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