1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
6 * Reiner Sailer <sailer@watson.ibm.com>
7 * Leendert van Doorn <leendert@watson.ibm.com>
8 * Mimi Zohar <zohar@us.ibm.com>
11 * initialization and cleanup functions
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>
23 /* name for boot aggregate entry */
24 const char boot_aggregate_name[] = "boot_aggregate";
25 struct tpm_chip *ima_tpm_chip;
27 /* Add the boot aggregate to the IMA measurement list and extend
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.
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.
42 static int __init ima_add_boot_aggregate(void)
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 };
53 struct ima_digest_data hdr;
54 char digest[TPM_MAX_DIGEST_SIZE];
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];
64 * With TPM 2.0 hash agility, TPM chips could support multiple TPM
65 * PCR banks, allowing firmware to configure and enable different
66 * banks. The SHA1 bank is not necessarily enabled.
68 * Use the same hash algorithm for reading the TPM PCRs as for
69 * calculating the boot aggregate digest. Preference is given to
70 * the configured IMA default hash algorithm. Otherwise, use the
71 * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2.
72 * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank
76 result = ima_calc_boot_aggregate(&hash.hdr);
78 audit_cause = "hashing_error";
83 result = ima_alloc_init_template(&event_data, &entry, NULL);
85 audit_cause = "alloc_entry";
89 result = ima_store_template(entry, violation, NULL,
91 CONFIG_IMA_MEASURE_PCR_IDX);
93 ima_free_template_entry(entry);
94 audit_cause = "store_entry";
99 integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
100 audit_cause, result, 0);
104 #ifdef CONFIG_IMA_LOAD_X509
105 void __init ima_load_x509(void)
107 int unset_flags = ima_policy_flag & IMA_APPRAISE;
109 ima_policy_flag &= ~unset_flags;
110 integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
111 ima_policy_flag |= unset_flags;
115 int __init ima_init(void)
119 ima_tpm_chip = tpm_default_chip();
121 pr_info("No TPM chip found, activating TPM-bypass!\n");
123 rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
127 rc = ima_init_crypto();
130 rc = ima_init_template();
134 /* It can be called before ima_init_digests(), it does not use TPM. */
135 ima_load_kexec_buffer();
137 rc = ima_init_digests();
140 rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */
150 ima_init_key_queue();
152 ima_measure_critical_data("kernel_info", "kernel_version",
153 UTS_RELEASE, strlen(UTS_RELEASE), false);