1 /**
2 * \file cipher.c
3 *
4 * \brief Generic cipher wrapper for mbed TLS
5 *
6 * \author Adriaan de Jong <dejong@fox-it.com>
7 *
8 * Copyright The Mbed TLS Contributors
9 * SPDX-License-Identifier: Apache-2.0
10 *
11 * Licensed under the Apache License, Version 2.0 (the "License"); you may
12 * not use this file except in compliance with the License.
13 * You may obtain a copy of the License at
14 *
15 * http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing, software
18 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
19 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20 * See the License for the specific language governing permissions and
21 * limitations under the License.
22 */
23
24 #include "common.h"
25
26 #if defined(MBEDTLS_CIPHER_C)
27
28 #include "mbedtls/cipher.h"
29 #include "cipher_wrap.h"
30 #include "mbedtls/platform_util.h"
31 #include "mbedtls/error.h"
32 #include "mbedtls/constant_time.h"
33
34 #include <stdlib.h>
35 #include <string.h>
36
37 #if defined(MBEDTLS_CHACHAPOLY_C)
38 #include "mbedtls/chachapoly.h"
39 #endif
40
41 #if defined(MBEDTLS_GCM_C)
42 #include "mbedtls/gcm.h"
43 #endif
44
45 #if defined(MBEDTLS_CCM_C)
46 #include "mbedtls/ccm.h"
47 #endif
48
49 #if defined(MBEDTLS_CHACHA20_C)
50 #include "mbedtls/chacha20.h"
51 #endif
52
53 #if defined(MBEDTLS_CMAC_C)
54 #include "mbedtls/cmac.h"
55 #endif
56
57 #if defined(MBEDTLS_USE_PSA_CRYPTO)
58 #include "psa/crypto.h"
59 #include "mbedtls/psa_util.h"
60 #endif /* MBEDTLS_USE_PSA_CRYPTO */
61
62 #if defined(MBEDTLS_NIST_KW_C)
63 #include "mbedtls/nist_kw.h"
64 #endif
65
66 #include "mbedtls/platform.h"
67
68 static int supported_init = 0;
69
mbedtls_cipher_list(void)70 const int *mbedtls_cipher_list(void)
71 {
72 const mbedtls_cipher_definition_t *def;
73 int *type;
74
75 if (!supported_init) {
76 def = mbedtls_cipher_definitions;
77 type = mbedtls_cipher_supported;
78
79 while (def->type != 0) {
80 *type++ = (*def++).type;
81 }
82
83 *type = 0;
84
85 supported_init = 1;
86 }
87
88 return mbedtls_cipher_supported;
89 }
90
mbedtls_cipher_info_from_type(const mbedtls_cipher_type_t cipher_type)91 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(
92 const mbedtls_cipher_type_t cipher_type)
93 {
94 const mbedtls_cipher_definition_t *def;
95
96 for (def = mbedtls_cipher_definitions; def->info != NULL; def++) {
97 if (def->type == cipher_type) {
98 return def->info;
99 }
100 }
101
102 return NULL;
103 }
104
mbedtls_cipher_info_from_string(const char * cipher_name)105 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(
106 const char *cipher_name)
107 {
108 const mbedtls_cipher_definition_t *def;
109
110 if (NULL == cipher_name) {
111 return NULL;
112 }
113
114 for (def = mbedtls_cipher_definitions; def->info != NULL; def++) {
115 if (!strcmp(def->info->name, cipher_name)) {
116 return def->info;
117 }
118 }
119
120 return NULL;
121 }
122
mbedtls_cipher_info_from_values(const mbedtls_cipher_id_t cipher_id,int key_bitlen,const mbedtls_cipher_mode_t mode)123 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(
124 const mbedtls_cipher_id_t cipher_id,
125 int key_bitlen,
126 const mbedtls_cipher_mode_t mode)
127 {
128 const mbedtls_cipher_definition_t *def;
129
130 for (def = mbedtls_cipher_definitions; def->info != NULL; def++) {
131 if (def->info->base->cipher == cipher_id &&
132 def->info->key_bitlen == (unsigned) key_bitlen &&
133 def->info->mode == mode) {
134 return def->info;
135 }
136 }
137
138 return NULL;
139 }
140
mbedtls_cipher_init(mbedtls_cipher_context_t * ctx)141 void mbedtls_cipher_init(mbedtls_cipher_context_t *ctx)
142 {
143 memset(ctx, 0, sizeof(mbedtls_cipher_context_t));
144 }
145
mbedtls_cipher_free(mbedtls_cipher_context_t * ctx)146 void mbedtls_cipher_free(mbedtls_cipher_context_t *ctx)
147 {
148 if (ctx == NULL) {
149 return;
150 }
151
152 #if defined(MBEDTLS_USE_PSA_CRYPTO)
153 if (ctx->psa_enabled == 1) {
154 if (ctx->cipher_ctx != NULL) {
155 mbedtls_cipher_context_psa * const cipher_psa =
156 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
157
158 if (cipher_psa->slot_state == MBEDTLS_CIPHER_PSA_KEY_OWNED) {
159 /* xxx_free() doesn't allow to return failures. */
160 (void) psa_destroy_key(cipher_psa->slot);
161 }
162
163 mbedtls_platform_zeroize(cipher_psa, sizeof(*cipher_psa));
164 mbedtls_free(cipher_psa);
165 }
166
167 mbedtls_platform_zeroize(ctx, sizeof(mbedtls_cipher_context_t));
168 return;
169 }
170 #endif /* MBEDTLS_USE_PSA_CRYPTO */
171
172 #if defined(MBEDTLS_CMAC_C)
173 if (ctx->cmac_ctx) {
174 mbedtls_platform_zeroize(ctx->cmac_ctx,
175 sizeof(mbedtls_cmac_context_t));
176 mbedtls_free(ctx->cmac_ctx);
177 }
178 #endif
179
180 if (ctx->cipher_ctx) {
181 ctx->cipher_info->base->ctx_free_func(ctx->cipher_ctx);
182 }
183
184 mbedtls_platform_zeroize(ctx, sizeof(mbedtls_cipher_context_t));
185 }
186
mbedtls_cipher_setup(mbedtls_cipher_context_t * ctx,const mbedtls_cipher_info_t * cipher_info)187 int mbedtls_cipher_setup(mbedtls_cipher_context_t *ctx,
188 const mbedtls_cipher_info_t *cipher_info)
189 {
190 if (cipher_info == NULL) {
191 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
192 }
193
194 memset(ctx, 0, sizeof(mbedtls_cipher_context_t));
195
196 if (NULL == (ctx->cipher_ctx = cipher_info->base->ctx_alloc_func())) {
197 return MBEDTLS_ERR_CIPHER_ALLOC_FAILED;
198 }
199
200 ctx->cipher_info = cipher_info;
201
202 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
203 /*
204 * Ignore possible errors caused by a cipher mode that doesn't use padding
205 */
206 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
207 (void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_PKCS7);
208 #else
209 (void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_NONE);
210 #endif
211 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
212
213 return 0;
214 }
215
216 #if defined(MBEDTLS_USE_PSA_CRYPTO)
217 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
mbedtls_cipher_setup_psa(mbedtls_cipher_context_t * ctx,const mbedtls_cipher_info_t * cipher_info,size_t taglen)218 int mbedtls_cipher_setup_psa(mbedtls_cipher_context_t *ctx,
219 const mbedtls_cipher_info_t *cipher_info,
220 size_t taglen)
221 {
222 psa_algorithm_t alg;
223 mbedtls_cipher_context_psa *cipher_psa;
224
225 if (NULL == cipher_info || NULL == ctx) {
226 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
227 }
228
229 /* Check that the underlying cipher mode and cipher type are
230 * supported by the underlying PSA Crypto implementation. */
231 alg = mbedtls_psa_translate_cipher_mode(cipher_info->mode, taglen);
232 if (alg == 0) {
233 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
234 }
235 if (mbedtls_psa_translate_cipher_type(cipher_info->type) == 0) {
236 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
237 }
238
239 memset(ctx, 0, sizeof(mbedtls_cipher_context_t));
240
241 cipher_psa = mbedtls_calloc(1, sizeof(mbedtls_cipher_context_psa));
242 if (cipher_psa == NULL) {
243 return MBEDTLS_ERR_CIPHER_ALLOC_FAILED;
244 }
245 cipher_psa->alg = alg;
246 ctx->cipher_ctx = cipher_psa;
247 ctx->cipher_info = cipher_info;
248 ctx->psa_enabled = 1;
249 return 0;
250 }
251 #endif /* MBEDTLS_DEPRECATED_REMOVED */
252 #endif /* MBEDTLS_USE_PSA_CRYPTO */
253
mbedtls_cipher_setkey(mbedtls_cipher_context_t * ctx,const unsigned char * key,int key_bitlen,const mbedtls_operation_t operation)254 int mbedtls_cipher_setkey(mbedtls_cipher_context_t *ctx,
255 const unsigned char *key,
256 int key_bitlen,
257 const mbedtls_operation_t operation)
258 {
259 if (operation != MBEDTLS_ENCRYPT && operation != MBEDTLS_DECRYPT) {
260 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
261 }
262 if (ctx->cipher_info == NULL) {
263 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
264 }
265
266 #if defined(MBEDTLS_USE_PSA_CRYPTO)
267 if (ctx->psa_enabled == 1) {
268 mbedtls_cipher_context_psa * const cipher_psa =
269 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
270
271 size_t const key_bytelen = ((size_t) key_bitlen + 7) / 8;
272
273 psa_status_t status;
274 psa_key_type_t key_type;
275 psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
276
277 /* PSA Crypto API only accepts byte-aligned keys. */
278 if (key_bitlen % 8 != 0) {
279 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
280 }
281
282 /* Don't allow keys to be set multiple times. */
283 if (cipher_psa->slot_state != MBEDTLS_CIPHER_PSA_KEY_UNSET) {
284 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
285 }
286
287 key_type = mbedtls_psa_translate_cipher_type(
288 ctx->cipher_info->type);
289 if (key_type == 0) {
290 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
291 }
292 psa_set_key_type(&attributes, key_type);
293
294 /* Mbed TLS' cipher layer doesn't enforce the mode of operation
295 * (encrypt vs. decrypt): it is possible to setup a key for encryption
296 * and use it for AEAD decryption. Until tests relying on this
297 * are changed, allow any usage in PSA. */
298 psa_set_key_usage_flags(&attributes,
299 /* mbedtls_psa_translate_cipher_operation( operation ); */
300 PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT);
301 psa_set_key_algorithm(&attributes, cipher_psa->alg);
302
303 status = psa_import_key(&attributes, key, key_bytelen,
304 &cipher_psa->slot);
305 switch (status) {
306 case PSA_SUCCESS:
307 break;
308 case PSA_ERROR_INSUFFICIENT_MEMORY:
309 return MBEDTLS_ERR_CIPHER_ALLOC_FAILED;
310 case PSA_ERROR_NOT_SUPPORTED:
311 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
312 default:
313 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
314 }
315 /* Indicate that we own the key slot and need to
316 * destroy it in mbedtls_cipher_free(). */
317 cipher_psa->slot_state = MBEDTLS_CIPHER_PSA_KEY_OWNED;
318
319 ctx->key_bitlen = key_bitlen;
320 ctx->operation = operation;
321 return 0;
322 }
323 #endif /* MBEDTLS_USE_PSA_CRYPTO */
324
325 if ((ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN) == 0 &&
326 (int) ctx->cipher_info->key_bitlen != key_bitlen) {
327 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
328 }
329
330 ctx->key_bitlen = key_bitlen;
331 ctx->operation = operation;
332
333 /*
334 * For OFB, CFB and CTR mode always use the encryption key schedule
335 */
336 if (MBEDTLS_ENCRYPT == operation ||
337 MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
338 MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
339 MBEDTLS_MODE_CTR == ctx->cipher_info->mode) {
340 return ctx->cipher_info->base->setkey_enc_func(ctx->cipher_ctx, key,
341 ctx->key_bitlen);
342 }
343
344 if (MBEDTLS_DECRYPT == operation) {
345 return ctx->cipher_info->base->setkey_dec_func(ctx->cipher_ctx, key,
346 ctx->key_bitlen);
347 }
348
349 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
350 }
351
mbedtls_cipher_set_iv(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len)352 int mbedtls_cipher_set_iv(mbedtls_cipher_context_t *ctx,
353 const unsigned char *iv,
354 size_t iv_len)
355 {
356 size_t actual_iv_size;
357
358 if (ctx->cipher_info == NULL) {
359 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
360 }
361 #if defined(MBEDTLS_USE_PSA_CRYPTO)
362 if (ctx->psa_enabled == 1) {
363 /* While PSA Crypto has an API for multipart
364 * operations, we currently don't make it
365 * accessible through the cipher layer. */
366 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
367 }
368 #endif /* MBEDTLS_USE_PSA_CRYPTO */
369
370 /* avoid buffer overflow in ctx->iv */
371 if (iv_len > MBEDTLS_MAX_IV_LENGTH) {
372 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
373 }
374
375 if ((ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_IV_LEN) != 0) {
376 actual_iv_size = iv_len;
377 } else {
378 actual_iv_size = ctx->cipher_info->iv_size;
379
380 /* avoid reading past the end of input buffer */
381 if (actual_iv_size > iv_len) {
382 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
383 }
384 }
385
386 #if defined(MBEDTLS_CHACHA20_C)
387 if (ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20) {
388 /* Even though the actual_iv_size is overwritten with a correct value
389 * of 12 from the cipher info, return an error to indicate that
390 * the input iv_len is wrong. */
391 if (iv_len != 12) {
392 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
393 }
394
395 if (0 != mbedtls_chacha20_starts((mbedtls_chacha20_context *) ctx->cipher_ctx,
396 iv,
397 0U)) { /* Initial counter value */
398 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
399 }
400 }
401 #if defined(MBEDTLS_CHACHAPOLY_C)
402 if (ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 &&
403 iv_len != 12) {
404 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
405 }
406 #endif
407 #endif
408
409 #if defined(MBEDTLS_GCM_C)
410 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
411 return mbedtls_gcm_starts((mbedtls_gcm_context *) ctx->cipher_ctx,
412 ctx->operation,
413 iv, iv_len);
414 }
415 #endif
416
417 #if defined(MBEDTLS_CCM_C)
418 if (MBEDTLS_MODE_CCM_STAR_NO_TAG == ctx->cipher_info->mode) {
419 int set_lengths_result;
420 int ccm_star_mode;
421
422 set_lengths_result = mbedtls_ccm_set_lengths(
423 (mbedtls_ccm_context *) ctx->cipher_ctx,
424 0, 0, 0);
425 if (set_lengths_result != 0) {
426 return set_lengths_result;
427 }
428
429 if (ctx->operation == MBEDTLS_DECRYPT) {
430 ccm_star_mode = MBEDTLS_CCM_STAR_DECRYPT;
431 } else if (ctx->operation == MBEDTLS_ENCRYPT) {
432 ccm_star_mode = MBEDTLS_CCM_STAR_ENCRYPT;
433 } else {
434 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
435 }
436
437 return mbedtls_ccm_starts((mbedtls_ccm_context *) ctx->cipher_ctx,
438 ccm_star_mode,
439 iv, iv_len);
440 }
441 #endif
442
443 if (actual_iv_size != 0) {
444 memcpy(ctx->iv, iv, actual_iv_size);
445 ctx->iv_size = actual_iv_size;
446 }
447
448 return 0;
449 }
450
mbedtls_cipher_reset(mbedtls_cipher_context_t * ctx)451 int mbedtls_cipher_reset(mbedtls_cipher_context_t *ctx)
452 {
453 if (ctx->cipher_info == NULL) {
454 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
455 }
456
457 #if defined(MBEDTLS_USE_PSA_CRYPTO)
458 if (ctx->psa_enabled == 1) {
459 /* We don't support resetting PSA-based
460 * cipher contexts, yet. */
461 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
462 }
463 #endif /* MBEDTLS_USE_PSA_CRYPTO */
464
465 ctx->unprocessed_len = 0;
466
467 return 0;
468 }
469
470 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
mbedtls_cipher_update_ad(mbedtls_cipher_context_t * ctx,const unsigned char * ad,size_t ad_len)471 int mbedtls_cipher_update_ad(mbedtls_cipher_context_t *ctx,
472 const unsigned char *ad, size_t ad_len)
473 {
474 if (ctx->cipher_info == NULL) {
475 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
476 }
477
478 #if defined(MBEDTLS_USE_PSA_CRYPTO)
479 if (ctx->psa_enabled == 1) {
480 /* While PSA Crypto has an API for multipart
481 * operations, we currently don't make it
482 * accessible through the cipher layer. */
483 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
484 }
485 #endif /* MBEDTLS_USE_PSA_CRYPTO */
486
487 #if defined(MBEDTLS_GCM_C)
488 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
489 return mbedtls_gcm_update_ad((mbedtls_gcm_context *) ctx->cipher_ctx,
490 ad, ad_len);
491 }
492 #endif
493
494 #if defined(MBEDTLS_CHACHAPOLY_C)
495 if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
496 int result;
497 mbedtls_chachapoly_mode_t mode;
498
499 mode = (ctx->operation == MBEDTLS_ENCRYPT)
500 ? MBEDTLS_CHACHAPOLY_ENCRYPT
501 : MBEDTLS_CHACHAPOLY_DECRYPT;
502
503 result = mbedtls_chachapoly_starts((mbedtls_chachapoly_context *) ctx->cipher_ctx,
504 ctx->iv,
505 mode);
506 if (result != 0) {
507 return result;
508 }
509
510 return mbedtls_chachapoly_update_aad((mbedtls_chachapoly_context *) ctx->cipher_ctx,
511 ad, ad_len);
512 }
513 #endif
514
515 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
516 }
517 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
518
mbedtls_cipher_update(mbedtls_cipher_context_t * ctx,const unsigned char * input,size_t ilen,unsigned char * output,size_t * olen)519 int mbedtls_cipher_update(mbedtls_cipher_context_t *ctx, const unsigned char *input,
520 size_t ilen, unsigned char *output, size_t *olen)
521 {
522 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
523 size_t block_size;
524
525 if (ctx->cipher_info == NULL) {
526 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
527 }
528
529 #if defined(MBEDTLS_USE_PSA_CRYPTO)
530 if (ctx->psa_enabled == 1) {
531 /* While PSA Crypto has an API for multipart
532 * operations, we currently don't make it
533 * accessible through the cipher layer. */
534 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
535 }
536 #endif /* MBEDTLS_USE_PSA_CRYPTO */
537
538 *olen = 0;
539 block_size = mbedtls_cipher_get_block_size(ctx);
540 if (0 == block_size) {
541 return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
542 }
543
544 if (ctx->cipher_info->mode == MBEDTLS_MODE_ECB) {
545 if (ilen != block_size) {
546 return MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED;
547 }
548
549 *olen = ilen;
550
551 if (0 != (ret = ctx->cipher_info->base->ecb_func(ctx->cipher_ctx,
552 ctx->operation, input, output))) {
553 return ret;
554 }
555
556 return 0;
557 }
558
559 #if defined(MBEDTLS_GCM_C)
560 if (ctx->cipher_info->mode == MBEDTLS_MODE_GCM) {
561 return mbedtls_gcm_update((mbedtls_gcm_context *) ctx->cipher_ctx,
562 input, ilen,
563 output, ilen, olen);
564 }
565 #endif
566
567 #if defined(MBEDTLS_CCM_C)
568 if (ctx->cipher_info->mode == MBEDTLS_MODE_CCM_STAR_NO_TAG) {
569 return mbedtls_ccm_update((mbedtls_ccm_context *) ctx->cipher_ctx,
570 input, ilen,
571 output, ilen, olen);
572 }
573 #endif
574
575 #if defined(MBEDTLS_CHACHAPOLY_C)
576 if (ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305) {
577 *olen = ilen;
578 return mbedtls_chachapoly_update((mbedtls_chachapoly_context *) ctx->cipher_ctx,
579 ilen, input, output);
580 }
581 #endif
582
583 if (input == output &&
584 (ctx->unprocessed_len != 0 || ilen % block_size)) {
585 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
586 }
587
588 #if defined(MBEDTLS_CIPHER_MODE_CBC)
589 if (ctx->cipher_info->mode == MBEDTLS_MODE_CBC) {
590 size_t copy_len = 0;
591
592 /*
593 * If there is not enough data for a full block, cache it.
594 */
595 if ((ctx->operation == MBEDTLS_DECRYPT && NULL != ctx->add_padding &&
596 ilen <= block_size - ctx->unprocessed_len) ||
597 (ctx->operation == MBEDTLS_DECRYPT && NULL == ctx->add_padding &&
598 ilen < block_size - ctx->unprocessed_len) ||
599 (ctx->operation == MBEDTLS_ENCRYPT &&
600 ilen < block_size - ctx->unprocessed_len)) {
601 memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]), input,
602 ilen);
603
604 ctx->unprocessed_len += ilen;
605 return 0;
606 }
607
608 /*
609 * Process cached data first
610 */
611 if (0 != ctx->unprocessed_len) {
612 copy_len = block_size - ctx->unprocessed_len;
613
614 memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]), input,
615 copy_len);
616
617 if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
618 ctx->operation, block_size, ctx->iv,
619 ctx->unprocessed_data, output))) {
620 return ret;
621 }
622
623 *olen += block_size;
624 output += block_size;
625 ctx->unprocessed_len = 0;
626
627 input += copy_len;
628 ilen -= copy_len;
629 }
630
631 /*
632 * Cache final, incomplete block
633 */
634 if (0 != ilen) {
635 /* Encryption: only cache partial blocks
636 * Decryption w/ padding: always keep at least one whole block
637 * Decryption w/o padding: only cache partial blocks
638 */
639 copy_len = ilen % block_size;
640 if (copy_len == 0 &&
641 ctx->operation == MBEDTLS_DECRYPT &&
642 NULL != ctx->add_padding) {
643 copy_len = block_size;
644 }
645
646 memcpy(ctx->unprocessed_data, &(input[ilen - copy_len]),
647 copy_len);
648
649 ctx->unprocessed_len += copy_len;
650 ilen -= copy_len;
651 }
652
653 /*
654 * Process remaining full blocks
655 */
656 if (ilen) {
657 if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
658 ctx->operation, ilen, ctx->iv, input,
659 output))) {
660 return ret;
661 }
662
663 *olen += ilen;
664 }
665
666 return 0;
667 }
668 #endif /* MBEDTLS_CIPHER_MODE_CBC */
669
670 #if defined(MBEDTLS_CIPHER_MODE_CFB)
671 if (ctx->cipher_info->mode == MBEDTLS_MODE_CFB) {
672 if (0 != (ret = ctx->cipher_info->base->cfb_func(ctx->cipher_ctx,
673 ctx->operation, ilen,
674 &ctx->unprocessed_len, ctx->iv,
675 input, output))) {
676 return ret;
677 }
678
679 *olen = ilen;
680
681 return 0;
682 }
683 #endif /* MBEDTLS_CIPHER_MODE_CFB */
684
685 #if defined(MBEDTLS_CIPHER_MODE_OFB)
686 if (ctx->cipher_info->mode == MBEDTLS_MODE_OFB) {
687 if (0 != (ret = ctx->cipher_info->base->ofb_func(ctx->cipher_ctx,
688 ilen, &ctx->unprocessed_len, ctx->iv,
689 input, output))) {
690 return ret;
691 }
692
693 *olen = ilen;
694
695 return 0;
696 }
697 #endif /* MBEDTLS_CIPHER_MODE_OFB */
698
699 #if defined(MBEDTLS_CIPHER_MODE_CTR)
700 if (ctx->cipher_info->mode == MBEDTLS_MODE_CTR) {
701 if (0 != (ret = ctx->cipher_info->base->ctr_func(ctx->cipher_ctx,
702 ilen, &ctx->unprocessed_len, ctx->iv,
703 ctx->unprocessed_data, input, output))) {
704 return ret;
705 }
706
707 *olen = ilen;
708
709 return 0;
710 }
711 #endif /* MBEDTLS_CIPHER_MODE_CTR */
712
713 #if defined(MBEDTLS_CIPHER_MODE_XTS)
714 if (ctx->cipher_info->mode == MBEDTLS_MODE_XTS) {
715 if (ctx->unprocessed_len > 0) {
716 /* We can only process an entire data unit at a time. */
717 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
718 }
719
720 ret = ctx->cipher_info->base->xts_func(ctx->cipher_ctx,
721 ctx->operation, ilen, ctx->iv, input, output);
722 if (ret != 0) {
723 return ret;
724 }
725
726 *olen = ilen;
727
728 return 0;
729 }
730 #endif /* MBEDTLS_CIPHER_MODE_XTS */
731
732 #if defined(MBEDTLS_CIPHER_MODE_STREAM)
733 if (ctx->cipher_info->mode == MBEDTLS_MODE_STREAM) {
734 if (0 != (ret = ctx->cipher_info->base->stream_func(ctx->cipher_ctx,
735 ilen, input, output))) {
736 return ret;
737 }
738
739 *olen = ilen;
740
741 return 0;
742 }
743 #endif /* MBEDTLS_CIPHER_MODE_STREAM */
744
745 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
746 }
747
748 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
749 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
750 /*
751 * PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len
752 */
add_pkcs_padding(unsigned char * output,size_t output_len,size_t data_len)753 static void add_pkcs_padding(unsigned char *output, size_t output_len,
754 size_t data_len)
755 {
756 size_t padding_len = output_len - data_len;
757 unsigned char i;
758
759 for (i = 0; i < padding_len; i++) {
760 output[data_len + i] = (unsigned char) padding_len;
761 }
762 }
763
get_pkcs_padding(unsigned char * input,size_t input_len,size_t * data_len)764 static int get_pkcs_padding(unsigned char *input, size_t input_len,
765 size_t *data_len)
766 {
767 size_t i, pad_idx;
768 unsigned char padding_len, bad = 0;
769
770 if (NULL == input || NULL == data_len) {
771 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
772 }
773
774 padding_len = input[input_len - 1];
775 *data_len = input_len - padding_len;
776
777 /* Avoid logical || since it results in a branch */
778 bad |= padding_len > input_len;
779 bad |= padding_len == 0;
780
781 /* The number of bytes checked must be independent of padding_len,
782 * so pick input_len, which is usually 8 or 16 (one block) */
783 pad_idx = input_len - padding_len;
784 for (i = 0; i < input_len; i++) {
785 bad |= (input[i] ^ padding_len) * (i >= pad_idx);
786 }
787
788 return MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0);
789 }
790 #endif /* MBEDTLS_CIPHER_PADDING_PKCS7 */
791
792 #if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
793 /*
794 * One and zeros padding: fill with 80 00 ... 00
795 */
add_one_and_zeros_padding(unsigned char * output,size_t output_len,size_t data_len)796 static void add_one_and_zeros_padding(unsigned char *output,
797 size_t output_len, size_t data_len)
798 {
799 size_t padding_len = output_len - data_len;
800 unsigned char i = 0;
801
802 output[data_len] = 0x80;
803 for (i = 1; i < padding_len; i++) {
804 output[data_len + i] = 0x00;
805 }
806 }
807
get_one_and_zeros_padding(unsigned char * input,size_t input_len,size_t * data_len)808 static int get_one_and_zeros_padding(unsigned char *input, size_t input_len,
809 size_t *data_len)
810 {
811 size_t i;
812 unsigned char done = 0, prev_done, bad;
813
814 if (NULL == input || NULL == data_len) {
815 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
816 }
817
818 bad = 0x80;
819 *data_len = 0;
820 for (i = input_len; i > 0; i--) {
821 prev_done = done;
822 done |= (input[i - 1] != 0);
823 *data_len |= (i - 1) * (done != prev_done);
824 bad ^= input[i - 1] * (done != prev_done);
825 }
826
827 return MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0);
828
829 }
830 #endif /* MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS */
831
832 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
833 /*
834 * Zeros and len padding: fill with 00 ... 00 ll, where ll is padding length
835 */
add_zeros_and_len_padding(unsigned char * output,size_t output_len,size_t data_len)836 static void add_zeros_and_len_padding(unsigned char *output,
837 size_t output_len, size_t data_len)
838 {
839 size_t padding_len = output_len - data_len;
840 unsigned char i = 0;
841
842 for (i = 1; i < padding_len; i++) {
843 output[data_len + i - 1] = 0x00;
844 }
845 output[output_len - 1] = (unsigned char) padding_len;
846 }
847
get_zeros_and_len_padding(unsigned char * input,size_t input_len,size_t * data_len)848 static int get_zeros_and_len_padding(unsigned char *input, size_t input_len,
849 size_t *data_len)
850 {
851 size_t i, pad_idx;
852 unsigned char padding_len, bad = 0;
853
854 if (NULL == input || NULL == data_len) {
855 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
856 }
857
858 padding_len = input[input_len - 1];
859 *data_len = input_len - padding_len;
860
861 /* Avoid logical || since it results in a branch */
862 bad |= padding_len > input_len;
863 bad |= padding_len == 0;
864
865 /* The number of bytes checked must be independent of padding_len */
866 pad_idx = input_len - padding_len;
867 for (i = 0; i < input_len - 1; i++) {
868 bad |= input[i] * (i >= pad_idx);
869 }
870
871 return MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0);
872 }
873 #endif /* MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN */
874
875 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
876 /*
877 * Zero padding: fill with 00 ... 00
878 */
add_zeros_padding(unsigned char * output,size_t output_len,size_t data_len)879 static void add_zeros_padding(unsigned char *output,
880 size_t output_len, size_t data_len)
881 {
882 size_t i;
883
884 for (i = data_len; i < output_len; i++) {
885 output[i] = 0x00;
886 }
887 }
888
get_zeros_padding(unsigned char * input,size_t input_len,size_t * data_len)889 static int get_zeros_padding(unsigned char *input, size_t input_len,
890 size_t *data_len)
891 {
892 size_t i;
893 unsigned char done = 0, prev_done;
894
895 if (NULL == input || NULL == data_len) {
896 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
897 }
898
899 *data_len = 0;
900 for (i = input_len; i > 0; i--) {
901 prev_done = done;
902 done |= (input[i-1] != 0);
903 *data_len |= i * (done != prev_done);
904 }
905
906 return 0;
907 }
908 #endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
909
910 /*
911 * No padding: don't pad :)
912 *
913 * There is no add_padding function (check for NULL in mbedtls_cipher_finish)
914 * but a trivial get_padding function
915 */
get_no_padding(unsigned char * input,size_t input_len,size_t * data_len)916 static int get_no_padding(unsigned char *input, size_t input_len,
917 size_t *data_len)
918 {
919 if (NULL == input || NULL == data_len) {
920 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
921 }
922
923 *data_len = input_len;
924
925 return 0;
926 }
927 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
928
mbedtls_cipher_finish(mbedtls_cipher_context_t * ctx,unsigned char * output,size_t * olen)929 int mbedtls_cipher_finish(mbedtls_cipher_context_t *ctx,
930 unsigned char *output, size_t *olen)
931 {
932 if (ctx->cipher_info == NULL) {
933 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
934 }
935
936 #if defined(MBEDTLS_USE_PSA_CRYPTO)
937 if (ctx->psa_enabled == 1) {
938 /* While PSA Crypto has an API for multipart
939 * operations, we currently don't make it
940 * accessible through the cipher layer. */
941 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
942 }
943 #endif /* MBEDTLS_USE_PSA_CRYPTO */
944
945 *olen = 0;
946
947 if (MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
948 MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
949 MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
950 MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
951 MBEDTLS_MODE_CCM_STAR_NO_TAG == ctx->cipher_info->mode ||
952 MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
953 MBEDTLS_MODE_STREAM == ctx->cipher_info->mode) {
954 return 0;
955 }
956
957 if ((MBEDTLS_CIPHER_CHACHA20 == ctx->cipher_info->type) ||
958 (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type)) {
959 return 0;
960 }
961
962 if (MBEDTLS_MODE_ECB == ctx->cipher_info->mode) {
963 if (ctx->unprocessed_len != 0) {
964 return MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED;
965 }
966
967 return 0;
968 }
969
970 #if defined(MBEDTLS_CIPHER_MODE_CBC)
971 if (MBEDTLS_MODE_CBC == ctx->cipher_info->mode) {
972 int ret = 0;
973
974 if (MBEDTLS_ENCRYPT == ctx->operation) {
975 /* check for 'no padding' mode */
976 if (NULL == ctx->add_padding) {
977 if (0 != ctx->unprocessed_len) {
978 return MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED;
979 }
980
981 return 0;
982 }
983
984 ctx->add_padding(ctx->unprocessed_data, mbedtls_cipher_get_iv_size(ctx),
985 ctx->unprocessed_len);
986 } else if (mbedtls_cipher_get_block_size(ctx) != ctx->unprocessed_len) {
987 /*
988 * For decrypt operations, expect a full block,
989 * or an empty block if no padding
990 */
991 if (NULL == ctx->add_padding && 0 == ctx->unprocessed_len) {
992 return 0;
993 }
994
995 return MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED;
996 }
997
998 /* cipher block */
999 if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
1000 ctx->operation,
1001 mbedtls_cipher_get_block_size(ctx),
1002 ctx->iv,
1003 ctx->unprocessed_data, output))) {
1004 return ret;
1005 }
1006
1007 /* Set output size for decryption */
1008 if (MBEDTLS_DECRYPT == ctx->operation) {
1009 return ctx->get_padding(output, mbedtls_cipher_get_block_size(ctx),
1010 olen);
1011 }
1012
1013 /* Set output size for encryption */
1014 *olen = mbedtls_cipher_get_block_size(ctx);
1015 return 0;
1016 }
1017 #else
1018 ((void) output);
1019 #endif /* MBEDTLS_CIPHER_MODE_CBC */
1020
1021 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1022 }
1023
1024 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t * ctx,mbedtls_cipher_padding_t mode)1025 int mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t *ctx,
1026 mbedtls_cipher_padding_t mode)
1027 {
1028 if (NULL == ctx->cipher_info || MBEDTLS_MODE_CBC != ctx->cipher_info->mode) {
1029 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1030 }
1031
1032 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1033 if (ctx->psa_enabled == 1) {
1034 /* While PSA Crypto knows about CBC padding
1035 * schemes, we currently don't make them
1036 * accessible through the cipher layer. */
1037 if (mode != MBEDTLS_PADDING_NONE) {
1038 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1039 }
1040
1041 return 0;
1042 }
1043 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1044
1045 switch (mode) {
1046 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
1047 case MBEDTLS_PADDING_PKCS7:
1048 ctx->add_padding = add_pkcs_padding;
1049 ctx->get_padding = get_pkcs_padding;
1050 break;
1051 #endif
1052 #if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
1053 case MBEDTLS_PADDING_ONE_AND_ZEROS:
1054 ctx->add_padding = add_one_and_zeros_padding;
1055 ctx->get_padding = get_one_and_zeros_padding;
1056 break;
1057 #endif
1058 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
1059 case MBEDTLS_PADDING_ZEROS_AND_LEN:
1060 ctx->add_padding = add_zeros_and_len_padding;
1061 ctx->get_padding = get_zeros_and_len_padding;
1062 break;
1063 #endif
1064 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
1065 case MBEDTLS_PADDING_ZEROS:
1066 ctx->add_padding = add_zeros_padding;
1067 ctx->get_padding = get_zeros_padding;
1068 break;
1069 #endif
1070 case MBEDTLS_PADDING_NONE:
1071 ctx->add_padding = NULL;
1072 ctx->get_padding = get_no_padding;
1073 break;
1074
1075 default:
1076 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1077 }
1078
1079 return 0;
1080 }
1081 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
1082
1083 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
mbedtls_cipher_write_tag(mbedtls_cipher_context_t * ctx,unsigned char * tag,size_t tag_len)1084 int mbedtls_cipher_write_tag(mbedtls_cipher_context_t *ctx,
1085 unsigned char *tag, size_t tag_len)
1086 {
1087 if (ctx->cipher_info == NULL) {
1088 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1089 }
1090
1091 if (MBEDTLS_ENCRYPT != ctx->operation) {
1092 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1093 }
1094
1095 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1096 if (ctx->psa_enabled == 1) {
1097 /* While PSA Crypto has an API for multipart
1098 * operations, we currently don't make it
1099 * accessible through the cipher layer. */
1100 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1101 }
1102 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1103
1104 #if defined(MBEDTLS_GCM_C)
1105 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
1106 size_t output_length;
1107 /* The code here doesn't yet support alternative implementations
1108 * that can delay up to a block of output. */
1109 return mbedtls_gcm_finish((mbedtls_gcm_context *) ctx->cipher_ctx,
1110 NULL, 0, &output_length,
1111 tag, tag_len);
1112 }
1113 #endif
1114
1115 #if defined(MBEDTLS_CHACHAPOLY_C)
1116 if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
1117 /* Don't allow truncated MAC for Poly1305 */
1118 if (tag_len != 16U) {
1119 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1120 }
1121
1122 return mbedtls_chachapoly_finish(
1123 (mbedtls_chachapoly_context *) ctx->cipher_ctx, tag);
1124 }
1125 #endif
1126
1127 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1128 }
1129
mbedtls_cipher_check_tag(mbedtls_cipher_context_t * ctx,const unsigned char * tag,size_t tag_len)1130 int mbedtls_cipher_check_tag(mbedtls_cipher_context_t *ctx,
1131 const unsigned char *tag, size_t tag_len)
1132 {
1133 unsigned char check_tag[16];
1134 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1135
1136 if (ctx->cipher_info == NULL) {
1137 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1138 }
1139
1140 if (MBEDTLS_DECRYPT != ctx->operation) {
1141 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1142 }
1143
1144 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1145 if (ctx->psa_enabled == 1) {
1146 /* While PSA Crypto has an API for multipart
1147 * operations, we currently don't make it
1148 * accessible through the cipher layer. */
1149 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1150 }
1151 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1152
1153 /* Status to return on a non-authenticated algorithm. */
1154 ret = MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1155
1156 #if defined(MBEDTLS_GCM_C)
1157 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
1158 size_t output_length;
1159 /* The code here doesn't yet support alternative implementations
1160 * that can delay up to a block of output. */
1161
1162 if (tag_len > sizeof(check_tag)) {
1163 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1164 }
1165
1166 if (0 != (ret = mbedtls_gcm_finish(
1167 (mbedtls_gcm_context *) ctx->cipher_ctx,
1168 NULL, 0, &output_length,
1169 check_tag, tag_len))) {
1170 return ret;
1171 }
1172
1173 /* Check the tag in "constant-time" */
1174 if (mbedtls_ct_memcmp(tag, check_tag, tag_len) != 0) {
1175 ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1176 goto exit;
1177 }
1178 }
1179 #endif /* MBEDTLS_GCM_C */
1180
1181 #if defined(MBEDTLS_CHACHAPOLY_C)
1182 if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
1183 /* Don't allow truncated MAC for Poly1305 */
1184 if (tag_len != sizeof(check_tag)) {
1185 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1186 }
1187
1188 ret = mbedtls_chachapoly_finish(
1189 (mbedtls_chachapoly_context *) ctx->cipher_ctx, check_tag);
1190 if (ret != 0) {
1191 return ret;
1192 }
1193
1194 /* Check the tag in "constant-time" */
1195 if (mbedtls_ct_memcmp(tag, check_tag, tag_len) != 0) {
1196 ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1197 goto exit;
1198 }
1199 }
1200 #endif /* MBEDTLS_CHACHAPOLY_C */
1201
1202 exit:
1203 mbedtls_platform_zeroize(check_tag, tag_len);
1204 return ret;
1205 }
1206 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
1207
1208 /*
1209 * Packet-oriented wrapper for non-AEAD modes
1210 */
mbedtls_cipher_crypt(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len,const unsigned char * input,size_t ilen,unsigned char * output,size_t * olen)1211 int mbedtls_cipher_crypt(mbedtls_cipher_context_t *ctx,
1212 const unsigned char *iv, size_t iv_len,
1213 const unsigned char *input, size_t ilen,
1214 unsigned char *output, size_t *olen)
1215 {
1216 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1217 size_t finish_olen;
1218
1219 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1220 if (ctx->psa_enabled == 1) {
1221 /* As in the non-PSA case, we don't check that
1222 * a key has been set. If not, the key slot will
1223 * still be in its default state of 0, which is
1224 * guaranteed to be invalid, hence the PSA-call
1225 * below will gracefully fail. */
1226 mbedtls_cipher_context_psa * const cipher_psa =
1227 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1228
1229 psa_status_t status;
1230 psa_cipher_operation_t cipher_op = PSA_CIPHER_OPERATION_INIT;
1231 size_t part_len;
1232
1233 if (ctx->operation == MBEDTLS_DECRYPT) {
1234 status = psa_cipher_decrypt_setup(&cipher_op,
1235 cipher_psa->slot,
1236 cipher_psa->alg);
1237 } else if (ctx->operation == MBEDTLS_ENCRYPT) {
1238 status = psa_cipher_encrypt_setup(&cipher_op,
1239 cipher_psa->slot,
1240 cipher_psa->alg);
1241 } else {
1242 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1243 }
1244
1245 /* In the following, we can immediately return on an error,
1246 * because the PSA Crypto API guarantees that cipher operations
1247 * are terminated by unsuccessful calls to psa_cipher_update(),
1248 * and by any call to psa_cipher_finish(). */
1249 if (status != PSA_SUCCESS) {
1250 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1251 }
1252
1253 if (ctx->cipher_info->mode != MBEDTLS_MODE_ECB) {
1254 status = psa_cipher_set_iv(&cipher_op, iv, iv_len);
1255 if (status != PSA_SUCCESS) {
1256 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1257 }
1258 }
1259
1260 status = psa_cipher_update(&cipher_op,
1261 input, ilen,
1262 output, ilen, olen);
1263 if (status != PSA_SUCCESS) {
1264 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1265 }
1266
1267 status = psa_cipher_finish(&cipher_op,
1268 output + *olen, ilen - *olen,
1269 &part_len);
1270 if (status != PSA_SUCCESS) {
1271 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1272 }
1273
1274 *olen += part_len;
1275 return 0;
1276 }
1277 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1278
1279 if ((ret = mbedtls_cipher_set_iv(ctx, iv, iv_len)) != 0) {
1280 return ret;
1281 }
1282
1283 if ((ret = mbedtls_cipher_reset(ctx)) != 0) {
1284 return ret;
1285 }
1286
1287 if ((ret = mbedtls_cipher_update(ctx, input, ilen,
1288 output, olen)) != 0) {
1289 return ret;
1290 }
1291
1292 if ((ret = mbedtls_cipher_finish(ctx, output + *olen,
1293 &finish_olen)) != 0) {
1294 return ret;
1295 }
1296
1297 *olen += finish_olen;
1298
1299 return 0;
1300 }
1301
1302 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1303 /*
1304 * Packet-oriented encryption for AEAD modes: internal function used by
1305 * mbedtls_cipher_auth_encrypt_ext().
1306 */
mbedtls_cipher_aead_encrypt(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len,const unsigned char * ad,size_t ad_len,const unsigned char * input,size_t ilen,unsigned char * output,size_t * olen,unsigned char * tag,size_t tag_len)1307 static int mbedtls_cipher_aead_encrypt(mbedtls_cipher_context_t *ctx,
1308 const unsigned char *iv, size_t iv_len,
1309 const unsigned char *ad, size_t ad_len,
1310 const unsigned char *input, size_t ilen,
1311 unsigned char *output, size_t *olen,
1312 unsigned char *tag, size_t tag_len)
1313 {
1314 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1315 if (ctx->psa_enabled == 1) {
1316 /* As in the non-PSA case, we don't check that
1317 * a key has been set. If not, the key slot will
1318 * still be in its default state of 0, which is
1319 * guaranteed to be invalid, hence the PSA-call
1320 * below will gracefully fail. */
1321 mbedtls_cipher_context_psa * const cipher_psa =
1322 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1323
1324 psa_status_t status;
1325
1326 /* PSA Crypto API always writes the authentication tag
1327 * at the end of the encrypted message. */
1328 if (output == NULL || tag != output + ilen) {
1329 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1330 }
1331
1332 status = psa_aead_encrypt(cipher_psa->slot,
1333 cipher_psa->alg,
1334 iv, iv_len,
1335 ad, ad_len,
1336 input, ilen,
1337 output, ilen + tag_len, olen);
1338 if (status != PSA_SUCCESS) {
1339 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1340 }
1341
1342 *olen -= tag_len;
1343 return 0;
1344 }
1345 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1346
1347 #if defined(MBEDTLS_GCM_C)
1348 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
1349 *olen = ilen;
1350 return mbedtls_gcm_crypt_and_tag(ctx->cipher_ctx, MBEDTLS_GCM_ENCRYPT,
1351 ilen, iv, iv_len, ad, ad_len,
1352 input, output, tag_len, tag);
1353 }
1354 #endif /* MBEDTLS_GCM_C */
1355 #if defined(MBEDTLS_CCM_C)
1356 if (MBEDTLS_MODE_CCM == ctx->cipher_info->mode) {
1357 *olen = ilen;
1358 return mbedtls_ccm_encrypt_and_tag(ctx->cipher_ctx, ilen,
1359 iv, iv_len, ad, ad_len, input, output,
1360 tag, tag_len);
1361 }
1362 #endif /* MBEDTLS_CCM_C */
1363 #if defined(MBEDTLS_CHACHAPOLY_C)
1364 if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
1365 /* ChachaPoly has fixed length nonce and MAC (tag) */
1366 if ((iv_len != ctx->cipher_info->iv_size) ||
1367 (tag_len != 16U)) {
1368 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1369 }
1370
1371 *olen = ilen;
1372 return mbedtls_chachapoly_encrypt_and_tag(ctx->cipher_ctx,
1373 ilen, iv, ad, ad_len, input, output, tag);
1374 }
1375 #endif /* MBEDTLS_CHACHAPOLY_C */
1376
1377 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1378 }
1379
1380 /*
1381 * Packet-oriented encryption for AEAD modes: internal function used by
1382 * mbedtls_cipher_auth_encrypt_ext().
1383 */
mbedtls_cipher_aead_decrypt(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len,const unsigned char * ad,size_t ad_len,const unsigned char * input,size_t ilen,unsigned char * output,size_t * olen,const unsigned char * tag,size_t tag_len)1384 static int mbedtls_cipher_aead_decrypt(mbedtls_cipher_context_t *ctx,
1385 const unsigned char *iv, size_t iv_len,
1386 const unsigned char *ad, size_t ad_len,
1387 const unsigned char *input, size_t ilen,
1388 unsigned char *output, size_t *olen,
1389 const unsigned char *tag, size_t tag_len)
1390 {
1391 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1392 if (ctx->psa_enabled == 1) {
1393 /* As in the non-PSA case, we don't check that
1394 * a key has been set. If not, the key slot will
1395 * still be in its default state of 0, which is
1396 * guaranteed to be invalid, hence the PSA-call
1397 * below will gracefully fail. */
1398 mbedtls_cipher_context_psa * const cipher_psa =
1399 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1400
1401 psa_status_t status;
1402
1403 /* PSA Crypto API always writes the authentication tag
1404 * at the end of the encrypted message. */
1405 if (input == NULL || tag != input + ilen) {
1406 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1407 }
1408
1409 status = psa_aead_decrypt(cipher_psa->slot,
1410 cipher_psa->alg,
1411 iv, iv_len,
1412 ad, ad_len,
1413 input, ilen + tag_len,
1414 output, ilen, olen);
1415 if (status == PSA_ERROR_INVALID_SIGNATURE) {
1416 return MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1417 } else if (status != PSA_SUCCESS) {
1418 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
1419 }
1420
1421 return 0;
1422 }
1423 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1424
1425 #if defined(MBEDTLS_GCM_C)
1426 if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
1427 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1428
1429 *olen = ilen;
1430 ret = mbedtls_gcm_auth_decrypt(ctx->cipher_ctx, ilen,
1431 iv, iv_len, ad, ad_len,
1432 tag, tag_len, input, output);
1433
1434 if (ret == MBEDTLS_ERR_GCM_AUTH_FAILED) {
1435 ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1436 }
1437
1438 return ret;
1439 }
1440 #endif /* MBEDTLS_GCM_C */
1441 #if defined(MBEDTLS_CCM_C)
1442 if (MBEDTLS_MODE_CCM == ctx->cipher_info->mode) {
1443 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1444
1445 *olen = ilen;
1446 ret = mbedtls_ccm_auth_decrypt(ctx->cipher_ctx, ilen,
1447 iv, iv_len, ad, ad_len,
1448 input, output, tag, tag_len);
1449
1450 if (ret == MBEDTLS_ERR_CCM_AUTH_FAILED) {
1451 ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1452 }
1453
1454 return ret;
1455 }
1456 #endif /* MBEDTLS_CCM_C */
1457 #if defined(MBEDTLS_CHACHAPOLY_C)
1458 if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
1459 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1460
1461 /* ChachaPoly has fixed length nonce and MAC (tag) */
1462 if ((iv_len != ctx->cipher_info->iv_size) ||
1463 (tag_len != 16U)) {
1464 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1465 }
1466
1467 *olen = ilen;
1468 ret = mbedtls_chachapoly_auth_decrypt(ctx->cipher_ctx, ilen,
1469 iv, ad, ad_len, tag, input, output);
1470
1471 if (ret == MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED) {
1472 ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1473 }
1474
1475 return ret;
1476 }
1477 #endif /* MBEDTLS_CHACHAPOLY_C */
1478
1479 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1480 }
1481 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1482
1483 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1484 /*
1485 * Packet-oriented encryption for AEAD/NIST_KW: public function.
1486 */
mbedtls_cipher_auth_encrypt_ext(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len,const unsigned char * ad,size_t ad_len,const unsigned char * input,size_t ilen,unsigned char * output,size_t output_len,size_t * olen,size_t tag_len)1487 int mbedtls_cipher_auth_encrypt_ext(mbedtls_cipher_context_t *ctx,
1488 const unsigned char *iv, size_t iv_len,
1489 const unsigned char *ad, size_t ad_len,
1490 const unsigned char *input, size_t ilen,
1491 unsigned char *output, size_t output_len,
1492 size_t *olen, size_t tag_len)
1493 {
1494 #if defined(MBEDTLS_NIST_KW_C)
1495 if (
1496 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1497 ctx->psa_enabled == 0 &&
1498 #endif
1499 (MBEDTLS_MODE_KW == ctx->cipher_info->mode ||
1500 MBEDTLS_MODE_KWP == ctx->cipher_info->mode)) {
1501 mbedtls_nist_kw_mode_t mode = (MBEDTLS_MODE_KW == ctx->cipher_info->mode) ?
1502 MBEDTLS_KW_MODE_KW : MBEDTLS_KW_MODE_KWP;
1503
1504 /* There is no iv, tag or ad associated with KW and KWP,
1505 * so these length should be 0 as documented. */
1506 if (iv_len != 0 || tag_len != 0 || ad_len != 0) {
1507 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1508 }
1509
1510 (void) iv;
1511 (void) ad;
1512
1513 return mbedtls_nist_kw_wrap(ctx->cipher_ctx, mode, input, ilen,
1514 output, olen, output_len);
1515 }
1516 #endif /* MBEDTLS_NIST_KW_C */
1517
1518 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1519 /* AEAD case: check length before passing on to shared function */
1520 if (output_len < ilen + tag_len) {
1521 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1522 }
1523
1524 int ret = mbedtls_cipher_aead_encrypt(ctx, iv, iv_len, ad, ad_len,
1525 input, ilen, output, olen,
1526 output + ilen, tag_len);
1527 *olen += tag_len;
1528 return ret;
1529 #else
1530 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1531 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1532 }
1533
1534 /*
1535 * Packet-oriented decryption for AEAD/NIST_KW: public function.
1536 */
mbedtls_cipher_auth_decrypt_ext(mbedtls_cipher_context_t * ctx,const unsigned char * iv,size_t iv_len,const unsigned char * ad,size_t ad_len,const unsigned char * input,size_t ilen,unsigned char * output,size_t output_len,size_t * olen,size_t tag_len)1537 int mbedtls_cipher_auth_decrypt_ext(mbedtls_cipher_context_t *ctx,
1538 const unsigned char *iv, size_t iv_len,
1539 const unsigned char *ad, size_t ad_len,
1540 const unsigned char *input, size_t ilen,
1541 unsigned char *output, size_t output_len,
1542 size_t *olen, size_t tag_len)
1543 {
1544 #if defined(MBEDTLS_NIST_KW_C)
1545 if (
1546 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1547 ctx->psa_enabled == 0 &&
1548 #endif
1549 (MBEDTLS_MODE_KW == ctx->cipher_info->mode ||
1550 MBEDTLS_MODE_KWP == ctx->cipher_info->mode)) {
1551 mbedtls_nist_kw_mode_t mode = (MBEDTLS_MODE_KW == ctx->cipher_info->mode) ?
1552 MBEDTLS_KW_MODE_KW : MBEDTLS_KW_MODE_KWP;
1553
1554 /* There is no iv, tag or ad associated with KW and KWP,
1555 * so these length should be 0 as documented. */
1556 if (iv_len != 0 || tag_len != 0 || ad_len != 0) {
1557 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1558 }
1559
1560 (void) iv;
1561 (void) ad;
1562
1563 return mbedtls_nist_kw_unwrap(ctx->cipher_ctx, mode, input, ilen,
1564 output, olen, output_len);
1565 }
1566 #endif /* MBEDTLS_NIST_KW_C */
1567
1568 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1569 /* AEAD case: check length before passing on to shared function */
1570 if (ilen < tag_len || output_len < ilen - tag_len) {
1571 return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
1572 }
1573
1574 return mbedtls_cipher_aead_decrypt(ctx, iv, iv_len, ad, ad_len,
1575 input, ilen - tag_len, output, olen,
1576 input + ilen - tag_len, tag_len);
1577 #else
1578 return MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE;
1579 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1580 }
1581 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1582
1583 #endif /* MBEDTLS_CIPHER_C */
1584