MdeModulePkg/Universal/SecurityStubDxe/SecurityStub.c

   1 /** @file
   2   This driver supports platform security service.
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15
  16 #include "SecurityStub.h"
  17
  18 //
  19 // Handle for the Security Architectural Protocol instance produced by this driver
  20 //
  21 EFI_HANDLE                  mSecurityArchProtocolHandle = NULL;
  22
  23 //
  24 // Security Architectural Protocol instance produced by this driver
  25 //
  26 EFI_SECURITY_ARCH_PROTOCOL  mSecurityStub = {
  27   SecurityStubAuthenticateState
  28 };
  29
  30
  31 /**
  32   The EFI_SECURITY_ARCH_PROTOCOL (SAP) is used to abstract platform-specific
  33   policy from the DXE core response to an attempt to use a file that returns a
  34   given status for the authentication check from the section extraction protocol.
  35
  36   The possible responses in a given SAP implementation may include locking
  37   flash upon failure to authenticate, attestation logging for all signed drivers,
  38   and other exception operations.  The File parameter allows for possible logging
  39   within the SAP of the driver.
  40
  41   If File is NULL, then EFI_INVALID_PARAMETER is returned.
  42
  43   If the file specified by File with an authentication status specified by
  44   AuthenticationStatus is safe for the DXE Core to use, then EFI_SUCCESS is returned.
  45
  46   If the file specified by File with an authentication status specified by
  47   AuthenticationStatus is not safe for the DXE Core to use under any circumstances,
  48   then EFI_ACCESS_DENIED is returned.
  49
  50   If the file specified by File with an authentication status specified by
  51   AuthenticationStatus is not safe for the DXE Core to use right now, but it
  52   might be possible to use it at a future time, then EFI_SECURITY_VIOLATION is
  53   returned.
  54
  55   @param  This             The EFI_SECURITY_ARCH_PROTOCOL instance.
  56   @param  AuthenticationStatus
  57                            This is the authentication type returned from the Section
  58                            Extraction protocol. See the Section Extraction Protocol
  59                            Specification for details on this type.
  60   @param  File             This is a pointer to the device path of the file that is
  61                            being dispatched. This will optionally be used for logging.
  62
  63   @retval EFI_SUCCESS           The file specified by File did authenticate, and the
  64                                 platform policy dictates that the DXE Core may use File.
  65   @retval EFI_INVALID_PARAMETER Driver is NULL.
  66   @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and
  67                                 the platform policy dictates that File should be placed
  68                                 in the untrusted state. A file may be promoted from
  69                                 the untrusted to the trusted state at a future time
  70                                 with a call to the Trust() DXE Service.
  71   @retval EFI_ACCESS_DENIED     The file specified by File did not authenticate, and
  72                                 the platform policy dictates that File should not be
  73                                 used for any purpose.
  74
  75 **/
  76 EFI_STATUS
  77 EFIAPI
  78 SecurityStubAuthenticateState (
  79   IN EFI_SECURITY_ARCH_PROTOCOL  *This,
  80   IN UINT32                      AuthenticationStatus,
  81   IN EFI_DEVICE_PATH_PROTOCOL    *File
  82   )
  83 {
  84   if (File == NULL) {
  85     return EFI_INVALID_PARAMETER;
  86   }
  87
  88   return EFI_SUCCESS;
  89 }
  90
  91
  92 /**
  93   The user Entry Point for DXE driver. The user code starts with this function
  94   as the real entry point for the image goes into a library that calls this
  95   function.
  96
  97   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
  98   @param[in] SystemTable    A pointer to the EFI System Table.
  99
 100   @retval EFI_SUCCESS       The entry point is executed successfully.
 101   @retval other             Some error occurs when executing this entry point.
 102
 103 **/
 104 EFI_STATUS
 105 EFIAPI
 106 SecurityStubInitialize (
 107   IN EFI_HANDLE        ImageHandle,
 108   IN EFI_SYSTEM_TABLE  *SystemTable
 109   )
 110 {
 111   EFI_STATUS  Status;
 112
 113   //
 114   // Make sure the Security Architectural Protocol is not already installed in the system
 115   //
 116   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiSecurityArchProtocolGuid);
 117
 118   //
 119   // Install the Security Architectural Protocol onto a new handle
 120   //
 121   Status = gBS->InstallMultipleProtocolInterfaces (
 122                   &mSecurityArchProtocolHandle,
 123                   &gEfiSecurityArchProtocolGuid,
 124                   &mSecurityStub,
 125                   NULL
 126                   );
 127   ASSERT_EFI_ERROR (Status);
 128
 129   return Status;
 130 }