// 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; }