1 /*
2 * \brief Generic file encryption program using generic wrappers for configured
3 * security.
4 *
5 * Copyright The Mbed TLS Contributors
6 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
7 */
8
9 /* Enable definition of fileno() even when compiling with -std=c99. Must be
10 * set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
11 * Harmless on other platforms. */
12 #define _POSIX_C_SOURCE 200112L
13
14 #include "mbedtls/build_info.h"
15
16 #include "mbedtls/platform.h"
17
18 #if defined(MBEDTLS_CIPHER_C) && defined(MBEDTLS_MD_C) && \
19 defined(MBEDTLS_FS_IO)
20 #include "mbedtls/cipher.h"
21 #include "mbedtls/md.h"
22 #include "mbedtls/platform_util.h"
23
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #endif
28
29 #if defined(_WIN32)
30 #include <windows.h>
31 #if !defined(_WIN32_WCE)
32 #include <io.h>
33 #endif
34 #else
35 #include <sys/types.h>
36 #include <unistd.h>
37 #endif
38
39 #define MODE_ENCRYPT 0
40 #define MODE_DECRYPT 1
41
42 #define USAGE \
43 "\n crypt_and_hash <mode> <input filename> <output filename> <cipher> <mbedtls_md> <key>\n" \
44 "\n <mode>: 0 = encrypt, 1 = decrypt\n" \
45 "\n example: crypt_and_hash 0 file file.aes AES-128-CBC SHA1 hex:E76B2413958B00E193\n" \
46 "\n"
47
48 #if !defined(MBEDTLS_CIPHER_C) || !defined(MBEDTLS_MD_C) || \
49 !defined(MBEDTLS_FS_IO)
main(void)50 int main(void)
51 {
52 mbedtls_printf("MBEDTLS_CIPHER_C and/or MBEDTLS_MD_C and/or MBEDTLS_FS_IO not defined.\n");
53 mbedtls_exit(0);
54 }
55 #else
56
57
main(int argc,char * argv[])58 int main(int argc, char *argv[])
59 {
60 int ret = 1, i;
61 unsigned n;
62 int exit_code = MBEDTLS_EXIT_FAILURE;
63 int mode;
64 size_t keylen, ilen, olen;
65 FILE *fkey, *fin = NULL, *fout = NULL;
66
67 char *p;
68 unsigned char IV[16];
69 unsigned char key[512];
70 unsigned char digest[MBEDTLS_MD_MAX_SIZE];
71 unsigned char buffer[1024];
72 unsigned char output[1024];
73 unsigned char diff;
74
75 const mbedtls_cipher_info_t *cipher_info;
76 const mbedtls_md_info_t *md_info;
77 mbedtls_cipher_context_t cipher_ctx;
78 mbedtls_md_context_t md_ctx;
79 mbedtls_cipher_mode_t cipher_mode;
80 unsigned int cipher_block_size;
81 unsigned char md_size;
82 #if defined(_WIN32_WCE)
83 long filesize, offset;
84 #elif defined(_WIN32)
85 LARGE_INTEGER li_size;
86 __int64 filesize, offset;
87 #else
88 off_t filesize, offset;
89 #endif
90
91 mbedtls_cipher_init(&cipher_ctx);
92 mbedtls_md_init(&md_ctx);
93
94 /*
95 * Parse the command-line arguments.
96 */
97 if (argc != 7) {
98 const int *list;
99
100 mbedtls_printf(USAGE);
101
102 mbedtls_printf("Available ciphers:\n");
103 list = mbedtls_cipher_list();
104 while (*list) {
105 cipher_info = mbedtls_cipher_info_from_type(*list);
106 const char *name = mbedtls_cipher_info_get_name(cipher_info);
107
108 if (name) {
109 mbedtls_printf(" %s\n", mbedtls_cipher_info_get_name(cipher_info));
110 }
111 list++;
112 }
113
114 mbedtls_printf("\nAvailable message digests:\n");
115 list = mbedtls_md_list();
116 while (*list) {
117 md_info = mbedtls_md_info_from_type(*list);
118 mbedtls_printf(" %s\n", mbedtls_md_get_name(md_info));
119 list++;
120 }
121
122 goto exit;
123 }
124
125 mode = atoi(argv[1]);
126
127 if (mode != MODE_ENCRYPT && mode != MODE_DECRYPT) {
128 mbedtls_fprintf(stderr, "invalid operation mode\n");
129 goto exit;
130 }
131
132 if (strcmp(argv[2], argv[3]) == 0) {
133 mbedtls_fprintf(stderr, "input and output filenames must differ\n");
134 goto exit;
135 }
136
137 if ((fin = fopen(argv[2], "rb")) == NULL) {
138 mbedtls_fprintf(stderr, "fopen(%s,rb) failed\n", argv[2]);
139 goto exit;
140 }
141
142 if ((fout = fopen(argv[3], "wb+")) == NULL) {
143 mbedtls_fprintf(stderr, "fopen(%s,wb+) failed\n", argv[3]);
144 goto exit;
145 }
146
147 /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
148 mbedtls_setbuf(fin, NULL);
149 mbedtls_setbuf(fout, NULL);
150
151 /*
152 * Read the Cipher and MD from the command line
153 */
154 cipher_info = mbedtls_cipher_info_from_string(argv[4]);
155 if (cipher_info == NULL) {
156 mbedtls_fprintf(stderr, "Cipher '%s' not found\n", argv[4]);
157 goto exit;
158 }
159 if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {
160 mbedtls_fprintf(stderr, "mbedtls_cipher_setup failed\n");
161 goto exit;
162 }
163
164 md_info = mbedtls_md_info_from_string(argv[5]);
165 if (md_info == NULL) {
166 mbedtls_fprintf(stderr, "Message Digest '%s' not found\n", argv[5]);
167 goto exit;
168 }
169
170 if (mbedtls_md_setup(&md_ctx, md_info, 1) != 0) {
171 mbedtls_fprintf(stderr, "mbedtls_md_setup failed\n");
172 goto exit;
173 }
174
175 /*
176 * Read the secret key from file or command line
177 */
178 if ((fkey = fopen(argv[6], "rb")) != NULL) {
179 keylen = fread(key, 1, sizeof(key), fkey);
180 fclose(fkey);
181 } else {
182 if (memcmp(argv[6], "hex:", 4) == 0) {
183 p = &argv[6][4];
184 keylen = 0;
185
186 while (sscanf(p, "%02X", (unsigned int *) &n) > 0 &&
187 keylen < (int) sizeof(key)) {
188 key[keylen++] = (unsigned char) n;
189 p += 2;
190 }
191 } else {
192 keylen = strlen(argv[6]);
193
194 if (keylen > (int) sizeof(key)) {
195 keylen = (int) sizeof(key);
196 }
197
198 memcpy(key, argv[6], keylen);
199 }
200 }
201
202 #if defined(_WIN32_WCE)
203 filesize = fseek(fin, 0L, SEEK_END);
204 #else
205 #if defined(_WIN32)
206 /*
207 * Support large files (> 2Gb) on Win32
208 */
209 li_size.QuadPart = 0;
210 li_size.LowPart =
211 SetFilePointer((HANDLE) _get_osfhandle(_fileno(fin)),
212 li_size.LowPart, &li_size.HighPart, FILE_END);
213
214 if (li_size.LowPart == 0xFFFFFFFF && GetLastError() != NO_ERROR) {
215 mbedtls_fprintf(stderr, "SetFilePointer(0,FILE_END) failed\n");
216 goto exit;
217 }
218
219 filesize = li_size.QuadPart;
220 #else
221 if ((filesize = lseek(fileno(fin), 0, SEEK_END)) < 0) {
222 perror("lseek");
223 goto exit;
224 }
225 #endif
226 #endif
227
228 if (fseek(fin, 0, SEEK_SET) < 0) {
229 mbedtls_fprintf(stderr, "fseek(0,SEEK_SET) failed\n");
230 goto exit;
231 }
232
233 md_size = mbedtls_md_get_size(md_info);
234 cipher_block_size = mbedtls_cipher_get_block_size(&cipher_ctx);
235
236 if (mode == MODE_ENCRYPT) {
237 /*
238 * Generate the initialization vector as:
239 * IV = MD( filesize || filename )[0..15]
240 */
241 for (i = 0; i < 8; i++) {
242 buffer[i] = (unsigned char) (filesize >> (i << 3));
243 }
244
245 p = argv[2];
246
247 if (mbedtls_md_starts(&md_ctx) != 0) {
248 mbedtls_fprintf(stderr, "mbedtls_md_starts() returned error\n");
249 goto exit;
250 }
251 if (mbedtls_md_update(&md_ctx, buffer, 8) != 0) {
252 mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
253 goto exit;
254 }
255 if (mbedtls_md_update(&md_ctx, (unsigned char *) p, strlen(p))
256 != 0) {
257 mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
258 goto exit;
259 }
260 if (mbedtls_md_finish(&md_ctx, digest) != 0) {
261 mbedtls_fprintf(stderr, "mbedtls_md_finish() returned error\n");
262 goto exit;
263 }
264
265 memcpy(IV, digest, 16);
266
267 /*
268 * Append the IV at the beginning of the output.
269 */
270 if (fwrite(IV, 1, 16, fout) != 16) {
271 mbedtls_fprintf(stderr, "fwrite(%d bytes) failed\n", 16);
272 goto exit;
273 }
274
275 /*
276 * Hash the IV and the secret key together 8192 times
277 * using the result to setup the AES context and HMAC.
278 */
279 memset(digest, 0, 32);
280 memcpy(digest, IV, 16);
281
282 for (i = 0; i < 8192; i++) {
283 if (mbedtls_md_starts(&md_ctx) != 0) {
284 mbedtls_fprintf(stderr,
285 "mbedtls_md_starts() returned error\n");
286 goto exit;
287 }
288 if (mbedtls_md_update(&md_ctx, digest, 32) != 0) {
289 mbedtls_fprintf(stderr,
290 "mbedtls_md_update() returned error\n");
291 goto exit;
292 }
293 if (mbedtls_md_update(&md_ctx, key, keylen) != 0) {
294 mbedtls_fprintf(stderr,
295 "mbedtls_md_update() returned error\n");
296 goto exit;
297 }
298 if (mbedtls_md_finish(&md_ctx, digest) != 0) {
299 mbedtls_fprintf(stderr,
300 "mbedtls_md_finish() returned error\n");
301 goto exit;
302 }
303
304 }
305
306 if (mbedtls_cipher_setkey(&cipher_ctx,
307 digest,
308 (int) mbedtls_cipher_info_get_key_bitlen(cipher_info),
309 MBEDTLS_ENCRYPT) != 0) {
310 mbedtls_fprintf(stderr, "mbedtls_cipher_setkey() returned error\n");
311 goto exit;
312 }
313 if (mbedtls_cipher_set_iv(&cipher_ctx, IV, 16) != 0) {
314 mbedtls_fprintf(stderr, "mbedtls_cipher_set_iv() returned error\n");
315 goto exit;
316 }
317 if (mbedtls_cipher_reset(&cipher_ctx) != 0) {
318 mbedtls_fprintf(stderr, "mbedtls_cipher_reset() returned error\n");
319 goto exit;
320 }
321
322 if (mbedtls_md_hmac_starts(&md_ctx, digest, 32) != 0) {
323 mbedtls_fprintf(stderr, "mbedtls_md_hmac_starts() returned error\n");
324 goto exit;
325 }
326
327 /*
328 * Encrypt and write the ciphertext.
329 */
330 for (offset = 0; offset < filesize; offset += cipher_block_size) {
331 ilen = ((unsigned int) filesize - offset > cipher_block_size) ?
332 cipher_block_size : (unsigned int) (filesize - offset);
333
334 if (fread(buffer, 1, ilen, fin) != ilen) {
335 mbedtls_fprintf(stderr, "fread(%ld bytes) failed\n", (long) ilen);
336 goto exit;
337 }
338
339 if (mbedtls_cipher_update(&cipher_ctx, buffer, ilen, output, &olen) != 0) {
340 mbedtls_fprintf(stderr, "mbedtls_cipher_update() returned error\n");
341 goto exit;
342 }
343
344 if (mbedtls_md_hmac_update(&md_ctx, output, olen) != 0) {
345 mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
346 goto exit;
347 }
348
349 if (fwrite(output, 1, olen, fout) != olen) {
350 mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
351 goto exit;
352 }
353 }
354
355 if (mbedtls_cipher_finish(&cipher_ctx, output, &olen) != 0) {
356 mbedtls_fprintf(stderr, "mbedtls_cipher_finish() returned error\n");
357 goto exit;
358 }
359 if (mbedtls_md_hmac_update(&md_ctx, output, olen) != 0) {
360 mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
361 goto exit;
362 }
363
364 if (fwrite(output, 1, olen, fout) != olen) {
365 mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
366 goto exit;
367 }
368
369 /*
370 * Finally write the HMAC.
371 */
372 if (mbedtls_md_hmac_finish(&md_ctx, digest) != 0) {
373 mbedtls_fprintf(stderr, "mbedtls_md_hmac_finish() returned error\n");
374 goto exit;
375 }
376
377 if (fwrite(digest, 1, md_size, fout) != md_size) {
378 mbedtls_fprintf(stderr, "fwrite(%d bytes) failed\n", md_size);
379 goto exit;
380 }
381 }
382
383 if (mode == MODE_DECRYPT) {
384 /*
385 * The encrypted file must be structured as follows:
386 *
387 * 00 .. 15 Initialization Vector
388 * 16 .. 31 Encrypted Block #1
389 * ..
390 * N*16 .. (N+1)*16 - 1 Encrypted Block #N
391 * (N+1)*16 .. (N+1)*16 + n Hash(ciphertext)
392 */
393 if (filesize < 16 + md_size) {
394 mbedtls_fprintf(stderr, "File too short to be encrypted.\n");
395 goto exit;
396 }
397
398 if (cipher_block_size == 0) {
399 mbedtls_fprintf(stderr, "Invalid cipher block size: 0. \n");
400 goto exit;
401 }
402
403 /*
404 * Check the file size.
405 */
406 cipher_mode = mbedtls_cipher_info_get_mode(cipher_info);
407 if (cipher_mode != MBEDTLS_MODE_GCM &&
408 cipher_mode != MBEDTLS_MODE_CTR &&
409 cipher_mode != MBEDTLS_MODE_CFB &&
410 cipher_mode != MBEDTLS_MODE_OFB &&
411 ((filesize - md_size) % cipher_block_size) != 0) {
412 mbedtls_fprintf(stderr, "File content not a multiple of the block size (%u).\n",
413 cipher_block_size);
414 goto exit;
415 }
416
417 /*
418 * Subtract the IV + HMAC length.
419 */
420 filesize -= (16 + md_size);
421
422 /*
423 * Read the IV and original filesize modulo 16.
424 */
425 if (fread(buffer, 1, 16, fin) != 16) {
426 mbedtls_fprintf(stderr, "fread(%d bytes) failed\n", 16);
427 goto exit;
428 }
429
430 memcpy(IV, buffer, 16);
431
432 /*
433 * Hash the IV and the secret key together 8192 times
434 * using the result to setup the AES context and HMAC.
435 */
436 memset(digest, 0, 32);
437 memcpy(digest, IV, 16);
438
439 for (i = 0; i < 8192; i++) {
440 if (mbedtls_md_starts(&md_ctx) != 0) {
441 mbedtls_fprintf(stderr, "mbedtls_md_starts() returned error\n");
442 goto exit;
443 }
444 if (mbedtls_md_update(&md_ctx, digest, 32) != 0) {
445 mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
446 goto exit;
447 }
448 if (mbedtls_md_update(&md_ctx, key, keylen) != 0) {
449 mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
450 goto exit;
451 }
452 if (mbedtls_md_finish(&md_ctx, digest) != 0) {
453 mbedtls_fprintf(stderr, "mbedtls_md_finish() returned error\n");
454 goto exit;
455 }
456 }
457
458 if (mbedtls_cipher_setkey(&cipher_ctx,
459 digest,
460 (int) mbedtls_cipher_info_get_key_bitlen(cipher_info),
461 MBEDTLS_DECRYPT) != 0) {
462 mbedtls_fprintf(stderr, "mbedtls_cipher_setkey() returned error\n");
463 goto exit;
464 }
465
466 if (mbedtls_cipher_set_iv(&cipher_ctx, IV, 16) != 0) {
467 mbedtls_fprintf(stderr, "mbedtls_cipher_set_iv() returned error\n");
468 goto exit;
469 }
470
471 if (mbedtls_cipher_reset(&cipher_ctx) != 0) {
472 mbedtls_fprintf(stderr, "mbedtls_cipher_reset() returned error\n");
473 goto exit;
474 }
475
476 if (mbedtls_md_hmac_starts(&md_ctx, digest, 32) != 0) {
477 mbedtls_fprintf(stderr, "mbedtls_md_hmac_starts() returned error\n");
478 goto exit;
479 }
480
481 /*
482 * Decrypt and write the plaintext.
483 */
484 for (offset = 0; offset < filesize; offset += cipher_block_size) {
485 ilen = ((unsigned int) filesize - offset > cipher_block_size) ?
486 cipher_block_size : (unsigned int) (filesize - offset);
487
488 if (fread(buffer, 1, ilen, fin) != ilen) {
489 mbedtls_fprintf(stderr, "fread(%u bytes) failed\n",
490 cipher_block_size);
491 goto exit;
492 }
493
494 if (mbedtls_md_hmac_update(&md_ctx, buffer, ilen) != 0) {
495 mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
496 goto exit;
497 }
498 if (mbedtls_cipher_update(&cipher_ctx, buffer, ilen, output,
499 &olen) != 0) {
500 mbedtls_fprintf(stderr, "mbedtls_cipher_update() returned error\n");
501 goto exit;
502 }
503
504 if (fwrite(output, 1, olen, fout) != olen) {
505 mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
506 goto exit;
507 }
508 }
509
510 /*
511 * Verify the message authentication code.
512 */
513 if (mbedtls_md_hmac_finish(&md_ctx, digest) != 0) {
514 mbedtls_fprintf(stderr, "mbedtls_md_hmac_finish() returned error\n");
515 goto exit;
516 }
517
518 if (fread(buffer, 1, md_size, fin) != md_size) {
519 mbedtls_fprintf(stderr, "fread(%d bytes) failed\n", md_size);
520 goto exit;
521 }
522
523 /* Use constant-time buffer comparison */
524 diff = 0;
525 for (i = 0; i < md_size; i++) {
526 diff |= digest[i] ^ buffer[i];
527 }
528
529 if (diff != 0) {
530 mbedtls_fprintf(stderr, "HMAC check failed: wrong key, "
531 "or file corrupted.\n");
532 goto exit;
533 }
534
535 /*
536 * Write the final block of data
537 */
538 if (mbedtls_cipher_finish(&cipher_ctx, output, &olen) != 0) {
539 mbedtls_fprintf(stderr, "mbedtls_cipher_finish() returned error\n");
540 goto exit;
541 }
542
543 if (fwrite(output, 1, olen, fout) != olen) {
544 mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
545 goto exit;
546 }
547 }
548
549 exit_code = MBEDTLS_EXIT_SUCCESS;
550
551 exit:
552 if (fin) {
553 fclose(fin);
554 }
555 if (fout) {
556 fclose(fout);
557 }
558
559 /* Zeroize all command line arguments to also cover
560 the case when the user has missed or reordered some,
561 in which case the key might not be in argv[6]. */
562 for (i = 0; i < argc; i++) {
563 mbedtls_platform_zeroize(argv[i], strlen(argv[i]));
564 }
565
566 mbedtls_platform_zeroize(IV, sizeof(IV));
567 mbedtls_platform_zeroize(key, sizeof(key));
568 mbedtls_platform_zeroize(buffer, sizeof(buffer));
569 mbedtls_platform_zeroize(output, sizeof(output));
570 mbedtls_platform_zeroize(digest, sizeof(digest));
571
572 mbedtls_cipher_free(&cipher_ctx);
573 mbedtls_md_free(&md_ctx);
574
575 mbedtls_exit(exit_code);
576 }
577 #endif /* MBEDTLS_CIPHER_C && MBEDTLS_MD_C && MBEDTLS_FS_IO */
578
