 (
OUT UINT32 *Rand
)
{
EFI_STATUS Status;

if (Rand == NULL) {
return FALSE;
}

Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT32));
if (EFI_ERROR (Status)) {
return FALSE;
}

return TRUE;
}

/**
Generates a 64-bit random number.
if Rand is NULL, return FALSE.
@param[out] Rand Buffer pointer to store the 64-bit random value.
@retval TRUE Random number generated successfully.
@retval FALSE Failed to generate the random number.
**/
BOOLEAN
EFIAPI
GetRandomNumber64 (
OUT UINT64 *Rand
)
{
EFI_STATUS Status;

if (Rand == NULL) {
return FALSE;
}

Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT64));
if (EFI_ERROR (Status)) {
return FALSE;
}

return TRUE;
}

/**
Generates a 128-bit random number.
if Rand is NULL, return FALSE.
@param[out] Rand Buffer pointer to store the 128-bit random value.
@retval TRUE Random number generated successfully.
@retval FALSE Failed to generate the random number.
**/
BOOLEAN
EFIAPI
GetRandomNumber128 (
OUT UINT64 *Rand
)
{
EFI_STATUS Status;

if (Rand == NULL) {
return FALSE;
}

Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, 2 * sizeof (UINT64));
if (EFI_ERROR (Status)) {
return FALSE;
}

return TRUE;
}

/**
Get a GUID identifying the RNG algorithm implementation.
@param [out] RngGuid If success, contains the GUID identifying
the RNG algorithm implementation.
@retval EFI_SUCCESS Success.
@retval EFI_UNSUPPORTED Not supported.
@retval EFI_INVALID_PARAMETER Invalid parameter.
**/
EFI_STATUS
EFIAPI
GetRngGuid (
GUID *RngGuid
)
{
// Similar to DxeRngLib, EFI_UNSUPPORTED is returned for this library instance since it is unknown
// which exact algorithm may be used for a given request.

return EFI_UNSUPPORTED;
}
43 changes: 43 additions & 0 deletions MdePkg/Library/PeiRngLib/PeiRngLib.inf
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## @file
# PPI-based Instance of RNG (Random Number Generator) Library.
#
# This library instance requires a RNG PPI to be produced so that the module may use
# it for RNG operations. A RNG PPI DEPEX will be placed on the module.
#
# Copyright (c) Microsoft Corporation.
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
# MU_CHANGE: WHOLE FILE
##

[Defines]
INF_VERSION = 0x0001001B
BASE_NAME = PeiRngLib
MODULE_UNI_FILE = PeiRngLib.uni
FILE_GUID = FF240232-C25D-4277-AB81-D6B0C51F2D25
VERSION_STRING = 1.0
MODULE_TYPE = PEIM
LIBRARY_CLASS = RngLib | PEIM

[Packages]
MdePkg/MdePkg.dec

[LibraryClasses]
BaseLib
DebugLib
PeiServicesLib

[Guids]
gEfiRngAlgorithmSp80090Ctr256Guid
gEfiRngAlgorithmSp80090Hash256Guid
gEfiRngAlgorithmSp80090Hmac256Guid
gEfiRngAlgorithmRaw

[Sources]
PeiRngLib.c

[Ppis]
gEfiRngPpiGuid ## CONSUMES

[Depex]
gEfiRngPpiGuid
13 changes: 13 additions & 0 deletions MdePkg/Library/PeiRngLib/PeiRngLib.uni
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// @file
// PEI Instance of the RNG (Random Number Generator) Library.
//
// A RngLib instance that uses the RNG PPI to provide random numbers.
//
// Copyright (c) Microsoft Corporation.
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//

#string STR_MODULE_ABSTRACT #language en-US "Instance of the RNG Library for PEI"

#string STR_MODULE_DESCRIPTION #language en-US "A library that uses the RNG PPI to provide random numbers"
1 change: 1 addition & 0 deletions MdePkg/MdePkg.dsc
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Expand Up @@ -146,6 +146,7 @@
MdePkg/Library/StackCheckLib/StackCheckLibDynamicInit.inf ## MU_CHANGE
MdePkg/Library/StackCheckFailureHookLibNull/StackCheckFailureHookLibNull.inf ## MU_CHANGE
MdePkg/Library/StackCheckLibNull/StackCheckLibNull.inf ## MU_CHANGE
MdePkg/Library/PeiRngLib/PeiRngLib.inf # MU_CHANGE: Add PeiRngLib

[Components.IA32, Components.X64, Components.ARM, Components.AARCH64]
#
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