linuxdebug/security/integrity/platform_certs/machine_keyring.c

78 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Machine keyring routines.
*
* Copyright (c) 2021, Oracle and/or its affiliates.
*/
#include <linux/efi.h>
#include "../integrity.h"
static bool trust_mok;
static __init int machine_keyring_init(void)
{
int rc;
rc = integrity_init_keyring(INTEGRITY_KEYRING_MACHINE);
if (rc)
return rc;
pr_notice("Machine keyring initialized\n");
return 0;
}
device_initcall(machine_keyring_init);
void __init add_to_machine_keyring(const char *source, const void *data, size_t len)
{
key_perm_t perm;
int rc;
perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW;
rc = integrity_load_cert(INTEGRITY_KEYRING_MACHINE, source, data, len, perm);
/*
* Some MOKList keys may not pass the machine keyring restrictions.
* If the restriction check does not pass and the platform keyring
* is configured, try to add it into that keyring instead.
*/
if (rc && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source,
data, len, perm);
if (rc)
pr_info("Error adding keys to machine keyring %s\n", source);
}
/*
* Try to load the MokListTrustedRT MOK variable to see if we should trust
* the MOK keys within the kernel. It is not an error if this variable
* does not exist. If it does not exist, MOK keys should not be trusted
* within the machine keyring.
*/
static __init bool uefi_check_trust_mok_keys(void)
{
struct efi_mokvar_table_entry *mokvar_entry;
mokvar_entry = efi_mokvar_entry_find("MokListTrustedRT");
if (mokvar_entry)
return true;
return false;
}
bool __init trust_moklist(void)
{
static bool initialized;
if (!initialized) {
initialized = true;
if (uefi_check_trust_mok_keys())
trust_mok = true;
}
return trust_mok;
}