[PATCH RESEND v1 6/7] MdePkg/AesLib: Add NULL instance of AesLib

["PierreGondois" <pierre.gondois@arm.com>]

From: Pierre Gondois <Pierre.Gondois@arm.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3970

The FIPS PUB 197: "Advanced Encryption Standard (AES)"
details the AES algorithm.

Add an AesLibNull implementation.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 MdePkg/Library/AesLibNull/AesLibNull.c   | 87 ++++++++++++++++++++++++
 MdePkg/Library/AesLibNull/AesLibNull.inf | 24 +++++++
 MdePkg/MdePkg.dsc                        |  1 +
 3 files changed, 112 insertions(+)
 create mode 100644 MdePkg/Library/AesLibNull/AesLibNull.c
 create mode 100644 MdePkg/Library/AesLibNull/AesLibNull.inf

diff --git a/MdePkg/Library/AesLibNull/AesLibNull.c b/MdePkg/Library/AesLibNull/AesLibNull.c
new file mode 100644
index 000000000000..3dd680fe37e4
--- /dev/null
+++ b/MdePkg/Library/AesLibNull/AesLibNull.c
@@ -0,0 +1,87 @@
+/** @file
+  Null AES Library
+
+  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Reference(s):
+   - FIPS 197 November 26, 2001:
+     Specification for the ADVANCED ENCRYPTION STANDARD (AES)
+**/
+
+#include <Library/AesLib.h>
+#include <Library/DebugLib.h>
+
+/** Encrypt an AES block.
+
+  Buffers are little-endian. Overlapping is not checked.
+
+  @param [in]  AesCtx    AES context.
+                         AesCtx is initialized with AesInitCtx ().
+  @param [in]  InBlock   Input Block. The block to cipher.
+  @param [out] OutBlock  Output Block. The ciphered block.
+
+  @retval EFI_SUCCESS            Success.
+  @retval EFI_INVALID_PARAMETER  Invalid parameter.
+  @retval EFI_UNSUPPORTED        Unsupported.
+**/
+EFI_STATUS
+EFIAPI
+AesEncrypt (
+  IN  AES_CTX      *AesCtx,
+  IN  UINT8 CONST  *InBlock,
+  OUT UINT8        *OutBlock
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+/** Decrypt an AES block.
+
+  Buffers are little-endian. Overlapping is not checked.
+
+  @param [in]  AesCtx    AES context.
+                         AesCtx is initialized with AesInitCtx ().
+  @param [in]  InBlock   Input Block. The block to de-cipher.
+  @param [out] OutBlock  Output Block. The de-ciphered block.
+
+  @retval EFI_SUCCESS            Success.
+  @retval EFI_INVALID_PARAMETER  Invalid parameter.
+  @retval EFI_UNSUPPORTED        Unsupported.
+**/
+EFI_STATUS
+EFIAPI
+AesDecrypt (
+  IN  AES_CTX      *AesCtx,
+  IN  UINT8 CONST  *InBlock,
+  OUT UINT8        *OutBlock
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+/** Initialize an AES_CTX structure.
+
+  @param [in]       Key       AES key. Buffer of KeySize bytes.
+                              The buffer is little endian.
+  @param [in]       KeySize   Size of the key. Must be one of 128|192|256.
+  @param [in, out]  AesCtx    AES context to initialize.
+
+  @retval EFI_SUCCESS            Success.
+  @retval EFI_INVALID_PARAMETER  Invalid parameter.
+  @retval EFI_UNSUPPORTED        Unsupported.
+**/
+EFI_STATUS
+EFIAPI
+AesInitCtx (
+  IN      UINT8    *Key,
+  IN      UINT32   KeySize,
+  IN OUT  AES_CTX  *AesCtx
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
diff --git a/MdePkg/Library/AesLibNull/AesLibNull.inf b/MdePkg/Library/AesLibNull/AesLibNull.inf
new file mode 100644
index 000000000000..3020e7b68571
--- /dev/null
+++ b/MdePkg/Library/AesLibNull/AesLibNull.inf
@@ -0,0 +1,24 @@
+## @file
+#  Null AES Library
+#
+#  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION    = 0x0001001B
+  BASE_NAME      = AesLibNull
+  FILE_GUID      = F6DED279-FC26-40F6-88B2-05FF5E6E538F
+  VERSION_STRING = 1.0
+  MODULE_TYPE    = DXE_DRIVER
+  LIBRARY_CLASS  = AesLib
+
+[Sources]
+  AesLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  DebugLib
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index 80e7233363d3..726350c215e5 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -68,6 +68,7 @@ [Components]
   MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf
   MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
   MdePkg/Library/BaseTrngLibNull/BaseTrngLibNull.inf
+  MdePkg/Library/AesLibNull/AesLibNull.inf
 
   MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.inf
   MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
-- 
2.25.1