SecurityPkg/RngDxe: Rename RdRandGenerateEntropy to generic name

Bugzilla: 3668 (https://bugzilla.tianocore.org/show_bug.cgi?id=3668)

Rename RdRandGenerateEntropy() to GenerateEntropy() to provide a
common interface to generate entropy on other architectures.
GenerateEntropy() is intended to generate high quality entropy.

Also move the definition to RngDxeInternals.h

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>

SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.c

@@ -1,15 +1,23 @@
 /** @file
-  Support routines for RDRAND instruction access.
+  Support routines for RDRAND instruction access, which will leverage
+  Intel Secure Key technology to provide high-quality random numbers for use
+  in applications, or entropy for seeding other random number generators.
+  Refer to http://software.intel.com/en-us/articles/intel-digital-random-number
+  -generator-drng-software-implementation-guide/ for more information about Intel
+  Secure Key technology.
 
+Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
 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/RngLib.h>
+#include <Library/TimerLib.h>
 
 #include "AesCore.h"
-#include "RdRand.h"
 #include "RngDxeInternals.h"
 
 /**
@@ -87,7 +95,7 @@ RdRandGetSeed128 (
 **/
 EFI_STATUS
 EFIAPI
-RdRandGenerateEntropy (
+GenerateEntropy (
   IN UINTN   Length,
   OUT UINT8  *Entropy
   )

SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RdRand.h

@@ -1,43 +0,0 @@
-/** @file
-  Header for the RDRAND APIs used by RNG DXE driver.
-
-  Support API definitions for RDRAND instruction access, which will leverage
-  Intel Secure Key technology to provide high-quality random numbers for use
-  in applications, or entropy for seeding other random number generators.
-  Refer to http://software.intel.com/en-us/articles/intel-digital-random-number
-  -generator-drng-software-implementation-guide/ for more information about Intel
-  Secure Key technology.
-
-Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
-(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
-SPDX-License-Identifier: BSD-2-Clause-Patent
-
-**/
-
-#ifndef __RD_RAND_H__
-#define __RD_RAND_H__
-
-#include <Library/BaseLib.h>
-#include <Library/BaseMemoryLib.h>
-#include <Library/UefiBootServicesTableLib.h>
-#include <Library/TimerLib.h>
-#include <Protocol/Rng.h>
-
-/**
-  Generate high-quality entropy source through RDRAND.
-
-  @param[in]   Length        Size of the buffer, in bytes, to fill with.
-  @param[out]  Entropy       Pointer to the buffer to store the entropy data.
-
-  @retval EFI_SUCCESS        Entropy generation succeeded.
-  @retval EFI_NOT_READY      Failed to request random data.
-
-**/
-EFI_STATUS
-EFIAPI
-RdRandGenerateEntropy (
-  IN UINTN   Length,
-  OUT UINT8  *Entropy
-  );
-
-#endif // __RD_RAND_H__

SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c

@@ -14,13 +14,16 @@
    - 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.<BR>
   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 "RdRand.h"
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+
 #include "RngDxeInternals.h"
 
 /**
@@ -88,7 +91,7 @@ RngGetRNG (
       return EFI_INVALID_PARAMETER;
     }
 
-    Status = RdRandGenerateEntropy (RNGValueLength, RNGValue);
+    Status = GenerateEntropy (RNGValueLength, RNGValue);
     return Status;
   }
 

SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf

@@ -10,6 +10,7 @@
 #
 #  Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
 #  (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
+#  Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 ##
@@ -36,7 +37,6 @@
 [Sources.IA32, Sources.X64]
   Rand/RngDxe.c
   Rand/RdRand.c
-  Rand/RdRand.h
   Rand/AesCore.c
   Rand/AesCore.h
 

SecurityPkg/RandomNumberGenerator/RngDxe/RngDxeInternals.h

@@ -10,6 +10,8 @@
 #ifndef RNGDXE_INTERNALS_H_
 #define RNGDXE_INTERNALS_H_
 
+#include <Protocol/Rng.h>
+
 /**
   Returns information about the random number generation implementation.
 
@@ -114,4 +116,21 @@ RngGetBytes (
   OUT UINT8  *RandBuffer
   );
 
+/**
+  Generate high-quality entropy source using a TRNG or through RDRAND.
+
+  @param[in]   Length        Size of the buffer, in bytes, to fill with.
+  @param[out]  Entropy       Pointer to the buffer to store the entropy data.
+
+  @retval EFI_SUCCESS        Entropy generation succeeded.
+  @retval EFI_NOT_READY      Failed to request random data.
+
+**/
+EFI_STATUS
+EFIAPI
+GenerateEntropy (
+  IN UINTN   Length,
+  OUT UINT8  *Entropy
+  );
+
 #endif // RNGDXE_INTERNALS_H_