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 - 2016, Intel Corporation. All rights reserved.<BR>
   8 This program and the accompanying materials
   9 are licensed and made available under the terms and conditions of the BSD License
  10 which accompanies this distribution.  The full text of the license may be found at
  11 http://opensource.org/licenses/bsd-license.php
  12
  13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17
  18 BOOLEAN       mUserPhysicalPresence      = FALSE;
  19
  20 /**
  21
  22   This function provides a platform-specific method to detect whether the platform
  23   is operating by a physically present user.
  24
  25   Programmatic changing of platform security policy (such as disable Secure Boot,
  26   or switch between Standard/Custom Secure Boot mode) MUST NOT be possible during
  27   Boot Services or after exiting EFI Boot Services. Only a physically present user
  28   is allowed to perform these operations.
  29
  30   NOTE THAT: This function cannot depend on any EFI Variable Service since they are
  31   not available when this function is called in AuthenticateVariable driver.
  32
  33   @retval  TRUE       The platform is operated by a physically present user.
  34   @retval  FALSE      The platform is NOT operated by a physically present user.
  35
  36 **/
  37 BOOLEAN
  38 EFIAPI
  39 UserPhysicalPresent (
  40   VOID
  41   )
  42 {
  43   return mUserPhysicalPresence;
  44 }
  45
  46
  47 /**
  48   Save user physical presence state from a PCD to mUserPhysicalPresence.
  49
  50   @param  ImageHandle   ImageHandle of the loaded driver.
  51   @param  SystemTable   Pointer to the EFI System Table.
  52
  53   @retval  EFI_SUCCESS          PcdUserPhysicalPresence is got successfully.
  54
  55 **/
  56 EFI_STATUS
  57 EFIAPI
  58 PlatformSecureLibNullConstructor (
  59   IN EFI_HANDLE        ImageHandle,
  60   IN EFI_SYSTEM_TABLE  *SystemTable
  61   )
  62 {
  63
  64   mUserPhysicalPresence = PcdGetBool(PcdUserPhysicalPresence);
  65
  66   return EFI_SUCCESS;
  67 }