/src/mbedtls/library/ccm.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * NIST SP800-38C compliant CCM implementation |
3 | | * |
4 | | * Copyright The Mbed TLS Contributors |
5 | | * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later |
6 | | */ |
7 | | |
8 | | /* |
9 | | * Definition of CCM: |
10 | | * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf |
11 | | * RFC 3610 "Counter with CBC-MAC (CCM)" |
12 | | * |
13 | | * Related: |
14 | | * RFC 5116 "An Interface and Algorithms for Authenticated Encryption" |
15 | | */ |
16 | | |
17 | | #include "common.h" |
18 | | |
19 | | #if defined(MBEDTLS_CCM_C) |
20 | | |
21 | | #include "mbedtls/ccm.h" |
22 | | #include "mbedtls/platform_util.h" |
23 | | #include "mbedtls/error.h" |
24 | | #include "mbedtls/constant_time.h" |
25 | | |
26 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
27 | | #include "block_cipher_internal.h" |
28 | | #endif |
29 | | |
30 | | #include <string.h> |
31 | | |
32 | | #if defined(MBEDTLS_PLATFORM_C) |
33 | | #include "mbedtls/platform.h" |
34 | | #else |
35 | | #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) |
36 | | #include <stdio.h> |
37 | | #define mbedtls_printf printf |
38 | | #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ |
39 | | #endif /* MBEDTLS_PLATFORM_C */ |
40 | | |
41 | | #if !defined(MBEDTLS_CCM_ALT) |
42 | | |
43 | | |
44 | | /* |
45 | | * Initialize context |
46 | | */ |
47 | | void mbedtls_ccm_init(mbedtls_ccm_context *ctx) |
48 | 96 | { |
49 | 96 | memset(ctx, 0, sizeof(mbedtls_ccm_context)); |
50 | 96 | } |
51 | | |
52 | | int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx, |
53 | | mbedtls_cipher_id_t cipher, |
54 | | const unsigned char *key, |
55 | | unsigned int keybits) |
56 | 37 | { |
57 | 37 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
58 | | |
59 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
60 | | mbedtls_block_cipher_free(&ctx->block_cipher_ctx); |
61 | | |
62 | | if ((ret = mbedtls_block_cipher_setup(&ctx->block_cipher_ctx, cipher)) != 0) { |
63 | | return MBEDTLS_ERR_CCM_BAD_INPUT; |
64 | | } |
65 | | |
66 | | if ((ret = mbedtls_block_cipher_setkey(&ctx->block_cipher_ctx, key, keybits)) != 0) { |
67 | | return MBEDTLS_ERR_CCM_BAD_INPUT; |
68 | | } |
69 | | #else |
70 | 37 | const mbedtls_cipher_info_t *cipher_info; |
71 | | |
72 | 37 | cipher_info = mbedtls_cipher_info_from_values(cipher, keybits, |
73 | 37 | MBEDTLS_MODE_ECB); |
74 | 37 | if (cipher_info == NULL) { |
75 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
76 | 0 | } |
77 | | |
78 | 37 | if (mbedtls_cipher_info_get_block_size(cipher_info) != 16) { |
79 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
80 | 0 | } |
81 | | |
82 | 37 | mbedtls_cipher_free(&ctx->cipher_ctx); |
83 | | |
84 | 37 | if ((ret = mbedtls_cipher_setup(&ctx->cipher_ctx, cipher_info)) != 0) { |
85 | 0 | return ret; |
86 | 0 | } |
87 | | |
88 | 37 | if ((ret = mbedtls_cipher_setkey(&ctx->cipher_ctx, key, keybits, |
89 | 37 | MBEDTLS_ENCRYPT)) != 0) { |
90 | 0 | return ret; |
91 | 0 | } |
92 | 37 | #endif |
93 | | |
94 | 37 | return ret; |
95 | 37 | } |
96 | | |
97 | | /* |
98 | | * Free context |
99 | | */ |
100 | | void mbedtls_ccm_free(mbedtls_ccm_context *ctx) |
101 | 96 | { |
102 | 96 | if (ctx == NULL) { |
103 | 0 | return; |
104 | 0 | } |
105 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
106 | | mbedtls_block_cipher_free(&ctx->block_cipher_ctx); |
107 | | #else |
108 | 96 | mbedtls_cipher_free(&ctx->cipher_ctx); |
109 | 96 | #endif |
110 | 96 | mbedtls_platform_zeroize(ctx, sizeof(mbedtls_ccm_context)); |
111 | 96 | } |
112 | | |
113 | 13 | #define CCM_STATE__CLEAR 0 |
114 | 48 | #define CCM_STATE__STARTED (1 << 0) |
115 | 46 | #define CCM_STATE__LENGTHS_SET (1 << 1) |
116 | 22 | #define CCM_STATE__AUTH_DATA_STARTED (1 << 2) |
117 | 33 | #define CCM_STATE__AUTH_DATA_FINISHED (1 << 3) |
118 | 41 | #define CCM_STATE__ERROR (1 << 4) |
119 | | |
120 | | /* |
121 | | * Encrypt or decrypt a partial block with CTR |
122 | | */ |
123 | | static int mbedtls_ccm_crypt(mbedtls_ccm_context *ctx, |
124 | | size_t offset, size_t use_len, |
125 | | const unsigned char *input, |
126 | | unsigned char *output) |
127 | 27 | { |
128 | 27 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
129 | 27 | unsigned char tmp_buf[16] = { 0 }; |
130 | | |
131 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
132 | | ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->ctr, tmp_buf); |
133 | | #else |
134 | 27 | size_t olen = 0; |
135 | 27 | ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->ctr, 16, tmp_buf, &olen); |
136 | 27 | #endif |
137 | 27 | if (ret != 0) { |
138 | 0 | ctx->state |= CCM_STATE__ERROR; |
139 | 0 | mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf)); |
140 | 0 | return ret; |
141 | 0 | } |
142 | | |
143 | 27 | mbedtls_xor(output, input, tmp_buf + offset, use_len); |
144 | | |
145 | 27 | mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf)); |
146 | 27 | return ret; |
147 | 27 | } |
148 | | |
149 | | static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx) |
150 | 13 | { |
151 | 13 | ctx->state = CCM_STATE__CLEAR; |
152 | 13 | memset(ctx->y, 0, 16); |
153 | 13 | memset(ctx->ctr, 0, 16); |
154 | 13 | } |
155 | | |
156 | | static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx) |
157 | 32 | { |
158 | 32 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
159 | 32 | unsigned char i; |
160 | 32 | size_t len_left; |
161 | 32 | #if !defined(MBEDTLS_BLOCK_CIPHER_C) |
162 | 32 | size_t olen; |
163 | 32 | #endif |
164 | | |
165 | | /* length calculation can be done only after both |
166 | | * mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed |
167 | | */ |
168 | 32 | if (!(ctx->state & CCM_STATE__STARTED) || !(ctx->state & CCM_STATE__LENGTHS_SET)) { |
169 | 16 | return 0; |
170 | 16 | } |
171 | | |
172 | | /* CCM expects non-empty tag. |
173 | | * CCM* allows empty tag. For CCM* without tag, the tag calculation is skipped. |
174 | | */ |
175 | 16 | if (ctx->tag_len == 0) { |
176 | 3 | if (ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT || ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) { |
177 | 2 | ctx->plaintext_len = 0; |
178 | 2 | return 0; |
179 | 2 | } else { |
180 | 1 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
181 | 1 | } |
182 | 3 | } |
183 | | |
184 | | /* |
185 | | * First block: |
186 | | * 0 .. 0 flags |
187 | | * 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts() |
188 | | * iv_len+1 .. 15 length |
189 | | * |
190 | | * With flags as (bits): |
191 | | * 7 0 |
192 | | * 6 add present? |
193 | | * 5 .. 3 (t - 2) / 2 |
194 | | * 2 .. 0 q - 1 |
195 | | */ |
196 | 13 | ctx->y[0] |= (ctx->add_len > 0) << 6; |
197 | 13 | ctx->y[0] |= ((ctx->tag_len - 2) / 2) << 3; |
198 | 13 | ctx->y[0] |= ctx->q - 1; |
199 | | |
200 | 52 | for (i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8) { |
201 | 39 | ctx->y[15-i] = MBEDTLS_BYTE_0(len_left); |
202 | 39 | } |
203 | | |
204 | 13 | if (len_left > 0) { |
205 | 0 | ctx->state |= CCM_STATE__ERROR; |
206 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
207 | 0 | } |
208 | | |
209 | | /* Start CBC-MAC with first block*/ |
210 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
211 | | ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y); |
212 | | #else |
213 | 13 | ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen); |
214 | 13 | #endif |
215 | 13 | if (ret != 0) { |
216 | 0 | ctx->state |= CCM_STATE__ERROR; |
217 | 0 | return ret; |
218 | 0 | } |
219 | | |
220 | 13 | return 0; |
221 | 13 | } |
222 | | |
223 | | int mbedtls_ccm_starts(mbedtls_ccm_context *ctx, |
224 | | int mode, |
225 | | const unsigned char *iv, |
226 | | size_t iv_len) |
227 | 17 | { |
228 | | /* Also implies q is within bounds */ |
229 | 17 | if (iv_len < 7 || iv_len > 13) { |
230 | 1 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
231 | 1 | } |
232 | | |
233 | 16 | ctx->mode = mode; |
234 | 16 | ctx->q = 16 - 1 - (unsigned char) iv_len; |
235 | | |
236 | | /* |
237 | | * Prepare counter block for encryption: |
238 | | * 0 .. 0 flags |
239 | | * 1 .. iv_len nonce (aka iv) |
240 | | * iv_len+1 .. 15 counter (initially 1) |
241 | | * |
242 | | * With flags as (bits): |
243 | | * 7 .. 3 0 |
244 | | * 2 .. 0 q - 1 |
245 | | */ |
246 | 16 | memset(ctx->ctr, 0, 16); |
247 | 16 | ctx->ctr[0] = ctx->q - 1; |
248 | 16 | memcpy(ctx->ctr + 1, iv, iv_len); |
249 | 16 | memset(ctx->ctr + 1 + iv_len, 0, ctx->q); |
250 | 16 | ctx->ctr[15] = 1; |
251 | | |
252 | | /* |
253 | | * See ccm_calculate_first_block_if_ready() for block layout description |
254 | | */ |
255 | 16 | memcpy(ctx->y + 1, iv, iv_len); |
256 | | |
257 | 16 | ctx->state |= CCM_STATE__STARTED; |
258 | 16 | return ccm_calculate_first_block_if_ready(ctx); |
259 | 17 | } |
260 | | |
261 | | int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx, |
262 | | size_t total_ad_len, |
263 | | size_t plaintext_len, |
264 | | size_t tag_len) |
265 | 16 | { |
266 | | /* |
267 | | * Check length requirements: SP800-38C A.1 |
268 | | * Additional requirement: a < 2^16 - 2^8 to simplify the code. |
269 | | * 'length' checked later (when writing it to the first block) |
270 | | * |
271 | | * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4). |
272 | | */ |
273 | 16 | if (tag_len == 2 || tag_len > 16 || tag_len % 2 != 0) { |
274 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
275 | 0 | } |
276 | | |
277 | 16 | if (total_ad_len >= 0xFF00) { |
278 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
279 | 0 | } |
280 | | |
281 | 16 | ctx->plaintext_len = plaintext_len; |
282 | 16 | ctx->add_len = total_ad_len; |
283 | 16 | ctx->tag_len = tag_len; |
284 | 16 | ctx->processed = 0; |
285 | | |
286 | 16 | ctx->state |= CCM_STATE__LENGTHS_SET; |
287 | 16 | return ccm_calculate_first_block_if_ready(ctx); |
288 | 16 | } |
289 | | |
290 | | int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx, |
291 | | const unsigned char *add, |
292 | | size_t add_len) |
293 | 13 | { |
294 | 13 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
295 | 13 | size_t use_len, offset; |
296 | 13 | #if !defined(MBEDTLS_BLOCK_CIPHER_C) |
297 | 13 | size_t olen; |
298 | 13 | #endif |
299 | | |
300 | 13 | if (ctx->state & CCM_STATE__ERROR) { |
301 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
302 | 0 | } |
303 | | |
304 | 13 | if (add_len > 0) { |
305 | 11 | if (ctx->state & CCM_STATE__AUTH_DATA_FINISHED) { |
306 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
307 | 0 | } |
308 | | |
309 | 11 | if (!(ctx->state & CCM_STATE__AUTH_DATA_STARTED)) { |
310 | 11 | if (add_len > ctx->add_len) { |
311 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
312 | 0 | } |
313 | | |
314 | 11 | ctx->y[0] ^= (unsigned char) ((ctx->add_len >> 8) & 0xFF); |
315 | 11 | ctx->y[1] ^= (unsigned char) ((ctx->add_len) & 0xFF); |
316 | | |
317 | 11 | ctx->state |= CCM_STATE__AUTH_DATA_STARTED; |
318 | 11 | } else if (ctx->processed + add_len > ctx->add_len) { |
319 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
320 | 0 | } |
321 | | |
322 | 22 | while (add_len > 0) { |
323 | 11 | offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1] |
324 | | * holding total auth data length */ |
325 | 11 | use_len = 16 - offset; |
326 | | |
327 | 11 | if (use_len > add_len) { |
328 | 11 | use_len = add_len; |
329 | 11 | } |
330 | | |
331 | 11 | mbedtls_xor(ctx->y + offset, ctx->y + offset, add, use_len); |
332 | | |
333 | 11 | ctx->processed += use_len; |
334 | 11 | add_len -= use_len; |
335 | 11 | add += use_len; |
336 | | |
337 | 11 | if (use_len + offset == 16 || ctx->processed == ctx->add_len) { |
338 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
339 | | ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y); |
340 | | #else |
341 | 11 | ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen); |
342 | 11 | #endif |
343 | 11 | if (ret != 0) { |
344 | 0 | ctx->state |= CCM_STATE__ERROR; |
345 | 0 | return ret; |
346 | 0 | } |
347 | 11 | } |
348 | 11 | } |
349 | | |
350 | 11 | if (ctx->processed == ctx->add_len) { |
351 | 11 | ctx->state |= CCM_STATE__AUTH_DATA_FINISHED; |
352 | 11 | ctx->processed = 0; // prepare for mbedtls_ccm_update() |
353 | 11 | } |
354 | 11 | } |
355 | | |
356 | 13 | return 0; |
357 | 13 | } |
358 | | |
359 | | int mbedtls_ccm_update(mbedtls_ccm_context *ctx, |
360 | | const unsigned char *input, size_t input_len, |
361 | | unsigned char *output, size_t output_size, |
362 | | size_t *output_len) |
363 | 15 | { |
364 | 15 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
365 | 15 | unsigned char i; |
366 | 15 | size_t use_len, offset; |
367 | 15 | #if !defined(MBEDTLS_BLOCK_CIPHER_C) |
368 | 15 | size_t olen; |
369 | 15 | #endif |
370 | | |
371 | 15 | unsigned char local_output[16]; |
372 | | |
373 | 15 | if (ctx->state & CCM_STATE__ERROR) { |
374 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
375 | 0 | } |
376 | | |
377 | | /* Check against plaintext length only if performing operation with |
378 | | * authentication |
379 | | */ |
380 | 15 | if (ctx->tag_len != 0 && ctx->processed + input_len > ctx->plaintext_len) { |
381 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
382 | 0 | } |
383 | | |
384 | 15 | if (output_size < input_len) { |
385 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
386 | 0 | } |
387 | 15 | *output_len = input_len; |
388 | | |
389 | 15 | ret = 0; |
390 | | |
391 | 29 | while (input_len > 0) { |
392 | 14 | offset = ctx->processed % 16; |
393 | | |
394 | 14 | use_len = 16 - offset; |
395 | | |
396 | 14 | if (use_len > input_len) { |
397 | 2 | use_len = input_len; |
398 | 2 | } |
399 | | |
400 | 14 | ctx->processed += use_len; |
401 | | |
402 | 14 | if (ctx->mode == MBEDTLS_CCM_ENCRYPT || \ |
403 | 14 | ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT) { |
404 | 0 | mbedtls_xor(ctx->y + offset, ctx->y + offset, input, use_len); |
405 | |
|
406 | 0 | if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { |
407 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
408 | | ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y); |
409 | | #else |
410 | 0 | ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen); |
411 | 0 | #endif |
412 | 0 | if (ret != 0) { |
413 | 0 | ctx->state |= CCM_STATE__ERROR; |
414 | 0 | goto exit; |
415 | 0 | } |
416 | 0 | } |
417 | | |
418 | 0 | ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, output); |
419 | 0 | if (ret != 0) { |
420 | 0 | goto exit; |
421 | 0 | } |
422 | 0 | } |
423 | | |
424 | 14 | if (ctx->mode == MBEDTLS_CCM_DECRYPT || \ |
425 | 14 | ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) { |
426 | | /* Since output may be in shared memory, we cannot be sure that |
427 | | * it will contain what we wrote to it. Therefore, we should avoid using |
428 | | * it as input to any operations. |
429 | | * Write decrypted data to local_output to avoid using output variable as |
430 | | * input in the XOR operation for Y. |
431 | | */ |
432 | 14 | ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, local_output); |
433 | 14 | if (ret != 0) { |
434 | 0 | goto exit; |
435 | 0 | } |
436 | | |
437 | 14 | mbedtls_xor(ctx->y + offset, ctx->y + offset, local_output, use_len); |
438 | | |
439 | 14 | memcpy(output, local_output, use_len); |
440 | | |
441 | 14 | if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { |
442 | | #if defined(MBEDTLS_BLOCK_CIPHER_C) |
443 | | ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y); |
444 | | #else |
445 | 12 | ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen); |
446 | 12 | #endif |
447 | 12 | if (ret != 0) { |
448 | 0 | ctx->state |= CCM_STATE__ERROR; |
449 | 0 | goto exit; |
450 | 0 | } |
451 | 12 | } |
452 | 14 | } |
453 | | |
454 | 14 | if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { |
455 | 12 | for (i = 0; i < ctx->q; i++) { |
456 | 12 | if (++(ctx->ctr)[15-i] != 0) { |
457 | 12 | break; |
458 | 12 | } |
459 | 12 | } |
460 | 12 | } |
461 | | |
462 | 14 | input_len -= use_len; |
463 | 14 | input += use_len; |
464 | 14 | output += use_len; |
465 | 14 | } |
466 | | |
467 | 15 | exit: |
468 | 15 | mbedtls_platform_zeroize(local_output, 16); |
469 | | |
470 | 15 | return ret; |
471 | 15 | } |
472 | | |
473 | | int mbedtls_ccm_finish(mbedtls_ccm_context *ctx, |
474 | | unsigned char *tag, size_t tag_len) |
475 | 13 | { |
476 | 13 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
477 | 13 | unsigned char i; |
478 | | |
479 | 13 | if (ctx->state & CCM_STATE__ERROR) { |
480 | 0 | return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
481 | 0 | } |
482 | | |
483 | 13 | if (ctx->add_len > 0 && !(ctx->state & CCM_STATE__AUTH_DATA_FINISHED)) { |
484 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
485 | 0 | } |
486 | | |
487 | 13 | if (ctx->plaintext_len > 0 && ctx->processed != ctx->plaintext_len) { |
488 | 0 | return MBEDTLS_ERR_CCM_BAD_INPUT; |
489 | 0 | } |
490 | | |
491 | | /* |
492 | | * Authentication: reset counter and crypt/mask internal tag |
493 | | */ |
494 | 52 | for (i = 0; i < ctx->q; i++) { |
495 | 39 | ctx->ctr[15-i] = 0; |
496 | 39 | } |
497 | | |
498 | 13 | ret = mbedtls_ccm_crypt(ctx, 0, 16, ctx->y, ctx->y); |
499 | 13 | if (ret != 0) { |
500 | 0 | return ret; |
501 | 0 | } |
502 | 13 | if (tag != NULL) { |
503 | 13 | memcpy(tag, ctx->y, tag_len); |
504 | 13 | } |
505 | 13 | mbedtls_ccm_clear_state(ctx); |
506 | | |
507 | 13 | return 0; |
508 | 13 | } |
509 | | |
510 | | /* |
511 | | * Authenticated encryption or decryption |
512 | | */ |
513 | | static int ccm_auth_crypt(mbedtls_ccm_context *ctx, int mode, size_t length, |
514 | | const unsigned char *iv, size_t iv_len, |
515 | | const unsigned char *add, size_t add_len, |
516 | | const unsigned char *input, unsigned char *output, |
517 | | unsigned char *tag, size_t tag_len) |
518 | 15 | { |
519 | 15 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
520 | 15 | size_t olen; |
521 | | |
522 | 15 | if ((ret = mbedtls_ccm_starts(ctx, mode, iv, iv_len)) != 0) { |
523 | 1 | return ret; |
524 | 1 | } |
525 | | |
526 | 14 | if ((ret = mbedtls_ccm_set_lengths(ctx, add_len, length, tag_len)) != 0) { |
527 | 1 | return ret; |
528 | 1 | } |
529 | | |
530 | 13 | if ((ret = mbedtls_ccm_update_ad(ctx, add, add_len)) != 0) { |
531 | 0 | return ret; |
532 | 0 | } |
533 | | |
534 | 13 | if ((ret = mbedtls_ccm_update(ctx, input, length, |
535 | 13 | output, length, &olen)) != 0) { |
536 | 0 | return ret; |
537 | 0 | } |
538 | | |
539 | 13 | if ((ret = mbedtls_ccm_finish(ctx, tag, tag_len)) != 0) { |
540 | 0 | return ret; |
541 | 0 | } |
542 | | |
543 | 13 | return 0; |
544 | 13 | } |
545 | | |
546 | | /* |
547 | | * Authenticated encryption |
548 | | */ |
549 | | int mbedtls_ccm_star_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length, |
550 | | const unsigned char *iv, size_t iv_len, |
551 | | const unsigned char *add, size_t add_len, |
552 | | const unsigned char *input, unsigned char *output, |
553 | | unsigned char *tag, size_t tag_len) |
554 | 0 | { |
555 | 0 | return ccm_auth_crypt(ctx, MBEDTLS_CCM_STAR_ENCRYPT, length, iv, iv_len, |
556 | 0 | add, add_len, input, output, tag, tag_len); |
557 | 0 | } |
558 | | |
559 | | int mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context *ctx, 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 | | unsigned char *tag, size_t tag_len) |
564 | 0 | { |
565 | 0 | return ccm_auth_crypt(ctx, MBEDTLS_CCM_ENCRYPT, length, iv, iv_len, |
566 | 0 | add, add_len, input, output, tag, tag_len); |
567 | 0 | } |
568 | | |
569 | | /* |
570 | | * Authenticated decryption |
571 | | */ |
572 | | static int mbedtls_ccm_compare_tags(const unsigned char *tag1, |
573 | | const unsigned char *tag2, |
574 | | size_t tag_len) |
575 | 13 | { |
576 | | /* Check tag in "constant-time" */ |
577 | 13 | int diff = mbedtls_ct_memcmp(tag1, tag2, tag_len); |
578 | | |
579 | 13 | if (diff != 0) { |
580 | 13 | return MBEDTLS_ERR_CCM_AUTH_FAILED; |
581 | 13 | } |
582 | | |
583 | 0 | return 0; |
584 | 13 | } |
585 | | |
586 | | static int ccm_auth_decrypt(mbedtls_ccm_context *ctx, int mode, size_t length, |
587 | | const unsigned char *iv, size_t iv_len, |
588 | | const unsigned char *add, size_t add_len, |
589 | | const unsigned char *input, unsigned char *output, |
590 | | const unsigned char *tag, size_t tag_len) |
591 | 15 | { |
592 | 15 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
593 | 15 | unsigned char check_tag[16]; |
594 | | |
595 | 15 | if ((ret = ccm_auth_crypt(ctx, mode, length, |
596 | 15 | iv, iv_len, add, add_len, |
597 | 15 | input, output, check_tag, tag_len)) != 0) { |
598 | 2 | return ret; |
599 | 2 | } |
600 | | |
601 | 13 | if ((ret = mbedtls_ccm_compare_tags(tag, check_tag, tag_len)) != 0) { |
602 | 13 | mbedtls_platform_zeroize(output, length); |
603 | 13 | return ret; |
604 | 13 | } |
605 | | |
606 | 0 | return 0; |
607 | 13 | } |
608 | | |
609 | | int mbedtls_ccm_star_auth_decrypt(mbedtls_ccm_context *ctx, size_t length, |
610 | | const unsigned char *iv, size_t iv_len, |
611 | | const unsigned char *add, size_t add_len, |
612 | | const unsigned char *input, unsigned char *output, |
613 | | const unsigned char *tag, size_t tag_len) |
614 | 0 | { |
615 | 0 | return ccm_auth_decrypt(ctx, MBEDTLS_CCM_STAR_DECRYPT, length, |
616 | 0 | iv, iv_len, add, add_len, |
617 | 0 | input, output, tag, tag_len); |
618 | 0 | } |
619 | | |
620 | | int mbedtls_ccm_auth_decrypt(mbedtls_ccm_context *ctx, size_t length, |
621 | | const unsigned char *iv, size_t iv_len, |
622 | | const unsigned char *add, size_t add_len, |
623 | | const unsigned char *input, unsigned char *output, |
624 | | const unsigned char *tag, size_t tag_len) |
625 | 15 | { |
626 | 15 | return ccm_auth_decrypt(ctx, MBEDTLS_CCM_DECRYPT, length, |
627 | 15 | iv, iv_len, add, add_len, |
628 | 15 | input, output, tag, tag_len); |
629 | 15 | } |
630 | | #endif /* !MBEDTLS_CCM_ALT */ |
631 | | |
632 | | #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_CCM_GCM_CAN_AES) |
633 | | /* |
634 | | * Examples 1 to 3 from SP800-38C Appendix C |
635 | | */ |
636 | | |
637 | 0 | #define NB_TESTS 3 |
638 | 0 | #define CCM_SELFTEST_PT_MAX_LEN 24 |
639 | 0 | #define CCM_SELFTEST_CT_MAX_LEN 32 |
640 | | /* |
641 | | * The data is the same for all tests, only the used length changes |
642 | | */ |
643 | | static const unsigned char key_test_data[] = { |
644 | | 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, |
645 | | 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f |
646 | | }; |
647 | | |
648 | | static const unsigned char iv_test_data[] = { |
649 | | 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, |
650 | | 0x18, 0x19, 0x1a, 0x1b |
651 | | }; |
652 | | |
653 | | static const unsigned char ad_test_data[] = { |
654 | | 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, |
655 | | 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, |
656 | | 0x10, 0x11, 0x12, 0x13 |
657 | | }; |
658 | | |
659 | | static const unsigned char msg_test_data[CCM_SELFTEST_PT_MAX_LEN] = { |
660 | | 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, |
661 | | 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, |
662 | | 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, |
663 | | }; |
664 | | |
665 | | static const size_t iv_len_test_data[NB_TESTS] = { 7, 8, 12 }; |
666 | | static const size_t add_len_test_data[NB_TESTS] = { 8, 16, 20 }; |
667 | | static const size_t msg_len_test_data[NB_TESTS] = { 4, 16, 24 }; |
668 | | static const size_t tag_len_test_data[NB_TESTS] = { 4, 6, 8 }; |
669 | | |
670 | | static const unsigned char res_test_data[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = { |
671 | | { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d }, |
672 | | { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62, |
673 | | 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d, |
674 | | 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd }, |
675 | | { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a, |
676 | | 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b, |
677 | | 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5, |
678 | | 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 } |
679 | | }; |
680 | | |
681 | | int mbedtls_ccm_self_test(int verbose) |
682 | 0 | { |
683 | 0 | mbedtls_ccm_context ctx; |
684 | | /* |
685 | | * Some hardware accelerators require the input and output buffers |
686 | | * would be in RAM, because the flash is not accessible. |
687 | | * Use buffers on the stack to hold the test vectors data. |
688 | | */ |
689 | 0 | unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN]; |
690 | 0 | unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN]; |
691 | 0 | size_t i; |
692 | 0 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
693 | |
|
694 | 0 | mbedtls_ccm_init(&ctx); |
695 | |
|
696 | 0 | if (mbedtls_ccm_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, key_test_data, |
697 | 0 | 8 * sizeof(key_test_data)) != 0) { |
698 | 0 | if (verbose != 0) { |
699 | 0 | mbedtls_printf(" CCM: setup failed"); |
700 | 0 | } |
701 | |
|
702 | 0 | return 1; |
703 | 0 | } |
704 | | |
705 | 0 | for (i = 0; i < NB_TESTS; i++) { |
706 | 0 | if (verbose != 0) { |
707 | 0 | mbedtls_printf(" CCM-AES #%u: ", (unsigned int) i + 1); |
708 | 0 | } |
709 | |
|
710 | 0 | memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN); |
711 | 0 | memset(ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN); |
712 | 0 | memcpy(plaintext, msg_test_data, msg_len_test_data[i]); |
713 | |
|
714 | 0 | ret = mbedtls_ccm_encrypt_and_tag(&ctx, msg_len_test_data[i], |
715 | 0 | iv_test_data, iv_len_test_data[i], |
716 | 0 | ad_test_data, add_len_test_data[i], |
717 | 0 | plaintext, ciphertext, |
718 | 0 | ciphertext + msg_len_test_data[i], |
719 | 0 | tag_len_test_data[i]); |
720 | |
|
721 | 0 | if (ret != 0 || |
722 | 0 | memcmp(ciphertext, res_test_data[i], |
723 | 0 | msg_len_test_data[i] + tag_len_test_data[i]) != 0) { |
724 | 0 | if (verbose != 0) { |
725 | 0 | mbedtls_printf("failed\n"); |
726 | 0 | } |
727 | |
|
728 | 0 | return 1; |
729 | 0 | } |
730 | 0 | memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN); |
731 | |
|
732 | 0 | ret = mbedtls_ccm_auth_decrypt(&ctx, msg_len_test_data[i], |
733 | 0 | iv_test_data, iv_len_test_data[i], |
734 | 0 | ad_test_data, add_len_test_data[i], |
735 | 0 | ciphertext, plaintext, |
736 | 0 | ciphertext + msg_len_test_data[i], |
737 | 0 | tag_len_test_data[i]); |
738 | |
|
739 | 0 | if (ret != 0 || |
740 | 0 | memcmp(plaintext, msg_test_data, msg_len_test_data[i]) != 0) { |
741 | 0 | if (verbose != 0) { |
742 | 0 | mbedtls_printf("failed\n"); |
743 | 0 | } |
744 | |
|
745 | 0 | return 1; |
746 | 0 | } |
747 | | |
748 | 0 | if (verbose != 0) { |
749 | 0 | mbedtls_printf("passed\n"); |
750 | 0 | } |
751 | 0 | } |
752 | | |
753 | 0 | mbedtls_ccm_free(&ctx); |
754 | |
|
755 | 0 | if (verbose != 0) { |
756 | 0 | mbedtls_printf("\n"); |
757 | 0 | } |
758 | |
|
759 | 0 | return 0; |
760 | 0 | } |
761 | | |
762 | | #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ |
763 | | |
764 | | #endif /* MBEDTLS_CCM_C */ |