/* * Copyright (C) 2020 Richard Hughes * * SPDX-License-Identifier: LGPL-2.1+ */ #include "config.h" #include "fu-efivar.h" #include "fu-efi-signature.h" #include "fu-uefi-dbx-common.h" #include "fu-uefi-dbx-device.h" struct _FuUefiDbxDevice { FuDevice parent_instance; }; G_DEFINE_TYPE (FuUefiDbxDevice, fu_uefi_dbx_device, FU_TYPE_DEVICE) static gboolean fu_uefi_dbx_device_write_firmware (FuDevice *device, FuFirmware *firmware, FwupdInstallFlags install_flags, GError **error) { const guint8 *buf; gsize bufsz = 0; g_autoptr(GBytes) fw = NULL; /* get default image */ fw = fu_firmware_get_bytes (firmware, error); if (fw == NULL) return FALSE; /* write entire chunk to efivarfs */ fu_device_set_status (device, FWUPD_STATUS_DEVICE_WRITE); buf = g_bytes_get_data (fw, &bufsz); if (!fu_efivar_set_data (FU_EFIVAR_GUID_SECURITY_DATABASE, "dbx", buf, bufsz, FU_EFIVAR_ATTR_APPEND_WRITE | FU_EFIVAR_ATTR_TIME_BASED_AUTHENTICATED_WRITE_ACCESS | FU_EFIVAR_ATTR_RUNTIME_ACCESS | FU_EFIVAR_ATTR_BOOTSERVICE_ACCESS | FU_EFIVAR_ATTR_NON_VOLATILE, error)) { return FALSE; } /* success! */ return TRUE; } static gboolean fu_uefi_dbx_device_set_version_number (FuDevice *device, GError **error) { g_autoptr(GBytes) dbx_blob = NULL; g_autoptr(FuFirmware) dbx = fu_efi_signature_list_new (); /* use the number of checksums in the dbx as a version number, ignoring * some owners that do not make sense */ dbx_blob = fu_efivar_get_data_bytes (FU_EFIVAR_GUID_SECURITY_DATABASE, "dbx", NULL, error); if (dbx_blob == NULL) return FALSE; if (!fu_firmware_parse (dbx, dbx_blob, FWUPD_INSTALL_FLAG_NO_SEARCH, error)) return FALSE; fu_device_set_version (device, fu_firmware_get_version (dbx)); fu_device_set_version_lowest (device, fu_firmware_get_version (dbx)); return TRUE; } static FuFirmware * fu_uefi_dbx_prepare_firmware (FuDevice *device, GBytes *fw, FwupdInstallFlags flags, GError **error) { g_autoptr(FuFirmware) siglist = fu_efi_signature_list_new (); /* parse dbx */ if (!fu_firmware_parse (siglist, fw, flags, error)) return NULL; /* validate this is safe to apply */ if ((flags & FWUPD_INSTALL_FLAG_FORCE) == 0) { fu_device_set_status (device, FWUPD_STATUS_DEVICE_VERIFY); if (!fu_uefi_dbx_signature_list_validate (FU_EFI_SIGNATURE_LIST (siglist), error)) { g_prefix_error (error, "Blocked executable in the ESP, " "ensure grub and shim are up to date: "); return NULL; } } /* default blob */ return fu_firmware_new_from_bytes (fw); } static gboolean fu_uefi_dbx_device_probe (FuDevice *device, GError **error) { g_autofree gchar *arch_up = NULL; g_autoptr(FuFirmware) kek = fu_efi_signature_list_new (); g_autoptr(GBytes) kek_blob = NULL; g_autoptr(GPtrArray) sigs = NULL; /* use each of the certificates in the KEK to generate the GUIDs */ kek_blob = fu_efivar_get_data_bytes (FU_EFIVAR_GUID_EFI_GLOBAL, "KEK", NULL, error); if (kek_blob == NULL) return FALSE; if (!fu_firmware_parse (kek, kek_blob, FWUPD_INSTALL_FLAG_NO_SEARCH, error)) return FALSE; arch_up = g_utf8_strup (EFI_MACHINE_TYPE_NAME, -1); sigs = fu_firmware_get_images (kek); for (guint j = 0; j < sigs->len; j++) { FuEfiSignature *sig = g_ptr_array_index (sigs, j); g_autofree gchar *checksum = NULL; g_autofree gchar *checksum_up = NULL; g_autofree gchar *devid1 = NULL; g_autofree gchar *devid2 = NULL; checksum = fu_firmware_get_checksum (FU_FIRMWARE (sig), G_CHECKSUM_SHA256, error); if (checksum == NULL) return FALSE; checksum_up = g_utf8_strup (checksum, -1); devid1 = g_strdup_printf ("UEFI\\CRT_%s", checksum_up); fu_device_add_instance_id (device, devid1); devid2 = g_strdup_printf ("UEFI\\CRT_%s&ARCH_%s", checksum_up, arch_up); fu_device_add_instance_id (device, devid2); } return fu_uefi_dbx_device_set_version_number (device, error); } static void fu_uefi_dbx_device_init (FuUefiDbxDevice *self) { fu_device_set_physical_id (FU_DEVICE (self), "dbx"); fu_device_set_name (FU_DEVICE (self), "UEFI dbx"); fu_device_set_summary (FU_DEVICE (self), "UEFI Revocation Database"); fu_device_add_vendor_id (FU_DEVICE (self), "UEFI:Linux Foundation"); fu_device_add_protocol (FU_DEVICE (self), "org.uefi.dbx"); fu_device_set_version_format (FU_DEVICE (self), FWUPD_VERSION_FORMAT_NUMBER); fu_device_set_install_duration (FU_DEVICE (self), 1); fu_device_add_icon (FU_DEVICE (self), "computer"); fu_device_add_flag (FU_DEVICE (self), FWUPD_DEVICE_FLAG_INTERNAL); fu_device_add_flag (FU_DEVICE (self), FWUPD_DEVICE_FLAG_NEEDS_REBOOT); fu_device_add_parent_guid (FU_DEVICE (self), "main-system-firmware"); if (!fu_common_is_live_media ()) fu_device_add_flag (FU_DEVICE (self), FWUPD_DEVICE_FLAG_UPDATABLE); } static void fu_uefi_dbx_device_class_init (FuUefiDbxDeviceClass *klass) { FuDeviceClass *klass_device = FU_DEVICE_CLASS (klass); klass_device->probe = fu_uefi_dbx_device_probe; klass_device->write_firmware = fu_uefi_dbx_device_write_firmware; klass_device->prepare_firmware = fu_uefi_dbx_prepare_firmware; } FuUefiDbxDevice * fu_uefi_dbx_device_new (void) { FuUefiDbxDevice *self; self = g_object_new (FU_TYPE_UEFI_DBX_DEVICE, NULL); return self; }