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) 50int 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 58int 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 551exit: 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