tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
3 *
4 * Authors:
5 * Reiner Sailer <sailer@watson.ibm.com>
6 * Leendert van Doorn <leendert@watson.ibm.com>
7 * Mimi Zohar <zohar@us.ibm.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 *
14 * File: ima_init.c
15 * initialization and cleanup functions
16 */
17
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20#include <linux/module.h>
21#include <linux/scatterlist.h>
22#include <linux/slab.h>
23#include <linux/err.h>
24#include <crypto/hash_info.h>
25#include "ima.h"
26
27/* name for boot aggregate entry */
28static const char *boot_aggregate_name = "boot_aggregate";
29int ima_used_chip;
30
31/* Add the boot aggregate to the IMA measurement list and extend
32 * the PCR register.
33 *
34 * Calculate the boot aggregate, a SHA1 over tpm registers 0-7,
35 * assuming a TPM chip exists, and zeroes if the TPM chip does not
36 * exist. Add the boot aggregate measurement to the measurement
37 * list and extend the PCR register.
38 *
39 * If a tpm chip does not exist, indicate the core root of trust is
40 * not hardware based by invalidating the aggregate PCR value.
41 * (The aggregate PCR value is invalidated by adding one value to
42 * the measurement list and extending the aggregate PCR value with
43 * a different value.) Violations add a zero entry to the measurement
44 * list and extend the aggregate PCR value with ff...ff's.
45 */
46static void __init ima_add_boot_aggregate(void)
47{
48 static const char op[] = "add_boot_aggregate";
49 const char *audit_cause = "ENOMEM";
50 struct ima_template_entry *entry;
51 struct integrity_iint_cache tmp_iint, *iint = &tmp_iint;
52 int result = -ENOMEM;
53 int violation = 0;
54 struct {
55 struct ima_digest_data hdr;
56 char digest[TPM_DIGEST_SIZE];
57 } hash;
58
59 memset(iint, 0, sizeof(*iint));
60 memset(&hash, 0, sizeof(hash));
61 iint->ima_hash = &hash.hdr;
62 iint->ima_hash->algo = HASH_ALGO_SHA1;
63 iint->ima_hash->length = SHA1_DIGEST_SIZE;
64
65 if (ima_used_chip) {
66 result = ima_calc_boot_aggregate(&hash.hdr);
67 if (result < 0) {
68 audit_cause = "hashing_error";
69 goto err_out;
70 }
71 }
72
73 result = ima_alloc_init_template(iint, NULL, boot_aggregate_name,
74 NULL, 0, &entry);
75 if (result < 0)
76 return;
77
78 result = ima_store_template(entry, violation, NULL,
79 boot_aggregate_name);
80 if (result < 0)
81 ima_free_template_entry(entry);
82 return;
83err_out:
84 integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
85 audit_cause, result, 0);
86}
87
88int __init ima_init(void)
89{
90 u8 pcr_i[TPM_DIGEST_SIZE];
91 int rc;
92
93 ima_used_chip = 0;
94 rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i);
95 if (rc == 0)
96 ima_used_chip = 1;
97
98 if (!ima_used_chip)
99 pr_info("No TPM chip found, activating TPM-bypass!\n");
100
101 rc = ima_init_crypto();
102 if (rc)
103 return rc;
104 rc = ima_init_template();
105 if (rc != 0)
106 return rc;
107
108 ima_add_boot_aggregate(); /* boot aggregate must be first entry */
109 ima_init_policy();
110
111 return ima_fs_init();
112}