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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (C) 2005,2006,2007,2008 IBM Corporation
- *
- * Authors:
- * Reiner Sailer <[email protected]>
- * Leendert van Doorn <[email protected]>
- * Mimi Zohar <[email protected]>
- *
- * File: ima_init.c
- * initialization and cleanup functions
- */
- #include <linux/init.h>
- #include <linux/scatterlist.h>
- #include <linux/slab.h>
- #include <linux/err.h>
- #include <linux/ima.h>
- #include <generated/utsrelease.h>
- #include "ima.h"
- /* name for boot aggregate entry */
- 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 hash 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 = iint,
- .filename = boot_aggregate_name };
- struct ima_max_digest_data hash;
- int result = -ENOMEM;
- int violation = 0;
- memset(iint, 0, sizeof(*iint));
- memset(&hash, 0, sizeof(hash));
- iint->ima_hash = &hash.hdr;
- iint->ima_hash->algo = ima_hash_algo;
- iint->ima_hash->length = hash_digest_size[ima_hash_algo];
- /*
- * With TPM 2.0 hash agility, TPM chips could support multiple TPM
- * PCR banks, allowing firmware to configure and enable different
- * banks. The SHA1 bank is not necessarily enabled.
- *
- * Use the same hash algorithm for reading the TPM PCRs as for
- * calculating the boot aggregate digest. Preference is given to
- * the configured IMA default hash algorithm. Otherwise, use the
- * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2.
- * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank
- * is not found.
- */
- 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, NULL);
- 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);
- /* load also EVM key to avoid appraisal */
- evm_load_x509();
- 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();
- rc = ima_fs_init();
- if (rc != 0)
- return rc;
- ima_init_key_queue();
- ima_measure_critical_data("kernel_info", "kernel_version",
- UTS_RELEASE, strlen(UTS_RELEASE), false,
- NULL, 0);
- return rc;
- }
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