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9#ifndef __UBOOT__
10#include <log.h>
11#include <dm/devres.h>
12#include <keys/asymmetric-subtype.h>
13#include <keys/asymmetric-parser.h>
14#endif
15#include <crypto/public_key.h>
16#ifdef __UBOOT__
17#include <linux/bug.h>
18#include <linux/compat.h>
19#include <linux/ctype.h>
20#include <linux/err.h>
21#include <linux/string.h>
22#else
23#include <linux/seq_file.h>
24#include <linux/module.h>
25#include <linux/slab.h>
26#include <linux/ctype.h>
27#endif
28#ifdef __UBOOT__
29#include <keys/asymmetric-type.h>
30#else
31#include <keys/system_keyring.h>
32#include <keys/user-type.h>
33#include "asymmetric_keys.h"
34#endif
35
36MODULE_LICENSE("GPL");
37
38#ifndef __UBOOT__
39const char *const key_being_used_for[NR__KEY_BEING_USED_FOR] = {
40 [VERIFYING_MODULE_SIGNATURE] = "mod sig",
41 [VERIFYING_FIRMWARE_SIGNATURE] = "firmware sig",
42 [VERIFYING_KEXEC_PE_SIGNATURE] = "kexec PE sig",
43 [VERIFYING_KEY_SIGNATURE] = "key sig",
44 [VERIFYING_KEY_SELF_SIGNATURE] = "key self sig",
45 [VERIFYING_UNSPECIFIED_SIGNATURE] = "unspec sig",
46};
47EXPORT_SYMBOL_GPL(key_being_used_for);
48
49static LIST_HEAD(asymmetric_key_parsers);
50static DECLARE_RWSEM(asymmetric_key_parsers_sem);
51
52
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55
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60
61
62
63struct key *find_asymmetric_key(struct key *keyring,
64 const struct asymmetric_key_id *id_0,
65 const struct asymmetric_key_id *id_1,
66 bool partial)
67{
68 struct key *key;
69 key_ref_t ref;
70 const char *lookup;
71 char *req, *p;
72 int len;
73
74 BUG_ON(!id_0 && !id_1);
75
76 if (id_0) {
77 lookup = id_0->data;
78 len = id_0->len;
79 } else {
80 lookup = id_1->data;
81 len = id_1->len;
82 }
83
84
85 p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL);
86 if (!req)
87 return ERR_PTR(-ENOMEM);
88
89 if (partial) {
90 *p++ = 'i';
91 *p++ = 'd';
92 } else {
93 *p++ = 'e';
94 *p++ = 'x';
95 }
96 *p++ = ':';
97 p = bin2hex(p, lookup, len);
98 *p = 0;
99
100 pr_debug("Look up: \"%s\"\n", req);
101
102 ref = keyring_search(make_key_ref(keyring, 1),
103 &key_type_asymmetric, req, true);
104 if (IS_ERR(ref))
105 pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref));
106 kfree(req);
107
108 if (IS_ERR(ref)) {
109 switch (PTR_ERR(ref)) {
110
111 case -EACCES:
112 case -ENOTDIR:
113 case -EAGAIN:
114 return ERR_PTR(-ENOKEY);
115 default:
116 return ERR_CAST(ref);
117 }
118 }
119
120 key = key_ref_to_ptr(ref);
121 if (id_0 && id_1) {
122 const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
123
124 if (!kids->id[1]) {
125 pr_debug("First ID matches, but second is missing\n");
126 goto reject;
127 }
128 if (!asymmetric_key_id_same(id_1, kids->id[1])) {
129 pr_debug("First ID matches, but second does not\n");
130 goto reject;
131 }
132 }
133
134 pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key));
135 return key;
136
137reject:
138 key_put(key);
139 return ERR_PTR(-EKEYREJECTED);
140}
141EXPORT_SYMBOL_GPL(find_asymmetric_key);
142#endif
143
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151
152
153struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1,
154 size_t len_1,
155 const void *val_2,
156 size_t len_2)
157{
158 struct asymmetric_key_id *kid;
159
160 kid = kmalloc(sizeof(struct asymmetric_key_id) + len_1 + len_2,
161 GFP_KERNEL);
162 if (!kid)
163 return ERR_PTR(-ENOMEM);
164 kid->len = len_1 + len_2;
165 memcpy(kid->data, val_1, len_1);
166 memcpy(kid->data + len_1, val_2, len_2);
167 return kid;
168}
169EXPORT_SYMBOL_GPL(asymmetric_key_generate_id);
170
171
172
173
174
175bool asymmetric_key_id_same(const struct asymmetric_key_id *kid1,
176 const struct asymmetric_key_id *kid2)
177{
178 if (!kid1 || !kid2)
179 return false;
180 if (kid1->len != kid2->len)
181 return false;
182 return memcmp(kid1->data, kid2->data, kid1->len) == 0;
183}
184EXPORT_SYMBOL_GPL(asymmetric_key_id_same);
185
186
187
188
189
190
191bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
192 const struct asymmetric_key_id *kid2)
193{
194 if (!kid1 || !kid2)
195 return false;
196 if (kid1->len < kid2->len)
197 return false;
198 return memcmp(kid1->data + (kid1->len - kid2->len),
199 kid2->data, kid2->len) == 0;
200}
201EXPORT_SYMBOL_GPL(asymmetric_key_id_partial);
202
203#ifndef __UBOOT__
204
205
206
207
208
209
210static bool asymmetric_match_key_ids(
211 const struct asymmetric_key_ids *kids,
212 const struct asymmetric_key_id *match_id,
213 bool (*match)(const struct asymmetric_key_id *kid1,
214 const struct asymmetric_key_id *kid2))
215{
216 int i;
217
218 if (!kids || !match_id)
219 return false;
220 for (i = 0; i < ARRAY_SIZE(kids->id); i++)
221 if (match(kids->id[i], match_id))
222 return true;
223 return false;
224}
225
226
227inline int __asymmetric_key_hex_to_key_id(const char *id,
228 struct asymmetric_key_id *match_id,
229 size_t hexlen)
230{
231 match_id->len = hexlen;
232 return hex2bin(match_id->data, id, hexlen);
233}
234
235
236
237
238
239struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id)
240{
241 struct asymmetric_key_id *match_id;
242 size_t asciihexlen;
243 int ret;
244
245 if (!*id)
246 return ERR_PTR(-EINVAL);
247 asciihexlen = strlen(id);
248 if (asciihexlen & 1)
249 return ERR_PTR(-EINVAL);
250
251 match_id = kmalloc(sizeof(struct asymmetric_key_id) + asciihexlen / 2,
252 GFP_KERNEL);
253 if (!match_id)
254 return ERR_PTR(-ENOMEM);
255 ret = __asymmetric_key_hex_to_key_id(id, match_id, asciihexlen / 2);
256 if (ret < 0) {
257 kfree(match_id);
258 return ERR_PTR(-EINVAL);
259 }
260 return match_id;
261}
262
263
264
265
266static bool asymmetric_key_cmp(const struct key *key,
267 const struct key_match_data *match_data)
268{
269 const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
270 const struct asymmetric_key_id *match_id = match_data->preparsed;
271
272 return asymmetric_match_key_ids(kids, match_id,
273 asymmetric_key_id_same);
274}
275
276
277
278
279static bool asymmetric_key_cmp_partial(const struct key *key,
280 const struct key_match_data *match_data)
281{
282 const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
283 const struct asymmetric_key_id *match_id = match_data->preparsed;
284
285 return asymmetric_match_key_ids(kids, match_id,
286 asymmetric_key_id_partial);
287}
288
289
290
291
292
293
294
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296
297
298
299
300
301
302static int asymmetric_key_match_preparse(struct key_match_data *match_data)
303{
304 struct asymmetric_key_id *match_id;
305 const char *spec = match_data->raw_data;
306 const char *id;
307 bool (*cmp)(const struct key *, const struct key_match_data *) =
308 asymmetric_key_cmp;
309
310 if (!spec || !*spec)
311 return -EINVAL;
312 if (spec[0] == 'i' &&
313 spec[1] == 'd' &&
314 spec[2] == ':') {
315 id = spec + 3;
316 cmp = asymmetric_key_cmp_partial;
317 } else if (spec[0] == 'e' &&
318 spec[1] == 'x' &&
319 spec[2] == ':') {
320 id = spec + 3;
321 } else {
322 goto default_match;
323 }
324
325 match_id = asymmetric_key_hex_to_key_id(id);
326 if (IS_ERR(match_id))
327 return PTR_ERR(match_id);
328
329 match_data->preparsed = match_id;
330 match_data->cmp = cmp;
331 match_data->lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE;
332 return 0;
333
334default_match:
335 return 0;
336}
337
338
339
340
341static void asymmetric_key_match_free(struct key_match_data *match_data)
342{
343 kfree(match_data->preparsed);
344}
345
346
347
348
349static void asymmetric_key_describe(const struct key *key, struct seq_file *m)
350{
351 const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
352 const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
353 const struct asymmetric_key_id *kid;
354 const unsigned char *p;
355 int n;
356
357 seq_puts(m, key->description);
358
359 if (subtype) {
360 seq_puts(m, ": ");
361 subtype->describe(key, m);
362
363 if (kids && kids->id[1]) {
364 kid = kids->id[1];
365 seq_putc(m, ' ');
366 n = kid->len;
367 p = kid->data;
368 if (n > 4) {
369 p += n - 4;
370 n = 4;
371 }
372 seq_printf(m, "%*phN", n, p);
373 }
374
375 seq_puts(m, " [");
376
377 seq_putc(m, ']');
378 }
379}
380
381
382
383
384
385
386
387
388static int asymmetric_key_preparse(struct key_preparsed_payload *prep)
389{
390 struct asymmetric_key_parser *parser;
391 int ret;
392
393 pr_devel("==>%s()\n", __func__);
394
395 if (prep->datalen == 0)
396 return -EINVAL;
397
398 down_read(&asymmetric_key_parsers_sem);
399
400 ret = -EBADMSG;
401 list_for_each_entry(parser, &asymmetric_key_parsers, link) {
402 pr_debug("Trying parser '%s'\n", parser->name);
403
404 ret = parser->parse(prep);
405 if (ret != -EBADMSG) {
406 pr_debug("Parser recognised the format (ret %d)\n",
407 ret);
408 break;
409 }
410 }
411
412 up_read(&asymmetric_key_parsers_sem);
413 pr_devel("<==%s() = %d\n", __func__, ret);
414 return ret;
415}
416
417
418
419
420static void asymmetric_key_free_kids(struct asymmetric_key_ids *kids)
421{
422 int i;
423
424 if (kids) {
425 for (i = 0; i < ARRAY_SIZE(kids->id); i++)
426 kfree(kids->id[i]);
427 kfree(kids);
428 }
429}
430
431
432
433
434static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep)
435{
436 struct asymmetric_key_subtype *subtype = prep->payload.data[asym_subtype];
437 struct asymmetric_key_ids *kids = prep->payload.data[asym_key_ids];
438
439 pr_devel("==>%s()\n", __func__);
440
441 if (subtype) {
442 subtype->destroy(prep->payload.data[asym_crypto],
443 prep->payload.data[asym_auth]);
444 module_put(subtype->owner);
445 }
446 asymmetric_key_free_kids(kids);
447 kfree(prep->description);
448}
449
450
451
452
453static void asymmetric_key_destroy(struct key *key)
454{
455 struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
456 struct asymmetric_key_ids *kids = key->payload.data[asym_key_ids];
457 void *data = key->payload.data[asym_crypto];
458 void *auth = key->payload.data[asym_auth];
459
460 key->payload.data[asym_crypto] = NULL;
461 key->payload.data[asym_subtype] = NULL;
462 key->payload.data[asym_key_ids] = NULL;
463 key->payload.data[asym_auth] = NULL;
464
465 if (subtype) {
466 subtype->destroy(data, auth);
467 module_put(subtype->owner);
468 }
469
470 asymmetric_key_free_kids(kids);
471}
472
473static struct key_restriction *asymmetric_restriction_alloc(
474 key_restrict_link_func_t check,
475 struct key *key)
476{
477 struct key_restriction *keyres =
478 kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
479
480 if (!keyres)
481 return ERR_PTR(-ENOMEM);
482
483 keyres->check = check;
484 keyres->key = key;
485 keyres->keytype = &key_type_asymmetric;
486
487 return keyres;
488}
489
490
491
492
493static struct key_restriction *asymmetric_lookup_restriction(
494 const char *restriction)
495{
496 char *restrict_method;
497 char *parse_buf;
498 char *next;
499 struct key_restriction *ret = ERR_PTR(-EINVAL);
500
501 if (strcmp("builtin_trusted", restriction) == 0)
502 return asymmetric_restriction_alloc(
503 restrict_link_by_builtin_trusted, NULL);
504
505 if (strcmp("builtin_and_secondary_trusted", restriction) == 0)
506 return asymmetric_restriction_alloc(
507 restrict_link_by_builtin_and_secondary_trusted, NULL);
508
509 parse_buf = kstrndup(restriction, PAGE_SIZE, GFP_KERNEL);
510 if (!parse_buf)
511 return ERR_PTR(-ENOMEM);
512
513 next = parse_buf;
514 restrict_method = strsep(&next, ":");
515
516 if ((strcmp(restrict_method, "key_or_keyring") == 0) && next) {
517 char *key_text;
518 key_serial_t serial;
519 struct key *key;
520 key_restrict_link_func_t link_fn =
521 restrict_link_by_key_or_keyring;
522 bool allow_null_key = false;
523
524 key_text = strsep(&next, ":");
525
526 if (next) {
527 if (strcmp(next, "chain") != 0)
528 goto out;
529
530 link_fn = restrict_link_by_key_or_keyring_chain;
531 allow_null_key = true;
532 }
533
534 if (kstrtos32(key_text, 0, &serial) < 0)
535 goto out;
536
537 if ((serial == 0) && allow_null_key) {
538 key = NULL;
539 } else {
540 key = key_lookup(serial);
541 if (IS_ERR(key)) {
542 ret = ERR_CAST(key);
543 goto out;
544 }
545 }
546
547 ret = asymmetric_restriction_alloc(link_fn, key);
548 if (IS_ERR(ret))
549 key_put(key);
550 }
551
552out:
553 kfree(parse_buf);
554 return ret;
555}
556
557int asymmetric_key_eds_op(struct kernel_pkey_params *params,
558 const void *in, void *out)
559{
560 const struct asymmetric_key_subtype *subtype;
561 struct key *key = params->key;
562 int ret;
563
564 pr_devel("==>%s()\n", __func__);
565
566 if (key->type != &key_type_asymmetric)
567 return -EINVAL;
568 subtype = asymmetric_key_subtype(key);
569 if (!subtype ||
570 !key->payload.data[0])
571 return -EINVAL;
572 if (!subtype->eds_op)
573 return -ENOTSUPP;
574
575 ret = subtype->eds_op(params, in, out);
576
577 pr_devel("<==%s() = %d\n", __func__, ret);
578 return ret;
579}
580
581static int asymmetric_key_verify_signature(struct kernel_pkey_params *params,
582 const void *in, const void *in2)
583{
584 struct public_key_signature sig = {
585 .s_size = params->in2_len,
586 .digest_size = params->in_len,
587 .encoding = params->encoding,
588 .hash_algo = params->hash_algo,
589 .digest = (void *)in,
590 .s = (void *)in2,
591 };
592
593 return verify_signature(params->key, &sig);
594}
595
596struct key_type key_type_asymmetric = {
597 .name = "asymmetric",
598 .preparse = asymmetric_key_preparse,
599 .free_preparse = asymmetric_key_free_preparse,
600 .instantiate = generic_key_instantiate,
601 .match_preparse = asymmetric_key_match_preparse,
602 .match_free = asymmetric_key_match_free,
603 .destroy = asymmetric_key_destroy,
604 .describe = asymmetric_key_describe,
605 .lookup_restriction = asymmetric_lookup_restriction,
606 .asym_query = query_asymmetric_key,
607 .asym_eds_op = asymmetric_key_eds_op,
608 .asym_verify_signature = asymmetric_key_verify_signature,
609};
610EXPORT_SYMBOL_GPL(key_type_asymmetric);
611
612
613
614
615
616int register_asymmetric_key_parser(struct asymmetric_key_parser *parser)
617{
618 struct asymmetric_key_parser *cursor;
619 int ret;
620
621 down_write(&asymmetric_key_parsers_sem);
622
623 list_for_each_entry(cursor, &asymmetric_key_parsers, link) {
624 if (strcmp(cursor->name, parser->name) == 0) {
625 pr_err("Asymmetric key parser '%s' already registered\n",
626 parser->name);
627 ret = -EEXIST;
628 goto out;
629 }
630 }
631
632 list_add_tail(&parser->link, &asymmetric_key_parsers);
633
634 pr_notice("Asymmetric key parser '%s' registered\n", parser->name);
635 ret = 0;
636
637out:
638 up_write(&asymmetric_key_parsers_sem);
639 return ret;
640}
641EXPORT_SYMBOL_GPL(register_asymmetric_key_parser);
642
643
644
645
646
647void unregister_asymmetric_key_parser(struct asymmetric_key_parser *parser)
648{
649 down_write(&asymmetric_key_parsers_sem);
650 list_del(&parser->link);
651 up_write(&asymmetric_key_parsers_sem);
652
653 pr_notice("Asymmetric key parser '%s' unregistered\n", parser->name);
654}
655EXPORT_SYMBOL_GPL(unregister_asymmetric_key_parser);
656
657
658
659
660static int __init asymmetric_key_init(void)
661{
662 return register_key_type(&key_type_asymmetric);
663}
664
665static void __exit asymmetric_key_cleanup(void)
666{
667 unregister_key_type(&key_type_asymmetric);
668}
669
670module_init(asymmetric_key_init);
671module_exit(asymmetric_key_cleanup);
672#endif
673