[PATCH v2] MdePkg: add null version of RngLib

["Wang, Jian J" <jian.j.wang@intel.com>]

>v2:
>  - Change the name from RngLibNull to BaseRngLibNull according to Laszlo's
>    comments
>  - Move the module from SecurityPkg to MdePkg according to Laszlo's comments
>  - Update commit message according to Laszlo and Ray's comments

This is null version of RngLib which should be used with modules that
inherit an (indirect) dependency on the RngLib class, but never actually
call RngLib APIs for consuming randomness.


Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
 .../Library/BaseRngLibNull/BaseRngLibNull.c   | 95 +++++++++++++++++++
 .../Library/BaseRngLibNull/BaseRngLibNull.inf | 31 ++++++
 .../Library/BaseRngLibNull/BaseRngLibNull.uni | 14 +++
 MdePkg/MdePkg.dsc                             |  1 +
 4 files changed, 141 insertions(+)
 create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
 create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
 create mode 100644 MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni

diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
new file mode 100644
index 0000000000..13677abc84
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.c
@@ -0,0 +1,95 @@
+/** @file
+  Null version of Random number generator services.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/RngLib.h>
+
+/**
+  Generates a 16-bit random number.
+
+  if Rand is NULL, then ASSERT().
+
+  @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
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
+
+/**
+  Generates a 32-bit random number.
+
+  if Rand is NULL, then ASSERT().
+
+  @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
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
+
+/**
+  Generates a 64-bit random number.
+
+  if Rand is NULL, then ASSERT().
+
+  @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
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
+
+/**
+  Generates a 128-bit random number.
+
+  if Rand is NULL, then ASSERT().
+
+  @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
+  )
+{
+  ASSERT (FALSE);
+  return FALSE;
+}
diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
new file mode 100644
index 0000000000..f456df1dae
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
@@ -0,0 +1,31 @@
+## @file
+#  Null instance of RNG (Random Number Generator) Library.
+#
+#  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = BaseRngLibNull
+  MODULE_UNI_FILE                = BaseRngLibNull.uni
+  FILE_GUID                      = CD8991F8-2061-4084-8C9E-9C6F352DC58D
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = RngLib
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64 ARM AARCH64
+#
+
+[Sources]
+  BaseRngLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
diff --git a/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
new file mode 100644
index 0000000000..f32be6a617
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibNull/BaseRngLibNull.uni
@@ -0,0 +1,14 @@
+// /** @file
+// Null Instance of RNG (Random Number Generator) Library.
+//
+// Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "Null Instance of RNG Library"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "This library instance should be used with modules that inherit an (indirect) dependency on the RngLib class, but never actually call RngLib APIs for consuming randomness."
+
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index c1278e7907..0aeafaaacc 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -61,6 +61,7 @@
   MdePkg/Library/BaseUefiDecompressLib/BaseUefiTianoCustomDecompressLib.inf
   MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
   MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
+  MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
 
   MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.inf
   MdePkg/Library/DxeCoreHobLib/DxeCoreHobLib.inf
-- 
2.17.1.windows.2