cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ima_init.c (4275B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
      4 *
      5 * Authors:
      6 * Reiner Sailer      <sailer@watson.ibm.com>
      7 * Leendert van Doorn <leendert@watson.ibm.com>
      8 * Mimi Zohar         <zohar@us.ibm.com>
      9 *
     10 * File: ima_init.c
     11 *             initialization and cleanup functions
     12 */
     13
     14#include <linux/init.h>
     15#include <linux/scatterlist.h>
     16#include <linux/slab.h>
     17#include <linux/err.h>
     18#include <linux/ima.h>
     19#include <generated/utsrelease.h>
     20
     21#include "ima.h"
     22
     23/* name for boot aggregate entry */
     24const char boot_aggregate_name[] = "boot_aggregate";
     25struct tpm_chip *ima_tpm_chip;
     26
     27/* Add the boot aggregate to the IMA measurement list and extend
     28 * the PCR register.
     29 *
     30 * Calculate the boot aggregate, a hash over tpm registers 0-7,
     31 * assuming a TPM chip exists, and zeroes if the TPM chip does not
     32 * exist.  Add the boot aggregate measurement to the measurement
     33 * list and extend the PCR register.
     34 *
     35 * If a tpm chip does not exist, indicate the core root of trust is
     36 * not hardware based by invalidating the aggregate PCR value.
     37 * (The aggregate PCR value is invalidated by adding one value to
     38 * the measurement list and extending the aggregate PCR value with
     39 * a different value.) Violations add a zero entry to the measurement
     40 * list and extend the aggregate PCR value with ff...ff's.
     41 */
     42static int __init ima_add_boot_aggregate(void)
     43{
     44	static const char op[] = "add_boot_aggregate";
     45	const char *audit_cause = "ENOMEM";
     46	struct ima_template_entry *entry;
     47	struct integrity_iint_cache tmp_iint, *iint = &tmp_iint;
     48	struct ima_event_data event_data = { .iint = iint,
     49					     .filename = boot_aggregate_name };
     50	struct ima_max_digest_data hash;
     51	int result = -ENOMEM;
     52	int violation = 0;
     53
     54	memset(iint, 0, sizeof(*iint));
     55	memset(&hash, 0, sizeof(hash));
     56	iint->ima_hash = &hash.hdr;
     57	iint->ima_hash->algo = ima_hash_algo;
     58	iint->ima_hash->length = hash_digest_size[ima_hash_algo];
     59
     60	/*
     61	 * With TPM 2.0 hash agility, TPM chips could support multiple TPM
     62	 * PCR banks, allowing firmware to configure and enable different
     63	 * banks.  The SHA1 bank is not necessarily enabled.
     64	 *
     65	 * Use the same hash algorithm for reading the TPM PCRs as for
     66	 * calculating the boot aggregate digest.  Preference is given to
     67	 * the configured IMA default hash algorithm.  Otherwise, use the
     68	 * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2.
     69	 * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank
     70	 * is not found.
     71	 */
     72	if (ima_tpm_chip) {
     73		result = ima_calc_boot_aggregate(&hash.hdr);
     74		if (result < 0) {
     75			audit_cause = "hashing_error";
     76			goto err_out;
     77		}
     78	}
     79
     80	result = ima_alloc_init_template(&event_data, &entry, NULL);
     81	if (result < 0) {
     82		audit_cause = "alloc_entry";
     83		goto err_out;
     84	}
     85
     86	result = ima_store_template(entry, violation, NULL,
     87				    boot_aggregate_name,
     88				    CONFIG_IMA_MEASURE_PCR_IDX);
     89	if (result < 0) {
     90		ima_free_template_entry(entry);
     91		audit_cause = "store_entry";
     92		goto err_out;
     93	}
     94	return 0;
     95err_out:
     96	integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
     97			    audit_cause, result, 0);
     98	return result;
     99}
    100
    101#ifdef CONFIG_IMA_LOAD_X509
    102void __init ima_load_x509(void)
    103{
    104	int unset_flags = ima_policy_flag & IMA_APPRAISE;
    105
    106	ima_policy_flag &= ~unset_flags;
    107	integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
    108
    109	/* load also EVM key to avoid appraisal */
    110	evm_load_x509();
    111
    112	ima_policy_flag |= unset_flags;
    113}
    114#endif
    115
    116int __init ima_init(void)
    117{
    118	int rc;
    119
    120	ima_tpm_chip = tpm_default_chip();
    121	if (!ima_tpm_chip)
    122		pr_info("No TPM chip found, activating TPM-bypass!\n");
    123
    124	rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
    125	if (rc)
    126		return rc;
    127
    128	rc = ima_init_crypto();
    129	if (rc)
    130		return rc;
    131	rc = ima_init_template();
    132	if (rc != 0)
    133		return rc;
    134
    135	/* It can be called before ima_init_digests(), it does not use TPM. */
    136	ima_load_kexec_buffer();
    137
    138	rc = ima_init_digests();
    139	if (rc != 0)
    140		return rc;
    141	rc = ima_add_boot_aggregate();	/* boot aggregate must be first entry */
    142	if (rc != 0)
    143		return rc;
    144
    145	ima_init_policy();
    146
    147	rc = ima_fs_init();
    148	if (rc != 0)
    149		return rc;
    150
    151	ima_init_key_queue();
    152
    153	ima_measure_critical_data("kernel_info", "kernel_version",
    154				  UTS_RELEASE, strlen(UTS_RELEASE), false,
    155				  NULL, 0);
    156
    157	return rc;
    158}