1 /*
2 * PSA ECP layer on top of Mbed TLS crypto
3 */
4 /*
5 * Copyright The Mbed TLS Contributors
6 * SPDX-License-Identifier: Apache-2.0
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License"); you may
9 * not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 #include "common.h"
22
23 #if defined(MBEDTLS_PSA_CRYPTO_C)
24
25 #include <psa/crypto.h>
26 #include "psa_crypto_core.h"
27 #include "psa_crypto_ecp.h"
28 #include "psa_crypto_random_impl.h"
29 #include "hash_info.h"
30
31 #include <stdlib.h>
32 #include <string.h>
33 #include "mbedtls/platform.h"
34
35 #include <mbedtls/ecdsa.h>
36 #include <mbedtls/ecdh.h>
37 #include <mbedtls/ecp.h>
38 #include <mbedtls/error.h>
39
40 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
41 defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
42 defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
43 defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \
44 defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
mbedtls_psa_ecp_load_representation(psa_key_type_t type,size_t curve_bits,const uint8_t * data,size_t data_length,mbedtls_ecp_keypair ** p_ecp)45 psa_status_t mbedtls_psa_ecp_load_representation(
46 psa_key_type_t type, size_t curve_bits,
47 const uint8_t *data, size_t data_length,
48 mbedtls_ecp_keypair **p_ecp)
49 {
50 mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
51 psa_status_t status;
52 mbedtls_ecp_keypair *ecp = NULL;
53 size_t curve_bytes = data_length;
54 int explicit_bits = (curve_bits != 0);
55
56 if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type) &&
57 PSA_KEY_TYPE_ECC_GET_FAMILY(type) != PSA_ECC_FAMILY_MONTGOMERY) {
58 /* A Weierstrass public key is represented as:
59 * - The byte 0x04;
60 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
61 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
62 * So its data length is 2m+1 where m is the curve size in bits.
63 */
64 if ((data_length & 1) == 0) {
65 return PSA_ERROR_INVALID_ARGUMENT;
66 }
67 curve_bytes = data_length / 2;
68
69 /* Montgomery public keys are represented in compressed format, meaning
70 * their curve_bytes is equal to the amount of input. */
71
72 /* Private keys are represented in uncompressed private random integer
73 * format, meaning their curve_bytes is equal to the amount of input. */
74 }
75
76 if (explicit_bits) {
77 /* With an explicit bit-size, the data must have the matching length. */
78 if (curve_bytes != PSA_BITS_TO_BYTES(curve_bits)) {
79 return PSA_ERROR_INVALID_ARGUMENT;
80 }
81 } else {
82 /* We need to infer the bit-size from the data. Since the only
83 * information we have is the length in bytes, the value of curve_bits
84 * at this stage is rounded up to the nearest multiple of 8. */
85 curve_bits = PSA_BYTES_TO_BITS(curve_bytes);
86 }
87
88 /* Allocate and initialize a key representation. */
89 ecp = mbedtls_calloc(1, sizeof(mbedtls_ecp_keypair));
90 if (ecp == NULL) {
91 return PSA_ERROR_INSUFFICIENT_MEMORY;
92 }
93 mbedtls_ecp_keypair_init(ecp);
94
95 /* Load the group. */
96 grp_id = mbedtls_ecc_group_of_psa(PSA_KEY_TYPE_ECC_GET_FAMILY(type),
97 curve_bits, !explicit_bits);
98 if (grp_id == MBEDTLS_ECP_DP_NONE) {
99 /* We can't distinguish between a nonsensical family/size combination
100 * (which would warrant PSA_ERROR_INVALID_ARGUMENT) and a
101 * well-regarded curve that Mbed TLS just doesn't know about (which
102 * would warrant PSA_ERROR_NOT_SUPPORTED). For uniformity with how
103 * curves that Mbed TLS knows about but for which support is disabled
104 * at build time, return NOT_SUPPORTED. */
105 status = PSA_ERROR_NOT_SUPPORTED;
106 goto exit;
107 }
108
109 status = mbedtls_to_psa_error(
110 mbedtls_ecp_group_load(&ecp->grp, grp_id));
111 if (status != PSA_SUCCESS) {
112 goto exit;
113 }
114
115 /* Load the key material. */
116 if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) {
117 /* Load the public value. */
118 status = mbedtls_to_psa_error(
119 mbedtls_ecp_point_read_binary(&ecp->grp, &ecp->Q,
120 data,
121 data_length));
122 if (status != PSA_SUCCESS) {
123 goto exit;
124 }
125
126 /* Check that the point is on the curve. */
127 status = mbedtls_to_psa_error(
128 mbedtls_ecp_check_pubkey(&ecp->grp, &ecp->Q));
129 if (status != PSA_SUCCESS) {
130 goto exit;
131 }
132 } else {
133 /* Load and validate the secret value. */
134 status = mbedtls_to_psa_error(
135 mbedtls_ecp_read_key(ecp->grp.id,
136 ecp,
137 data,
138 data_length));
139 if (status != PSA_SUCCESS) {
140 goto exit;
141 }
142 }
143
144 *p_ecp = ecp;
145 exit:
146 if (status != PSA_SUCCESS) {
147 mbedtls_ecp_keypair_free(ecp);
148 mbedtls_free(ecp);
149 }
150
151 return status;
152 }
153 #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
154 * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
155 * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
156 * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) ||
157 * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */
158
159 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
160 defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
161
mbedtls_psa_ecp_import_key(const psa_key_attributes_t * attributes,const uint8_t * data,size_t data_length,uint8_t * key_buffer,size_t key_buffer_size,size_t * key_buffer_length,size_t * bits)162 psa_status_t mbedtls_psa_ecp_import_key(
163 const psa_key_attributes_t *attributes,
164 const uint8_t *data, size_t data_length,
165 uint8_t *key_buffer, size_t key_buffer_size,
166 size_t *key_buffer_length, size_t *bits)
167 {
168 psa_status_t status;
169 mbedtls_ecp_keypair *ecp = NULL;
170
171 /* Parse input */
172 status = mbedtls_psa_ecp_load_representation(attributes->core.type,
173 attributes->core.bits,
174 data,
175 data_length,
176 &ecp);
177 if (status != PSA_SUCCESS) {
178 goto exit;
179 }
180
181 if (PSA_KEY_TYPE_ECC_GET_FAMILY(attributes->core.type) ==
182 PSA_ECC_FAMILY_MONTGOMERY) {
183 *bits = ecp->grp.nbits + 1;
184 } else {
185 *bits = ecp->grp.nbits;
186 }
187
188 /* Re-export the data to PSA export format. There is currently no support
189 * for other input formats then the export format, so this is a 1-1
190 * copy operation. */
191 status = mbedtls_psa_ecp_export_key(attributes->core.type,
192 ecp,
193 key_buffer,
194 key_buffer_size,
195 key_buffer_length);
196 exit:
197 /* Always free the PK object (will also free contained ECP context) */
198 mbedtls_ecp_keypair_free(ecp);
199 mbedtls_free(ecp);
200
201 return status;
202 }
203
mbedtls_psa_ecp_export_key(psa_key_type_t type,mbedtls_ecp_keypair * ecp,uint8_t * data,size_t data_size,size_t * data_length)204 psa_status_t mbedtls_psa_ecp_export_key(psa_key_type_t type,
205 mbedtls_ecp_keypair *ecp,
206 uint8_t *data,
207 size_t data_size,
208 size_t *data_length)
209 {
210 psa_status_t status;
211
212 if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) {
213 /* Check whether the public part is loaded */
214 if (mbedtls_ecp_is_zero(&ecp->Q)) {
215 /* Calculate the public key */
216 status = mbedtls_to_psa_error(
217 mbedtls_ecp_mul(&ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G,
218 mbedtls_psa_get_random,
219 MBEDTLS_PSA_RANDOM_STATE));
220 if (status != PSA_SUCCESS) {
221 return status;
222 }
223 }
224
225 status = mbedtls_to_psa_error(
226 mbedtls_ecp_point_write_binary(&ecp->grp, &ecp->Q,
227 MBEDTLS_ECP_PF_UNCOMPRESSED,
228 data_length,
229 data,
230 data_size));
231 if (status != PSA_SUCCESS) {
232 memset(data, 0, data_size);
233 }
234
235 return status;
236 } else {
237 if (data_size < PSA_BITS_TO_BYTES(ecp->grp.nbits)) {
238 return PSA_ERROR_BUFFER_TOO_SMALL;
239 }
240
241 status = mbedtls_to_psa_error(
242 mbedtls_ecp_write_key(ecp,
243 data,
244 PSA_BITS_TO_BYTES(ecp->grp.nbits)));
245 if (status == PSA_SUCCESS) {
246 *data_length = PSA_BITS_TO_BYTES(ecp->grp.nbits);
247 } else {
248 memset(data, 0, data_size);
249 }
250
251 return status;
252 }
253 }
254
mbedtls_psa_ecp_export_public_key(const psa_key_attributes_t * attributes,const uint8_t * key_buffer,size_t key_buffer_size,uint8_t * data,size_t data_size,size_t * data_length)255 psa_status_t mbedtls_psa_ecp_export_public_key(
256 const psa_key_attributes_t *attributes,
257 const uint8_t *key_buffer, size_t key_buffer_size,
258 uint8_t *data, size_t data_size, size_t *data_length)
259 {
260 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
261 mbedtls_ecp_keypair *ecp = NULL;
262
263 status = mbedtls_psa_ecp_load_representation(
264 attributes->core.type, attributes->core.bits,
265 key_buffer, key_buffer_size, &ecp);
266 if (status != PSA_SUCCESS) {
267 return status;
268 }
269
270 status = mbedtls_psa_ecp_export_key(
271 PSA_KEY_TYPE_ECC_PUBLIC_KEY(
272 PSA_KEY_TYPE_ECC_GET_FAMILY(attributes->core.type)),
273 ecp, data, data_size, data_length);
274
275 mbedtls_ecp_keypair_free(ecp);
276 mbedtls_free(ecp);
277
278 return status;
279 }
280 #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
281 * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
282
283 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
mbedtls_psa_ecp_generate_key(const psa_key_attributes_t * attributes,uint8_t * key_buffer,size_t key_buffer_size,size_t * key_buffer_length)284 psa_status_t mbedtls_psa_ecp_generate_key(
285 const psa_key_attributes_t *attributes,
286 uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length)
287 {
288 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
289 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
290
291 psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
292 attributes->core.type);
293 mbedtls_ecp_group_id grp_id =
294 mbedtls_ecc_group_of_psa(curve, attributes->core.bits, 0);
295
296 const mbedtls_ecp_curve_info *curve_info =
297 mbedtls_ecp_curve_info_from_grp_id(grp_id);
298 mbedtls_ecp_keypair ecp;
299
300 if (attributes->domain_parameters_size != 0) {
301 return PSA_ERROR_NOT_SUPPORTED;
302 }
303
304 if (grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL) {
305 return PSA_ERROR_NOT_SUPPORTED;
306 }
307
308 mbedtls_ecp_keypair_init(&ecp);
309 ret = mbedtls_ecp_gen_key(grp_id, &ecp,
310 mbedtls_psa_get_random,
311 MBEDTLS_PSA_RANDOM_STATE);
312 if (ret != 0) {
313 mbedtls_ecp_keypair_free(&ecp);
314 return mbedtls_to_psa_error(ret);
315 }
316
317 status = mbedtls_to_psa_error(
318 mbedtls_ecp_write_key(&ecp, key_buffer, key_buffer_size));
319
320 mbedtls_ecp_keypair_free(&ecp);
321
322 if (status == PSA_SUCCESS) {
323 *key_buffer_length = key_buffer_size;
324 }
325
326 return status;
327 }
328 #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */
329
330 /****************************************************************/
331 /* ECDSA sign/verify */
332 /****************************************************************/
333
334 #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
335 defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
mbedtls_psa_ecdsa_sign_hash(const psa_key_attributes_t * attributes,const uint8_t * key_buffer,size_t key_buffer_size,psa_algorithm_t alg,const uint8_t * hash,size_t hash_length,uint8_t * signature,size_t signature_size,size_t * signature_length)336 psa_status_t mbedtls_psa_ecdsa_sign_hash(
337 const psa_key_attributes_t *attributes,
338 const uint8_t *key_buffer, size_t key_buffer_size,
339 psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
340 uint8_t *signature, size_t signature_size, size_t *signature_length)
341 {
342 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
343 mbedtls_ecp_keypair *ecp = NULL;
344 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
345 size_t curve_bytes;
346 mbedtls_mpi r, s;
347
348 status = mbedtls_psa_ecp_load_representation(attributes->core.type,
349 attributes->core.bits,
350 key_buffer,
351 key_buffer_size,
352 &ecp);
353 if (status != PSA_SUCCESS) {
354 return status;
355 }
356
357 curve_bytes = PSA_BITS_TO_BYTES(ecp->grp.pbits);
358 mbedtls_mpi_init(&r);
359 mbedtls_mpi_init(&s);
360
361 if (signature_size < 2 * curve_bytes) {
362 ret = MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL;
363 goto cleanup;
364 }
365
366 if (PSA_ALG_ECDSA_IS_DETERMINISTIC(alg)) {
367 #if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
368 psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH(alg);
369 mbedtls_md_type_t md_alg = mbedtls_hash_info_md_from_psa(hash_alg);
370 MBEDTLS_MPI_CHK(mbedtls_ecdsa_sign_det_ext(
371 &ecp->grp, &r, &s,
372 &ecp->d, hash,
373 hash_length, md_alg,
374 mbedtls_psa_get_random,
375 MBEDTLS_PSA_RANDOM_STATE));
376 #else
377 ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
378 goto cleanup;
379 #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
380 } else {
381 (void) alg;
382 MBEDTLS_MPI_CHK(mbedtls_ecdsa_sign(&ecp->grp, &r, &s, &ecp->d,
383 hash, hash_length,
384 mbedtls_psa_get_random,
385 MBEDTLS_PSA_RANDOM_STATE));
386 }
387
388 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&r,
389 signature,
390 curve_bytes));
391 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&s,
392 signature + curve_bytes,
393 curve_bytes));
394 cleanup:
395 mbedtls_mpi_free(&r);
396 mbedtls_mpi_free(&s);
397 if (ret == 0) {
398 *signature_length = 2 * curve_bytes;
399 }
400
401 mbedtls_ecp_keypair_free(ecp);
402 mbedtls_free(ecp);
403
404 return mbedtls_to_psa_error(ret);
405 }
406
mbedtls_psa_ecp_load_public_part(mbedtls_ecp_keypair * ecp)407 psa_status_t mbedtls_psa_ecp_load_public_part(mbedtls_ecp_keypair *ecp)
408 {
409 int ret = 0;
410
411 /* Check whether the public part is loaded. If not, load it. */
412 if (mbedtls_ecp_is_zero(&ecp->Q)) {
413 ret = mbedtls_ecp_mul(&ecp->grp, &ecp->Q,
414 &ecp->d, &ecp->grp.G,
415 mbedtls_psa_get_random,
416 MBEDTLS_PSA_RANDOM_STATE);
417 }
418
419 return mbedtls_to_psa_error(ret);
420 }
421
mbedtls_psa_ecdsa_verify_hash(const psa_key_attributes_t * attributes,const uint8_t * key_buffer,size_t key_buffer_size,psa_algorithm_t alg,const uint8_t * hash,size_t hash_length,const uint8_t * signature,size_t signature_length)422 psa_status_t mbedtls_psa_ecdsa_verify_hash(
423 const psa_key_attributes_t *attributes,
424 const uint8_t *key_buffer, size_t key_buffer_size,
425 psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
426 const uint8_t *signature, size_t signature_length)
427 {
428 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
429 mbedtls_ecp_keypair *ecp = NULL;
430 size_t curve_bytes;
431 mbedtls_mpi r, s;
432
433 (void) alg;
434
435 status = mbedtls_psa_ecp_load_representation(attributes->core.type,
436 attributes->core.bits,
437 key_buffer,
438 key_buffer_size,
439 &ecp);
440 if (status != PSA_SUCCESS) {
441 return status;
442 }
443
444 curve_bytes = PSA_BITS_TO_BYTES(ecp->grp.pbits);
445 mbedtls_mpi_init(&r);
446 mbedtls_mpi_init(&s);
447
448 if (signature_length != 2 * curve_bytes) {
449 status = PSA_ERROR_INVALID_SIGNATURE;
450 goto cleanup;
451 }
452
453 status = mbedtls_to_psa_error(mbedtls_mpi_read_binary(&r,
454 signature,
455 curve_bytes));
456 if (status != PSA_SUCCESS) {
457 goto cleanup;
458 }
459
460 status = mbedtls_to_psa_error(mbedtls_mpi_read_binary(&s,
461 signature + curve_bytes,
462 curve_bytes));
463 if (status != PSA_SUCCESS) {
464 goto cleanup;
465 }
466
467 status = mbedtls_psa_ecp_load_public_part(ecp);
468 if (status != PSA_SUCCESS) {
469 goto cleanup;
470 }
471
472 status = mbedtls_to_psa_error(mbedtls_ecdsa_verify(&ecp->grp, hash,
473 hash_length, &ecp->Q,
474 &r, &s));
475 cleanup:
476 mbedtls_mpi_free(&r);
477 mbedtls_mpi_free(&s);
478 mbedtls_ecp_keypair_free(ecp);
479 mbedtls_free(ecp);
480
481 return status;
482 }
483
484 #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
485 * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
486
487 /****************************************************************/
488 /* ECDH Key Agreement */
489 /****************************************************************/
490
491 #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
mbedtls_psa_key_agreement_ecdh(const psa_key_attributes_t * attributes,const uint8_t * key_buffer,size_t key_buffer_size,psa_algorithm_t alg,const uint8_t * peer_key,size_t peer_key_length,uint8_t * shared_secret,size_t shared_secret_size,size_t * shared_secret_length)492 psa_status_t mbedtls_psa_key_agreement_ecdh(
493 const psa_key_attributes_t *attributes,
494 const uint8_t *key_buffer, size_t key_buffer_size,
495 psa_algorithm_t alg, const uint8_t *peer_key, size_t peer_key_length,
496 uint8_t *shared_secret, size_t shared_secret_size,
497 size_t *shared_secret_length)
498 {
499 psa_status_t status;
500 if (!PSA_KEY_TYPE_IS_ECC_KEY_PAIR(attributes->core.type) ||
501 !PSA_ALG_IS_ECDH(alg)) {
502 return PSA_ERROR_INVALID_ARGUMENT;
503 }
504 mbedtls_ecp_keypair *ecp = NULL;
505 status = mbedtls_psa_ecp_load_representation(
506 attributes->core.type,
507 attributes->core.bits,
508 key_buffer,
509 key_buffer_size,
510 &ecp);
511 if (status != PSA_SUCCESS) {
512 return status;
513 }
514 mbedtls_ecp_keypair *their_key = NULL;
515 mbedtls_ecdh_context ecdh;
516 size_t bits = 0;
517 psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(ecp->grp.id, &bits);
518 mbedtls_ecdh_init(&ecdh);
519
520 status = mbedtls_psa_ecp_load_representation(
521 PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve),
522 bits,
523 peer_key,
524 peer_key_length,
525 &their_key);
526 if (status != PSA_SUCCESS) {
527 goto exit;
528 }
529
530 status = mbedtls_to_psa_error(
531 mbedtls_ecdh_get_params(&ecdh, their_key, MBEDTLS_ECDH_THEIRS));
532 if (status != PSA_SUCCESS) {
533 goto exit;
534 }
535 status = mbedtls_to_psa_error(
536 mbedtls_ecdh_get_params(&ecdh, ecp, MBEDTLS_ECDH_OURS));
537 if (status != PSA_SUCCESS) {
538 goto exit;
539 }
540
541 status = mbedtls_to_psa_error(
542 mbedtls_ecdh_calc_secret(&ecdh,
543 shared_secret_length,
544 shared_secret, shared_secret_size,
545 mbedtls_psa_get_random,
546 MBEDTLS_PSA_RANDOM_STATE));
547 if (status != PSA_SUCCESS) {
548 goto exit;
549 }
550 if (PSA_BITS_TO_BYTES(bits) != *shared_secret_length) {
551 status = PSA_ERROR_CORRUPTION_DETECTED;
552 }
553 exit:
554 if (status != PSA_SUCCESS) {
555 mbedtls_platform_zeroize(shared_secret, shared_secret_size);
556 }
557 mbedtls_ecdh_free(&ecdh);
558 mbedtls_ecp_keypair_free(their_key);
559 mbedtls_free(their_key);
560 mbedtls_ecp_keypair_free(ecp);
561 mbedtls_free(ecp);
562 return status;
563 }
564 #endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
565
566
567 #endif /* MBEDTLS_PSA_CRYPTO_C */
568
