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