1 /*
2 * NIST SP800-38C compliant CCM implementation
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 /*
21 * Definition of CCM:
22 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
23 * RFC 3610 "Counter with CBC-MAC (CCM)"
24 *
25 * Related:
26 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
27 */
28
29 #include "common.h"
30
31 #if defined(MBEDTLS_CCM_C)
32
33 #include "mbedtls/ccm.h"
34 #include "mbedtls/platform_util.h"
35 #include "mbedtls/error.h"
36
37 #include <string.h>
38
39 #if defined(MBEDTLS_PLATFORM_C)
40 #include "mbedtls/platform.h"
41 #else
42 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
43 #include <stdio.h>
44 #define mbedtls_printf printf
45 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
46 #endif /* MBEDTLS_PLATFORM_C */
47
48 #if !defined(MBEDTLS_CCM_ALT)
49
50
51 /*
52 * Initialize context
53 */
mbedtls_ccm_init(mbedtls_ccm_context * ctx)54 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
55 {
56 memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
57 }
58
mbedtls_ccm_setkey(mbedtls_ccm_context * ctx,mbedtls_cipher_id_t cipher,const unsigned char * key,unsigned int keybits)59 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
60 mbedtls_cipher_id_t cipher,
61 const unsigned char *key,
62 unsigned int keybits )
63 {
64 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
65 const mbedtls_cipher_info_t *cipher_info;
66
67 cipher_info = mbedtls_cipher_info_from_values( cipher, keybits,
68 MBEDTLS_MODE_ECB );
69 if( cipher_info == NULL )
70 return( MBEDTLS_ERR_CCM_BAD_INPUT );
71
72 if( cipher_info->block_size != 16 )
73 return( MBEDTLS_ERR_CCM_BAD_INPUT );
74
75 mbedtls_cipher_free( &ctx->cipher_ctx );
76
77 if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
78 return( ret );
79
80 if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits,
81 MBEDTLS_ENCRYPT ) ) != 0 )
82 {
83 return( ret );
84 }
85
86 return( 0 );
87 }
88
89 /*
90 * Free context
91 */
mbedtls_ccm_free(mbedtls_ccm_context * ctx)92 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
93 {
94 if( ctx == NULL )
95 return;
96 mbedtls_cipher_free( &ctx->cipher_ctx );
97 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
98 }
99
100 #define CCM_STATE__CLEAR 0
101 #define CCM_STATE__STARTED (1 << 0)
102 #define CCM_STATE__LENGHTS_SET (1 << 1)
103 #define CCM_STATE__AUTH_DATA_STARTED (1 << 2)
104 #define CCM_STATE__AUTH_DATA_FINISHED (1 << 3)
105 #define CCM_STATE__ERROR (1 << 4)
106
107 /*
108 * Encrypt or decrypt a partial block with CTR
109 */
mbedtls_ccm_crypt(mbedtls_ccm_context * ctx,size_t offset,size_t use_len,const unsigned char * input,unsigned char * output)110 static int mbedtls_ccm_crypt( mbedtls_ccm_context *ctx,
111 size_t offset, size_t use_len,
112 const unsigned char *input,
113 unsigned char *output )
114 {
115 size_t i;
116 size_t olen = 0;
117 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
118 unsigned char tmp_buf[16] = {0};
119
120 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctx->ctr, 16, tmp_buf,
121 &olen ) ) != 0 )
122 {
123 ctx->state |= CCM_STATE__ERROR;
124 mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
125 return ret;
126 }
127
128 for( i = 0; i < use_len; i++ )
129 output[i] = input[i] ^ tmp_buf[offset + i];
130
131 mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
132 return ret;
133 }
134
mbedtls_ccm_clear_state(mbedtls_ccm_context * ctx)135 static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx) {
136 ctx->state = CCM_STATE__CLEAR;
137 memset( ctx->y, 0, 16);
138 memset( ctx->ctr, 0, 16);
139 }
140
ccm_calculate_first_block_if_ready(mbedtls_ccm_context * ctx)141 static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx)
142 {
143 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
144 unsigned char i;
145 size_t len_left, olen;
146
147 /* length calulcation can be done only after both
148 * mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed
149 */
150 if( !(ctx->state & CCM_STATE__STARTED) || !(ctx->state & CCM_STATE__LENGHTS_SET) )
151 return 0;
152
153 /* CCM expects non-empty tag.
154 * CCM* allows empty tag. For CCM* without tag, ignore plaintext length.
155 */
156 if( ctx->tag_len == 0 )
157 {
158 if( ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT || ctx->mode == MBEDTLS_CCM_STAR_DECRYPT )
159 {
160 ctx->plaintext_len = 0;
161 }
162 else
163 {
164 return( MBEDTLS_ERR_CCM_BAD_INPUT );
165 }
166 }
167
168 /*
169 * First block:
170 * 0 .. 0 flags
171 * 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts()
172 * iv_len+1 .. 15 length
173 *
174 * With flags as (bits):
175 * 7 0
176 * 6 add present?
177 * 5 .. 3 (t - 2) / 2
178 * 2 .. 0 q - 1
179 */
180 ctx->y[0] |= ( ctx->add_len > 0 ) << 6;
181 ctx->y[0] |= ( ( ctx->tag_len - 2 ) / 2 ) << 3;
182 ctx->y[0] |= ctx->q - 1;
183
184 for( i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8 )
185 ctx->y[15-i] = MBEDTLS_BYTE_0( len_left );
186
187 if( len_left > 0 )
188 {
189 ctx->state |= CCM_STATE__ERROR;
190 return( MBEDTLS_ERR_CCM_BAD_INPUT );
191 }
192
193 /* Start CBC-MAC with first block*/
194 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen ) ) != 0 )
195 {
196 ctx->state |= CCM_STATE__ERROR;
197 return( ret );
198 }
199
200 return (0);
201 }
202
mbedtls_ccm_starts(mbedtls_ccm_context * ctx,int mode,const unsigned char * iv,size_t iv_len)203 int mbedtls_ccm_starts( mbedtls_ccm_context *ctx,
204 int mode,
205 const unsigned char *iv,
206 size_t iv_len )
207 {
208 /* Also implies q is within bounds */
209 if( iv_len < 7 || iv_len > 13 )
210 return( MBEDTLS_ERR_CCM_BAD_INPUT );
211
212 ctx->mode = mode;
213 ctx->q = 16 - 1 - (unsigned char) iv_len;
214
215 /*
216 * Prepare counter block for encryption:
217 * 0 .. 0 flags
218 * 1 .. iv_len nonce (aka iv)
219 * iv_len+1 .. 15 counter (initially 1)
220 *
221 * With flags as (bits):
222 * 7 .. 3 0
223 * 2 .. 0 q - 1
224 */
225 memset( ctx->ctr, 0, 16);
226 ctx->ctr[0] = ctx->q - 1;
227 memcpy( ctx->ctr + 1, iv, iv_len );
228 memset( ctx->ctr + 1 + iv_len, 0, ctx->q );
229 ctx->ctr[15] = 1;
230
231 /*
232 * See ccm_calculate_first_block_if_ready() for block layout description
233 */
234 memcpy( ctx->y + 1, iv, iv_len );
235
236 ctx->state |= CCM_STATE__STARTED;
237 return ccm_calculate_first_block_if_ready(ctx);
238 }
239
mbedtls_ccm_set_lengths(mbedtls_ccm_context * ctx,size_t total_ad_len,size_t plaintext_len,size_t tag_len)240 int mbedtls_ccm_set_lengths( mbedtls_ccm_context *ctx,
241 size_t total_ad_len,
242 size_t plaintext_len,
243 size_t tag_len )
244 {
245 /*
246 * Check length requirements: SP800-38C A.1
247 * Additional requirement: a < 2^16 - 2^8 to simplify the code.
248 * 'length' checked later (when writing it to the first block)
249 *
250 * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
251 */
252 if( tag_len == 2 || tag_len > 16 || tag_len % 2 != 0 )
253 return( MBEDTLS_ERR_CCM_BAD_INPUT );
254
255 if( total_ad_len >= 0xFF00 )
256 return( MBEDTLS_ERR_CCM_BAD_INPUT );
257
258 ctx->plaintext_len = plaintext_len;
259 ctx->add_len = total_ad_len;
260 ctx->tag_len = tag_len;
261 ctx->processed = 0;
262
263 ctx->state |= CCM_STATE__LENGHTS_SET;
264 return ccm_calculate_first_block_if_ready(ctx);
265 }
266
mbedtls_ccm_update_ad(mbedtls_ccm_context * ctx,const unsigned char * add,size_t add_len)267 int mbedtls_ccm_update_ad( mbedtls_ccm_context *ctx,
268 const unsigned char *add,
269 size_t add_len )
270 {
271 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
272 unsigned char i;
273 size_t olen, use_len, offset;
274
275 if( ctx->state & CCM_STATE__ERROR )
276 {
277 return MBEDTLS_ERR_CCM_BAD_INPUT;
278 }
279
280 if( add_len > 0 )
281 {
282 if( ctx->state & CCM_STATE__AUTH_DATA_FINISHED )
283 {
284 return MBEDTLS_ERR_CCM_BAD_INPUT;
285 }
286
287 if( !(ctx->state & CCM_STATE__AUTH_DATA_STARTED) )
288 {
289 if ( add_len > ctx->add_len )
290 {
291 return MBEDTLS_ERR_CCM_BAD_INPUT;
292 }
293
294 ctx->y[0] ^= (unsigned char)( ( ctx->add_len >> 8 ) & 0xFF );
295 ctx->y[1] ^= (unsigned char)( ( ctx->add_len ) & 0xFF );
296
297 ctx->state |= CCM_STATE__AUTH_DATA_STARTED;
298 }
299 else if ( ctx->processed + add_len > ctx->add_len )
300 {
301 return MBEDTLS_ERR_CCM_BAD_INPUT;
302 }
303
304 while( add_len > 0 )
305 {
306 offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1]
307 * holding total auth data length */
308 use_len = 16 - offset;
309
310 if( use_len > add_len )
311 use_len = add_len;
312
313 for( i = 0; i < use_len; i++ )
314 ctx->y[i + offset] ^= add[i];
315
316 ctx->processed += use_len;
317 add_len -= use_len;
318 add += use_len;
319
320 if( use_len + offset == 16 || ctx->processed == ctx->add_len )
321 {
322 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen ) ) != 0 )
323 {
324 ctx->state |= CCM_STATE__ERROR;
325 return( ret );
326 }
327 }
328 }
329
330 if( ctx->processed == ctx->add_len )
331 {
332 ctx->state |= CCM_STATE__AUTH_DATA_FINISHED;
333 ctx->processed = 0; // prepare for mbedtls_ccm_update()
334 }
335 }
336
337 return (0);
338 }
339
mbedtls_ccm_update(mbedtls_ccm_context * ctx,const unsigned char * input,size_t input_len,unsigned char * output,size_t output_size,size_t * output_len)340 int mbedtls_ccm_update( mbedtls_ccm_context *ctx,
341 const unsigned char *input, size_t input_len,
342 unsigned char *output, size_t output_size,
343 size_t *output_len )
344 {
345 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
346 unsigned char i;
347 size_t use_len, offset, olen;
348
349 unsigned char local_output[16];
350
351 if( ctx->state & CCM_STATE__ERROR )
352 {
353 return MBEDTLS_ERR_CCM_BAD_INPUT;
354 }
355
356 /* Check against plaintext length only if performing operation with
357 * authentication
358 */
359 if( ctx->tag_len != 0 && ctx->processed + input_len > ctx->plaintext_len )
360 {
361 return MBEDTLS_ERR_CCM_BAD_INPUT;
362 }
363
364 if( output_size < input_len )
365 return( MBEDTLS_ERR_CCM_BAD_INPUT );
366 *output_len = input_len;
367
368 ret = 0;
369
370 while ( input_len > 0 )
371 {
372 offset = ctx->processed % 16;
373
374 use_len = 16 - offset;
375
376 if( use_len > input_len )
377 use_len = input_len;
378
379 ctx->processed += use_len;
380
381 if( ctx->mode == MBEDTLS_CCM_ENCRYPT || \
382 ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT )
383 {
384 for( i = 0; i < use_len; i++ )
385 ctx->y[i + offset] ^= input[i];
386
387 if( use_len + offset == 16 || ctx->processed == ctx->plaintext_len )
388 {
389 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen ) ) != 0 )
390 {
391 ctx->state |= CCM_STATE__ERROR;
392 goto exit;
393 }
394 }
395
396 ret = mbedtls_ccm_crypt( ctx, offset, use_len, input, output );
397 if( ret != 0 )
398 goto exit;
399 }
400
401 if( ctx->mode == MBEDTLS_CCM_DECRYPT || \
402 ctx->mode == MBEDTLS_CCM_STAR_DECRYPT )
403 {
404 /* Since output may be in shared memory, we cannot be sure that
405 * it will contain what we wrote to it. Therefore, we should avoid using
406 * it as input to any operations.
407 * Write decrypted data to local_output to avoid using output variable as
408 * input in the XOR operation for Y.
409 */
410 ret = mbedtls_ccm_crypt( ctx, offset, use_len, input, local_output );
411 if( ret != 0 )
412 goto exit;
413
414 for( i = 0; i < use_len; i++ )
415 ctx->y[i + offset] ^= local_output[i];
416
417 memcpy( output, local_output, use_len );
418 mbedtls_platform_zeroize( local_output, 16 );
419
420 if( use_len + offset == 16 || ctx->processed == ctx->plaintext_len )
421 {
422 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen ) ) != 0 )
423 {
424 ctx->state |= CCM_STATE__ERROR;
425 goto exit;
426 }
427 }
428 }
429
430 if( use_len + offset == 16 || ctx->processed == ctx->plaintext_len )
431 {
432 for( i = 0; i < ctx->q; i++ )
433 if( ++(ctx->ctr)[15-i] != 0 )
434 break;
435 }
436
437 input_len -= use_len;
438 input += use_len;
439 output += use_len;
440 }
441
442 exit:
443 mbedtls_platform_zeroize( local_output, 16 );
444
445 return ret;
446 }
447
mbedtls_ccm_finish(mbedtls_ccm_context * ctx,unsigned char * tag,size_t tag_len)448 int mbedtls_ccm_finish( mbedtls_ccm_context *ctx,
449 unsigned char *tag, size_t tag_len )
450 {
451 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
452 unsigned char i;
453
454 if( ctx->state & CCM_STATE__ERROR )
455 {
456 return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
457 }
458
459 if( ctx->add_len > 0 && !( ctx->state & CCM_STATE__AUTH_DATA_FINISHED ) )
460 {
461 return MBEDTLS_ERR_CCM_BAD_INPUT;
462 }
463
464 if( ctx->plaintext_len > 0 && ctx->processed != ctx->plaintext_len )
465 {
466 return MBEDTLS_ERR_CCM_BAD_INPUT;
467 }
468
469 /*
470 * Authentication: reset counter and crypt/mask internal tag
471 */
472 for( i = 0; i < ctx->q; i++ )
473 ctx->ctr[15-i] = 0;
474
475 ret = mbedtls_ccm_crypt( ctx, 0, 16, ctx->y, ctx->y );
476 if( ret != 0 )
477 return ret;
478 if( tag != NULL )
479 memcpy( tag, ctx->y, tag_len );
480 mbedtls_ccm_clear_state(ctx);
481
482 return( 0 );
483 }
484
485 /*
486 * Authenticated encryption or decryption
487 */
ccm_auth_crypt(mbedtls_ccm_context * ctx,int mode,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,unsigned char * tag,size_t tag_len)488 static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
489 const unsigned char *iv, size_t iv_len,
490 const unsigned char *add, size_t add_len,
491 const unsigned char *input, unsigned char *output,
492 unsigned char *tag, size_t tag_len )
493 {
494 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
495 size_t olen;
496
497 if( ( ret = mbedtls_ccm_starts( ctx, mode, iv, iv_len ) ) != 0 )
498 return( ret );
499
500 if( ( ret = mbedtls_ccm_set_lengths( ctx, add_len, length, tag_len ) ) != 0 )
501 return( ret );
502
503 if( ( ret = mbedtls_ccm_update_ad( ctx, add, add_len ) ) != 0 )
504 return( ret );
505
506 if( ( ret = mbedtls_ccm_update( ctx, input, length,
507 output, length, &olen ) ) != 0 )
508 return( ret );
509
510 if( ( ret = mbedtls_ccm_finish( ctx, tag, tag_len ) ) != 0 )
511 return( ret );
512
513 return( 0 );
514 }
515
516 /*
517 * Authenticated encryption
518 */
mbedtls_ccm_star_encrypt_and_tag(mbedtls_ccm_context * ctx,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,unsigned char * tag,size_t tag_len)519 int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
520 const unsigned char *iv, size_t iv_len,
521 const unsigned char *add, size_t add_len,
522 const unsigned char *input, unsigned char *output,
523 unsigned char *tag, size_t tag_len )
524 {
525 return( ccm_auth_crypt( ctx, MBEDTLS_CCM_STAR_ENCRYPT, length, iv, iv_len,
526 add, add_len, input, output, tag, tag_len ) );
527 }
528
mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context * ctx,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,unsigned char * tag,size_t tag_len)529 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
530 const unsigned char *iv, size_t iv_len,
531 const unsigned char *add, size_t add_len,
532 const unsigned char *input, unsigned char *output,
533 unsigned char *tag, size_t tag_len )
534 {
535 return( ccm_auth_crypt( ctx, MBEDTLS_CCM_ENCRYPT, length, iv, iv_len,
536 add, add_len, input, output, tag, tag_len ) );
537 }
538
539 /*
540 * Authenticated decryption
541 */
mbedtls_ccm_compare_tags(const unsigned char * tag1,const unsigned char * tag2,size_t tag_len)542 static int mbedtls_ccm_compare_tags(const unsigned char *tag1, const unsigned char *tag2, size_t tag_len)
543 {
544 unsigned char i;
545 int diff;
546
547 /* Check tag in "constant-time" */
548 for( diff = 0, i = 0; i < tag_len; i++ )
549 diff |= tag1[i] ^ tag2[i];
550
551 if( diff != 0 )
552 {
553 return( MBEDTLS_ERR_CCM_AUTH_FAILED );
554 }
555
556 return( 0 );
557 }
558
ccm_auth_decrypt(mbedtls_ccm_context * ctx,int mode,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,const unsigned char * tag,size_t tag_len)559 static int ccm_auth_decrypt( mbedtls_ccm_context *ctx, int mode, size_t length,
560 const unsigned char *iv, size_t iv_len,
561 const unsigned char *add, size_t add_len,
562 const unsigned char *input, unsigned char *output,
563 const unsigned char *tag, size_t tag_len )
564 {
565 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
566 unsigned char check_tag[16];
567
568 if( ( ret = ccm_auth_crypt( ctx, mode, length,
569 iv, iv_len, add, add_len,
570 input, output, check_tag, tag_len ) ) != 0 )
571 {
572 return( ret );
573 }
574
575 if( ( ret = mbedtls_ccm_compare_tags( tag, check_tag, tag_len ) ) != 0 )
576 {
577 mbedtls_platform_zeroize( output, length );
578 return( ret );
579 }
580
581 return( 0 );
582 }
583
mbedtls_ccm_star_auth_decrypt(mbedtls_ccm_context * ctx,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,const unsigned char * tag,size_t tag_len)584 int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
585 const unsigned char *iv, size_t iv_len,
586 const unsigned char *add, size_t add_len,
587 const unsigned char *input, unsigned char *output,
588 const unsigned char *tag, size_t tag_len )
589 {
590 return ccm_auth_decrypt( ctx, MBEDTLS_CCM_STAR_DECRYPT, length,
591 iv, iv_len, add, add_len,
592 input, output, tag, tag_len );
593 }
594
mbedtls_ccm_auth_decrypt(mbedtls_ccm_context * ctx,size_t length,const unsigned char * iv,size_t iv_len,const unsigned char * add,size_t add_len,const unsigned char * input,unsigned char * output,const unsigned char * tag,size_t tag_len)595 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
596 const unsigned char *iv, size_t iv_len,
597 const unsigned char *add, size_t add_len,
598 const unsigned char *input, unsigned char *output,
599 const unsigned char *tag, size_t tag_len )
600 {
601 return ccm_auth_decrypt( ctx, MBEDTLS_CCM_DECRYPT, length,
602 iv, iv_len, add, add_len,
603 input, output, tag, tag_len );
604 }
605 #endif /* !MBEDTLS_CCM_ALT */
606
607 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
608 /*
609 * Examples 1 to 3 from SP800-38C Appendix C
610 */
611
612 #define NB_TESTS 3
613 #define CCM_SELFTEST_PT_MAX_LEN 24
614 #define CCM_SELFTEST_CT_MAX_LEN 32
615 /*
616 * The data is the same for all tests, only the used length changes
617 */
618 static const unsigned char key_test_data[] = {
619 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
620 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
621 };
622
623 static const unsigned char iv_test_data[] = {
624 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
625 0x18, 0x19, 0x1a, 0x1b
626 };
627
628 static const unsigned char ad_test_data[] = {
629 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
630 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
631 0x10, 0x11, 0x12, 0x13
632 };
633
634 static const unsigned char msg_test_data[CCM_SELFTEST_PT_MAX_LEN] = {
635 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
636 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
637 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
638 };
639
640 static const size_t iv_len_test_data [NB_TESTS] = { 7, 8, 12 };
641 static const size_t add_len_test_data[NB_TESTS] = { 8, 16, 20 };
642 static const size_t msg_len_test_data[NB_TESTS] = { 4, 16, 24 };
643 static const size_t tag_len_test_data[NB_TESTS] = { 4, 6, 8 };
644
645 static const unsigned char res_test_data[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = {
646 { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
647 { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
648 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
649 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
650 { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
651 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
652 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
653 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
654 };
655
mbedtls_ccm_self_test(int verbose)656 int mbedtls_ccm_self_test( int verbose )
657 {
658 mbedtls_ccm_context ctx;
659 /*
660 * Some hardware accelerators require the input and output buffers
661 * would be in RAM, because the flash is not accessible.
662 * Use buffers on the stack to hold the test vectors data.
663 */
664 unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN];
665 unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN];
666 size_t i;
667 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
668
669 mbedtls_ccm_init( &ctx );
670
671 if( mbedtls_ccm_setkey( &ctx, MBEDTLS_CIPHER_ID_AES, key_test_data,
672 8 * sizeof key_test_data ) != 0 )
673 {
674 if( verbose != 0 )
675 mbedtls_printf( " CCM: setup failed" );
676
677 return( 1 );
678 }
679
680 for( i = 0; i < NB_TESTS; i++ )
681 {
682 if( verbose != 0 )
683 mbedtls_printf( " CCM-AES #%u: ", (unsigned int) i + 1 );
684
685 memset( plaintext, 0, CCM_SELFTEST_PT_MAX_LEN );
686 memset( ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN );
687 memcpy( plaintext, msg_test_data, msg_len_test_data[i] );
688
689 ret = mbedtls_ccm_encrypt_and_tag( &ctx, msg_len_test_data[i],
690 iv_test_data, iv_len_test_data[i],
691 ad_test_data, add_len_test_data[i],
692 plaintext, ciphertext,
693 ciphertext + msg_len_test_data[i],
694 tag_len_test_data[i] );
695
696 if( ret != 0 ||
697 memcmp( ciphertext, res_test_data[i],
698 msg_len_test_data[i] + tag_len_test_data[i] ) != 0 )
699 {
700 if( verbose != 0 )
701 mbedtls_printf( "failed\n" );
702
703 return( 1 );
704 }
705 memset( plaintext, 0, CCM_SELFTEST_PT_MAX_LEN );
706
707 ret = mbedtls_ccm_auth_decrypt( &ctx, msg_len_test_data[i],
708 iv_test_data, iv_len_test_data[i],
709 ad_test_data, add_len_test_data[i],
710 ciphertext, plaintext,
711 ciphertext + msg_len_test_data[i],
712 tag_len_test_data[i] );
713
714 if( ret != 0 ||
715 memcmp( plaintext, msg_test_data, msg_len_test_data[i] ) != 0 )
716 {
717 if( verbose != 0 )
718 mbedtls_printf( "failed\n" );
719
720 return( 1 );
721 }
722
723 if( verbose != 0 )
724 mbedtls_printf( "passed\n" );
725 }
726
727 mbedtls_ccm_free( &ctx );
728
729 if( verbose != 0 )
730 mbedtls_printf( "\n" );
731
732 return( 0 );
733 }
734
735 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
736
737 #endif /* MBEDTLS_CCM_C */
738