summaryrefslogtreecommitdiff
path: root/security/integrity/ima/ima_init.c
blob: 6c92954497514c734a1b93837ebf10eb69d4bdcf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer      <sailer@watson.ibm.com>
 * Leendert van Doorn <leendert@watson.ibm.com>
 * Mimi Zohar         <zohar@us.ibm.com>
 *
 * This program 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, version 2 of the
 * License.
 *
 * File: ima_init.c
 *             initialization and cleanup functions
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/err.h>

#include "ima.h"

/* name for boot aggregate entry */
static const char boot_aggregate_name[] = "boot_aggregate";
struct tpm_chip *ima_tpm_chip;

/* Add the boot aggregate to the IMA measurement list and extend
 * the PCR register.
 *
 * Calculate the boot aggregate, a SHA1 over tpm registers 0-7,
 * assuming a TPM chip exists, and zeroes if the TPM chip does not
 * exist.  Add the boot aggregate measurement to the measurement
 * list and extend the PCR register.
 *
 * If a tpm chip does not exist, indicate the core root of trust is
 * not hardware based by invalidating the aggregate PCR value.
 * (The aggregate PCR value is invalidated by adding one value to
 * the measurement list and extending the aggregate PCR value with
 * a different value.) Violations add a zero entry to the measurement
 * list and extend the aggregate PCR value with ff...ff's.
 */
static int __init ima_add_boot_aggregate(void)
{
	static const char op[] = "add_boot_aggregate";
	const char *audit_cause = "ENOMEM";
	struct ima_template_entry *entry;
	struct integrity_iint_cache tmp_iint, *iint = &tmp_iint;
	struct ima_event_data event_data = {iint, NULL, boot_aggregate_name,
					    NULL, 0, NULL};
	int result = -ENOMEM;
	int violation = 0;
	struct {
		struct ima_digest_data hdr;
		char digest[TPM_DIGEST_SIZE];
	} hash;

	memset(iint, 0, sizeof(*iint));
	memset(&hash, 0, sizeof(hash));
	iint->ima_hash = &hash.hdr;
	iint->ima_hash->algo = HASH_ALGO_SHA1;
	iint->ima_hash->length = SHA1_DIGEST_SIZE;

	if (ima_tpm_chip) {
		result = ima_calc_boot_aggregate(&hash.hdr);
		if (result < 0) {
			audit_cause = "hashing_error";
			goto err_out;
		}
	}

	result = ima_alloc_init_template(&event_data, &entry);
	if (result < 0) {
		audit_cause = "alloc_entry";
		goto err_out;
	}

	result = ima_store_template(entry, violation, NULL,
				    boot_aggregate_name,
				    CONFIG_IMA_MEASURE_PCR_IDX);
	if (result < 0) {
		ima_free_template_entry(entry);
		audit_cause = "store_entry";
		goto err_out;
	}
	return 0;
err_out:
	integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
			    audit_cause, result, 0);
	return result;
}

#ifdef CONFIG_IMA_LOAD_X509
void __init ima_load_x509(void)
{
	int unset_flags = ima_policy_flag & IMA_APPRAISE;

	ima_policy_flag &= ~unset_flags;
	integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
	ima_policy_flag |= unset_flags;
}
#endif

int __init ima_init(void)
{
	int rc;

	ima_tpm_chip = tpm_default_chip();
	if (!ima_tpm_chip)
		pr_info("No TPM chip found, activating TPM-bypass!\n");

	rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
	if (rc)
		return rc;

	rc = ima_init_crypto();
	if (rc)
		return rc;
	rc = ima_init_template();
	if (rc != 0)
		return rc;

	/* It can be called before ima_init_digests(), it does not use TPM. */
	ima_load_kexec_buffer();

	rc = ima_init_digests();
	if (rc != 0)
		return rc;
	rc = ima_add_boot_aggregate();	/* boot aggregate must be first entry */
	if (rc != 0)
		return rc;

	ima_init_policy();

	return ima_fs_init();
}