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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/init.h>
17 #include <linux/scatterlist.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
20
21 #include "ima.h"
22
23 /* name for boot aggregate entry */
24 static const char boot_aggregate_name[] = "boot_aggregate";
25 struct 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 SHA1 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 */
ima_add_boot_aggregate(void)42 static 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 int result = -ENOMEM;
51 int violation = 0;
52 struct {
53 struct ima_digest_data hdr;
54 char digest[TPM_DIGEST_SIZE];
55 } hash;
56
57 memset(iint, 0, sizeof(*iint));
58 memset(&hash, 0, sizeof(hash));
59 iint->ima_hash = &hash.hdr;
60 iint->ima_hash->algo = HASH_ALGO_SHA1;
61 iint->ima_hash->length = SHA1_DIGEST_SIZE;
62
63 if (ima_tpm_chip) {
64 result = ima_calc_boot_aggregate(&hash.hdr);
65 if (result < 0) {
66 audit_cause = "hashing_error";
67 goto err_out;
68 }
69 }
70
71 result = ima_alloc_init_template(&event_data, &entry, NULL);
72 if (result < 0) {
73 audit_cause = "alloc_entry";
74 goto err_out;
75 }
76
77 result = ima_store_template(entry, violation, NULL,
78 boot_aggregate_name,
79 CONFIG_IMA_MEASURE_PCR_IDX);
80 if (result < 0) {
81 ima_free_template_entry(entry);
82 audit_cause = "store_entry";
83 goto err_out;
84 }
85 return 0;
86 err_out:
87 integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
88 audit_cause, result, 0);
89 return result;
90 }
91
92 #ifdef CONFIG_IMA_LOAD_X509
ima_load_x509(void)93 void __init ima_load_x509(void)
94 {
95 int unset_flags = ima_policy_flag & IMA_APPRAISE;
96
97 ima_policy_flag &= ~unset_flags;
98 integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
99 ima_policy_flag |= unset_flags;
100 }
101 #endif
102
ima_init(void)103 int __init ima_init(void)
104 {
105 int rc;
106
107 ima_tpm_chip = tpm_default_chip();
108 if (!ima_tpm_chip)
109 pr_info("No TPM chip found, activating TPM-bypass!\n");
110
111 rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
112 if (rc)
113 return rc;
114
115 rc = ima_init_crypto();
116 if (rc)
117 return rc;
118 rc = ima_init_template();
119 if (rc != 0)
120 return rc;
121
122 /* It can be called before ima_init_digests(), it does not use TPM. */
123 ima_load_kexec_buffer();
124
125 rc = ima_init_digests();
126 if (rc != 0)
127 return rc;
128 rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */
129 if (rc != 0)
130 return rc;
131
132 ima_init_policy();
133
134 return ima_fs_init();
135 }
136
