SecurityPkg/Library/PlatformSecureLibNull/PlatformSecureLibNull.c

   1 /** @file
   2   NULL PlatformSecureLib instance does NOT really detect whether a physical present
   3   user exists but return TRUE directly. This instance can be used to verify security
   4   related features during platform enabling and development. It should be replaced
   5   by a platform-specific method(e.g. Button pressed) in a real platform for product.
   6
   7 Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved.<BR>
   8 SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <Uefi/UefiBaseType.h>
  13
  14 BOOLEAN       mUserPhysicalPresence      = FALSE;
  15
  16 /**
  17
  18   This function provides a platform-specific method to detect whether the platform
  19   is operating by a physically present user.
  20
  21   Programmatic changing of platform security policy (such as disable Secure Boot,
  22   or switch between Standard/Custom Secure Boot mode) MUST NOT be possible during
  23   Boot Services or after exiting EFI Boot Services. Only a physically present user
  24   is allowed to perform these operations.
  25
  26   NOTE THAT: This function cannot depend on any EFI Variable Service since they are
  27   not available when this function is called in AuthenticateVariable driver.
  28
  29   @retval  TRUE       The platform is operated by a physically present user.
  30   @retval  FALSE      The platform is NOT operated by a physically present user.
  31
  32 **/
  33 BOOLEAN
  34 EFIAPI
  35 UserPhysicalPresent (
  36   VOID
  37   )
  38 {
  39   return mUserPhysicalPresence;
  40 }
  41
  42
  43 /**
  44   Save user physical presence state from a PCD to mUserPhysicalPresence.
  45
  46   @retval  EFI_SUCCESS          PcdUserPhysicalPresence is got successfully.
  47
  48 **/
  49 RETURN_STATUS
  50 EFIAPI
  51 PlatformSecureLibNullConstructor (
  52   VOID
  53   )
  54 {
  55
  56   mUserPhysicalPresence = PcdGetBool(PcdUserPhysicalPresence);
  57
  58   return RETURN_SUCCESS;
  59 }