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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 IBM Corporation
* Author: Nayna Jain
*/
#include <linux/ima.h>
#include <asm/secure_boot.h>
bool arch_ima_get_secureboot(void)
{
return is_ppc_secureboot_enabled();
}
/*
* The "secure_rules" are enabled only on "secureboot" enabled systems.
* These rules verify the file signatures against known good values.
* The "appraise_type=imasig|modsig" option allows the known good signature
* to be stored as an xattr or as an appended signature.
*
* To avoid duplicate signature verification as much as possible, the IMA
* policy rule for module appraisal is added only if CONFIG_MODULE_SIG
* is not enabled.
*/
static const char *const secure_rules[] = {
"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
#ifndef CONFIG_MODULE_SIG
"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
#endif
NULL
};
/*
* The "trusted_rules" are enabled only on "trustedboot" enabled systems.
* These rules add the kexec kernel image and kernel modules file hashes to
* the IMA measurement list.
*/
static const char *const trusted_rules[] = {
"measure func=KEXEC_KERNEL_CHECK",
"measure func=MODULE_CHECK",
NULL
};
/*
* The "secure_and_trusted_rules" contains rules for both the secure boot and
* trusted boot. The "template=ima-modsig" option includes the appended
* signature, when available, in the IMA measurement list.
*/
static const char *const secure_and_trusted_rules[] = {
"measure func=KEXEC_KERNEL_CHECK template=ima-modsig",
"measure func=MODULE_CHECK template=ima-modsig",
"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
#ifndef CONFIG_MODULE_SIG
"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
#endif
NULL
};
/*
* Returns the relevant IMA arch-specific policies based on the system secure
* boot state.
*/
const char *const *arch_get_ima_policy(void)
{
if (is_ppc_secureboot_enabled()) {
if (IS_ENABLED(CONFIG_MODULE_SIG))
set_module_sig_enforced();
if (is_ppc_trustedboot_enabled())
return secure_and_trusted_rules;
else
return secure_rules;
} else if (is_ppc_trustedboot_enabled()) {
return trusted_rules;
}
return NULL;
}
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