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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
4 *
5 * Authors:
6 * Reiner Sailer <[email protected]>
7 * Leendert van Doorn <[email protected]>
8 * Mimi Zohar <[email protected]>
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";
25const char boot_aggregate_late_name[] = "boot_aggregate_late";
26struct tpm_chip *ima_tpm_chip;
27
28/* Add the boot aggregate to the IMA measurement list and extend
29 * the PCR register.
30 *
31 * Calculate the boot aggregate, a hash over tpm registers 0-7,
32 * assuming a TPM chip exists, and zeroes if the TPM chip does not
33 * exist. Add the boot aggregate measurement to the measurement
34 * list and extend the PCR register.
35 *
36 * If a tpm chip does not exist, indicate the core root of trust is
37 * not hardware based by invalidating the aggregate PCR value.
38 * (The aggregate PCR value is invalidated by adding one value to
39 * the measurement list and extending the aggregate PCR value with
40 * a different value.) Violations add a zero entry to the measurement
41 * list and extend the aggregate PCR value with ff...ff's.
42 */
43static int __init ima_add_boot_aggregate(void)
44{
45 static const char op[] = "add_boot_aggregate";
46 const char *audit_cause = "ENOMEM";
47 struct ima_template_entry *entry;
48 struct ima_iint_cache tmp_iint, *iint = &tmp_iint;
49 struct ima_event_data event_data = { .iint = iint };
50 struct ima_max_digest_data hash;
51 struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
52 struct ima_digest_data, hdr);
53 const char *filename;
54 int result = -ENOMEM;
55 int violation = 0;
56
57 memset(iint, 0, sizeof(*iint));
58 memset(&hash, 0, sizeof(hash));
59 iint->ima_hash = hash_hdr;
60 iint->ima_hash->algo = ima_hash_algo;
61 iint->ima_hash->length = hash_digest_size[ima_hash_algo];
62
63 if (IS_ENABLED(CONFIG_IMA_INIT_LATE_SYNC))
64 filename = boot_aggregate_late_name;
65 else
66 filename = boot_aggregate_name;
67 event_data.filename = filename;
68
69 /*
70 * With TPM 2.0 hash agility, TPM chips could support multiple TPM
71 * PCR banks, allowing firmware to configure and enable different
72 * banks. The SHA1 bank is not necessarily enabled.
73 *
74 * Use the same hash algorithm for reading the TPM PCRs as for
75 * calculating the boot aggregate digest. Preference is given to
76 * the configured IMA default hash algorithm. Otherwise, use the
77 * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2.
78 * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank
79 * is not found.
80 */
81 if (ima_tpm_chip) {
82 result = ima_calc_boot_aggregate(hash_hdr);
83 if (result < 0) {
84 audit_cause = "hashing_error";
85 goto err_out;
86 }
87 }
88
89 result = ima_alloc_init_template(&event_data, &entry, NULL);
90 if (result < 0) {
91 audit_cause = "alloc_entry";
92 goto err_out;
93 }
94
95 result = ima_store_template(entry, violation, NULL,
96 filename,
97 CONFIG_IMA_MEASURE_PCR_IDX);
98 if (result < 0) {
99 ima_free_template_entry(entry);
100 audit_cause = "store_entry";
101 goto err_out;
102 }
103 return 0;
104err_out:
105 integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, filename, op,
106 audit_cause, result, 0);
107 return result;
108}
109
110#ifdef CONFIG_IMA_LOAD_X509
111void __init ima_load_x509(void)
112{
113 int unset_flags = ima_policy_flag & IMA_APPRAISE;
114
115 ima_policy_flag &= ~unset_flags;
116 integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
117
118 /* load also EVM key to avoid appraisal */
119 evm_load_x509();
120
121 ima_policy_flag |= unset_flags;
122}
123#endif
124
125int __init ima_init(void)
126{
127 int rc;
128
129 ima_tpm_chip = tpm_default_chip();
130 if (!ima_tpm_chip)
131 pr_info("No TPM chip found, activating TPM-bypass!\n");
132
133 rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
134 if (rc)
135 return rc;
136
137 rc = ima_init_crypto();
138 if (rc)
139 return rc;
140 rc = ima_init_template();
141 if (rc != 0)
142 return rc;
143
144 /* It can be called before ima_init_digests(), it does not use TPM. */
145 ima_load_kexec_buffer();
146
147 rc = ima_init_digests();
148 if (rc != 0)
149 return rc;
150
151 rc = ima_init_htable();
152 if (rc != 0)
153 return rc;
154
155 rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */
156 if (rc != 0)
157 return rc;
158
159 ima_init_policy();
160
161 rc = ima_fs_init();
162 if (rc != 0)
163 return rc;
164
165 ima_init_key_queue();
166
167 ima_init_reboot_notifier();
168
169 ima_measure_critical_data("kernel_info", "kernel_version",
170 UTS_RELEASE, strlen(UTS_RELEASE), false,
171 NULL, 0);
172
173 return rc;
174}