63 lines
1.7 KiB
C
63 lines
1.7 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* Secure boot handling.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2013,2014 Linaro Limited
|
||
|
|
* Roy Franz <roy.franz@linaro.org
|
||
|
|
* Copyright (C) 2013 Red Hat, Inc.
|
||
|
|
* Mark Salter <msalter@redhat.com>
|
||
|
|
*/
|
||
|
|
#include <linux/efi.h>
|
||
|
|
#include <asm/efi.h>
|
||
|
|
|
||
|
|
#include "efistub.h"
|
||
|
|
|
||
|
|
/* SHIM variables */
|
||
|
|
static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
|
||
|
|
static const efi_char16_t shim_MokSBState_name[] = L"MokSBStateRT";
|
||
|
|
|
||
|
|
static efi_status_t get_var(efi_char16_t *name, efi_guid_t *vendor, u32 *attr,
|
||
|
|
unsigned long *data_size, void *data)
|
||
|
|
{
|
||
|
|
return get_efi_var(name, vendor, attr, data_size, data);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Determine whether we're in secure boot mode.
|
||
|
|
*/
|
||
|
|
enum efi_secureboot_mode efi_get_secureboot(void)
|
||
|
|
{
|
||
|
|
u32 attr;
|
||
|
|
unsigned long size;
|
||
|
|
enum efi_secureboot_mode mode;
|
||
|
|
efi_status_t status;
|
||
|
|
u8 moksbstate;
|
||
|
|
|
||
|
|
mode = efi_get_secureboot_mode(get_var);
|
||
|
|
if (mode == efi_secureboot_mode_unknown) {
|
||
|
|
efi_err("Could not determine UEFI Secure Boot status.\n");
|
||
|
|
return efi_secureboot_mode_unknown;
|
||
|
|
}
|
||
|
|
if (mode != efi_secureboot_mode_enabled)
|
||
|
|
return mode;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* See if a user has put the shim into insecure mode. If so, and if the
|
||
|
|
* variable doesn't have the non-volatile attribute set, we might as
|
||
|
|
* well honor that.
|
||
|
|
*/
|
||
|
|
size = sizeof(moksbstate);
|
||
|
|
status = get_efi_var(shim_MokSBState_name, &shim_guid,
|
||
|
|
&attr, &size, &moksbstate);
|
||
|
|
|
||
|
|
/* If it fails, we don't care why. Default to secure */
|
||
|
|
if (status != EFI_SUCCESS)
|
||
|
|
goto secure_boot_enabled;
|
||
|
|
if (!(attr & EFI_VARIABLE_NON_VOLATILE) && moksbstate == 1)
|
||
|
|
return efi_secureboot_mode_disabled;
|
||
|
|
|
||
|
|
secure_boot_enabled:
|
||
|
|
efi_info("UEFI Secure Boot is enabled.\n");
|
||
|
|
return efi_secureboot_mode_enabled;
|
||
|
|
}
|