[PATCH v5 15/19] SecurityPkg: Add null encryption variable libs

["Judah Vang" <judah.vang@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2594

V4: Applied code review - Remove empty Guids section
from .inf file. Update description in *.c. Remove *.uni file
and reference to it.

V1: Provide null ecryption variable libraries.
These will be used by default for platforms that don't
support protected variable encryption.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Nishant C Mistry <nishant.c.mistry@intel.com>
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Signed-off-by: Nishant C Mistry <nishant.c.mistry@intel.com>
Signed-off-by: Judah Vang <judah.vang@intel.com>
---
 SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariableLibNull.inf | 34 ++++++++
 SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariable.c          | 92 ++++++++++++++++++++
 2 files changed, 126 insertions(+)

diff --git a/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariableLibNull.inf b/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariableLibNull.inf
new file mode 100644
index 000000000000..185b6f9bedf7
--- /dev/null
+++ b/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariableLibNull.inf
@@ -0,0 +1,34 @@
+## @file
+#  Provides NULL version of encryption variable services.
+#
+#  Copyright (c) 2015 - 2022, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = EncryptionVariableLibNull
+  FILE_GUID                      = 3972E6FE-74D5-45C3-A9FB-DB9E5E5C9C17
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = EncryptionVariableLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  EncryptionVariable.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  SecurityPkg/SecurityPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
diff --git a/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariable.c b/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariable.c
new file mode 100644
index 000000000000..52ee8a7b5aae
--- /dev/null
+++ b/SecurityPkg/Library/EncryptionVariableLibNull/EncryptionVariable.c
@@ -0,0 +1,92 @@
+/** @file
+  NULL implementation of EncryptionVariableLib.
+
+Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Library/EncryptionVariableLib.h>
+#include <Library/DebugLib.h>
+
+/**
+  Encrypt variable data.
+
+  Null version.
+
+  @param[in, out]   VarEncInfo   Pointer to structure containing detailed
+                                 information about a variable.
+
+  @retval EFI_UNSUPPORTED         Unsupported to encrypt variable.
+
+**/
+EFI_STATUS
+EFIAPI
+EncryptVariable (
+  IN OUT VARIABLE_ENCRYPTION_INFO  *VarEncInfo
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  Decrypt variable data.
+
+  Null version.
+
+  @param[in, out]   VarEncInfo   Pointer to structure containing detailed
+                                 information about a variable.
+
+  @retval EFI_UNSUPPORTED         Unsupported to encrypt variable.
+
+**/
+EFI_STATUS
+EFIAPI
+DecryptVariable (
+  IN OUT VARIABLE_ENCRYPTION_INFO  *VarEncInfo
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  Get cipher information.
+
+  Null version.
+
+  @param[in]   VarEncInfo   Pointer to structure containing detailed
+                            information about a variable.
+
+  @retval EFI_UNSUPPORTED         Unsupported interface.
+
+**/
+EFI_STATUS
+EFIAPI
+GetCipherDataInfo (
+  IN VARIABLE_ENCRYPTION_INFO  *VarEncInfo
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  Set cipher information for a variable.
+
+  Null version.
+
+  @param[in]   VarEncInfo   Pointer to structure containing detailed
+                            information about a variable.
+
+  @retval EFI_UNSUPPORTED         If this method is not supported.
+
+**/
+EFI_STATUS
+EFIAPI
+SetCipherDataInfo (
+  IN VARIABLE_ENCRYPTION_INFO  *VarEncInfo
+  )
+{
+  return EFI_UNSUPPORTED;
+}
-- 
2.35.1.windows.2