1 /**
2  *  \brief Use and generate random data into a file via the CTR_DBRG based on AES
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0
6  *
7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
8  *  not use this file except in compliance with the License.
9  *  You may obtain a copy of the License at
10  *
11  *  http://www.apache.org/licenses/LICENSE-2.0
12  *
13  *  Unless required by applicable law or agreed to in writing, software
14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  *  See the License for the specific language governing permissions and
17  *  limitations under the License.
18  */
19 
20 #include "mbedtls/build_info.h"
21 
22 #if defined(MBEDTLS_PLATFORM_C)
23 #include "mbedtls/platform.h"
24 #else
25 #include <stdio.h>
26 #include <stdlib.h>
27 #define mbedtls_fprintf         fprintf
28 #define mbedtls_printf          printf
29 #define mbedtls_exit            exit
30 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
31 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
32 #endif /* MBEDTLS_PLATFORM_C */
33 
34 #if defined(MBEDTLS_CTR_DRBG_C) && defined(MBEDTLS_ENTROPY_C) && \
35  defined(MBEDTLS_FS_IO)
36 #include "mbedtls/entropy.h"
37 #include "mbedtls/ctr_drbg.h"
38 
39 #include <stdio.h>
40 #endif
41 
42 #if !defined(MBEDTLS_CTR_DRBG_C) || !defined(MBEDTLS_ENTROPY_C) || \
43  !defined(MBEDTLS_FS_IO)
main(void)44 int main( void )
45 {
46     mbedtls_printf("MBEDTLS_CTR_DRBG_C and/or MBEDTLS_ENTROPY_C and/or MBEDTLS_FS_IO not defined.\n");
47     mbedtls_exit( 0 );
48 }
49 #else
50 
51 
main(int argc,char * argv[])52 int main( int argc, char *argv[] )
53 {
54     FILE *f;
55     int i, k, ret = 1;
56     int exit_code = MBEDTLS_EXIT_FAILURE;
57     mbedtls_ctr_drbg_context ctr_drbg;
58     mbedtls_entropy_context entropy;
59     unsigned char buf[1024];
60 
61     mbedtls_ctr_drbg_init( &ctr_drbg );
62 
63     if( argc < 2 )
64     {
65         mbedtls_fprintf( stderr, "usage: %s <output filename>\n", argv[0] );
66         mbedtls_exit( exit_code );
67     }
68 
69     if( ( f = fopen( argv[1], "wb+" ) ) == NULL )
70     {
71         mbedtls_printf( "failed to open '%s' for writing.\n", argv[1] );
72         mbedtls_exit( exit_code );
73     }
74 
75     mbedtls_entropy_init( &entropy );
76     ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy, (const unsigned char *) "RANDOM_GEN", 10 );
77     if( ret != 0 )
78     {
79         mbedtls_printf( "failed in mbedtls_ctr_drbg_seed: %d\n", ret );
80         goto cleanup;
81     }
82     mbedtls_ctr_drbg_set_prediction_resistance( &ctr_drbg, MBEDTLS_CTR_DRBG_PR_OFF );
83 
84 #if defined(MBEDTLS_FS_IO)
85     ret = mbedtls_ctr_drbg_update_seed_file( &ctr_drbg, "seedfile" );
86 
87     if( ret == MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR )
88     {
89         mbedtls_printf( "Failed to open seedfile. Generating one.\n" );
90         ret = mbedtls_ctr_drbg_write_seed_file( &ctr_drbg, "seedfile" );
91         if( ret != 0 )
92         {
93             mbedtls_printf( "failed in mbedtls_ctr_drbg_write_seed_file: %d\n", ret );
94             goto cleanup;
95         }
96     }
97     else if( ret != 0 )
98     {
99         mbedtls_printf( "failed in mbedtls_ctr_drbg_update_seed_file: %d\n", ret );
100         goto cleanup;
101     }
102 #endif
103 
104     for( i = 0, k = 768; i < k; i++ )
105     {
106         ret = mbedtls_ctr_drbg_random( &ctr_drbg, buf, sizeof( buf ) );
107         if( ret != 0 )
108         {
109             mbedtls_printf("failed!\n");
110             goto cleanup;
111         }
112 
113         fwrite( buf, 1, sizeof( buf ), f );
114 
115         mbedtls_printf( "Generating %ldkb of data in file '%s'... %04.1f" \
116                 "%% done\r", (long)(sizeof(buf) * k / 1024), argv[1], (100 * (float) (i + 1)) / k );
117         fflush( stdout );
118     }
119 
120     exit_code = MBEDTLS_EXIT_SUCCESS;
121 
122 cleanup:
123     mbedtls_printf("\n");
124 
125     fclose( f );
126     mbedtls_ctr_drbg_free( &ctr_drbg );
127     mbedtls_entropy_free( &entropy );
128 
129     mbedtls_exit( exit_code );
130 }
131 #endif /* MBEDTLS_CTR_DRBG_C && MBEDTLS_ENTROPY_C */
132