1 // SPDX-License-Identifier: GPL-2.0-or-later 1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Instantiate a public key crypto key from an 2 /* Instantiate a public key crypto key from an X.509 Certificate
3 * 3 *
4 * Copyright (C) 2012, 2016 Red Hat, Inc. All 4 * Copyright (C) 2012, 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.c 5 * Written by David Howells (dhowells@redhat.com)
6 */ 6 */
7 7
8 #define pr_fmt(fmt) "ASYM: "fmt 8 #define pr_fmt(fmt) "ASYM: "fmt
9 #include <linux/module.h> 9 #include <linux/module.h>
10 #include <linux/kernel.h> 10 #include <linux/kernel.h>
11 #include <linux/err.h> 11 #include <linux/err.h>
12 #include <crypto/public_key.h> 12 #include <crypto/public_key.h>
13 #include "asymmetric_keys.h" 13 #include "asymmetric_keys.h"
14 14
15 static bool use_builtin_keys; 15 static bool use_builtin_keys;
16 static struct asymmetric_key_id *ca_keyid; 16 static struct asymmetric_key_id *ca_keyid;
17 17
18 #ifndef MODULE 18 #ifndef MODULE
19 static struct { 19 static struct {
20 struct asymmetric_key_id id; 20 struct asymmetric_key_id id;
21 unsigned char data[10]; 21 unsigned char data[10];
22 } cakey; 22 } cakey;
23 23
24 static int __init ca_keys_setup(char *str) 24 static int __init ca_keys_setup(char *str)
25 { 25 {
26 if (!str) /* default sys 26 if (!str) /* default system keyring */
27 return 1; 27 return 1;
28 28
29 if (strncmp(str, "id:", 3) == 0) { 29 if (strncmp(str, "id:", 3) == 0) {
30 struct asymmetric_key_id *p = 30 struct asymmetric_key_id *p = &cakey.id;
31 size_t hexlen = (strlen(str) - 31 size_t hexlen = (strlen(str) - 3) / 2;
32 int ret; 32 int ret;
33 33
34 if (hexlen == 0 || hexlen > si 34 if (hexlen == 0 || hexlen > sizeof(cakey.data)) {
35 pr_err("Missing or inv 35 pr_err("Missing or invalid ca_keys id\n");
36 return 1; 36 return 1;
37 } 37 }
38 38
39 ret = __asymmetric_key_hex_to_ 39 ret = __asymmetric_key_hex_to_key_id(str + 3, p, hexlen);
40 if (ret < 0) 40 if (ret < 0)
41 pr_err("Unparsable ca_ 41 pr_err("Unparsable ca_keys id hex string\n");
42 else 42 else
43 ca_keyid = p; /* own 43 ca_keyid = p; /* owner key 'id:xxxxxx' */
44 } else if (strcmp(str, "builtin") == 0 44 } else if (strcmp(str, "builtin") == 0) {
45 use_builtin_keys = true; 45 use_builtin_keys = true;
46 } 46 }
47 47
48 return 1; 48 return 1;
49 } 49 }
50 __setup("ca_keys=", ca_keys_setup); 50 __setup("ca_keys=", ca_keys_setup);
51 #endif 51 #endif
52 52
53 /** 53 /**
54 * restrict_link_by_signature - Restrict addit 54 * restrict_link_by_signature - Restrict additions to a ring of public keys
55 * @dest_keyring: Keyring being linked to. 55 * @dest_keyring: Keyring being linked to.
56 * @type: The type of key being added. 56 * @type: The type of key being added.
57 * @payload: The payload of the new key. 57 * @payload: The payload of the new key.
58 * @trust_keyring: A ring of keys that can be 58 * @trust_keyring: A ring of keys that can be used to vouch for the new cert.
59 * 59 *
60 * Check the new certificate against the ones 60 * Check the new certificate against the ones in the trust keyring. If one of
61 * those is the signing key and validates the 61 * those is the signing key and validates the new certificate, then mark the
62 * new certificate as being trusted. 62 * new certificate as being trusted.
63 * 63 *
64 * Returns 0 if the new certificate was accept 64 * Returns 0 if the new certificate was accepted, -ENOKEY if we couldn't find a
65 * matching parent certificate in the trusted 65 * matching parent certificate in the trusted list, -EKEYREJECTED if the
66 * signature check fails or the key is blackli 66 * signature check fails or the key is blacklisted, -ENOPKG if the signature
67 * uses unsupported crypto, or some other erro 67 * uses unsupported crypto, or some other error if there is a matching
68 * certificate but the signature check cannot 68 * certificate but the signature check cannot be performed.
69 */ 69 */
70 int restrict_link_by_signature(struct key *des 70 int restrict_link_by_signature(struct key *dest_keyring,
71 const struct ke 71 const struct key_type *type,
72 const union key 72 const union key_payload *payload,
73 struct key *tru 73 struct key *trust_keyring)
74 { 74 {
75 const struct public_key_signature *sig 75 const struct public_key_signature *sig;
76 struct key *key; 76 struct key *key;
77 int ret; 77 int ret;
78 78
79 pr_devel("==>%s()\n", __func__); 79 pr_devel("==>%s()\n", __func__);
80 80
81 if (!trust_keyring) 81 if (!trust_keyring)
82 return -ENOKEY; 82 return -ENOKEY;
83 83
84 if (type != &key_type_asymmetric) 84 if (type != &key_type_asymmetric)
85 return -EOPNOTSUPP; 85 return -EOPNOTSUPP;
86 86
87 sig = payload->data[asym_auth]; 87 sig = payload->data[asym_auth];
88 if (!sig) 88 if (!sig)
89 return -ENOPKG; 89 return -ENOPKG;
90 if (!sig->auth_ids[0] && !sig->auth_id !! 90 if (!sig->auth_ids[0] && !sig->auth_ids[1])
91 return -ENOKEY; 91 return -ENOKEY;
92 92
93 if (ca_keyid && !asymmetric_key_id_par 93 if (ca_keyid && !asymmetric_key_id_partial(sig->auth_ids[1], ca_keyid))
94 return -EPERM; 94 return -EPERM;
95 95
96 /* See if we have a key that signed th 96 /* See if we have a key that signed this one. */
97 key = find_asymmetric_key(trust_keyrin 97 key = find_asymmetric_key(trust_keyring,
98 sig->auth_id 98 sig->auth_ids[0], sig->auth_ids[1],
99 sig->auth_id !! 99 false);
100 if (IS_ERR(key)) 100 if (IS_ERR(key))
101 return -ENOKEY; 101 return -ENOKEY;
102 102
103 if (use_builtin_keys && !test_bit(KEY_ 103 if (use_builtin_keys && !test_bit(KEY_FLAG_BUILTIN, &key->flags))
104 ret = -ENOKEY; 104 ret = -ENOKEY;
105 else if (IS_BUILTIN(CONFIG_SECONDARY_T <<
106 !strcmp(dest_keyring->descrip <<
107 !test_bit(KEY_FLAG_BUILTIN, & <<
108 ret = -ENOKEY; <<
109 else 105 else
110 ret = verify_signature(key, si 106 ret = verify_signature(key, sig);
111 key_put(key); 107 key_put(key);
112 return ret; 108 return ret;
113 } 109 }
114 110
115 /** !! 111 static bool match_either_id(const struct asymmetric_key_ids *pair,
116 * restrict_link_by_ca - Restrict additions to <<
117 * @dest_keyring: Keyring being linked to. <<
118 * @type: The type of key being added. <<
119 * @payload: The payload of the new key. <<
120 * @trust_keyring: Unused. <<
121 * <<
122 * Check if the new certificate is a CA. If it <<
123 * certificate as being ok to link. <<
124 * <<
125 * Returns 0 if the new certificate was accept <<
126 * certificate is not a CA. -ENOPKG if the sig <<
127 * crypto, or some other error if there is a m <<
128 * the signature check cannot be performed. <<
129 */ <<
130 int restrict_link_by_ca(struct key *dest_keyri <<
131 const struct key_type <<
132 const union key_payloa <<
133 struct key *trust_keyr <<
134 { <<
135 const struct public_key *pkey; <<
136 <<
137 if (type != &key_type_asymmetric) <<
138 return -EOPNOTSUPP; <<
139 <<
140 pkey = payload->data[asym_crypto]; <<
141 if (!pkey) <<
142 return -ENOPKG; <<
143 if (!test_bit(KEY_EFLAG_CA, &pkey->key <<
144 return -ENOKEY; <<
145 if (!test_bit(KEY_EFLAG_KEYCERTSIGN, & <<
146 return -ENOKEY; <<
147 if (!IS_ENABLED(CONFIG_INTEGRITY_CA_MA <<
148 return 0; <<
149 if (test_bit(KEY_EFLAG_DIGITALSIG, &pk <<
150 return -ENOKEY; <<
151 <<
152 return 0; <<
153 } <<
154 <<
155 /** <<
156 * restrict_link_by_digsig - Restrict addition <<
157 * @dest_keyring: Keyring being linked to. <<
158 * @type: The type of key being added. <<
159 * @payload: The payload of the new key. <<
160 * @trust_keyring: A ring of keys that can be <<
161 * <<
162 * Check if the new certificate has digitalSig <<
163 * then mark the new certificate as being ok t <<
164 * the new certificate against the ones in the <<
165 * <<
166 * Returns 0 if the new certificate was accept <<
167 * certificate is not a digsig. -ENOPKG if the <<
168 * crypto, or some other error if there is a m <<
169 * the signature check cannot be performed. <<
170 */ <<
171 int restrict_link_by_digsig(struct key *dest_k <<
172 const struct key_t <<
173 const union key_pa <<
174 struct key *trust_ <<
175 { <<
176 const struct public_key *pkey; <<
177 <<
178 if (type != &key_type_asymmetric) <<
179 return -EOPNOTSUPP; <<
180 <<
181 pkey = payload->data[asym_crypto]; <<
182 <<
183 if (!pkey) <<
184 return -ENOPKG; <<
185 <<
186 if (!test_bit(KEY_EFLAG_DIGITALSIG, &p <<
187 return -ENOKEY; <<
188 <<
189 if (test_bit(KEY_EFLAG_CA, &pkey->key_ <<
190 return -ENOKEY; <<
191 <<
192 if (test_bit(KEY_EFLAG_KEYCERTSIGN, &p <<
193 return -ENOKEY; <<
194 <<
195 return restrict_link_by_signature(dest <<
196 trus <<
197 } <<
198 <<
199 static bool match_either_id(const struct asymm <<
200 const struct asymm 112 const struct asymmetric_key_id *single)
201 { 113 {
202 return (asymmetric_key_id_same(pair[0] !! 114 return (asymmetric_key_id_same(pair->id[0], single) ||
203 asymmetric_key_id_same(pair[1] !! 115 asymmetric_key_id_same(pair->id[1], single));
204 } 116 }
205 117
206 static int key_or_keyring_common(struct key *d 118 static int key_or_keyring_common(struct key *dest_keyring,
207 const struct 119 const struct key_type *type,
208 const union k 120 const union key_payload *payload,
209 struct key *t 121 struct key *trusted, bool check_dest)
210 { 122 {
211 const struct public_key_signature *sig 123 const struct public_key_signature *sig;
212 struct key *key = NULL; 124 struct key *key = NULL;
213 int ret; 125 int ret;
214 126
215 pr_devel("==>%s()\n", __func__); 127 pr_devel("==>%s()\n", __func__);
216 128
217 if (!dest_keyring) 129 if (!dest_keyring)
218 return -ENOKEY; 130 return -ENOKEY;
219 else if (dest_keyring->type != &key_ty 131 else if (dest_keyring->type != &key_type_keyring)
220 return -EOPNOTSUPP; 132 return -EOPNOTSUPP;
221 133
222 if (!trusted && !check_dest) 134 if (!trusted && !check_dest)
223 return -ENOKEY; 135 return -ENOKEY;
224 136
225 if (type != &key_type_asymmetric) 137 if (type != &key_type_asymmetric)
226 return -EOPNOTSUPP; 138 return -EOPNOTSUPP;
227 139
228 sig = payload->data[asym_auth]; 140 sig = payload->data[asym_auth];
229 if (!sig) 141 if (!sig)
230 return -ENOPKG; 142 return -ENOPKG;
231 if (!sig->auth_ids[0] && !sig->auth_id !! 143 if (!sig->auth_ids[0] && !sig->auth_ids[1])
232 return -ENOKEY; 144 return -ENOKEY;
233 145
234 if (trusted) { 146 if (trusted) {
235 if (trusted->type == &key_type 147 if (trusted->type == &key_type_keyring) {
236 /* See if we have a ke 148 /* See if we have a key that signed this one. */
237 key = find_asymmetric_ 149 key = find_asymmetric_key(trusted, sig->auth_ids[0],
238 !! 150 sig->auth_ids[1], false);
239 <<
240 if (IS_ERR(key)) 151 if (IS_ERR(key))
241 key = NULL; 152 key = NULL;
242 } else if (trusted->type == &k 153 } else if (trusted->type == &key_type_asymmetric) {
243 const struct asymmetri !! 154 const struct asymmetric_key_ids *signer_ids;
244 155
245 signer_ids = (const st !! 156 signer_ids = asymmetric_key_ids(trusted);
246 asymmetric_key <<
247 157
248 /* 158 /*
249 * The auth_ids come f 159 * The auth_ids come from the candidate key (the
250 * one that is being c 160 * one that is being considered for addition to
251 * dest_keyring) and i 161 * dest_keyring) and identify the key that was
252 * used to sign. 162 * used to sign.
253 * 163 *
254 * The signer_ids are 164 * The signer_ids are identifiers for the
255 * signing key specifi 165 * signing key specified for dest_keyring.
256 * 166 *
257 * The first auth_id i !! 167 * The first auth_id is the preferred id, and
258 * 3rd are the fallbac !! 168 * the second is the fallback. If only one
259 * auth_ids[0] and aut !! 169 * auth_id is present, it may match against
260 * match either signer !! 170 * either signer_id. If two auth_ids are
261 * If both are present !! 171 * present, the first auth_id must match one
262 * either signed_id bu !! 172 * signer_id and the second auth_id must match
263 * the second signer_i !! 173 * the second signer_id.
264 * available, auth_ids <<
265 * signer_ids[2] as a <<
266 */ 174 */
267 if (!sig->auth_ids[0] !! 175 if (!sig->auth_ids[0] || !sig->auth_ids[1]) {
268 if (asymmetric <<
269 <<
270 key = <<
271 <<
272 } else if (!sig->auth_ <<
273 const struct a 176 const struct asymmetric_key_id *auth_id;
274 177
275 auth_id = sig- 178 auth_id = sig->auth_ids[0] ?: sig->auth_ids[1];
276 if (match_eith 179 if (match_either_id(signer_ids, auth_id))
277 key = 180 key = __key_get(trusted);
278 181
279 } else if (asymmetric_ !! 182 } else if (asymmetric_key_id_same(signer_ids->id[1],
280 183 sig->auth_ids[1]) &&
281 match_eithe 184 match_either_id(signer_ids,
282 185 sig->auth_ids[0])) {
283 key = __key_ge 186 key = __key_get(trusted);
284 } 187 }
285 } else { 188 } else {
286 return -EOPNOTSUPP; 189 return -EOPNOTSUPP;
287 } 190 }
288 } 191 }
289 192
290 if (check_dest && !key) { 193 if (check_dest && !key) {
291 /* See if the destination has 194 /* See if the destination has a key that signed this one. */
292 key = find_asymmetric_key(dest 195 key = find_asymmetric_key(dest_keyring, sig->auth_ids[0],
293 sig- !! 196 sig->auth_ids[1], false);
294 fals <<
295 if (IS_ERR(key)) 197 if (IS_ERR(key))
296 key = NULL; 198 key = NULL;
297 } 199 }
298 200
299 if (!key) 201 if (!key)
300 return -ENOKEY; 202 return -ENOKEY;
301 203
302 ret = key_validate(key); 204 ret = key_validate(key);
303 if (ret == 0) 205 if (ret == 0)
304 ret = verify_signature(key, si 206 ret = verify_signature(key, sig);
305 207
306 key_put(key); 208 key_put(key);
307 return ret; 209 return ret;
308 } 210 }
309 211
310 /** 212 /**
311 * restrict_link_by_key_or_keyring - Restrict 213 * restrict_link_by_key_or_keyring - Restrict additions to a ring of public
312 * keys using the restrict_key information sto 214 * keys using the restrict_key information stored in the ring.
313 * @dest_keyring: Keyring being linked to. 215 * @dest_keyring: Keyring being linked to.
314 * @type: The type of key being added. 216 * @type: The type of key being added.
315 * @payload: The payload of the new key. 217 * @payload: The payload of the new key.
316 * @trusted: A key or ring of keys that can be 218 * @trusted: A key or ring of keys that can be used to vouch for the new cert.
317 * 219 *
318 * Check the new certificate only against the 220 * Check the new certificate only against the key or keys passed in the data
319 * parameter. If one of those is the signing k 221 * parameter. If one of those is the signing key and validates the new
320 * certificate, then mark the new certificate 222 * certificate, then mark the new certificate as being ok to link.
321 * 223 *
322 * Returns 0 if the new certificate was accept 224 * Returns 0 if the new certificate was accepted, -ENOKEY if we
323 * couldn't find a matching parent certificate 225 * couldn't find a matching parent certificate in the trusted list,
324 * -EKEYREJECTED if the signature check fails, 226 * -EKEYREJECTED if the signature check fails, -ENOPKG if the signature uses
325 * unsupported crypto, or some other error if 227 * unsupported crypto, or some other error if there is a matching certificate
326 * but the signature check cannot be performed 228 * but the signature check cannot be performed.
327 */ 229 */
328 int restrict_link_by_key_or_keyring(struct key 230 int restrict_link_by_key_or_keyring(struct key *dest_keyring,
329 const stru 231 const struct key_type *type,
330 const unio 232 const union key_payload *payload,
331 struct key 233 struct key *trusted)
332 { 234 {
333 return key_or_keyring_common(dest_keyr 235 return key_or_keyring_common(dest_keyring, type, payload, trusted,
334 false); 236 false);
335 } 237 }
336 238
337 /** 239 /**
338 * restrict_link_by_key_or_keyring_chain - Res 240 * restrict_link_by_key_or_keyring_chain - Restrict additions to a ring of
339 * public keys using the restrict_key informat 241 * public keys using the restrict_key information stored in the ring.
340 * @dest_keyring: Keyring being linked to. 242 * @dest_keyring: Keyring being linked to.
341 * @type: The type of key being added. 243 * @type: The type of key being added.
342 * @payload: The payload of the new key. 244 * @payload: The payload of the new key.
343 * @trusted: A key or ring of keys that can be 245 * @trusted: A key or ring of keys that can be used to vouch for the new cert.
344 * 246 *
345 * Check the new certificate against the key o 247 * Check the new certificate against the key or keys passed in the data
346 * parameter and against the keys already link 248 * parameter and against the keys already linked to the destination keyring. If
347 * one of those is the signing key and validat 249 * one of those is the signing key and validates the new certificate, then mark
348 * the new certificate as being ok to link. 250 * the new certificate as being ok to link.
349 * 251 *
350 * Returns 0 if the new certificate was accept 252 * Returns 0 if the new certificate was accepted, -ENOKEY if we
351 * couldn't find a matching parent certificate 253 * couldn't find a matching parent certificate in the trusted list,
352 * -EKEYREJECTED if the signature check fails, 254 * -EKEYREJECTED if the signature check fails, -ENOPKG if the signature uses
353 * unsupported crypto, or some other error if 255 * unsupported crypto, or some other error if there is a matching certificate
354 * but the signature check cannot be performed 256 * but the signature check cannot be performed.
355 */ 257 */
356 int restrict_link_by_key_or_keyring_chain(stru 258 int restrict_link_by_key_or_keyring_chain(struct key *dest_keyring,
357 cons 259 const struct key_type *type,
358 cons 260 const union key_payload *payload,
359 stru 261 struct key *trusted)
360 { 262 {
361 return key_or_keyring_common(dest_keyr 263 return key_or_keyring_common(dest_keyring, type, payload, trusted,
362 true); 264 true);
363 } 265 }
364 266
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