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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
8607c501 DK |
2 | /* |
3 | * Copyright (C) 2011 Intel Corporation | |
4 | * | |
5 | * Author: | |
6 | * Dmitry Kasatkin <dmitry.kasatkin@intel.com> | |
8607c501 DK |
7 | */ |
8 | ||
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
10 | ||
11 | #include <linux/err.h> | |
7d2ce232 | 12 | #include <linux/sched.h> |
65d543b2 | 13 | #include <linux/slab.h> |
7d2ce232 | 14 | #include <linux/cred.h> |
8607c501 DK |
15 | #include <linux/key-type.h> |
16 | #include <linux/digsig.h> | |
120f3b11 | 17 | #include <linux/vmalloc.h> |
a511e1af DH |
18 | #include <crypto/public_key.h> |
19 | #include <keys/system_keyring.h> | |
8607c501 DK |
20 | |
21 | #include "integrity.h" | |
22 | ||
23 | static struct key *keyring[INTEGRITY_KEYRING_MAX]; | |
24 | ||
b2724d58 | 25 | static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = { |
f4dc3778 | 26 | #ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING |
8607c501 | 27 | "_evm", |
8607c501 | 28 | "_ima", |
7d2ce232 | 29 | #else |
f4dc3778 | 30 | ".evm", |
7d2ce232 MZ |
31 | ".ima", |
32 | #endif | |
9dc92c45 | 33 | ".platform", |
8607c501 DK |
34 | }; |
35 | ||
56104cf2 DH |
36 | #ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY |
37 | #define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted | |
a511e1af | 38 | #else |
56104cf2 | 39 | #define restrict_link_to_ima restrict_link_by_builtin_trusted |
a511e1af DH |
40 | #endif |
41 | ||
8607c501 | 42 | int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, |
089bc8e9 | 43 | const char *digest, int digestlen) |
8607c501 | 44 | { |
b4bfec7f | 45 | if (id >= INTEGRITY_KEYRING_MAX || siglen < 2) |
8607c501 DK |
46 | return -EINVAL; |
47 | ||
48 | if (!keyring[id]) { | |
49 | keyring[id] = | |
34ef7bd3 | 50 | request_key(&key_type_keyring, keyring_name[id], NULL); |
8607c501 DK |
51 | if (IS_ERR(keyring[id])) { |
52 | int err = PTR_ERR(keyring[id]); | |
53 | pr_err("no %s keyring: %d\n", keyring_name[id], err); | |
54 | keyring[id] = NULL; | |
55 | return err; | |
56 | } | |
57 | } | |
58 | ||
b1aaab22 | 59 | switch (sig[1]) { |
e0751257 | 60 | case 1: |
b1aaab22 DK |
61 | /* v1 API expect signature without xattr type */ |
62 | return digsig_verify(keyring[id], sig + 1, siglen - 1, | |
e0751257 DK |
63 | digest, digestlen); |
64 | case 2: | |
65 | return asymmetric_verify(keyring[id], sig, siglen, | |
66 | digest, digestlen); | |
67 | } | |
68 | ||
69 | return -EOPNOTSUPP; | |
8607c501 | 70 | } |
7d2ce232 | 71 | |
9dc92c45 NJ |
72 | static int __integrity_init_keyring(const unsigned int id, key_perm_t perm, |
73 | struct key_restriction *restriction) | |
7d2ce232 MZ |
74 | { |
75 | const struct cred *cred = current_cred(); | |
76 | int err = 0; | |
77 | ||
78 | keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0), | |
9dc92c45 | 79 | KGIDT_INIT(0), cred, perm, |
60740acc | 80 | KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL); |
5ac7eace | 81 | if (IS_ERR(keyring[id])) { |
7d2ce232 MZ |
82 | err = PTR_ERR(keyring[id]); |
83 | pr_info("Can't allocate %s keyring (%d)\n", | |
84 | keyring_name[id], err); | |
85 | keyring[id] = NULL; | |
219a3e86 KS |
86 | } else { |
87 | if (id == INTEGRITY_KEYRING_PLATFORM) | |
88 | set_platform_trusted_keys(keyring[id]); | |
7d2ce232 | 89 | } |
9dc92c45 | 90 | |
7d2ce232 MZ |
91 | return err; |
92 | } | |
65d543b2 | 93 | |
9dc92c45 NJ |
94 | int __init integrity_init_keyring(const unsigned int id) |
95 | { | |
96 | struct key_restriction *restriction; | |
97 | key_perm_t perm; | |
98 | ||
99 | perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | |
100 | | KEY_USR_READ | KEY_USR_SEARCH; | |
101 | ||
102 | if (id == INTEGRITY_KEYRING_PLATFORM) { | |
103 | restriction = NULL; | |
104 | goto out; | |
105 | } | |
106 | ||
107 | if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING)) | |
108 | return 0; | |
109 | ||
110 | restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL); | |
111 | if (!restriction) | |
112 | return -ENOMEM; | |
113 | ||
114 | restriction->check = restrict_link_to_ima; | |
115 | perm |= KEY_USR_WRITE; | |
116 | ||
117 | out: | |
118 | return __integrity_init_keyring(id, perm, restriction); | |
119 | } | |
120 | ||
60740acc NJ |
121 | int __init integrity_add_key(const unsigned int id, const void *data, |
122 | off_t size, key_perm_t perm) | |
65d543b2 DK |
123 | { |
124 | key_ref_t key; | |
60740acc | 125 | int rc = 0; |
65d543b2 DK |
126 | |
127 | if (!keyring[id]) | |
128 | return -EINVAL; | |
129 | ||
60740acc NJ |
130 | key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric", |
131 | NULL, data, size, perm, | |
132 | KEY_ALLOC_NOT_IN_QUOTA); | |
133 | if (IS_ERR(key)) { | |
134 | rc = PTR_ERR(key); | |
135 | pr_err("Problem loading X.509 certificate %d\n", rc); | |
136 | } else { | |
137 | pr_notice("Loaded X.509 cert '%s'\n", | |
138 | key_ref_to_ptr(key)->description); | |
139 | key_ref_put(key); | |
140 | } | |
141 | ||
142 | return rc; | |
143 | ||
144 | } | |
145 | ||
146 | int __init integrity_load_x509(const unsigned int id, const char *path) | |
147 | { | |
148 | void *data; | |
149 | loff_t size; | |
150 | int rc; | |
151 | key_perm_t perm; | |
152 | ||
a7d3d039 CH |
153 | rc = kernel_read_file_from_path(path, &data, &size, 0, |
154 | READING_X509_CERTIFICATE); | |
155 | if (rc < 0) { | |
156 | pr_err("Unable to open file: %s (%d)", path, rc); | |
65d543b2 | 157 | return rc; |
a7d3d039 | 158 | } |
65d543b2 | 159 | |
60740acc NJ |
160 | perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ; |
161 | ||
162 | pr_info("Loading X.509 certificate: %s\n", path); | |
163 | rc = integrity_add_key(id, (const void *)data, size, perm); | |
164 | ||
a7d3d039 | 165 | vfree(data); |
60740acc NJ |
166 | return rc; |
167 | } | |
168 | ||
169 | int __init integrity_load_cert(const unsigned int id, const char *source, | |
170 | const void *data, size_t len, key_perm_t perm) | |
171 | { | |
172 | if (!data) | |
173 | return -EINVAL; | |
174 | ||
175 | pr_info("Loading X.509 certificate: %s\n", source); | |
176 | return integrity_add_key(id, data, len, perm); | |
65d543b2 | 177 | } |