EdkModulePkg/Universal/Security/SecurityStub/Dxe/SecurityStub.c

/*++

Copyright (c) 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:

  SecurityStub.c

Abstract:
  
  This driver supports platform security service

--*/

#include "SecurityStub.h"

//
// Handle for the Security Architectural Protocol instance produced by this driver
//
EFI_HANDLE                  mSecurityArchProtocolHandle = NULL;

//
// Security Architectural Protocol instance produced by this driver
//
EFI_SECURITY_ARCH_PROTOCOL  mSecurityStub = { 
  SecurityStubAuthenticateState 
};

//
// Worker functions
//
EFI_STATUS
EFIAPI
SecurityStubAuthenticateState (
  IN EFI_SECURITY_ARCH_PROTOCOL  *This,
  IN UINT32                      AuthenticationStatus,
  IN EFI_DEVICE_PATH_PROTOCOL    *File
  )
/*++

Routine Description:

  The EFI_SECURITY_ARCH_PROTOCOL (SAP) is used to abstract platform-specific 
  policy from the DXE core response to an attempt to use a file that returns a 
  given status for the authentication check from the section extraction protocol.  

  The possible responses in a given SAP implementation may include locking 
  flash upon failure to authenticate, attestation logging for all signed drivers, 
  and other exception operations.  The File parameter allows for possible logging 
  within the SAP of the driver.

  If File is NULL, then EFI_INVALID_PARAMETER is returned.

  If the file specified by File with an authentication status specified by 
  AuthenticationStatus is safe for the DXE Core to use, then EFI_SUCCESS is returned.

  If the file specified by File with an authentication status specified by 
  AuthenticationStatus is not safe for the DXE Core to use under any circumstances, 
  then EFI_ACCESS_DENIED is returned.

  If the file specified by File with an authentication status specified by 
  AuthenticationStatus is not safe for the DXE Core to use right now, but it 
  might be possible to use it at a future time, then EFI_SECURITY_VIOLATION is 
  returned.

Arguments:

  This                 - The EFI_SECURITY_ARCH_PROTOCOL instance.

  AuthenticationStatus - This is the authentication type returned from the Section 
                         Extraction protocol.  See the Section Extraction Protocol 
                         Specification for details on this type.

  File                 - This is a pointer to the device path of the file that is 
                         being dispatched.  This will optionally be used for logging.

Returns:

  EFI_SUCCESS            - The file specified by File did authenticate, and the 
                           platform policy dictates that the DXE Core may use File.

  EFI_INVALID_PARAMETER  - File is NULL.

  EFI_SECURITY_VIOLATION - The file specified by File did not authenticate, and 
                           the platform policy dictates that File should be placed 
                           in the untrusted state.   A file may be promoted from 
                           the untrusted to the trusted state at a future time 
                           with a call to the Trust() DXE Service.

  EFI_ACCESS_DENIED      - The file specified by File did not authenticate, and 
                           the platform policy dictates that File should not be 
                           used for any purpose. 

--*/
{
  if (File == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
SecurityStubInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
/*++

Routine Description:

  Initialize the state information for the Security Architectural Protocol

Arguments:

  ImageHandle of the loaded driver
  Pointer to the System Table

Returns:

  Status

  EFI_SUCCESS           - successful installation of the service
  EFI_OUT_OF_RESOURCES  - cannot allocate protocol data structure
  EFI_DEVICE_ERROR      - cannot create the timer service

--*/
{
  EFI_STATUS  Status;

  //
  // Make sure the Security Architectural Protocol is not already installed in the system
  //
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiSecurityArchProtocolGuid);

  //
  // Install the Security Architectural Protocol onto a new handle
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mSecurityArchProtocolHandle,
                  &gEfiSecurityArchProtocolGuid,
                  &mSecurityStub,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);

  return Status;
}