Re: [PATCH v4 06/28] MdeModulePkg: Add Null ProtectedVariable Library

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

Reviewed-by: Jian J Wang <jian.j.wang@intel.com>

Regards,
Jian

> -----Original Message-----
> From: Vang, Judah <judah.vang@intel.com>
> Sent: Thursday, August 11, 2022 2:53 PM
> To: devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Gao, Liming
> <gaoliming@byosoft.com.cn>; Mistry, Nishant C <nishant.c.mistry@intel.com>
> Subject: [PATCH v4 06/28] MdeModulePkg: Add Null ProtectedVariable Library
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2594
> 
> V4: Applied code review comments - removed APIs that are not being
> used.
> 
> V1: Add Null versions of the ProtectedVariable Library.
> This will be the default libraries for platforms that
> do not support ProtectedVariable.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> 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>
> ---
>  MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariableLibNull.inf
> |  34 ++
>  MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariable.c          |
> 336 ++++++++++++++++++++
>  2 files changed, 370 insertions(+)
> 
> diff --git
> a/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariableLibNull.in
> f
> b/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariableLibNull.in
> f
> new file mode 100644
> index 000000000000..6a17191c4e1e
> --- /dev/null
> +++
> b/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariableLibNull.in
> f
> @@ -0,0 +1,34 @@
> +## @file
> +#  Provides null version of protected variable services.
> +#
> +#  Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 0x00010029
> +  BASE_NAME                      = ProtectedVariableLibNull
> +  FILE_GUID                      = 352C6A1B-403A-4E37-8517-FAA50BC45251
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 0.1
> +  LIBRARY_CLASS                  = ProtectedVariableLib
> +
> +#
> +# The following information is for reference only and not required by the build
> tools.
> +#
> +#  VALID_ARCHITECTURES           = IA32 X64
> +#
> +
> +[Sources]
> +  ProtectedVariable.c
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  BaseMemoryLib
> +  DebugLib
> +
> diff --git
> a/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariable.c
> b/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariable.c
> new file mode 100644
> index 000000000000..074559f84f52
> --- /dev/null
> +++ b/MdeModulePkg/Library/ProtectedVariableLibNull/ProtectedVariable.c
> @@ -0,0 +1,336 @@
> +/** @file
> +  NULL version of ProtectedVariableLib used to disable protected variable
> services.
> +
> +Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> +SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <PiDxe.h>
> +#include <Uefi.h>
> +
> +#include <Library/DebugLib.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/ProtectedVariableLib.h>
> +
> +/**
> +
> +  Initialization for protected varibale services.
> +
> +  @param[in]  ContextIn   Pointer to variable service context needed by
> +                          protected variable.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibInitialize (
> +  IN  PROTECTED_VARIABLE_CONTEXT_IN  *ContextIn
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Prepare for variable update.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibWriteInit (
> +  VOID
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Update a variable with protection provided by this library.
> +
> +  @param[in,out]  CurrVariable        Variable to be updated. It's NULL if
> +                                      adding a new variable.
> +  @param[in]      CurrVariableInDel   In-delete-transiion copy of updating
> variable.
> +  @param[in,out]  NewVariable         Buffer of new variable data.
> +                                      Buffer of "MetaDataHmacVar" and new
> +                                      variable (encrypted).
> +  @param[in,out]  NewVariableSize     Size of NewVariable.
> +                                      Size of (encrypted) NewVariable and
> +                                      "MetaDataHmacVar".
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibUpdate (
> +  IN  OUT VARIABLE_HEADER  *CurrVariable,
> +  IN      VARIABLE_HEADER  *CurrVariableInDel,
> +  IN  OUT VARIABLE_HEADER  *NewVariable,
> +  IN  OUT UINTN            *NewVariableSize
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Finalize a variable updating after it's written to NV variable storage
> +  successfully.
> +
> +  @param[in]      NewVariable       Buffer of new variables and
> MetaDataHmacVar.
> +  @param[in]      VariableSize      Size of buffer pointed by NewVariable.
> +  @param[in]      StoreIndex        New index of the variable in store.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibWriteFinal (
> +  IN  VARIABLE_HEADER  *NewVariable,
> +  IN  UINTN            VariableSize,
> +  IN  UINT64           StoreIndex
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Retrieve plain data, if encrypted, of given variable.
> +
> +  @param[in]      Variable           Pointer to header of a Variable.
> +  @param[in,out]  Data               Pointer to plain data of the given variable.
> +  @param[in,out]  DataSize           Size of data returned or data buffer needed.
> +  @param[in]      AuthFlag           Auth-variable indicator.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGetData (
> +  IN      VARIABLE_HEADER  *Variable,
> +  IN  OUT VOID             *Data,
> +  IN  OUT UINT32           *DataSize,
> +  IN      BOOLEAN          AuthFlag
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Get the specified protected variable.
> +
> +  @param[in]      VariableName      Pointer to variable name.
> +  @param[in]      VariableGuid      Pointer to vairable GUID.
> +  @param[out]     Attributes        Pointer to attributes.
> +  @param[in,out]  DataSize          Pointer to data size.
> +  @param[out]     Data              Pointer to data.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGet (
> +  IN      CONST  CHAR16    *VariableName,
> +  IN      CONST  EFI_GUID  *VariableGuid,
> +  OUT UINT32               *Attributes,
> +  IN  OUT UINTN            *DataSize,
> +  OUT VOID                 *Data OPTIONAL
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Find the protected variable.
> +
> +  @param[in,out]      VarInfo     Pointer to structure containing variable
> information.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibFind (
> +  IN  OUT PROTECTED_VARIABLE_INFO  *VarInfo
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Find next protected variable.
> +
> +  @param[in,out]      VariableNameSize    Pointer to size of variable name.
> +  @param[in,out]      VariableName        Pointer to variable name.
> +  @param[in,out]      VariableGuid        Pointer to vairable GUID.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibFindNext (
> +  IN OUT UINTN     *VariableNameSize,
> +  IN OUT CHAR16    *VariableName,
> +  IN OUT EFI_GUID  *VariableGuid
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Find next protected variable stub.
> +
> +  @param[in,out]      VarInfo     Pointer to structure containing variable
> information.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibFindNextEx (
> +  IN  OUT PROTECTED_VARIABLE_INFO  *VarInfo
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Get protected variable by information.
> +
> +  @param[in,out]      VarInfo     Pointer to structure containing variable
> information.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGetByInfo (
> +  IN  OUT PROTECTED_VARIABLE_INFO  *VarInfo
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Get protected variable by name.
> +
> +  @param[in]      VariableName      Pointer to variable name.
> +  @param[in]      VariableGuid      Pointer to vairable GUID.
> +  @param[out]     Attributes        Pointer to attributes.
> +  @param[in,out]  DataSize          Pointer to data size.
> +  @param[out]     Data              Pointer to data.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGetByName (
> +  IN      CONST  CHAR16    *VariableName,
> +  IN      CONST  EFI_GUID  *VariableGuid,
> +  OUT UINT32               *Attributes,
> +  IN  OUT UINTN            *DataSize,
> +  OUT VOID                 *Data OPTIONAL
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Get protected variable by name.
> +
> +  @param[in]      Variable      Pointer to variable name.
> +  @param[in,out]  Data          Pointer to variable data.
> +  @param[in,out]  DataSize      Pointer to data size.
> +  @param[in]      AuthFlag      Authenticate flag.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGetByBuffer (
> +  IN      VARIABLE_HEADER  *Variable,
> +  IN  OUT VOID             *Data,
> +  IN  OUT UINT32           *DataSize,
> +  IN      BOOLEAN          AuthFlag
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +  Refresh variable information changed by variable service.
> +
> +  @param[in]  Variable         Pointer to buffer of the updated variable.
> +  @param[in]  VariableSize     Size of variable pointed by Variable.
> +  @param[in]  StoreIndex       New index of the variable in store.
> +  @param[in]  RefreshData      Flag to indicate if the variable has been updated.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibRefresh (
> +  IN  VARIABLE_HEADER  *Variable,
> +  IN  UINTN            VariableSize,
> +  IN  UINT64           StoreIndex,
> +  IN  BOOLEAN          RefreshData
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Get sorted protected variable list.
> +
> +  @param[in,out]  Buffer        Pointer to buffer.
> +  @param[in,out]  NumElements   Pointer to number of elements.
> +
> +  @retval EFI_UNSUPPORTED           Unsupported to process protected variable.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ProtectedVariableLibGetSortedList (
> +  IN  OUT  EFI_PHYSICAL_ADDRESS  **Buffer,
> +  IN  OUT  UINTN                 *NumElements
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +
> +  Determine if the variable is the HMAC variable.
> +
> +  @param[in]  VariableName   Pointer to variable name.
> +
> +  @return FALSE     Variable is not HMAC variable
> +
> +**/
> +BOOLEAN
> +ProtectedVariableLibIsHmac (
> +  IN CHAR16  *VariableName
> +  )
> +{
> +  return FALSE;
> +}
> --
> 2.35.1.windows.2