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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
7  *
8  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
9  *  not use this file except in compliance with the License.
10  *  You may obtain a copy of the License at
11  *
12  *  http://www.apache.org/licenses/LICENSE-2.0
13  *
14  *  Unless required by applicable law or agreed to in writing, software
15  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  *  See the License for the specific language governing permissions and
18  *  limitations under the License.
19  */
20 
21 /* Enable definition of fileno() even when compiling with -std=c99. Must be
22  * set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
23  * Harmless on other platforms. */
24 #define _POSIX_C_SOURCE 200112L
25 
26 #include "mbedtls/build_info.h"
27 
28 #if defined(MBEDTLS_PLATFORM_C)
29 #include "mbedtls/platform.h"
30 #else
31 #include <stdio.h>
32 #include <stdlib.h>
33 #define mbedtls_fprintf         fprintf
34 #define mbedtls_printf          printf
35 #define mbedtls_exit            exit
36 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
37 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
38 #endif /* MBEDTLS_PLATFORM_C */
39 
40 #if defined(MBEDTLS_CIPHER_C) && defined(MBEDTLS_MD_C) && \
41  defined(MBEDTLS_FS_IO)
42 #include "mbedtls/cipher.h"
43 #include "mbedtls/md.h"
44 #include "mbedtls/platform_util.h"
45 
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #endif
50 
51 #if defined(_WIN32)
52 #include <windows.h>
53 #if !defined(_WIN32_WCE)
54 #include <io.h>
55 #endif
56 #else
57 #include <sys/types.h>
58 #include <unistd.h>
59 #endif
60 
61 #define MODE_ENCRYPT    0
62 #define MODE_DECRYPT    1
63 
64 #define USAGE   \
65     "\n  crypt_and_hash <mode> <input filename> <output filename> <cipher> <mbedtls_md> <key>\n" \
66     "\n   <mode>: 0 = encrypt, 1 = decrypt\n" \
67     "\n  example: crypt_and_hash 0 file file.aes AES-128-CBC SHA1 hex:E76B2413958B00E193\n" \
68     "\n"
69 
70 #if !defined(MBEDTLS_CIPHER_C) || !defined(MBEDTLS_MD_C) || \
71     !defined(MBEDTLS_FS_IO)
main(void)72 int main( void )
73 {
74     mbedtls_printf("MBEDTLS_CIPHER_C and/or MBEDTLS_MD_C and/or MBEDTLS_FS_IO not defined.\n");
75     mbedtls_exit( 0 );
76 }
77 #else
78 
79 
main(int argc,char * argv[])80 int main( int argc, char *argv[] )
81 {
82     int ret = 1, i;
83     unsigned n;
84     int exit_code = MBEDTLS_EXIT_FAILURE;
85     int mode;
86     size_t keylen, ilen, olen;
87     FILE *fkey, *fin = NULL, *fout = NULL;
88 
89     char *p;
90     unsigned char IV[16];
91     unsigned char key[512];
92     unsigned char digest[MBEDTLS_MD_MAX_SIZE];
93     unsigned char buffer[1024];
94     unsigned char output[1024];
95     unsigned char diff;
96 
97     const mbedtls_cipher_info_t *cipher_info;
98     const mbedtls_md_info_t *md_info;
99     mbedtls_cipher_context_t cipher_ctx;
100     mbedtls_md_context_t md_ctx;
101 #if defined(_WIN32_WCE)
102     long filesize, offset;
103 #elif defined(_WIN32)
104        LARGE_INTEGER li_size;
105     __int64 filesize, offset;
106 #else
107       off_t filesize, offset;
108 #endif
109 
110     mbedtls_cipher_init( &cipher_ctx );
111     mbedtls_md_init( &md_ctx );
112 
113     /*
114      * Parse the command-line arguments.
115      */
116     if( argc != 7 )
117     {
118         const int *list;
119 
120         mbedtls_printf( USAGE );
121 
122         mbedtls_printf( "Available ciphers:\n" );
123         list = mbedtls_cipher_list();
124         while( *list )
125         {
126             cipher_info = mbedtls_cipher_info_from_type( *list );
127             mbedtls_printf( "  %s\n", mbedtls_cipher_info_get_name( cipher_info ) );
128             list++;
129         }
130 
131         mbedtls_printf( "\nAvailable message digests:\n" );
132         list = mbedtls_md_list();
133         while( *list )
134         {
135             md_info = mbedtls_md_info_from_type( *list );
136             mbedtls_printf( "  %s\n", mbedtls_md_get_name( md_info ) );
137             list++;
138         }
139 
140 #if defined(_WIN32)
141         mbedtls_printf( "\n  Press Enter to exit this program.\n" );
142         fflush( stdout ); getchar();
143 #endif
144 
145         goto exit;
146     }
147 
148     mode = atoi( argv[1] );
149 
150     if( mode != MODE_ENCRYPT && mode != MODE_DECRYPT )
151     {
152         mbedtls_fprintf( stderr, "invalid operation mode\n" );
153         goto exit;
154     }
155 
156     if( strcmp( argv[2], argv[3] ) == 0 )
157     {
158         mbedtls_fprintf( stderr, "input and output filenames must differ\n" );
159         goto exit;
160     }
161 
162     if( ( fin = fopen( argv[2], "rb" ) ) == NULL )
163     {
164         mbedtls_fprintf( stderr, "fopen(%s,rb) failed\n", argv[2] );
165         goto exit;
166     }
167 
168     if( ( fout = fopen( argv[3], "wb+" ) ) == NULL )
169     {
170         mbedtls_fprintf( stderr, "fopen(%s,wb+) failed\n", argv[3] );
171         goto exit;
172     }
173 
174     /*
175      * Read the Cipher and MD from the command line
176      */
177     cipher_info = mbedtls_cipher_info_from_string( argv[4] );
178     if( cipher_info == NULL )
179     {
180         mbedtls_fprintf( stderr, "Cipher '%s' not found\n", argv[4] );
181         goto exit;
182     }
183     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info) ) != 0 )
184     {
185         mbedtls_fprintf( stderr, "mbedtls_cipher_setup failed\n" );
186         goto exit;
187     }
188 
189     md_info = mbedtls_md_info_from_string( argv[5] );
190     if( md_info == NULL )
191     {
192         mbedtls_fprintf( stderr, "Message Digest '%s' not found\n", argv[5] );
193         goto exit;
194     }
195 
196     if( mbedtls_md_setup( &md_ctx, md_info, 1 ) != 0 )
197     {
198         mbedtls_fprintf( stderr, "mbedtls_md_setup failed\n" );
199         goto exit;
200     }
201 
202     /*
203      * Read the secret key from file or command line
204      */
205     if( ( fkey = fopen( argv[6], "rb" ) ) != NULL )
206     {
207         keylen = fread( key, 1, sizeof( key ), fkey );
208         fclose( fkey );
209     }
210     else
211     {
212         if( memcmp( argv[6], "hex:", 4 ) == 0 )
213         {
214             p = &argv[6][4];
215             keylen = 0;
216 
217             while( sscanf( p, "%02X", (unsigned int*) &n ) > 0 &&
218                    keylen < (int) sizeof( key ) )
219             {
220                 key[keylen++] = (unsigned char) n;
221                 p += 2;
222             }
223         }
224         else
225         {
226             keylen = strlen( argv[6] );
227 
228             if( keylen > (int) sizeof( key ) )
229                 keylen = (int) sizeof( key );
230 
231             memcpy( key, argv[6], keylen );
232         }
233     }
234 
235 #if defined(_WIN32_WCE)
236     filesize = fseek( fin, 0L, SEEK_END );
237 #else
238 #if defined(_WIN32)
239     /*
240      * Support large files (> 2Gb) on Win32
241      */
242     li_size.QuadPart = 0;
243     li_size.LowPart  =
244         SetFilePointer( (HANDLE) _get_osfhandle( _fileno( fin ) ),
245                         li_size.LowPart, &li_size.HighPart, FILE_END );
246 
247     if( li_size.LowPart == 0xFFFFFFFF && GetLastError() != NO_ERROR )
248     {
249         mbedtls_fprintf( stderr, "SetFilePointer(0,FILE_END) failed\n" );
250         goto exit;
251     }
252 
253     filesize = li_size.QuadPart;
254 #else
255     if( ( filesize = lseek( fileno( fin ), 0, SEEK_END ) ) < 0 )
256     {
257         perror( "lseek" );
258         goto exit;
259     }
260 #endif
261 #endif
262 
263     if( fseek( fin, 0, SEEK_SET ) < 0 )
264     {
265         mbedtls_fprintf( stderr, "fseek(0,SEEK_SET) failed\n" );
266         goto exit;
267     }
268 
269     if( mode == MODE_ENCRYPT )
270     {
271         /*
272          * Generate the initialization vector as:
273          * IV = MD( filesize || filename )[0..15]
274          */
275         for( i = 0; i < 8; i++ )
276             buffer[i] = (unsigned char)( filesize >> ( i << 3 ) );
277 
278         p = argv[2];
279 
280         if( mbedtls_md_starts( &md_ctx ) != 0 )
281         {
282             mbedtls_fprintf( stderr, "mbedtls_md_starts() returned error\n" );
283             goto exit;
284         }
285         if( mbedtls_md_update( &md_ctx, buffer, 8 ) != 0 )
286         {
287             mbedtls_fprintf( stderr, "mbedtls_md_update() returned error\n" );
288             goto exit;
289         }
290         if( mbedtls_md_update( &md_ctx, ( unsigned char * ) p, strlen( p ) )
291             != 0 )
292         {
293             mbedtls_fprintf( stderr, "mbedtls_md_update() returned error\n" );
294             goto exit;
295         }
296         if( mbedtls_md_finish( &md_ctx, digest ) != 0 )
297         {
298             mbedtls_fprintf( stderr, "mbedtls_md_finish() returned error\n" );
299             goto exit;
300         }
301 
302         memcpy( IV, digest, 16 );
303 
304         /*
305          * Append the IV at the beginning of the output.
306          */
307         if( fwrite( IV, 1, 16, fout ) != 16 )
308         {
309             mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", 16 );
310             goto exit;
311         }
312 
313         /*
314          * Hash the IV and the secret key together 8192 times
315          * using the result to setup the AES context and HMAC.
316          */
317         memset( digest, 0,  32 );
318         memcpy( digest, IV, 16 );
319 
320         for( i = 0; i < 8192; i++ )
321         {
322             if( mbedtls_md_starts( &md_ctx ) != 0 )
323             {
324                 mbedtls_fprintf( stderr,
325                                  "mbedtls_md_starts() returned error\n" );
326                 goto exit;
327             }
328             if( mbedtls_md_update( &md_ctx, digest, 32 ) != 0 )
329             {
330                 mbedtls_fprintf( stderr,
331                                  "mbedtls_md_update() returned error\n" );
332                 goto exit;
333             }
334             if( mbedtls_md_update( &md_ctx, key, keylen ) != 0 )
335             {
336                 mbedtls_fprintf( stderr,
337                                  "mbedtls_md_update() returned error\n" );
338                 goto exit;
339             }
340             if( mbedtls_md_finish( &md_ctx, digest ) != 0 )
341             {
342                 mbedtls_fprintf( stderr,
343                                  "mbedtls_md_finish() returned error\n" );
344                 goto exit;
345             }
346 
347         }
348 
349         if( mbedtls_cipher_setkey( &cipher_ctx,
350                                    digest,
351                                    (int) mbedtls_cipher_info_get_key_bitlen( cipher_info ),
352                            MBEDTLS_ENCRYPT ) != 0 )
353         {
354             mbedtls_fprintf( stderr, "mbedtls_cipher_setkey() returned error\n");
355             goto exit;
356         }
357         if( mbedtls_cipher_set_iv( &cipher_ctx, IV, 16 ) != 0 )
358         {
359             mbedtls_fprintf( stderr, "mbedtls_cipher_set_iv() returned error\n");
360             goto exit;
361         }
362         if( mbedtls_cipher_reset( &cipher_ctx ) != 0 )
363         {
364             mbedtls_fprintf( stderr, "mbedtls_cipher_reset() returned error\n");
365             goto exit;
366         }
367 
368         if( mbedtls_md_hmac_starts( &md_ctx, digest, 32 ) != 0 )
369         {
370             mbedtls_fprintf( stderr, "mbedtls_md_hmac_starts() returned error\n" );
371             goto exit;
372         }
373 
374         /*
375          * Encrypt and write the ciphertext.
376          */
377         for( offset = 0; offset < filesize; offset += mbedtls_cipher_get_block_size( &cipher_ctx ) )
378         {
379             ilen = ( (unsigned int) filesize - offset > mbedtls_cipher_get_block_size( &cipher_ctx ) ) ?
380                 mbedtls_cipher_get_block_size( &cipher_ctx ) : (unsigned int) ( filesize - offset );
381 
382             if( fread( buffer, 1, ilen, fin ) != ilen )
383             {
384                 mbedtls_fprintf( stderr, "fread(%ld bytes) failed\n", (long) ilen );
385                 goto exit;
386             }
387 
388             if( mbedtls_cipher_update( &cipher_ctx, buffer, ilen, output, &olen ) != 0 )
389             {
390                 mbedtls_fprintf( stderr, "mbedtls_cipher_update() returned error\n");
391                 goto exit;
392             }
393 
394             if( mbedtls_md_hmac_update( &md_ctx, output, olen ) != 0 )
395             {
396                 mbedtls_fprintf( stderr, "mbedtls_md_hmac_update() returned error\n" );
397                 goto exit;
398             }
399 
400             if( fwrite( output, 1, olen, fout ) != olen )
401             {
402                 mbedtls_fprintf( stderr, "fwrite(%ld bytes) failed\n", (long) olen );
403                 goto exit;
404             }
405         }
406 
407         if( mbedtls_cipher_finish( &cipher_ctx, output, &olen ) != 0 )
408         {
409             mbedtls_fprintf( stderr, "mbedtls_cipher_finish() returned error\n" );
410             goto exit;
411         }
412         if( mbedtls_md_hmac_update( &md_ctx, output, olen ) != 0 )
413         {
414             mbedtls_fprintf( stderr, "mbedtls_md_hmac_update() returned error\n" );
415             goto exit;
416         }
417 
418         if( fwrite( output, 1, olen, fout ) != olen )
419         {
420             mbedtls_fprintf( stderr, "fwrite(%ld bytes) failed\n", (long) olen );
421             goto exit;
422         }
423 
424         /*
425          * Finally write the HMAC.
426          */
427         if( mbedtls_md_hmac_finish( &md_ctx, digest ) != 0 )
428         {
429             mbedtls_fprintf( stderr, "mbedtls_md_hmac_finish() returned error\n" );
430             goto exit;
431         }
432 
433         if( fwrite( digest, 1, mbedtls_md_get_size( md_info ), fout ) != mbedtls_md_get_size( md_info ) )
434         {
435             mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", mbedtls_md_get_size( md_info ) );
436             goto exit;
437         }
438     }
439 
440     if( mode == MODE_DECRYPT )
441     {
442         /*
443          *  The encrypted file must be structured as follows:
444          *
445          *        00 .. 15              Initialization Vector
446          *        16 .. 31              Encrypted Block #1
447          *           ..
448          *      N*16 .. (N+1)*16 - 1    Encrypted Block #N
449          *  (N+1)*16 .. (N+1)*16 + n    Hash(ciphertext)
450          */
451         if( filesize < 16 + mbedtls_md_get_size( md_info ) )
452         {
453             mbedtls_fprintf( stderr, "File too short to be encrypted.\n" );
454             goto exit;
455         }
456 
457         if( mbedtls_cipher_get_block_size( &cipher_ctx ) == 0 )
458         {
459             mbedtls_fprintf( stderr, "Invalid cipher block size: 0. \n" );
460             goto exit;
461         }
462 
463         /*
464          * Check the file size.
465          */
466         if( mbedtls_cipher_info_get_mode( cipher_info ) != MBEDTLS_MODE_GCM &&
467             ( ( filesize - mbedtls_md_get_size( md_info ) ) %
468                 mbedtls_cipher_get_block_size( &cipher_ctx ) ) != 0 )
469         {
470             mbedtls_fprintf( stderr, "File content not a multiple of the block size (%u).\n",
471                      mbedtls_cipher_get_block_size( &cipher_ctx ));
472             goto exit;
473         }
474 
475         /*
476          * Subtract the IV + HMAC length.
477          */
478         filesize -= ( 16 + mbedtls_md_get_size( md_info ) );
479 
480         /*
481          * Read the IV and original filesize modulo 16.
482          */
483         if( fread( buffer, 1, 16, fin ) != 16 )
484         {
485             mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", 16 );
486             goto exit;
487         }
488 
489         memcpy( IV, buffer, 16 );
490 
491         /*
492          * Hash the IV and the secret key together 8192 times
493          * using the result to setup the AES context and HMAC.
494          */
495         memset( digest, 0,  32 );
496         memcpy( digest, IV, 16 );
497 
498         for( i = 0; i < 8192; i++ )
499         {
500             if( mbedtls_md_starts( &md_ctx ) != 0 )
501             {
502                 mbedtls_fprintf( stderr, "mbedtls_md_starts() returned error\n" );
503                 goto exit;
504             }
505             if( mbedtls_md_update( &md_ctx, digest, 32 ) != 0 )
506             {
507                 mbedtls_fprintf( stderr, "mbedtls_md_update() returned error\n" );
508                 goto exit;
509             }
510             if( mbedtls_md_update( &md_ctx, key, keylen ) != 0 )
511             {
512                 mbedtls_fprintf( stderr, "mbedtls_md_update() returned error\n" );
513                 goto exit;
514             }
515             if( mbedtls_md_finish( &md_ctx, digest ) != 0 )
516             {
517                 mbedtls_fprintf( stderr, "mbedtls_md_finish() returned error\n" );
518                 goto exit;
519             }
520         }
521 
522         if( mbedtls_cipher_setkey( &cipher_ctx,
523                                    digest,
524                                    (int) mbedtls_cipher_info_get_key_bitlen( cipher_info ),
525                            MBEDTLS_DECRYPT ) != 0 )
526         {
527             mbedtls_fprintf( stderr, "mbedtls_cipher_setkey() returned error\n" );
528             goto exit;
529         }
530 
531         if( mbedtls_cipher_set_iv( &cipher_ctx, IV, 16 ) != 0 )
532         {
533             mbedtls_fprintf( stderr, "mbedtls_cipher_set_iv() returned error\n" );
534             goto exit;
535         }
536 
537         if( mbedtls_cipher_reset( &cipher_ctx ) != 0 )
538         {
539             mbedtls_fprintf( stderr, "mbedtls_cipher_reset() returned error\n" );
540             goto exit;
541         }
542 
543         if( mbedtls_md_hmac_starts( &md_ctx, digest, 32 ) != 0 )
544         {
545             mbedtls_fprintf( stderr, "mbedtls_md_hmac_starts() returned error\n" );
546             goto exit;
547         }
548 
549         /*
550          * Decrypt and write the plaintext.
551          */
552         for( offset = 0; offset < filesize; offset += mbedtls_cipher_get_block_size( &cipher_ctx ) )
553         {
554             ilen = ( (unsigned int) filesize - offset > mbedtls_cipher_get_block_size( &cipher_ctx ) ) ?
555                 mbedtls_cipher_get_block_size( &cipher_ctx ) : (unsigned int) ( filesize - offset );
556 
557             if( fread( buffer, 1, ilen, fin ) != ilen )
558             {
559                 mbedtls_fprintf( stderr, "fread(%u bytes) failed\n",
560                     mbedtls_cipher_get_block_size( &cipher_ctx ) );
561                 goto exit;
562             }
563 
564             if( mbedtls_md_hmac_update( &md_ctx, buffer, ilen ) != 0 )
565             {
566                 mbedtls_fprintf( stderr, "mbedtls_md_hmac_update() returned error\n" );
567                 goto exit;
568             }
569             if( mbedtls_cipher_update( &cipher_ctx, buffer, ilen, output,
570                                        &olen ) != 0 )
571             {
572                 mbedtls_fprintf( stderr, "mbedtls_cipher_update() returned error\n" );
573                 goto exit;
574             }
575 
576             if( fwrite( output, 1, olen, fout ) != olen )
577             {
578                 mbedtls_fprintf( stderr, "fwrite(%ld bytes) failed\n", (long) olen );
579                 goto exit;
580             }
581         }
582 
583         /*
584          * Verify the message authentication code.
585          */
586         if( mbedtls_md_hmac_finish( &md_ctx, digest ) != 0 )
587         {
588             mbedtls_fprintf( stderr, "mbedtls_md_hmac_finish() returned error\n" );
589             goto exit;
590         }
591 
592         if( fread( buffer, 1, mbedtls_md_get_size( md_info ), fin ) != mbedtls_md_get_size( md_info ) )
593         {
594             mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", mbedtls_md_get_size( md_info ) );
595             goto exit;
596         }
597 
598         /* Use constant-time buffer comparison */
599         diff = 0;
600         for( i = 0; i < mbedtls_md_get_size( md_info ); i++ )
601             diff |= digest[i] ^ buffer[i];
602 
603         if( diff != 0 )
604         {
605             mbedtls_fprintf( stderr, "HMAC check failed: wrong key, "
606                              "or file corrupted.\n" );
607             goto exit;
608         }
609 
610         /*
611          * Write the final block of data
612          */
613         if( mbedtls_cipher_finish( &cipher_ctx, output, &olen ) != 0 )
614         {
615             mbedtls_fprintf( stderr, "mbedtls_cipher_finish() returned error\n" );
616             goto exit;
617         }
618 
619         if( fwrite( output, 1, olen, fout ) != olen )
620         {
621             mbedtls_fprintf( stderr, "fwrite(%ld bytes) failed\n", (long) olen );
622             goto exit;
623         }
624     }
625 
626     exit_code = MBEDTLS_EXIT_SUCCESS;
627 
628 exit:
629     if( fin )
630         fclose( fin );
631     if( fout )
632         fclose( fout );
633 
634     /* Zeroize all command line arguments to also cover
635        the case when the user has missed or reordered some,
636        in which case the key might not be in argv[6]. */
637     for( i = 0; i < argc; i++ )
638         mbedtls_platform_zeroize( argv[i], strlen( argv[i] ) );
639 
640     mbedtls_platform_zeroize( IV,     sizeof( IV ) );
641     mbedtls_platform_zeroize( key,    sizeof( key ) );
642     mbedtls_platform_zeroize( buffer, sizeof( buffer ) );
643     mbedtls_platform_zeroize( output, sizeof( output ) );
644     mbedtls_platform_zeroize( digest, sizeof( digest ) );
645 
646     mbedtls_cipher_free( &cipher_ctx );
647     mbedtls_md_free( &md_ctx );
648 
649     mbedtls_exit( exit_code );
650 }
651 #endif /* MBEDTLS_CIPHER_C && MBEDTLS_MD_C && MBEDTLS_FS_IO */
652