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Merge pull request #8 from mjg59/master

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Add some more secure boot infrastructure to grub
This commit is contained in:
mjg59 2015-04-22 16:02:19 -07:00
commit 19c075a7ac
6 changed files with 212 additions and 2 deletions
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7
grub-core/Makefile.core.def
View file

@ -821,6 +821,13 @@ module = {
enable = x86_64_efi;
};
module = {
name = getenv;
common = commands/efi/getenv.c;
enable = i386_efi;
enable = x86_64_efi;
};
module = {
name = gptsync;
common = commands/gptsync.c;

153
grub-core/commands/efi/getenv.c Normal file
View file

@ -0,0 +1,153 @@
/* getenv.c - retrieve EFI variables. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
* Copyright (C) 2014 CoreOS, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/efi/efi.h>
#include <grub/dl.h>
#include <grub/env.h>
#include <grub/err.h>
#include <grub/extcmd.h>
#include <grub/i18n.h>
#include <grub/misc.h>
#include <grub/mm.h>
GRUB_MOD_LICENSE ("GPLv3+");
static const struct grub_arg_option options_getenv[] = {
{"var-name", 'e', 0,
N_("Environment variable to query"),
N_("VARNAME"), ARG_TYPE_STRING},
{"var-guid", 'g', 0,
N_("GUID of environment variable to query"),
N_("GUID"), ARG_TYPE_STRING},
{"binary", 'b', 0,
N_("Read binary data and represent it as hex"),
0, ARG_TYPE_NONE},
{0, 0, 0, 0, 0, 0}
};
enum options_getenv
{
GETENV_VAR_NAME,
GETENV_VAR_GUID,
GETENV_BINARY,
};
static grub_err_t
grub_cmd_getenv (grub_extcmd_context_t ctxt, int argc, char **args)
{
struct grub_arg_list *state = ctxt->state;
char *envvar = NULL, *guid = NULL, *bindata = NULL, *data = NULL;
grub_size_t datasize;
grub_efi_guid_t efi_var_guid;
grub_efi_boolean_t binary = state[GETENV_BINARY].set;
unsigned int i;
if (!state[GETENV_VAR_NAME].set || !state[GETENV_VAR_GUID].set)
{
grub_error (GRUB_ERR_INVALID_COMMAND, N_("-e and -g are required"));
goto done;
}
if (argc != 1)
{
grub_error (GRUB_ERR_BAD_ARGUMENT, N_("unexpected arguments"));
goto done;
}
envvar = state[GETENV_VAR_NAME].arg;
guid = state[GETENV_VAR_GUID].arg;
if (grub_strlen(guid) != 36 ||
guid[8] != '-' ||
guid[13] != '-' ||
guid[18] != '-' ||
guid[23] != '-')
{
grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid GUID"));
goto done;
}
/* Forgive me father for I have sinned */
guid[8] = 0;
efi_var_guid.data1 = grub_strtoul(guid, NULL, 16);
guid[13] = 0;
efi_var_guid.data2 = grub_strtoul(guid + 9, NULL, 16);
guid[18] = 0;
efi_var_guid.data3 = grub_strtoul(guid + 14, NULL, 16);
efi_var_guid.data4[7] = grub_strtoul(guid + 34, NULL, 16);
guid[34] = 0;
efi_var_guid.data4[6] = grub_strtoul(guid + 32, NULL, 16);
guid[32] = 0;
efi_var_guid.data4[5] = grub_strtoul(guid + 30, NULL, 16);
guid[30] = 0;
efi_var_guid.data4[4] = grub_strtoul(guid + 28, NULL, 16);
guid[28] = 0;
efi_var_guid.data4[3] = grub_strtoul(guid + 26, NULL, 16);
guid[26] = 0;
efi_var_guid.data4[2] = grub_strtoul(guid + 24, NULL, 16);
guid[23] = 0;
efi_var_guid.data4[1] = grub_strtoul(guid + 21, NULL, 16);
guid[21] = 0;
efi_var_guid.data4[0] = grub_strtoul(guid + 19, NULL, 16);
data = grub_efi_get_variable(envvar, &efi_var_guid, &datasize);
if (!data || !datasize)
{
grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("No such variable"));
goto done;
}
if (binary)
{
bindata = grub_zalloc(datasize * 2 + 1);
for (i=0; i<datasize; i++)
grub_snprintf(bindata + i*2, 3, "%02x", data[i]);
if (grub_env_set (args[0], bindata))
goto done;
}
else if (grub_env_set (args[0], data))
{
goto done;
}
grub_errno = GRUB_ERR_NONE;
done:
grub_free(bindata);
grub_free(data);
return grub_errno;
}
static grub_extcmd_t cmd_getenv;
GRUB_MOD_INIT(getenv)
{
cmd_getenv = grub_register_extcmd ("getenv", grub_cmd_getenv, 0,
N_("-e envvar -g guidenv setvar"),
N_("Read a firmware environment variable"),
options_getenv);
}
GRUB_MOD_FINI(getenv)
{
grub_unregister_extcmd (cmd_getenv);
}

17
grub-core/kern/dl.c
View file

@ -38,6 +38,14 @@
#define GRUB_MODULES_MACHINE_READONLY
#endif
#ifdef GRUB_MACHINE_EMU
#include <sys/mman.h>
#endif
#ifdef GRUB_MACHINE_EFI
#include <grub/efi/efi.h>
#endif
#pragma GCC diagnostic ignored "-Wcast-align"
@ -680,6 +688,15 @@ grub_dl_load_file (const char *filename)
void *core = 0;
grub_dl_t mod = 0;
#ifdef GRUB_MACHINE_EFI
if (grub_efi_secure_boot ())
{
grub_error (GRUB_ERR_ACCESS_DENIED,
"Secure Boot forbids loading module from %s", filename);
return 0;
}
#endif
grub_boot_time ("Loading module %s", filename);
file = grub_file_open (filename);

28
grub-core/kern/efi/efi.c
View file

@ -259,6 +259,34 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
return NULL;
}
grub_efi_boolean_t
grub_efi_secure_boot (void)
{
grub_efi_guid_t efi_var_guid = GRUB_EFI_GLOBAL_VARIABLE_GUID;
grub_size_t datasize;
char *secure_boot = NULL;
char *setup_mode = NULL;
grub_efi_boolean_t ret = 0;
secure_boot = grub_efi_get_variable("SecureBoot", &efi_var_guid, &datasize);
if (datasize != 1 || !secure_boot)
goto out;
setup_mode = grub_efi_get_variable("SetupMode", &efi_var_guid, &datasize);
if (datasize != 1 || !setup_mode)
goto out;
if (*secure_boot && !*setup_mode)
ret = 1;
out:
grub_free (secure_boot);
grub_free (setup_mode);
return ret;
}
#pragma GCC diagnostic ignored "-Wcast-align"
/* Search the mods section from the PE32/PE32+ image. This code uses

6
grub-core/loader/i386/efi/linux.c
View file

@ -57,8 +57,12 @@ grub_linuxefi_secure_validate (void *data, grub_uint32_t size)
shim_lock = grub_efi_locate_protocol(&guid, NULL);
if (!shim_lock)
if (!shim_lock) {
if (grub_efi_secure_boot())
return 0;
else
return 1;
}
if (shim_lock->verify(data, size) == GRUB_EFI_SUCCESS)
return 1;

1
include/grub/efi/efi.h
View file

@ -72,6 +72,7 @@ EXPORT_FUNC (grub_efi_set_variable) (const char *var,
const grub_efi_guid_t *guid,
void *data,
grub_size_t datasize);
grub_efi_boolean_t EXPORT_FUNC (grub_efi_secure_boot) (void);
int
EXPORT_FUNC (grub_efi_compare_device_paths) (const grub_efi_device_path_t *dp1,
const grub_efi_device_path_t *dp2);