root/security/integrity/ima/ima_init.c

DEFINITIONS

1. ima_add_boot_aggregate
2. ima_load_x509
3. ima_init

   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  */
  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
  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 
 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 }