Re: [PATCH v8 2/5] MdePkg: BaseRngLibDxe: Add RngLib that uses RngDxe

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

On 8/19/20 9:37 PM, matthewfcarlson@gmail.com wrote:
> From: Matthew Carlson <macarl@microsoft.com>
> 
> This adds a RngLib that uses the RngProtocol to provide randomness.
> This means that the RngLib is meant to be used with DXE_DRIVERS.
> 
> Ref: https://github.com/tianocore/edk2/pull/845
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Zhiguang Liu <zhiguang.liu@intel.com>
> Signed-off-by: Matthew Carlson <matthewfcarlson@gmail.com>
> ---
>   MdePkg/Library/DxeRngLib/DxeRngLib.c   | 206 ++++++++++++++++++++
>   MdePkg/Library/DxeRngLib/DxeRngLib.inf |  38 ++++
>   MdePkg/Library/DxeRngLib/DxeRngLib.uni |  15 ++
>   MdePkg/MdePkg.dsc                      |   4 +-
>   4 files changed, 262 insertions(+), 1 deletion(-)
> 
> diff --git a/MdePkg/Library/DxeRngLib/DxeRngLib.c b/MdePkg/Library/DxeRngLib/DxeRngLib.c
> new file mode 100644
> index 000000000000..0bd6585357b5
> --- /dev/null
> +++ b/MdePkg/Library/DxeRngLib/DxeRngLib.c
> @@ -0,0 +1,206 @@
> +/** @file
> + Provides an implementation of the library class RngLib that uses the Rng protocol.
> +
> + Copyright (c) Microsoft Corporation. All rights reserved.
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +#include <Uefi.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/RngLib.h>
> +#include <Protocol/Rng.h>
> +
> +/**
> +Routine Description:
> +
> +    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.
> +
> +    Arguments:
> +
> +    Buffer      -- Buffer to receive the random number.
> +    BufferSize  -- Number of bytes in Buffer.
> +
> +Return Value:
> +
> +    EFI_SUCCESS or underlying failure code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +GenerateRandomNumberViaNist800Algorithm (
> +  OUT UINT8 *Buffer,
> +  IN  UINTN  BufferSize
> +  )
> +{
> +  EFI_STATUS        Status;
> +  EFI_RNG_PROTOCOL *RngProtocol;

Align * with variable name please

> +
> +  RngProtocol = NULL;
> +
> +  if (Buffer == NULL) {
> +      DEBUG((DEBUG_ERROR, "[%a] Buffer == NULL.\n", __FUNCTION__));

Space before (

Also, drop the [] around %a for consistency with other code.

> +      return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Status = gBS->LocateProtocol (&gEfiRngProtocolGuid, NULL, (VOID **)&RngProtocol);
> +  if (EFI_ERROR (Status) || RngProtocol == NULL) {
> +      DEBUG((DEBUG_ERROR, "%a: Could not locate RNG prototocol, Status = %r\n", __FUNCTION__, Status));

Space before (

> +      return Status;
> +  }
> +
> +  Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Ctr256Guid, BufferSize, Buffer);
> +  DEBUG((DEBUG_INFO, "%a: GetRNG algorithm CTR-256 - Status = %r\n", __FUNCTION__, Status));

Same here

> +  if(!EFI_ERROR(Status)) {

Space after if

I think I mentioned this the last time around: please make sure that you 
adhere to the coding style, and fix *all* occurrences, not just the ones 
that were pointed out to you.

> +    return Status;
> +  }
> +
> +  Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Hmac256Guid, BufferSize, Buffer);
> +  DEBUG((DEBUG_INFO, "%a: GetRNG algorithm HMAC-256 - Status = %r\n", __FUNCTION__, Status));
> +  if(!EFI_ERROR(Status)) {
> +    return Status;
> +  }
> +
> +  Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Hash256Guid, BufferSize, Buffer);
> +  DEBUG((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __FUNCTION__, Status));
> +  if (!EFI_ERROR(Status)) {
> +    return Status;
> +  }
> +  // If all the other methods have failed, use the default method from the RngProtocol
> +  Status = RngProtocol->GetRNG (RngProtocol, NULL, BufferSize, Buffer);
> +  DEBUG((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __FUNCTION__, 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", __FUNCTION__, 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)
> +  {

Opening brace should be on the previous line.

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

Same here

> +    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, 4);
> +  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, 8);
> +  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, 16);
> +  if (EFI_ERROR (Status)) {
> +    return FALSE;
> +  }
> +  return TRUE;
> +}
> diff --git a/MdePkg/Library/DxeRngLib/DxeRngLib.inf b/MdePkg/Library/DxeRngLib/DxeRngLib.inf
> new file mode 100644
> index 000000000000..f4838aa05b7e
> --- /dev/null
> +++ b/MdePkg/Library/DxeRngLib/DxeRngLib.inf
> @@ -0,0 +1,38 @@
> +# @file
> +# Provides implementation of the library class RngLib that uses the RngProtocol
> +#
> +# @copyright
> +# Copyright (c) Microsoft Corporation. All rights reserved.
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION     = 0x00010017

Please use 1.27 (or 0x00001001B) for new modules.

> +  BASE_NAME       = DxeRngLib
> +  MODULE_UNI_FILE = DxeRngLib.uni
> +  FILE_GUID       = FF9F84C5-A33E-44E3-9BB5-0D654B2D4149
> +  MODULE_TYPE     = DXE_DRIVER
> +  VERSION_STRING  = 1.0
> +  LIBRARY_CLASS   = RngLib|DXE_DRIVER UEFI_APPLICATION UEFI_DRIVER
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +
> +[Sources]
> +  DxeRngLib.c
> +
> +[LibraryClasses]
> +  DebugLib
> +  UefiBootServicesTableLib
> +
> +[Protocols]
> +  gEfiRngProtocolGuid                 ## CONSUMES
> +
> +[Depex]
> +  gEfiRngProtocolGuid
> +
> +[Guids]
> +  gEfiRngAlgorithmSp80090Ctr256Guid
> +  gEfiRngAlgorithmSp80090Hash256Guid
> +  gEfiRngAlgorithmSp80090Hmac256Guid
> diff --git a/MdePkg/Library/DxeRngLib/DxeRngLib.uni b/MdePkg/Library/DxeRngLib/DxeRngLib.uni
> new file mode 100644
> index 000000000000..c904e54b6fb0
> --- /dev/null
> +++ b/MdePkg/Library/DxeRngLib/DxeRngLib.uni
> @@ -0,0 +1,15 @@
> +// @file
> +// Instance of RNG (Random Number Generator) Library.
> +//
> +// RngLib that uses the Rng Protocol to provide random numbers.
> +//
> +// Copyright (c) Microsoft Corporation.
> +//
> +// SPDX-License-Identifier: BSD-2-Clause-Patent
> +//
> +
> +
> +#string STR_MODULE_ABSTRACT     #language en-US "Instance of RNG Library"
> +
> +#string STR_MODULE_DESCRIPTION  #language en-US "BaseRng Library that uses the Rng Protocol to provide random numbers"
> +
> diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
> index d7ba3a730909..2c3b7966b086 100644
> --- a/MdePkg/MdePkg.dsc
> +++ b/MdePkg/MdePkg.dsc
> @@ -62,8 +62,10 @@
>     MdePkg/Library/BasePostCodeLibPort80/BasePostCodeLibPort80.inf
>     MdePkg/Library/BasePrintLib/BasePrintLib.inf
>     MdePkg/Library/BaseReportStatusCodeLibNull/BaseReportStatusCodeLibNull.inf
> -  MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
> +  MdePkg/Library/DxeRngLib/DxeRngLib.inf
>     MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
> +  MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
> +
>     MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.inf
>     MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
>     MdePkg/Library/BaseTimerLibNullTemplate/BaseTimerLibNullTemplate.inf
>