1 /*
2 * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <openssl/core_names.h>
11 #include "internal/cryptlib.h"
12 #include "internal/nelem.h"
13 #include "crypto/evp.h"
14 #include "internal/core.h"
15 #include "internal/provider.h"
16 #include "evp_local.h"
17
18 /*
19 * match_type() checks if two EVP_KEYMGMT are matching key types. This
20 * function assumes that the caller has made all the necessary NULL checks.
21 */
match_type(const EVP_KEYMGMT * keymgmt1,const EVP_KEYMGMT * keymgmt2)22 static int match_type(const EVP_KEYMGMT *keymgmt1, const EVP_KEYMGMT *keymgmt2)
23 {
24 const char *name2 = EVP_KEYMGMT_get0_name(keymgmt2);
25
26 return EVP_KEYMGMT_is_a(keymgmt1, name2);
27 }
28
evp_keymgmt_util_try_import(const OSSL_PARAM params[],void * arg)29 int evp_keymgmt_util_try_import(const OSSL_PARAM params[], void *arg)
30 {
31 struct evp_keymgmt_util_try_import_data_st *data = arg;
32 int delete_on_error = 0;
33
34 /* Just in time creation of keydata */
35 if (data->keydata == NULL) {
36 if ((data->keydata = evp_keymgmt_newdata(data->keymgmt)) == NULL) {
37 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
38 return 0;
39 }
40 delete_on_error = 1;
41 }
42
43 /*
44 * It's fine if there was no data to transfer, we just end up with an
45 * empty destination key.
46 */
47 if (params[0].key == NULL)
48 return 1;
49
50 if (evp_keymgmt_import(data->keymgmt, data->keydata, data->selection,
51 params))
52 return 1;
53 if (delete_on_error) {
54 evp_keymgmt_freedata(data->keymgmt, data->keydata);
55 data->keydata = NULL;
56 }
57 return 0;
58 }
59
evp_keymgmt_util_assign_pkey(EVP_PKEY * pkey,EVP_KEYMGMT * keymgmt,void * keydata)60 int evp_keymgmt_util_assign_pkey(EVP_PKEY *pkey, EVP_KEYMGMT *keymgmt,
61 void *keydata)
62 {
63 if (pkey == NULL || keymgmt == NULL || keydata == NULL
64 || !EVP_PKEY_set_type_by_keymgmt(pkey, keymgmt)) {
65 ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
66 return 0;
67 }
68 pkey->keydata = keydata;
69 evp_keymgmt_util_cache_keyinfo(pkey);
70 return 1;
71 }
72
evp_keymgmt_util_make_pkey(EVP_KEYMGMT * keymgmt,void * keydata)73 EVP_PKEY *evp_keymgmt_util_make_pkey(EVP_KEYMGMT *keymgmt, void *keydata)
74 {
75 EVP_PKEY *pkey = NULL;
76
77 if (keymgmt == NULL
78 || keydata == NULL
79 || (pkey = EVP_PKEY_new()) == NULL
80 || !evp_keymgmt_util_assign_pkey(pkey, keymgmt, keydata)) {
81 EVP_PKEY_free(pkey);
82 return NULL;
83 }
84 return pkey;
85 }
86
evp_keymgmt_util_export(const EVP_PKEY * pk,int selection,OSSL_CALLBACK * export_cb,void * export_cbarg)87 int evp_keymgmt_util_export(const EVP_PKEY *pk, int selection,
88 OSSL_CALLBACK *export_cb, void *export_cbarg)
89 {
90 if (pk == NULL || export_cb == NULL)
91 return 0;
92 return evp_keymgmt_export(pk->keymgmt, pk->keydata, selection,
93 export_cb, export_cbarg);
94 }
95
evp_keymgmt_util_export_to_provider(EVP_PKEY * pk,EVP_KEYMGMT * keymgmt)96 void *evp_keymgmt_util_export_to_provider(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt)
97 {
98 struct evp_keymgmt_util_try_import_data_st import_data;
99 OP_CACHE_ELEM *op;
100
101 /* Export to where? */
102 if (keymgmt == NULL)
103 return NULL;
104
105 /* If we have an unassigned key, give up */
106 if (pk->keydata == NULL)
107 return NULL;
108
109 /*
110 * If |keymgmt| matches the "origin" |keymgmt|, there is no more to do.
111 * The "origin" is determined by the |keymgmt| pointers being identical
112 * or when the provider and the name ID match. The latter case handles the
113 * situation where the fetch cache is flushed and a "new" key manager is
114 * created.
115 */
116 if (pk->keymgmt == keymgmt
117 || (pk->keymgmt->name_id == keymgmt->name_id
118 && pk->keymgmt->prov == keymgmt->prov))
119 return pk->keydata;
120
121 if (!CRYPTO_THREAD_read_lock(pk->lock))
122 return NULL;
123 /*
124 * If the provider native "origin" hasn't changed since last time, we
125 * try to find our keymgmt in the operation cache. If it has changed
126 * and our keymgmt isn't found, we will clear the cache further down.
127 */
128 if (pk->dirty_cnt == pk->dirty_cnt_copy) {
129 /* If this key is already exported to |keymgmt|, no more to do */
130 op = evp_keymgmt_util_find_operation_cache(pk, keymgmt);
131 if (op != NULL && op->keymgmt != NULL) {
132 void *ret = op->keydata;
133
134 CRYPTO_THREAD_unlock(pk->lock);
135 return ret;
136 }
137 }
138 CRYPTO_THREAD_unlock(pk->lock);
139
140 /* If the "origin" |keymgmt| doesn't support exporting, give up */
141 if (pk->keymgmt->export == NULL)
142 return NULL;
143
144 /*
145 * Make sure that the type of the keymgmt to export to matches the type
146 * of the "origin"
147 */
148 if (!ossl_assert(match_type(pk->keymgmt, keymgmt)))
149 return NULL;
150
151 /*
152 * We look at the already cached provider keys, and import from the
153 * first that supports it (i.e. use its export function), and export
154 * the imported data to the new provider.
155 */
156
157 /* Setup for the export callback */
158 import_data.keydata = NULL; /* evp_keymgmt_util_try_import will create it */
159 import_data.keymgmt = keymgmt;
160 import_data.selection = OSSL_KEYMGMT_SELECT_ALL;
161
162 /*
163 * The export function calls the callback (evp_keymgmt_util_try_import),
164 * which does the import for us. If successful, we're done.
165 */
166 if (!evp_keymgmt_util_export(pk, OSSL_KEYMGMT_SELECT_ALL,
167 &evp_keymgmt_util_try_import, &import_data))
168 /* If there was an error, bail out */
169 return NULL;
170
171 if (!CRYPTO_THREAD_write_lock(pk->lock)) {
172 evp_keymgmt_freedata(keymgmt, import_data.keydata);
173 return NULL;
174 }
175 /* Check to make sure some other thread didn't get there first */
176 op = evp_keymgmt_util_find_operation_cache(pk, keymgmt);
177 if (op != NULL && op->keydata != NULL) {
178 void *ret = op->keydata;
179
180 CRYPTO_THREAD_unlock(pk->lock);
181
182 /*
183 * Another thread seemms to have already exported this so we abandon
184 * all the work we just did.
185 */
186 evp_keymgmt_freedata(keymgmt, import_data.keydata);
187
188 return ret;
189 }
190
191 /*
192 * If the dirty counter changed since last time, then clear the
193 * operation cache. In that case, we know that |i| is zero.
194 */
195 if (pk->dirty_cnt != pk->dirty_cnt_copy)
196 evp_keymgmt_util_clear_operation_cache(pk, 0);
197
198 /* Add the new export to the operation cache */
199 if (!evp_keymgmt_util_cache_keydata(pk, keymgmt, import_data.keydata)) {
200 evp_keymgmt_freedata(keymgmt, import_data.keydata);
201 return NULL;
202 }
203
204 /* Synchronize the dirty count */
205 pk->dirty_cnt_copy = pk->dirty_cnt;
206
207 CRYPTO_THREAD_unlock(pk->lock);
208
209 return import_data.keydata;
210 }
211
op_cache_free(OP_CACHE_ELEM * e)212 static void op_cache_free(OP_CACHE_ELEM *e)
213 {
214 evp_keymgmt_freedata(e->keymgmt, e->keydata);
215 EVP_KEYMGMT_free(e->keymgmt);
216 OPENSSL_free(e);
217 }
218
evp_keymgmt_util_clear_operation_cache(EVP_PKEY * pk,int locking)219 int evp_keymgmt_util_clear_operation_cache(EVP_PKEY *pk, int locking)
220 {
221 if (pk != NULL) {
222 if (locking && pk->lock != NULL && !CRYPTO_THREAD_write_lock(pk->lock))
223 return 0;
224 sk_OP_CACHE_ELEM_pop_free(pk->operation_cache, op_cache_free);
225 pk->operation_cache = NULL;
226 if (locking && pk->lock != NULL)
227 CRYPTO_THREAD_unlock(pk->lock);
228 }
229
230 return 1;
231 }
232
evp_keymgmt_util_find_operation_cache(EVP_PKEY * pk,EVP_KEYMGMT * keymgmt)233 OP_CACHE_ELEM *evp_keymgmt_util_find_operation_cache(EVP_PKEY *pk,
234 EVP_KEYMGMT *keymgmt)
235 {
236 int i, end = sk_OP_CACHE_ELEM_num(pk->operation_cache);
237 OP_CACHE_ELEM *p;
238
239 /*
240 * A comparison and sk_P_CACHE_ELEM_find() are avoided to not cause
241 * problems when we've only a read lock.
242 */
243 for (i = 0; i < end; i++) {
244 p = sk_OP_CACHE_ELEM_value(pk->operation_cache, i);
245 if (keymgmt == p->keymgmt)
246 return p;
247 }
248 return NULL;
249 }
250
evp_keymgmt_util_cache_keydata(EVP_PKEY * pk,EVP_KEYMGMT * keymgmt,void * keydata)251 int evp_keymgmt_util_cache_keydata(EVP_PKEY *pk,
252 EVP_KEYMGMT *keymgmt, void *keydata)
253 {
254 OP_CACHE_ELEM *p = NULL;
255
256 if (keydata != NULL) {
257 if (pk->operation_cache == NULL) {
258 pk->operation_cache = sk_OP_CACHE_ELEM_new_null();
259 if (pk->operation_cache == NULL)
260 return 0;
261 }
262
263 p = OPENSSL_malloc(sizeof(*p));
264 if (p == NULL)
265 return 0;
266 p->keydata = keydata;
267 p->keymgmt = keymgmt;
268
269 if (!EVP_KEYMGMT_up_ref(keymgmt)) {
270 OPENSSL_free(p);
271 return 0;
272 }
273
274 if (!sk_OP_CACHE_ELEM_push(pk->operation_cache, p)) {
275 EVP_KEYMGMT_free(keymgmt);
276 OPENSSL_free(p);
277 return 0;
278 }
279 }
280 return 1;
281 }
282
evp_keymgmt_util_cache_keyinfo(EVP_PKEY * pk)283 void evp_keymgmt_util_cache_keyinfo(EVP_PKEY *pk)
284 {
285 /*
286 * Cache information about the provider "origin" key.
287 *
288 * This services functions like EVP_PKEY_get_size, EVP_PKEY_get_bits, etc
289 */
290 if (pk->keydata != NULL) {
291 int bits = 0;
292 int security_bits = 0;
293 int size = 0;
294 OSSL_PARAM params[4];
295
296 params[0] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_BITS, &bits);
297 params[1] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_SECURITY_BITS,
298 &security_bits);
299 params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_MAX_SIZE, &size);
300 params[3] = OSSL_PARAM_construct_end();
301 if (evp_keymgmt_get_params(pk->keymgmt, pk->keydata, params)) {
302 pk->cache.size = size;
303 pk->cache.bits = bits;
304 pk->cache.security_bits = security_bits;
305 }
306 }
307 }
308
evp_keymgmt_util_fromdata(EVP_PKEY * target,EVP_KEYMGMT * keymgmt,int selection,const OSSL_PARAM params[])309 void *evp_keymgmt_util_fromdata(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
310 int selection, const OSSL_PARAM params[])
311 {
312 void *keydata = NULL;
313
314 if ((keydata = evp_keymgmt_newdata(keymgmt)) == NULL
315 || !evp_keymgmt_import(keymgmt, keydata, selection, params)
316 || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
317 evp_keymgmt_freedata(keymgmt, keydata);
318 keydata = NULL;
319 }
320 return keydata;
321 }
322
evp_keymgmt_util_has(EVP_PKEY * pk,int selection)323 int evp_keymgmt_util_has(EVP_PKEY *pk, int selection)
324 {
325 /* Check if key is even assigned */
326 if (pk->keymgmt == NULL)
327 return 0;
328
329 return evp_keymgmt_has(pk->keymgmt, pk->keydata, selection);
330 }
331
332 /*
333 * evp_keymgmt_util_match() doesn't just look at the provider side "origin",
334 * but also in the operation cache to see if there's any common keymgmt that
335 * supplies OP_keymgmt_match.
336 *
337 * evp_keymgmt_util_match() adheres to the return values that EVP_PKEY_eq()
338 * and EVP_PKEY_parameters_eq() return, i.e.:
339 *
340 * 1 same key
341 * 0 not same key
342 * -1 not same key type
343 * -2 unsupported operation
344 */
evp_keymgmt_util_match(EVP_PKEY * pk1,EVP_PKEY * pk2,int selection)345 int evp_keymgmt_util_match(EVP_PKEY *pk1, EVP_PKEY *pk2, int selection)
346 {
347 EVP_KEYMGMT *keymgmt1 = NULL, *keymgmt2 = NULL;
348 void *keydata1 = NULL, *keydata2 = NULL;
349
350 if (pk1 == NULL || pk2 == NULL) {
351 if (pk1 == NULL && pk2 == NULL)
352 return 1;
353 return 0;
354 }
355
356 keymgmt1 = pk1->keymgmt;
357 keydata1 = pk1->keydata;
358 keymgmt2 = pk2->keymgmt;
359 keydata2 = pk2->keydata;
360
361 if (keymgmt1 != keymgmt2) {
362 /*
363 * The condition for a successful cross export is that the
364 * keydata to be exported is NULL (typed, but otherwise empty
365 * EVP_PKEY), or that it was possible to export it with
366 * evp_keymgmt_util_export_to_provider().
367 *
368 * We use |ok| to determine if it's ok to cross export one way,
369 * but also to determine if we should attempt a cross export
370 * the other way. There's no point doing it both ways.
371 */
372 int ok = 1;
373
374 /* Complex case, where the keymgmt differ */
375 if (keymgmt1 != NULL
376 && keymgmt2 != NULL
377 && !match_type(keymgmt1, keymgmt2)) {
378 ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
379 return -1; /* Not the same type */
380 }
381
382 /*
383 * The key types are determined to match, so we try cross export,
384 * but only to keymgmt's that supply a matching function.
385 */
386 if (keymgmt2 != NULL
387 && keymgmt2->match != NULL) {
388 void *tmp_keydata = NULL;
389
390 ok = 1;
391 if (keydata1 != NULL) {
392 tmp_keydata =
393 evp_keymgmt_util_export_to_provider(pk1, keymgmt2);
394 ok = (tmp_keydata != NULL);
395 }
396 if (ok) {
397 keymgmt1 = keymgmt2;
398 keydata1 = tmp_keydata;
399 }
400 }
401 /*
402 * If we've successfully cross exported one way, there's no point
403 * doing it the other way, hence the |!ok| check.
404 */
405 if (!ok
406 && keymgmt1 != NULL
407 && keymgmt1->match != NULL) {
408 void *tmp_keydata = NULL;
409
410 ok = 1;
411 if (keydata2 != NULL) {
412 tmp_keydata =
413 evp_keymgmt_util_export_to_provider(pk2, keymgmt1);
414 ok = (tmp_keydata != NULL);
415 }
416 if (ok) {
417 keymgmt2 = keymgmt1;
418 keydata2 = tmp_keydata;
419 }
420 }
421 }
422
423 /* If we still don't have matching keymgmt implementations, we give up */
424 if (keymgmt1 != keymgmt2)
425 return -2;
426
427 /* If both keydata are NULL, then they're the same key */
428 if (keydata1 == NULL && keydata2 == NULL)
429 return 1;
430 /* If only one of the keydata is NULL, then they're different keys */
431 if (keydata1 == NULL || keydata2 == NULL)
432 return 0;
433 /* If both keydata are non-NULL, we let the backend decide */
434 return evp_keymgmt_match(keymgmt1, keydata1, keydata2, selection);
435 }
436
evp_keymgmt_util_copy(EVP_PKEY * to,EVP_PKEY * from,int selection)437 int evp_keymgmt_util_copy(EVP_PKEY *to, EVP_PKEY *from, int selection)
438 {
439 /* Save copies of pointers we want to play with without affecting |to| */
440 EVP_KEYMGMT *to_keymgmt = to->keymgmt;
441 void *to_keydata = to->keydata, *alloc_keydata = NULL;
442
443 /* An unassigned key can't be copied */
444 if (from == NULL || from->keydata == NULL)
445 return 0;
446
447 /*
448 * If |to| is unassigned, ensure it gets the same KEYMGMT as |from|,
449 * Note that the final setting of KEYMGMT is done further down, with
450 * EVP_PKEY_set_type_by_keymgmt(); we don't want to do that prematurely.
451 */
452 if (to_keymgmt == NULL)
453 to_keymgmt = from->keymgmt;
454
455 if (to_keymgmt == from->keymgmt && to_keymgmt->dup != NULL
456 && to_keydata == NULL) {
457 to_keydata = alloc_keydata = evp_keymgmt_dup(to_keymgmt,
458 from->keydata,
459 selection);
460 if (to_keydata == NULL)
461 return 0;
462 } else if (match_type(to_keymgmt, from->keymgmt)) {
463 struct evp_keymgmt_util_try_import_data_st import_data;
464
465 import_data.keymgmt = to_keymgmt;
466 import_data.keydata = to_keydata;
467 import_data.selection = selection;
468
469 if (!evp_keymgmt_util_export(from, selection,
470 &evp_keymgmt_util_try_import,
471 &import_data))
472 return 0;
473
474 /*
475 * In case to_keydata was previously unallocated,
476 * evp_keymgmt_util_try_import() may have created it for us.
477 */
478 if (to_keydata == NULL)
479 to_keydata = alloc_keydata = import_data.keydata;
480 } else {
481 ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
482 return 0;
483 }
484
485 /*
486 * We only need to set the |to| type when its |keymgmt| isn't set.
487 * We can then just set its |keydata| to what we have, which might
488 * be exactly what it had when entering this function.
489 * This is a bit different from using evp_keymgmt_util_assign_pkey(),
490 * which isn't as careful with |to|'s original |keymgmt|, since it's
491 * meant to forcibly reassign an EVP_PKEY no matter what, which is
492 * why we don't use that one here.
493 */
494 if (to->keymgmt == NULL
495 && !EVP_PKEY_set_type_by_keymgmt(to, to_keymgmt)) {
496 evp_keymgmt_freedata(to_keymgmt, alloc_keydata);
497 return 0;
498 }
499 to->keydata = to_keydata;
500 evp_keymgmt_util_cache_keyinfo(to);
501
502 return 1;
503 }
504
evp_keymgmt_util_gen(EVP_PKEY * target,EVP_KEYMGMT * keymgmt,void * genctx,OSSL_CALLBACK * cb,void * cbarg)505 void *evp_keymgmt_util_gen(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
506 void *genctx, OSSL_CALLBACK *cb, void *cbarg)
507 {
508 void *keydata = NULL;
509
510 if ((keydata = evp_keymgmt_gen(keymgmt, genctx, cb, cbarg)) == NULL
511 || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
512 evp_keymgmt_freedata(keymgmt, keydata);
513 keydata = NULL;
514 }
515
516 return keydata;
517 }
518
519 /*
520 * Returns the same numbers as EVP_PKEY_get_default_digest_name()
521 * When the string from the EVP_KEYMGMT implementation is "", we use
522 * SN_undef, since that corresponds to what EVP_PKEY_get_default_nid()
523 * returns for no digest.
524 */
evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT * keymgmt,void * keydata,char * mdname,size_t mdname_sz)525 int evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT *keymgmt,
526 void *keydata,
527 char *mdname, size_t mdname_sz)
528 {
529 OSSL_PARAM params[3];
530 char mddefault[100] = "";
531 char mdmandatory[100] = "";
532 char *result = NULL;
533 int rv = -2;
534
535 params[0] =
536 OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST,
537 mddefault, sizeof(mddefault));
538 params[1] =
539 OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_MANDATORY_DIGEST,
540 mdmandatory,
541 sizeof(mdmandatory));
542 params[2] = OSSL_PARAM_construct_end();
543
544 if (!evp_keymgmt_get_params(keymgmt, keydata, params))
545 return 0;
546
547 if (OSSL_PARAM_modified(params + 1)) {
548 if (params[1].return_size <= 1) /* Only a NUL byte */
549 result = SN_undef;
550 else
551 result = mdmandatory;
552 rv = 2;
553 } else if (OSSL_PARAM_modified(params)) {
554 if (params[0].return_size <= 1) /* Only a NUL byte */
555 result = SN_undef;
556 else
557 result = mddefault;
558 rv = 1;
559 }
560 if (rv > 0)
561 OPENSSL_strlcpy(mdname, result, mdname_sz);
562 return rv;
563 }
564