SecurityPkg/RngDxe: Documentation/include/parameter cleanup

[mirror_edk2.git] / SecurityPkg / RandomNumberGenerator / RngDxe / RngDxe.c

/** @file\r
  RNG Driver to produce the UEFI Random Number Generator protocol.\r
\r
  The driver uses CPU RNG instructions to produce high-quality,\r
  high-performance entropy and random number.\r
\r
  RNG Algorithms defined in UEFI 2.4:\r
   - EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID\r
   - EFI_RNG_ALGORITHM_RAW\r
   - EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID\r
   - EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID\r
   - EFI_RNG_ALGORITHM_X9_31_3DES_GUID\r
   - EFI_RNG_ALGORITHM_X9_31_AES_GUID\r
\r
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>\r
(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>\r
\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Library/BaseLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/RngLib.h>\r
#include <Protocol/Rng.h>\r
\r
#include "RngDxeInternals.h"\r
\r
//\r
// The Random Number Generator (RNG) protocol\r
//\r
EFI_RNG_PROTOCOL  mRngRdRand = {\r
  RngGetInfo,\r
  RngGetRNG\r
};\r
\r
/**\r
  The user Entry Point for the Random Number Generator (RNG) driver.\r
\r
  @param[in] ImageHandle    The firmware allocated handle for the EFI image.\r
  @param[in] SystemTable    A pointer to the EFI System Table.\r
\r
  @retval EFI_SUCCESS       The entry point is executed successfully.\r
  @retval EFI_NOT_SUPPORTED Platform does not support RNG.\r
  @retval Other             Some error occurs when executing this entry point.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
RngDriverEntry (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
  //\r
  // Install UEFI RNG (Random Number Generator) Protocol\r
  //\r
  Handle = NULL;\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &Handle,\r
                  &gEfiRngProtocolGuid,\r
                  &mRngRdRand,\r
                  NULL\r
                  );\r
\r
  return Status;\r
}\r
\r
/**\r
  Runs CPU RNG instruction to fill a buffer of arbitrary size with random bytes.\r
\r
  @param[in]   Length        Size of the buffer, in bytes,  to fill with.\r
  @param[out]  RandBuffer    Pointer to the buffer to store the random result.\r
\r
  @retval EFI_SUCCESS        Random bytes generation succeeded.\r
  @retval EFI_NOT_READY      Failed to request random bytes.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
RngGetBytes (\r
  IN UINTN   Length,\r
  OUT UINT8  *RandBuffer\r
  )\r
{\r
  BOOLEAN  IsRandom;\r
  UINT64   TempRand[2];\r
\r
  while (Length > 0) {\r
    IsRandom = GetRandomNumber128 (TempRand);\r
    if (!IsRandom) {\r
      return EFI_NOT_READY;\r
    }\r
\r
    if (Length >= sizeof (TempRand)) {\r
      WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[0]);\r
      RandBuffer += sizeof (UINT64);\r
      WriteUnaligned64 ((UINT64 *)RandBuffer, TempRand[1]);\r
      RandBuffer += sizeof (UINT64);\r
      Length     -= sizeof (TempRand);\r
    } else {\r
      CopyMem (RandBuffer, TempRand, Length);\r
      Length = 0;\r
    }\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r