From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/firmware/efi/libstub/secureboot.c | 62 +++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 drivers/firmware/efi/libstub/secureboot.c (limited to 'drivers/firmware/efi/libstub/secureboot.c') diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c new file mode 100644 index 000000000..516f4f006 --- /dev/null +++ b/drivers/firmware/efi/libstub/secureboot.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Secure boot handling. + * + * Copyright (C) 2013,2014 Linaro Limited + * Roy Franz + */ +#include +#include + +#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; +} -- cgit v1.2.3