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 "mbedtls/cipher_internal.h"
30 #include "mbedtls/platform_util.h"
31 #include "mbedtls/error.h"
32 
33 #include <stdlib.h>
34 #include <string.h>
35 
36 #if defined(MBEDTLS_CHACHAPOLY_C)
37 #include "mbedtls/chachapoly.h"
38 #endif
39 
40 #if defined(MBEDTLS_GCM_C)
41 #include "mbedtls/gcm.h"
42 #endif
43 
44 #if defined(MBEDTLS_CCM_C)
45 #include "mbedtls/ccm.h"
46 #endif
47 
48 #if defined(MBEDTLS_CHACHA20_C)
49 #include "mbedtls/chacha20.h"
50 #endif
51 
52 #if defined(MBEDTLS_CMAC_C)
53 #include "mbedtls/cmac.h"
54 #endif
55 
56 #if defined(MBEDTLS_USE_PSA_CRYPTO)
57 #include "psa/crypto.h"
chachapoly_pad_aad(mbedtls_chachapoly_context * ctx)58 #include "mbedtls/psa_util.h"
59 #endif /* MBEDTLS_USE_PSA_CRYPTO */
60 
61 #if defined(MBEDTLS_NIST_KW_C)
62 #include "mbedtls/nist_kw.h"
63 #endif
64 
65 #if defined(MBEDTLS_PLATFORM_C)
66 #include "mbedtls/platform.h"
67 #else
68 #define mbedtls_calloc calloc
69 #define mbedtls_free   free
70 #endif
71 
72 #define CIPHER_VALIDATE_RET( cond )    \
73     MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA )
74 #define CIPHER_VALIDATE( cond )        \
75     MBEDTLS_INTERNAL_VALIDATE( cond )
76 
77 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
78 /* Compare the contents of two buffers in constant time.
79  * Returns 0 if the contents are bitwise identical, otherwise returns
80  * a non-zero value.
81  * This is currently only used by GCM and ChaCha20+Poly1305.
82  */
83 static int mbedtls_constant_time_memcmp( const void *v1, const void *v2,
84                                          size_t len )
85 {
86     const unsigned char *p1 = (const unsigned char*) v1;
87     const unsigned char *p2 = (const unsigned char*) v2;
88     size_t i;
89     unsigned char diff;
90 
91     for( diff = 0, i = 0; i < len; i++ )
92         diff |= p1[i] ^ p2[i];
93 
94     return( (int)diff );
95 }
96 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
97 
98 static int supported_init = 0;
99 
100 const int *mbedtls_cipher_list( void )
101 {
102     const mbedtls_cipher_definition_t *def;
103     int *type;
mbedtls_chachapoly_free(mbedtls_chachapoly_context * ctx)104 
105     if( ! supported_init )
106     {
107         def = mbedtls_cipher_definitions;
108         type = mbedtls_cipher_supported;
109 
110         while( def->type != 0 )
111             *type++ = (*def++).type;
112 
113         *type = 0;
114 
115         supported_init = 1;
116     }
mbedtls_chachapoly_setkey(mbedtls_chachapoly_context * ctx,const unsigned char key[32])117 
118     return( mbedtls_cipher_supported );
119 }
120 
121 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(
122     const mbedtls_cipher_type_t cipher_type )
123 {
124     const mbedtls_cipher_definition_t *def;
125 
126     for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
127         if( def->type == cipher_type )
128             return( def->info );
mbedtls_chachapoly_starts(mbedtls_chachapoly_context * ctx,const unsigned char nonce[12],mbedtls_chachapoly_mode_t mode)129 
130     return( NULL );
131 }
132 
133 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(
134     const char *cipher_name )
135 {
136     const mbedtls_cipher_definition_t *def;
137 
138     if( NULL == cipher_name )
139         return( NULL );
140 
141     for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
142         if( !  strcmp( def->info->name, cipher_name ) )
143             return( def->info );
144 
145     return( NULL );
146 }
147 
148 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(
149     const mbedtls_cipher_id_t cipher_id,
150     int key_bitlen,
151     const mbedtls_cipher_mode_t mode )
152 {
153     const mbedtls_cipher_definition_t *def;
154 
155     for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
156         if( def->info->base->cipher == cipher_id &&
157             def->info->key_bitlen == (unsigned) key_bitlen &&
158             def->info->mode == mode )
159             return( def->info );
160 
161     return( NULL );
162 }
163 
164 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx )
165 {
166     CIPHER_VALIDATE( ctx != NULL );
167     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
168 }
mbedtls_chachapoly_update_aad(mbedtls_chachapoly_context * ctx,const unsigned char * aad,size_t aad_len)169 
170 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx )
171 {
172     if( ctx == NULL )
173         return;
174 
175 #if defined(MBEDTLS_USE_PSA_CRYPTO)
176     if( ctx->psa_enabled == 1 )
177     {
178         if( ctx->cipher_ctx != NULL )
179         {
180             mbedtls_cipher_context_psa * const cipher_psa =
181                 (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
182 
183             if( cipher_psa->slot_state == MBEDTLS_CIPHER_PSA_KEY_OWNED )
184             {
185                 /* xxx_free() doesn't allow to return failures. */
186                 (void) psa_destroy_key( cipher_psa->slot );
187             }
188 
189             mbedtls_platform_zeroize( cipher_psa, sizeof( *cipher_psa ) );
190             mbedtls_free( cipher_psa );
191         }
192 
193         mbedtls_platform_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
194         return;
195     }
196 #endif /* MBEDTLS_USE_PSA_CRYPTO */
197 
198 #if defined(MBEDTLS_CMAC_C)
199     if( ctx->cmac_ctx )
200     {
201        mbedtls_platform_zeroize( ctx->cmac_ctx,
202                                  sizeof( mbedtls_cmac_context_t ) );
203        mbedtls_free( ctx->cmac_ctx );
204     }
205 #endif
206 
207     if( ctx->cipher_ctx )
208         ctx->cipher_info->base->ctx_free_func( ctx->cipher_ctx );
209 
210     mbedtls_platform_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
211 }
212 
213 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
214                           const mbedtls_cipher_info_t *cipher_info )
215 {
216     CIPHER_VALIDATE_RET( ctx != NULL );
217     if( cipher_info == NULL )
218         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
219 
220     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
221 
222     if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) )
223         return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
224 
225     ctx->cipher_info = cipher_info;
226 
227 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
228     /*
229      * Ignore possible errors caused by a cipher mode that doesn't use padding
230      */
231 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
232     (void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_PKCS7 );
233 #else
234     (void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_NONE );
mbedtls_chachapoly_finish(mbedtls_chachapoly_context * ctx,unsigned char mac[16])235 #endif
236 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
237 
238     return( 0 );
239 }
240 
241 #if defined(MBEDTLS_USE_PSA_CRYPTO)
242 int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
243                               const mbedtls_cipher_info_t *cipher_info,
244                               size_t taglen )
245 {
246     psa_algorithm_t alg;
247     mbedtls_cipher_context_psa *cipher_psa;
248 
249     if( NULL == cipher_info || NULL == ctx )
250         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
251 
252     /* Check that the underlying cipher mode and cipher type are
253      * supported by the underlying PSA Crypto implementation. */
254     alg = mbedtls_psa_translate_cipher_mode( cipher_info->mode, taglen );
255     if( alg == 0 )
256         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
257     if( mbedtls_psa_translate_cipher_type( cipher_info->type ) == 0 )
258         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
259 
260     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
261 
262     cipher_psa = mbedtls_calloc( 1, sizeof(mbedtls_cipher_context_psa ) );
263     if( cipher_psa == NULL )
264         return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
265     cipher_psa->alg  = alg;
266     ctx->cipher_ctx  = cipher_psa;
267     ctx->cipher_info = cipher_info;
268     ctx->psa_enabled = 1;
269     return( 0 );
270 }
271 #endif /* MBEDTLS_USE_PSA_CRYPTO */
272 
273 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
274                            const unsigned char *key,
275                            int key_bitlen,
276                            const mbedtls_operation_t operation )
277 {
278     CIPHER_VALIDATE_RET( ctx != NULL );
279     CIPHER_VALIDATE_RET( key != NULL );
280     CIPHER_VALIDATE_RET( operation == MBEDTLS_ENCRYPT ||
281                          operation == MBEDTLS_DECRYPT );
282     if( ctx->cipher_info == NULL )
283         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
284 
285 #if defined(MBEDTLS_USE_PSA_CRYPTO)
286     if( ctx->psa_enabled == 1 )
287     {
288         mbedtls_cipher_context_psa * const cipher_psa =
289             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
290 
291         size_t const key_bytelen = ( (size_t) key_bitlen + 7 ) / 8;
chachapoly_crypt_and_tag(mbedtls_chachapoly_context * ctx,mbedtls_chachapoly_mode_t mode,size_t length,const unsigned char nonce[12],const unsigned char * aad,size_t aad_len,const unsigned char * input,unsigned char * output,unsigned char tag[16])292 
293         psa_status_t status;
294         psa_key_type_t key_type;
295         psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
296 
297         /* PSA Crypto API only accepts byte-aligned keys. */
298         if( key_bitlen % 8 != 0 )
299             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
300 
301         /* Don't allow keys to be set multiple times. */
302         if( cipher_psa->slot_state != MBEDTLS_CIPHER_PSA_KEY_UNSET )
303             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
304 
305         key_type = mbedtls_psa_translate_cipher_type(
306             ctx->cipher_info->type );
307         if( key_type == 0 )
308             return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
309         psa_set_key_type( &attributes, key_type );
310 
311         /* Mbed TLS' cipher layer doesn't enforce the mode of operation
312          * (encrypt vs. decrypt): it is possible to setup a key for encryption
313          * and use it for AEAD decryption. Until tests relying on this
314          * are changed, allow any usage in PSA. */
315         psa_set_key_usage_flags( &attributes,
316                                  /* mbedtls_psa_translate_cipher_operation( operation ); */
317                                  PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT );
318         psa_set_key_algorithm( &attributes, cipher_psa->alg );
319 
320         status = psa_import_key( &attributes, key, key_bytelen,
321                                  &cipher_psa->slot );
mbedtls_chachapoly_encrypt_and_tag(mbedtls_chachapoly_context * ctx,size_t length,const unsigned char nonce[12],const unsigned char * aad,size_t aad_len,const unsigned char * input,unsigned char * output,unsigned char tag[16])322         switch( status )
323         {
324             case PSA_SUCCESS:
325                 break;
326             case PSA_ERROR_INSUFFICIENT_MEMORY:
327                 return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
328             case PSA_ERROR_NOT_SUPPORTED:
329                 return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
330             default:
331                 return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
332         }
333         /* Indicate that we own the key slot and need to
334          * destroy it in mbedtls_cipher_free(). */
335         cipher_psa->slot_state = MBEDTLS_CIPHER_PSA_KEY_OWNED;
336 
337         ctx->key_bitlen = key_bitlen;
338         ctx->operation = operation;
339         return( 0 );
340     }
341 #endif /* MBEDTLS_USE_PSA_CRYPTO */
342 
mbedtls_chachapoly_auth_decrypt(mbedtls_chachapoly_context * ctx,size_t length,const unsigned char nonce[12],const unsigned char * aad,size_t aad_len,const unsigned char tag[16],const unsigned char * input,unsigned char * output)343     if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN ) == 0 &&
344         (int) ctx->cipher_info->key_bitlen != key_bitlen )
345     {
346         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
347     }
348 
349     ctx->key_bitlen = key_bitlen;
350     ctx->operation = operation;
351 
352     /*
353      * For OFB, CFB and CTR mode always use the encryption key schedule
354      */
355     if( MBEDTLS_ENCRYPT == operation ||
356         MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
357         MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
358         MBEDTLS_MODE_CTR == ctx->cipher_info->mode )
359     {
360         return( ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
361                                                          ctx->key_bitlen ) );
362     }
363 
364     if( MBEDTLS_DECRYPT == operation )
365         return( ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key,
366                                                          ctx->key_bitlen ) );
367 
368     return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
369 }
370 
371 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
372                            const unsigned char *iv,
373                            size_t iv_len )
374 {
375     size_t actual_iv_size;
376 
377     CIPHER_VALIDATE_RET( ctx != NULL );
378     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
379     if( ctx->cipher_info == NULL )
380         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
381 #if defined(MBEDTLS_USE_PSA_CRYPTO)
382     if( ctx->psa_enabled == 1 )
383     {
384         /* While PSA Crypto has an API for multipart
385          * operations, we currently don't make it
386          * accessible through the cipher layer. */
387         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
388     }
389 #endif /* MBEDTLS_USE_PSA_CRYPTO */
390 
391     /* avoid buffer overflow in ctx->iv */
392     if( iv_len > MBEDTLS_MAX_IV_LENGTH )
393         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
394 
395     if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_IV_LEN ) != 0 )
396         actual_iv_size = iv_len;
397     else
398     {
399         actual_iv_size = ctx->cipher_info->iv_size;
400 
401         /* avoid reading past the end of input buffer */
402         if( actual_iv_size > iv_len )
403             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
404     }
405 
406 #if defined(MBEDTLS_CHACHA20_C)
407     if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
408     {
409         if ( 0 != mbedtls_chacha20_starts( (mbedtls_chacha20_context*)ctx->cipher_ctx,
410                                            iv,
411                                            0U ) ) /* Initial counter value */
412         {
413             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
414         }
415     }
416 #endif
417 
418     if ( actual_iv_size != 0 )
419     {
420         memcpy( ctx->iv, iv, actual_iv_size );
421         ctx->iv_size = actual_iv_size;
422     }
423 
424     return( 0 );
425 }
426 
427 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
428 {
429     CIPHER_VALIDATE_RET( ctx != NULL );
430     if( ctx->cipher_info == NULL )
431         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
432 
433 #if defined(MBEDTLS_USE_PSA_CRYPTO)
434     if( ctx->psa_enabled == 1 )
435     {
436         /* We don't support resetting PSA-based
437          * cipher contexts, yet. */
438         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
439     }
440 #endif /* MBEDTLS_USE_PSA_CRYPTO */
441 
442     ctx->unprocessed_len = 0;
443 
444     return( 0 );
445 }
446 
447 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
448 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
449                       const unsigned char *ad, size_t ad_len )
450 {
451     CIPHER_VALIDATE_RET( ctx != NULL );
452     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
453     if( ctx->cipher_info == NULL )
454         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
455 
456 #if defined(MBEDTLS_USE_PSA_CRYPTO)
457     if( ctx->psa_enabled == 1 )
458     {
459         /* While PSA Crypto has an API for multipart
460          * operations, we currently don't make it
461          * accessible through the cipher layer. */
462         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
463     }
464 #endif /* MBEDTLS_USE_PSA_CRYPTO */
465 
466 #if defined(MBEDTLS_GCM_C)
467     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
468     {
469         return( mbedtls_gcm_starts( (mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
470                                     ctx->iv, ctx->iv_size, ad, ad_len ) );
471     }
472 #endif
473 
474 #if defined(MBEDTLS_CHACHAPOLY_C)
475     if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
476     {
477         int result;
478         mbedtls_chachapoly_mode_t mode;
479 
480         mode = ( ctx->operation == MBEDTLS_ENCRYPT )
481                 ? MBEDTLS_CHACHAPOLY_ENCRYPT
482                 : MBEDTLS_CHACHAPOLY_DECRYPT;
483 
484         result = mbedtls_chachapoly_starts( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
485                                                         ctx->iv,
486                                                         mode );
487         if ( result != 0 )
488             return( result );
mbedtls_chachapoly_self_test(int verbose)489 
490         return( mbedtls_chachapoly_update_aad( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
491                                                ad, ad_len ) );
492     }
493 #endif
494 
495     return( 0 );
496 }
497 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
498 
499 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
500                    size_t ilen, unsigned char *output, size_t *olen )
501 {
502     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
503     size_t block_size;
504 
505     CIPHER_VALIDATE_RET( ctx != NULL );
506     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
507     CIPHER_VALIDATE_RET( output != NULL );
508     CIPHER_VALIDATE_RET( olen != NULL );
509     if( ctx->cipher_info == NULL )
510         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
511 
512 #if defined(MBEDTLS_USE_PSA_CRYPTO)
513     if( ctx->psa_enabled == 1 )
514     {
515         /* While PSA Crypto has an API for multipart
516          * operations, we currently don't make it
517          * accessible through the cipher layer. */
518         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
519     }
520 #endif /* MBEDTLS_USE_PSA_CRYPTO */
521 
522     *olen = 0;
523     block_size = mbedtls_cipher_get_block_size( ctx );
524     if ( 0 == block_size )
525     {
526         return( MBEDTLS_ERR_CIPHER_INVALID_CONTEXT );
527     }
528 
529     if( ctx->cipher_info->mode == MBEDTLS_MODE_ECB )
530     {
531         if( ilen != block_size )
532             return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
533 
534         *olen = ilen;
535 
536         if( 0 != ( ret = ctx->cipher_info->base->ecb_func( ctx->cipher_ctx,
537                     ctx->operation, input, output ) ) )
538         {
539             return( ret );
540         }
541 
542         return( 0 );
543     }
544 
545 #if defined(MBEDTLS_GCM_C)
546     if( ctx->cipher_info->mode == MBEDTLS_MODE_GCM )
547     {
548         *olen = ilen;
549         return( mbedtls_gcm_update( (mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
550                                     output ) );
551     }
552 #endif
553 
554 #if defined(MBEDTLS_CHACHAPOLY_C)
555     if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
556     {
557         *olen = ilen;
558         return( mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
559                                            ilen, input, output ) );
560     }
561 #endif
562 
563     if( input == output &&
564        ( ctx->unprocessed_len != 0 || ilen % block_size ) )
565     {
566         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
567     }
568 
569 #if defined(MBEDTLS_CIPHER_MODE_CBC)
570     if( ctx->cipher_info->mode == MBEDTLS_MODE_CBC )
571     {
572         size_t copy_len = 0;
573 
574         /*
575          * If there is not enough data for a full block, cache it.
576          */
577         if( ( ctx->operation == MBEDTLS_DECRYPT && NULL != ctx->add_padding &&
578                 ilen <= block_size - ctx->unprocessed_len ) ||
579             ( ctx->operation == MBEDTLS_DECRYPT && NULL == ctx->add_padding &&
580                 ilen < block_size - ctx->unprocessed_len ) ||
581              ( ctx->operation == MBEDTLS_ENCRYPT &&
582                 ilen < block_size - ctx->unprocessed_len ) )
583         {
584             memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
585                     ilen );
586 
587             ctx->unprocessed_len += ilen;
588             return( 0 );
589         }
590 
591         /*
592          * Process cached data first
593          */
594         if( 0 != ctx->unprocessed_len )
595         {
596             copy_len = block_size - ctx->unprocessed_len;
597 
598             memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
599                     copy_len );
600 
601             if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
602                     ctx->operation, block_size, ctx->iv,
603                     ctx->unprocessed_data, output ) ) )
604             {
605                 return( ret );
606             }
607 
608             *olen += block_size;
609             output += block_size;
610             ctx->unprocessed_len = 0;
611 
612             input += copy_len;
613             ilen -= copy_len;
614         }
615 
616         /*
617          * Cache final, incomplete block
618          */
619         if( 0 != ilen )
620         {
621             /* Encryption: only cache partial blocks
622              * Decryption w/ padding: always keep at least one whole block
623              * Decryption w/o padding: only cache partial blocks
624              */
625             copy_len = ilen % block_size;
626             if( copy_len == 0 &&
627                 ctx->operation == MBEDTLS_DECRYPT &&
628                 NULL != ctx->add_padding)
629             {
630                 copy_len = block_size;
631             }
632 
633             memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
634                     copy_len );
635 
636             ctx->unprocessed_len += copy_len;
637             ilen -= copy_len;
638         }
639 
640         /*
641          * Process remaining full blocks
642          */
643         if( ilen )
644         {
645             if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
646                     ctx->operation, ilen, ctx->iv, input, output ) ) )
647             {
648                 return( ret );
649             }
650 
651             *olen += ilen;
652         }
653 
654         return( 0 );
655     }
656 #endif /* MBEDTLS_CIPHER_MODE_CBC */
657 
658 #if defined(MBEDTLS_CIPHER_MODE_CFB)
659     if( ctx->cipher_info->mode == MBEDTLS_MODE_CFB )
660     {
661         if( 0 != ( ret = ctx->cipher_info->base->cfb_func( ctx->cipher_ctx,
662                 ctx->operation, ilen, &ctx->unprocessed_len, ctx->iv,
663                 input, output ) ) )
664         {
665             return( ret );
666         }
667 
668         *olen = ilen;
669 
670         return( 0 );
671     }
672 #endif /* MBEDTLS_CIPHER_MODE_CFB */
673 
674 #if defined(MBEDTLS_CIPHER_MODE_OFB)
675     if( ctx->cipher_info->mode == MBEDTLS_MODE_OFB )
676     {
677         if( 0 != ( ret = ctx->cipher_info->base->ofb_func( ctx->cipher_ctx,
678                 ilen, &ctx->unprocessed_len, ctx->iv, input, output ) ) )
679         {
680             return( ret );
681         }
682 
683         *olen = ilen;
684 
685         return( 0 );
686     }
687 #endif /* MBEDTLS_CIPHER_MODE_OFB */
688 
689 #if defined(MBEDTLS_CIPHER_MODE_CTR)
690     if( ctx->cipher_info->mode == MBEDTLS_MODE_CTR )
691     {
692         if( 0 != ( ret = ctx->cipher_info->base->ctr_func( ctx->cipher_ctx,
693                 ilen, &ctx->unprocessed_len, ctx->iv,
694                 ctx->unprocessed_data, input, output ) ) )
695         {
696             return( ret );
697         }
698 
699         *olen = ilen;
700 
701         return( 0 );
702     }
703 #endif /* MBEDTLS_CIPHER_MODE_CTR */
704 
705 #if defined(MBEDTLS_CIPHER_MODE_XTS)
706     if( ctx->cipher_info->mode == MBEDTLS_MODE_XTS )
707     {
708         if( ctx->unprocessed_len > 0 ) {
709             /* We can only process an entire data unit at a time. */
710             return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
711         }
712 
713         ret = ctx->cipher_info->base->xts_func( ctx->cipher_ctx,
714                 ctx->operation, ilen, ctx->iv, input, output );
715         if( ret != 0 )
716         {
717             return( ret );
718         }
719 
720         *olen = ilen;
721 
722         return( 0 );
723     }
724 #endif /* MBEDTLS_CIPHER_MODE_XTS */
725 
726 #if defined(MBEDTLS_CIPHER_MODE_STREAM)
727     if( ctx->cipher_info->mode == MBEDTLS_MODE_STREAM )
728     {
729         if( 0 != ( ret = ctx->cipher_info->base->stream_func( ctx->cipher_ctx,
730                                                     ilen, input, output ) ) )
731         {
732             return( ret );
733         }
734 
735         *olen = ilen;
736 
737         return( 0 );
738     }
739 #endif /* MBEDTLS_CIPHER_MODE_STREAM */
740 
741     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
742 }
743 
744 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
745 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
746 /*
747  * PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len
748  */
749 static void add_pkcs_padding( unsigned char *output, size_t output_len,
750         size_t data_len )
751 {
752     size_t padding_len = output_len - data_len;
753     unsigned char i;
754 
755     for( i = 0; i < padding_len; i++ )
756         output[data_len + i] = (unsigned char) padding_len;
757 }
758 
759 static int get_pkcs_padding( unsigned char *input, size_t input_len,
760         size_t *data_len )
761 {
762     size_t i, pad_idx;
763     unsigned char padding_len, bad = 0;
764 
765     if( NULL == input || NULL == data_len )
766         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
767 
768     padding_len = input[input_len - 1];
769     *data_len = input_len - padding_len;
770 
771     /* Avoid logical || since it results in a branch */
772     bad |= padding_len > input_len;
773     bad |= padding_len == 0;
774 
775     /* The number of bytes checked must be independent of padding_len,
776      * so pick input_len, which is usually 8 or 16 (one block) */
777     pad_idx = input_len - padding_len;
778     for( i = 0; i < input_len; i++ )
779         bad |= ( input[i] ^ padding_len ) * ( i >= pad_idx );
780 
781     return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
782 }
783 #endif /* MBEDTLS_CIPHER_PADDING_PKCS7 */
784 
785 #if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
786 /*
787  * One and zeros padding: fill with 80 00 ... 00
788  */
789 static void add_one_and_zeros_padding( unsigned char *output,
790                                        size_t output_len, size_t data_len )
791 {
792     size_t padding_len = output_len - data_len;
793     unsigned char i = 0;
794 
795     output[data_len] = 0x80;
796     for( i = 1; i < padding_len; i++ )
797         output[data_len + i] = 0x00;
798 }
799 
800 static int get_one_and_zeros_padding( unsigned char *input, size_t input_len,
801                                       size_t *data_len )
802 {
803     size_t i;
804     unsigned char done = 0, prev_done, bad;
805 
806     if( NULL == input || NULL == data_len )
807         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
808 
809     bad = 0x80;
810     *data_len = 0;
811     for( i = input_len; i > 0; i-- )
812     {
813         prev_done = done;
814         done |= ( input[i - 1] != 0 );
815         *data_len |= ( i - 1 ) * ( done != prev_done );
816         bad ^= input[i - 1] * ( done != prev_done );
817     }
818 
819     return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
820 
821 }
822 #endif /* MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS */
823 
824 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
825 /*
826  * Zeros and len padding: fill with 00 ... 00 ll, where ll is padding length
827  */
828 static void add_zeros_and_len_padding( unsigned char *output,
829                                        size_t output_len, size_t data_len )
830 {
831     size_t padding_len = output_len - data_len;
832     unsigned char i = 0;
833 
834     for( i = 1; i < padding_len; i++ )
835         output[data_len + i - 1] = 0x00;
836     output[output_len - 1] = (unsigned char) padding_len;
837 }
838 
839 static int get_zeros_and_len_padding( unsigned char *input, size_t input_len,
840                                       size_t *data_len )
841 {
842     size_t i, pad_idx;
843     unsigned char padding_len, bad = 0;
844 
845     if( NULL == input || NULL == data_len )
846         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
847 
848     padding_len = input[input_len - 1];
849     *data_len = input_len - padding_len;
850 
851     /* Avoid logical || since it results in a branch */
852     bad |= padding_len > input_len;
853     bad |= padding_len == 0;
854 
855     /* The number of bytes checked must be independent of padding_len */
856     pad_idx = input_len - padding_len;
857     for( i = 0; i < input_len - 1; i++ )
858         bad |= input[i] * ( i >= pad_idx );
859 
860     return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
861 }
862 #endif /* MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN */
863 
864 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
865 /*
866  * Zero padding: fill with 00 ... 00
867  */
868 static void add_zeros_padding( unsigned char *output,
869                                size_t output_len, size_t data_len )
870 {
871     size_t i;
872 
873     for( i = data_len; i < output_len; i++ )
874         output[i] = 0x00;
875 }
876 
877 static int get_zeros_padding( unsigned char *input, size_t input_len,
878                               size_t *data_len )
879 {
880     size_t i;
881     unsigned char done = 0, prev_done;
882 
883     if( NULL == input || NULL == data_len )
884         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
885 
886     *data_len = 0;
887     for( i = input_len; i > 0; i-- )
888     {
889         prev_done = done;
890         done |= ( input[i-1] != 0 );
891         *data_len |= i * ( done != prev_done );
892     }
893 
894     return( 0 );
895 }
896 #endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
897 
898 /*
899  * No padding: don't pad :)
900  *
901  * There is no add_padding function (check for NULL in mbedtls_cipher_finish)
902  * but a trivial get_padding function
903  */
904 static int get_no_padding( unsigned char *input, size_t input_len,
905                               size_t *data_len )
906 {
907     if( NULL == input || NULL == data_len )
908         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
909 
910     *data_len = input_len;
911 
912     return( 0 );
913 }
914 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
915 
916 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
917                    unsigned char *output, size_t *olen )
918 {
919     CIPHER_VALIDATE_RET( ctx != NULL );
920     CIPHER_VALIDATE_RET( output != NULL );
921     CIPHER_VALIDATE_RET( olen != NULL );
922     if( ctx->cipher_info == NULL )
923         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
924 
925 #if defined(MBEDTLS_USE_PSA_CRYPTO)
926     if( ctx->psa_enabled == 1 )
927     {
928         /* While PSA Crypto has an API for multipart
929          * operations, we currently don't make it
930          * accessible through the cipher layer. */
931         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
932     }
933 #endif /* MBEDTLS_USE_PSA_CRYPTO */
934 
935     *olen = 0;
936 
937     if( MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
938         MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
939         MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
940         MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
941         MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
942         MBEDTLS_MODE_STREAM == ctx->cipher_info->mode )
943     {
944         return( 0 );
945     }
946 
947     if ( ( MBEDTLS_CIPHER_CHACHA20          == ctx->cipher_info->type ) ||
948          ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type ) )
949     {
950         return( 0 );
951     }
952 
953     if( MBEDTLS_MODE_ECB == ctx->cipher_info->mode )
954     {
955         if( ctx->unprocessed_len != 0 )
956             return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
957 
958         return( 0 );
959     }
960 
961 #if defined(MBEDTLS_CIPHER_MODE_CBC)
962     if( MBEDTLS_MODE_CBC == ctx->cipher_info->mode )
963     {
964         int ret = 0;
965 
966         if( MBEDTLS_ENCRYPT == ctx->operation )
967         {
968             /* check for 'no padding' mode */
969             if( NULL == ctx->add_padding )
970             {
971                 if( 0 != ctx->unprocessed_len )
972                     return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
973 
974                 return( 0 );
975             }
976 
977             ctx->add_padding( ctx->unprocessed_data, mbedtls_cipher_get_iv_size( ctx ),
978                     ctx->unprocessed_len );
979         }
980         else if( mbedtls_cipher_get_block_size( ctx ) != ctx->unprocessed_len )
981         {
982             /*
983              * For decrypt operations, expect a full block,
984              * or an empty block if no padding
985              */
986             if( NULL == ctx->add_padding && 0 == ctx->unprocessed_len )
987                 return( 0 );
988 
989             return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
990         }
991 
992         /* cipher block */
993         if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
994                 ctx->operation, mbedtls_cipher_get_block_size( ctx ), ctx->iv,
995                 ctx->unprocessed_data, output ) ) )
996         {
997             return( ret );
998         }
999 
1000         /* Set output size for decryption */
1001         if( MBEDTLS_DECRYPT == ctx->operation )
1002             return( ctx->get_padding( output, mbedtls_cipher_get_block_size( ctx ),
1003                                       olen ) );
1004 
1005         /* Set output size for encryption */
1006         *olen = mbedtls_cipher_get_block_size( ctx );
1007         return( 0 );
1008     }
1009 #else
1010     ((void) output);
1011 #endif /* MBEDTLS_CIPHER_MODE_CBC */
1012 
1013     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1014 }
1015 
1016 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
1017 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
1018                                      mbedtls_cipher_padding_t mode )
1019 {
1020     CIPHER_VALIDATE_RET( ctx != NULL );
1021 
1022     if( NULL == ctx->cipher_info || MBEDTLS_MODE_CBC != ctx->cipher_info->mode )
1023     {
1024         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1025     }
1026 
1027 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1028     if( ctx->psa_enabled == 1 )
1029     {
1030         /* While PSA Crypto knows about CBC padding
1031          * schemes, we currently don't make them
1032          * accessible through the cipher layer. */
1033         if( mode != MBEDTLS_PADDING_NONE )
1034             return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1035 
1036         return( 0 );
1037     }
1038 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1039 
1040     switch( mode )
1041     {
1042 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
1043     case MBEDTLS_PADDING_PKCS7:
1044         ctx->add_padding = add_pkcs_padding;
1045         ctx->get_padding = get_pkcs_padding;
1046         break;
1047 #endif
1048 #if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
1049     case MBEDTLS_PADDING_ONE_AND_ZEROS:
1050         ctx->add_padding = add_one_and_zeros_padding;
1051         ctx->get_padding = get_one_and_zeros_padding;
1052         break;
1053 #endif
1054 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
1055     case MBEDTLS_PADDING_ZEROS_AND_LEN:
1056         ctx->add_padding = add_zeros_and_len_padding;
1057         ctx->get_padding = get_zeros_and_len_padding;
1058         break;
1059 #endif
1060 #if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
1061     case MBEDTLS_PADDING_ZEROS:
1062         ctx->add_padding = add_zeros_padding;
1063         ctx->get_padding = get_zeros_padding;
1064         break;
1065 #endif
1066     case MBEDTLS_PADDING_NONE:
1067         ctx->add_padding = NULL;
1068         ctx->get_padding = get_no_padding;
1069         break;
1070 
1071     default:
1072         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1073     }
1074 
1075     return( 0 );
1076 }
1077 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
1078 
1079 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
1080 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
1081                       unsigned char *tag, size_t tag_len )
1082 {
1083     CIPHER_VALIDATE_RET( ctx != NULL );
1084     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
1085     if( ctx->cipher_info == NULL )
1086         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1087 
1088     if( MBEDTLS_ENCRYPT != ctx->operation )
1089         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1090 
1091 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1092     if( ctx->psa_enabled == 1 )
1093     {
1094         /* While PSA Crypto has an API for multipart
1095          * operations, we currently don't make it
1096          * accessible through the cipher layer. */
1097         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1098     }
1099 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1100 
1101 #if defined(MBEDTLS_GCM_C)
1102     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
1103         return( mbedtls_gcm_finish( (mbedtls_gcm_context *) ctx->cipher_ctx,
1104                                     tag, tag_len ) );
1105 #endif
1106 
1107 #if defined(MBEDTLS_CHACHAPOLY_C)
1108     if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
1109     {
1110         /* Don't allow truncated MAC for Poly1305 */
1111         if ( tag_len != 16U )
1112             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1113 
1114         return( mbedtls_chachapoly_finish(
1115                     (mbedtls_chachapoly_context*) ctx->cipher_ctx, tag ) );
1116     }
1117 #endif
1118 
1119     return( 0 );
1120 }
1121 
1122 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
1123                       const unsigned char *tag, size_t tag_len )
1124 {
1125     unsigned char check_tag[16];
1126     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1127 
1128     CIPHER_VALIDATE_RET( ctx != NULL );
1129     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
1130     if( ctx->cipher_info == NULL )
1131         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1132 
1133     if( MBEDTLS_DECRYPT != ctx->operation )
1134     {
1135         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1136     }
1137 
1138 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1139     if( ctx->psa_enabled == 1 )
1140     {
1141         /* While PSA Crypto has an API for multipart
1142          * operations, we currently don't make it
1143          * accessible through the cipher layer. */
1144         return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1145     }
1146 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1147 
1148 #if defined(MBEDTLS_GCM_C)
1149     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
1150     {
1151         if( tag_len > sizeof( check_tag ) )
1152             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1153 
1154         if( 0 != ( ret = mbedtls_gcm_finish(
1155                        (mbedtls_gcm_context *) ctx->cipher_ctx,
1156                        check_tag, tag_len ) ) )
1157         {
1158             return( ret );
1159         }
1160 
1161         /* Check the tag in "constant-time" */
1162         if( mbedtls_constant_time_memcmp( tag, check_tag, tag_len ) != 0 )
1163             return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
1164 
1165         return( 0 );
1166     }
1167 #endif /* MBEDTLS_GCM_C */
1168 
1169 #if defined(MBEDTLS_CHACHAPOLY_C)
1170     if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
1171     {
1172         /* Don't allow truncated MAC for Poly1305 */
1173         if ( tag_len != sizeof( check_tag ) )
1174             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1175 
1176         ret = mbedtls_chachapoly_finish(
1177             (mbedtls_chachapoly_context*) ctx->cipher_ctx, check_tag );
1178         if ( ret != 0 )
1179         {
1180             return( ret );
1181         }
1182 
1183         /* Check the tag in "constant-time" */
1184         if( mbedtls_constant_time_memcmp( tag, check_tag, tag_len ) != 0 )
1185             return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
1186 
1187         return( 0 );
1188     }
1189 #endif /* MBEDTLS_CHACHAPOLY_C */
1190 
1191     return( 0 );
1192 }
1193 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
1194 
1195 /*
1196  * Packet-oriented wrapper for non-AEAD modes
1197  */
1198 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
1199                   const unsigned char *iv, size_t iv_len,
1200                   const unsigned char *input, size_t ilen,
1201                   unsigned char *output, size_t *olen )
1202 {
1203     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1204     size_t finish_olen;
1205 
1206     CIPHER_VALIDATE_RET( ctx != NULL );
1207     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
1208     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
1209     CIPHER_VALIDATE_RET( output != NULL );
1210     CIPHER_VALIDATE_RET( olen != NULL );
1211 
1212 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1213     if( ctx->psa_enabled == 1 )
1214     {
1215         /* As in the non-PSA case, we don't check that
1216          * a key has been set. If not, the key slot will
1217          * still be in its default state of 0, which is
1218          * guaranteed to be invalid, hence the PSA-call
1219          * below will gracefully fail. */
1220         mbedtls_cipher_context_psa * const cipher_psa =
1221             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1222 
1223         psa_status_t status;
1224         psa_cipher_operation_t cipher_op = PSA_CIPHER_OPERATION_INIT;
1225         size_t part_len;
1226 
1227         if( ctx->operation == MBEDTLS_DECRYPT )
1228         {
1229             status = psa_cipher_decrypt_setup( &cipher_op,
1230                                                cipher_psa->slot,
1231                                                cipher_psa->alg );
1232         }
1233         else if( ctx->operation == MBEDTLS_ENCRYPT )
1234         {
1235             status = psa_cipher_encrypt_setup( &cipher_op,
1236                                                cipher_psa->slot,
1237                                                cipher_psa->alg );
1238         }
1239         else
1240             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1241 
1242         /* In the following, we can immediately return on an error,
1243          * because the PSA Crypto API guarantees that cipher operations
1244          * are terminated by unsuccessful calls to psa_cipher_update(),
1245          * and by any call to psa_cipher_finish(). */
1246         if( status != PSA_SUCCESS )
1247             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1248 
1249         status = psa_cipher_set_iv( &cipher_op, iv, iv_len );
1250         if( status != PSA_SUCCESS )
1251             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1252 
1253         status = psa_cipher_update( &cipher_op,
1254                                     input, ilen,
1255                                     output, ilen, olen );
1256         if( status != PSA_SUCCESS )
1257             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1258 
1259         status = psa_cipher_finish( &cipher_op,
1260                                     output + *olen, ilen - *olen,
1261                                     &part_len );
1262         if( status != PSA_SUCCESS )
1263             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1264 
1265         *olen += part_len;
1266         return( 0 );
1267     }
1268 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1269 
1270     if( ( ret = mbedtls_cipher_set_iv( ctx, iv, iv_len ) ) != 0 )
1271         return( ret );
1272 
1273     if( ( ret = mbedtls_cipher_reset( ctx ) ) != 0 )
1274         return( ret );
1275 
1276     if( ( ret = mbedtls_cipher_update( ctx, input, ilen,
1277                                        output, olen ) ) != 0 )
1278         return( ret );
1279 
1280     if( ( ret = mbedtls_cipher_finish( ctx, output + *olen,
1281                                        &finish_olen ) ) != 0 )
1282         return( ret );
1283 
1284     *olen += finish_olen;
1285 
1286     return( 0 );
1287 }
1288 
1289 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1290 /*
1291  * Packet-oriented encryption for AEAD modes: internal function shared by
1292  * mbedtls_cipher_auth_encrypt() and mbedtls_cipher_auth_encrypt_ext().
1293  */
1294 static int mbedtls_cipher_aead_encrypt( mbedtls_cipher_context_t *ctx,
1295                          const unsigned char *iv, size_t iv_len,
1296                          const unsigned char *ad, size_t ad_len,
1297                          const unsigned char *input, size_t ilen,
1298                          unsigned char *output, size_t *olen,
1299                          unsigned char *tag, size_t tag_len )
1300 {
1301 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1302     if( ctx->psa_enabled == 1 )
1303     {
1304         /* As in the non-PSA case, we don't check that
1305          * a key has been set. If not, the key slot will
1306          * still be in its default state of 0, which is
1307          * guaranteed to be invalid, hence the PSA-call
1308          * below will gracefully fail. */
1309         mbedtls_cipher_context_psa * const cipher_psa =
1310             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1311 
1312         psa_status_t status;
1313 
1314         /* PSA Crypto API always writes the authentication tag
1315          * at the end of the encrypted message. */
1316         if( output == NULL || tag != output + ilen )
1317             return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1318 
1319         status = psa_aead_encrypt( cipher_psa->slot,
1320                                    cipher_psa->alg,
1321                                    iv, iv_len,
1322                                    ad, ad_len,
1323                                    input, ilen,
1324                                    output, ilen + tag_len, olen );
1325         if( status != PSA_SUCCESS )
1326             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1327 
1328         *olen -= tag_len;
1329         return( 0 );
1330     }
1331 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1332 
1333 #if defined(MBEDTLS_GCM_C)
1334     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
1335     {
1336         *olen = ilen;
1337         return( mbedtls_gcm_crypt_and_tag( ctx->cipher_ctx, MBEDTLS_GCM_ENCRYPT,
1338                                            ilen, iv, iv_len, ad, ad_len,
1339                                            input, output, tag_len, tag ) );
1340     }
1341 #endif /* MBEDTLS_GCM_C */
1342 #if defined(MBEDTLS_CCM_C)
1343     if( MBEDTLS_MODE_CCM == ctx->cipher_info->mode )
1344     {
1345         *olen = ilen;
1346         return( mbedtls_ccm_encrypt_and_tag( ctx->cipher_ctx, ilen,
1347                                      iv, iv_len, ad, ad_len, input, output,
1348                                      tag, tag_len ) );
1349     }
1350 #endif /* MBEDTLS_CCM_C */
1351 #if defined(MBEDTLS_CHACHAPOLY_C)
1352     if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
1353     {
1354         /* ChachaPoly has fixed length nonce and MAC (tag) */
1355         if ( ( iv_len != ctx->cipher_info->iv_size ) ||
1356              ( tag_len != 16U ) )
1357         {
1358             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1359         }
1360 
1361         *olen = ilen;
1362         return( mbedtls_chachapoly_encrypt_and_tag( ctx->cipher_ctx,
1363                                 ilen, iv, ad, ad_len, input, output, tag ) );
1364     }
1365 #endif /* MBEDTLS_CHACHAPOLY_C */
1366 
1367     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1368 }
1369 
1370 /*
1371  * Packet-oriented encryption for AEAD modes: internal function shared by
1372  * mbedtls_cipher_auth_encrypt() and mbedtls_cipher_auth_encrypt_ext().
1373  */
1374 static int mbedtls_cipher_aead_decrypt( mbedtls_cipher_context_t *ctx,
1375                          const unsigned char *iv, size_t iv_len,
1376                          const unsigned char *ad, size_t ad_len,
1377                          const unsigned char *input, size_t ilen,
1378                          unsigned char *output, size_t *olen,
1379                          const unsigned char *tag, size_t tag_len )
1380 {
1381 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1382     if( ctx->psa_enabled == 1 )
1383     {
1384         /* As in the non-PSA case, we don't check that
1385          * a key has been set. If not, the key slot will
1386          * still be in its default state of 0, which is
1387          * guaranteed to be invalid, hence the PSA-call
1388          * below will gracefully fail. */
1389         mbedtls_cipher_context_psa * const cipher_psa =
1390             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
1391 
1392         psa_status_t status;
1393 
1394         /* PSA Crypto API always writes the authentication tag
1395          * at the end of the encrypted message. */
1396         if( input == NULL || tag != input + ilen )
1397             return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1398 
1399         status = psa_aead_decrypt( cipher_psa->slot,
1400                                    cipher_psa->alg,
1401                                    iv, iv_len,
1402                                    ad, ad_len,
1403                                    input, ilen + tag_len,
1404                                    output, ilen, olen );
1405         if( status == PSA_ERROR_INVALID_SIGNATURE )
1406             return( MBEDTLS_ERR_CIPHER_AUTH_FAILED );
1407         else if( status != PSA_SUCCESS )
1408             return( MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED );
1409 
1410         return( 0 );
1411     }
1412 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1413 
1414 #if defined(MBEDTLS_GCM_C)
1415     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
1416     {
1417         int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1418 
1419         *olen = ilen;
1420         ret = mbedtls_gcm_auth_decrypt( ctx->cipher_ctx, ilen,
1421                                 iv, iv_len, ad, ad_len,
1422                                 tag, tag_len, input, output );
1423 
1424         if( ret == MBEDTLS_ERR_GCM_AUTH_FAILED )
1425             ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1426 
1427         return( ret );
1428     }
1429 #endif /* MBEDTLS_GCM_C */
1430 #if defined(MBEDTLS_CCM_C)
1431     if( MBEDTLS_MODE_CCM == ctx->cipher_info->mode )
1432     {
1433         int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1434 
1435         *olen = ilen;
1436         ret = mbedtls_ccm_auth_decrypt( ctx->cipher_ctx, ilen,
1437                                 iv, iv_len, ad, ad_len,
1438                                 input, output, tag, tag_len );
1439 
1440         if( ret == MBEDTLS_ERR_CCM_AUTH_FAILED )
1441             ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1442 
1443         return( ret );
1444     }
1445 #endif /* MBEDTLS_CCM_C */
1446 #if defined(MBEDTLS_CHACHAPOLY_C)
1447     if ( MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type )
1448     {
1449         int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1450 
1451         /* ChachaPoly has fixed length nonce and MAC (tag) */
1452         if ( ( iv_len != ctx->cipher_info->iv_size ) ||
1453              ( tag_len != 16U ) )
1454         {
1455             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1456         }
1457 
1458         *olen = ilen;
1459         ret = mbedtls_chachapoly_auth_decrypt( ctx->cipher_ctx, ilen,
1460                                 iv, ad, ad_len, tag, input, output );
1461 
1462         if( ret == MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED )
1463             ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
1464 
1465         return( ret );
1466     }
1467 #endif /* MBEDTLS_CHACHAPOLY_C */
1468 
1469     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1470 }
1471 
1472 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
1473 /*
1474  * Packet-oriented encryption for AEAD modes: public legacy function.
1475  */
1476 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
1477                          const unsigned char *iv, size_t iv_len,
1478                          const unsigned char *ad, size_t ad_len,
1479                          const unsigned char *input, size_t ilen,
1480                          unsigned char *output, size_t *olen,
1481                          unsigned char *tag, size_t tag_len )
1482 {
1483     CIPHER_VALIDATE_RET( ctx != NULL );
1484     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
1485     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
1486     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
1487     CIPHER_VALIDATE_RET( ilen == 0 || output != NULL );
1488     CIPHER_VALIDATE_RET( olen != NULL );
1489     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
1490 
1491     return( mbedtls_cipher_aead_encrypt( ctx, iv, iv_len, ad, ad_len,
1492                                          input, ilen, output, olen,
1493                                          tag, tag_len ) );
1494 }
1495 
1496 /*
1497  * Packet-oriented decryption for AEAD modes: public legacy function.
1498  */
1499 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
1500                          const unsigned char *iv, size_t iv_len,
1501                          const unsigned char *ad, size_t ad_len,
1502                          const unsigned char *input, size_t ilen,
1503                          unsigned char *output, size_t *olen,
1504                          const unsigned char *tag, size_t tag_len )
1505 {
1506     CIPHER_VALIDATE_RET( ctx != NULL );
1507     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
1508     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
1509     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
1510     CIPHER_VALIDATE_RET( ilen == 0 || output != NULL );
1511     CIPHER_VALIDATE_RET( olen != NULL );
1512     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
1513 
1514     return( mbedtls_cipher_aead_decrypt( ctx, iv, iv_len, ad, ad_len,
1515                                          input, ilen, output, olen,
1516                                          tag, tag_len ) );
1517 }
1518 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
1519 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1520 
1521 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1522 /*
1523  * Packet-oriented encryption for AEAD/NIST_KW: public function.
1524  */
1525 int mbedtls_cipher_auth_encrypt_ext( mbedtls_cipher_context_t *ctx,
1526                          const unsigned char *iv, size_t iv_len,
1527                          const unsigned char *ad, size_t ad_len,
1528                          const unsigned char *input, size_t ilen,
1529                          unsigned char *output, size_t output_len,
1530                          size_t *olen, size_t tag_len )
1531 {
1532     CIPHER_VALIDATE_RET( ctx != NULL );
1533     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
1534     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
1535     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
1536     CIPHER_VALIDATE_RET( output != NULL );
1537     CIPHER_VALIDATE_RET( olen != NULL );
1538 
1539 #if defined(MBEDTLS_NIST_KW_C)
1540     if(
1541 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1542         ctx->psa_enabled == 0 &&
1543 #endif
1544         ( MBEDTLS_MODE_KW == ctx->cipher_info->mode ||
1545           MBEDTLS_MODE_KWP == ctx->cipher_info->mode ) )
1546     {
1547         mbedtls_nist_kw_mode_t mode = ( MBEDTLS_MODE_KW == ctx->cipher_info->mode ) ?
1548                                         MBEDTLS_KW_MODE_KW : MBEDTLS_KW_MODE_KWP;
1549 
1550         /* There is no iv, tag or ad associated with KW and KWP,
1551          * so these length should be 0 as documented. */
1552         if( iv_len != 0 || tag_len != 0 || ad_len != 0 )
1553             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1554 
1555         (void) iv;
1556         (void) ad;
1557 
1558         return( mbedtls_nist_kw_wrap( ctx->cipher_ctx, mode, input, ilen,
1559                                       output, olen, output_len ) );
1560     }
1561 #endif /* MBEDTLS_NIST_KW_C */
1562 
1563 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1564     /* AEAD case: check length before passing on to shared function */
1565     if( output_len < ilen + tag_len )
1566         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1567 
1568     int ret = mbedtls_cipher_aead_encrypt( ctx, iv, iv_len, ad, ad_len,
1569                                        input, ilen, output, olen,
1570                                        output + ilen, tag_len );
1571     *olen += tag_len;
1572     return( ret );
1573 #else
1574     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1575 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1576 }
1577 
1578 /*
1579  * Packet-oriented decryption for AEAD/NIST_KW: public function.
1580  */
1581 int mbedtls_cipher_auth_decrypt_ext( mbedtls_cipher_context_t *ctx,
1582                          const unsigned char *iv, size_t iv_len,
1583                          const unsigned char *ad, size_t ad_len,
1584                          const unsigned char *input, size_t ilen,
1585                          unsigned char *output, size_t output_len,
1586                          size_t *olen, size_t tag_len )
1587 {
1588     CIPHER_VALIDATE_RET( ctx != NULL );
1589     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
1590     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
1591     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
1592     CIPHER_VALIDATE_RET( output_len == 0 || output != NULL );
1593     CIPHER_VALIDATE_RET( olen != NULL );
1594 
1595 #if defined(MBEDTLS_NIST_KW_C)
1596     if(
1597 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1598         ctx->psa_enabled == 0 &&
1599 #endif
1600         ( MBEDTLS_MODE_KW == ctx->cipher_info->mode ||
1601           MBEDTLS_MODE_KWP == ctx->cipher_info->mode ) )
1602     {
1603         mbedtls_nist_kw_mode_t mode = ( MBEDTLS_MODE_KW == ctx->cipher_info->mode ) ?
1604                                         MBEDTLS_KW_MODE_KW : MBEDTLS_KW_MODE_KWP;
1605 
1606         /* There is no iv, tag or ad associated with KW and KWP,
1607          * so these length should be 0 as documented. */
1608         if( iv_len != 0 || tag_len != 0 || ad_len != 0 )
1609             return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1610 
1611         (void) iv;
1612         (void) ad;
1613 
1614         return( mbedtls_nist_kw_unwrap( ctx->cipher_ctx, mode, input, ilen,
1615                                         output, olen, output_len ) );
1616     }
1617 #endif /* MBEDTLS_NIST_KW_C */
1618 
1619 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
1620     /* AEAD case: check length before passing on to shared function */
1621     if( ilen < tag_len || output_len < ilen - tag_len )
1622         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
1623 
1624     return( mbedtls_cipher_aead_decrypt( ctx, iv, iv_len, ad, ad_len,
1625                                          input, ilen - tag_len, output, olen,
1626                                          input + ilen - tag_len, tag_len ) );
1627 #else
1628     return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
1629 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1630 }
1631 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1632 
1633 #endif /* MBEDTLS_CIPHER_C */
1634