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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 | ||
39b07096 | 42 | static struct key *integrity_keyring_from_id(const unsigned int id) |
8607c501 | 43 | { |
39b07096 TJB |
44 | if (id >= INTEGRITY_KEYRING_MAX) |
45 | return ERR_PTR(-EINVAL); | |
8607c501 DK |
46 | |
47 | if (!keyring[id]) { | |
48 | keyring[id] = | |
028db3e2 | 49 | request_key(&key_type_keyring, keyring_name[id], NULL); |
8607c501 DK |
50 | if (IS_ERR(keyring[id])) { |
51 | int err = PTR_ERR(keyring[id]); | |
52 | pr_err("no %s keyring: %d\n", keyring_name[id], err); | |
53 | keyring[id] = NULL; | |
39b07096 | 54 | return ERR_PTR(err); |
8607c501 DK |
55 | } |
56 | } | |
57 | ||
39b07096 TJB |
58 | return keyring[id]; |
59 | } | |
60 | ||
61 | int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, | |
62 | const char *digest, int digestlen) | |
63 | { | |
64 | struct key *keyring; | |
65 | ||
66 | if (siglen < 2) | |
67 | return -EINVAL; | |
68 | ||
69 | keyring = integrity_keyring_from_id(id); | |
70 | if (IS_ERR(keyring)) | |
71 | return PTR_ERR(keyring); | |
72 | ||
b1aaab22 | 73 | switch (sig[1]) { |
e0751257 | 74 | case 1: |
b1aaab22 | 75 | /* v1 API expect signature without xattr type */ |
39b07096 TJB |
76 | return digsig_verify(keyring, sig + 1, siglen - 1, digest, |
77 | digestlen); | |
e0751257 | 78 | case 2: |
39b07096 TJB |
79 | return asymmetric_verify(keyring, sig, siglen, digest, |
80 | digestlen); | |
e0751257 DK |
81 | } |
82 | ||
83 | return -EOPNOTSUPP; | |
8607c501 | 84 | } |
7d2ce232 | 85 | |
39b07096 TJB |
86 | int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig) |
87 | { | |
88 | struct key *keyring; | |
89 | ||
90 | keyring = integrity_keyring_from_id(id); | |
91 | if (IS_ERR(keyring)) | |
92 | return PTR_ERR(keyring); | |
93 | ||
94 | return ima_modsig_verify(keyring, modsig); | |
95 | } | |
96 | ||
8c655784 | 97 | static int __init __integrity_init_keyring(const unsigned int id, |
028db3e2 | 98 | key_perm_t perm, |
8c655784 | 99 | struct key_restriction *restriction) |
7d2ce232 MZ |
100 | { |
101 | const struct cred *cred = current_cred(); | |
102 | int err = 0; | |
103 | ||
104 | keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0), | |
028db3e2 | 105 | KGIDT_INIT(0), cred, perm, |
60740acc | 106 | KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL); |
5ac7eace | 107 | if (IS_ERR(keyring[id])) { |
7d2ce232 MZ |
108 | err = PTR_ERR(keyring[id]); |
109 | pr_info("Can't allocate %s keyring (%d)\n", | |
110 | keyring_name[id], err); | |
111 | keyring[id] = NULL; | |
219a3e86 KS |
112 | } else { |
113 | if (id == INTEGRITY_KEYRING_PLATFORM) | |
114 | set_platform_trusted_keys(keyring[id]); | |
7d2ce232 | 115 | } |
9dc92c45 | 116 | |
7d2ce232 MZ |
117 | return err; |
118 | } | |
65d543b2 | 119 | |
9dc92c45 NJ |
120 | int __init integrity_init_keyring(const unsigned int id) |
121 | { | |
122 | struct key_restriction *restriction; | |
028db3e2 LT |
123 | key_perm_t perm; |
124 | ||
125 | perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | |
126 | | KEY_USR_READ | KEY_USR_SEARCH; | |
9dc92c45 NJ |
127 | |
128 | if (id == INTEGRITY_KEYRING_PLATFORM) { | |
129 | restriction = NULL; | |
130 | goto out; | |
131 | } | |
132 | ||
133 | if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING)) | |
134 | return 0; | |
135 | ||
136 | restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL); | |
137 | if (!restriction) | |
138 | return -ENOMEM; | |
139 | ||
140 | restriction->check = restrict_link_to_ima; | |
028db3e2 | 141 | perm |= KEY_USR_WRITE; |
9dc92c45 NJ |
142 | |
143 | out: | |
028db3e2 | 144 | return __integrity_init_keyring(id, perm, restriction); |
9dc92c45 NJ |
145 | } |
146 | ||
028db3e2 LT |
147 | int __init integrity_add_key(const unsigned int id, const void *data, |
148 | off_t size, key_perm_t perm) | |
65d543b2 DK |
149 | { |
150 | key_ref_t key; | |
60740acc | 151 | int rc = 0; |
65d543b2 DK |
152 | |
153 | if (!keyring[id]) | |
154 | return -EINVAL; | |
155 | ||
60740acc | 156 | key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric", |
028db3e2 | 157 | NULL, data, size, perm, |
60740acc NJ |
158 | KEY_ALLOC_NOT_IN_QUOTA); |
159 | if (IS_ERR(key)) { | |
160 | rc = PTR_ERR(key); | |
161 | pr_err("Problem loading X.509 certificate %d\n", rc); | |
162 | } else { | |
163 | pr_notice("Loaded X.509 cert '%s'\n", | |
164 | key_ref_to_ptr(key)->description); | |
165 | key_ref_put(key); | |
166 | } | |
167 | ||
168 | return rc; | |
169 | ||
170 | } | |
171 | ||
172 | int __init integrity_load_x509(const unsigned int id, const char *path) | |
173 | { | |
174 | void *data; | |
175 | loff_t size; | |
176 | int rc; | |
028db3e2 | 177 | key_perm_t perm; |
60740acc | 178 | |
a7d3d039 CH |
179 | rc = kernel_read_file_from_path(path, &data, &size, 0, |
180 | READING_X509_CERTIFICATE); | |
181 | if (rc < 0) { | |
182 | pr_err("Unable to open file: %s (%d)", path, rc); | |
65d543b2 | 183 | return rc; |
a7d3d039 | 184 | } |
65d543b2 | 185 | |
028db3e2 LT |
186 | perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ; |
187 | ||
60740acc | 188 | pr_info("Loading X.509 certificate: %s\n", path); |
028db3e2 | 189 | rc = integrity_add_key(id, (const void *)data, size, perm); |
60740acc | 190 | |
a7d3d039 | 191 | vfree(data); |
60740acc NJ |
192 | return rc; |
193 | } | |
194 | ||
195 | int __init integrity_load_cert(const unsigned int id, const char *source, | |
028db3e2 | 196 | const void *data, size_t len, key_perm_t perm) |
60740acc NJ |
197 | { |
198 | if (!data) | |
199 | return -EINVAL; | |
200 | ||
201 | pr_info("Loading X.509 certificate: %s\n", source); | |
028db3e2 | 202 | return integrity_add_key(id, data, len, perm); |
65d543b2 | 203 | } |