1 /*
2 * Public key-based simple decryption program
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 *
7 * This file is provided under the Apache License 2.0, or the
8 * GNU General Public License v2.0 or later.
9 *
10 * **********
11 * Apache License 2.0:
12 *
13 * Licensed under the Apache License, Version 2.0 (the "License"); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
16 *
17 * http://www.apache.org/licenses/LICENSE-2.0
18 *
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
24 *
25 * **********
26 *
27 * **********
28 * GNU General Public License v2.0 or later:
29 *
30 * This program is free software; you can redistribute it and/or modify
31 * it under the terms of the GNU General Public License as published by
32 * the Free Software Foundation; either version 2 of the License, or
33 * (at your option) any later version.
34 *
35 * This program is distributed in the hope that it will be useful,
36 * but WITHOUT ANY WARRANTY; without even the implied warranty of
37 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38 * GNU General Public License for more details.
39 *
40 * You should have received a copy of the GNU General Public License along
41 * with this program; if not, write to the Free Software Foundation, Inc.,
42 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
43 *
44 * **********
45 */
46
47 #if !defined(MBEDTLS_CONFIG_FILE)
48 #include "mbedtls/config.h"
49 #else
50 #include MBEDTLS_CONFIG_FILE
51 #endif
52
53 #if defined(MBEDTLS_PLATFORM_C)
54 #include "mbedtls/platform.h"
55 #else
56 #include <stdio.h>
57 #include <stdlib.h>
58 #define mbedtls_printf printf
59 #define mbedtls_exit exit
60 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
61 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
62 #endif /* MBEDTLS_PLATFORM_C */
63
64 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_PK_PARSE_C) && \
65 defined(MBEDTLS_FS_IO) && defined(MBEDTLS_ENTROPY_C) && \
66 defined(MBEDTLS_CTR_DRBG_C)
67 #include "mbedtls/error.h"
68 #include "mbedtls/pk.h"
69 #include "mbedtls/entropy.h"
70 #include "mbedtls/ctr_drbg.h"
71
72 #include <stdio.h>
73 #include <string.h>
74 #endif
75
76 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_PK_PARSE_C) || \
77 !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
78 !defined(MBEDTLS_CTR_DRBG_C)
main(void)79 int main( void )
80 {
81 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_PK_PARSE_C and/or "
82 "MBEDTLS_FS_IO and/or MBEDTLS_ENTROPY_C and/or "
83 "MBEDTLS_CTR_DRBG_C not defined.\n");
84 mbedtls_exit( 0 );
85 }
86 #else
87
88
main(int argc,char * argv[])89 int main( int argc, char *argv[] )
90 {
91 FILE *f;
92 int ret = 1;
93 unsigned c;
94 int exit_code = MBEDTLS_EXIT_FAILURE;
95 size_t i, olen = 0;
96 mbedtls_pk_context pk;
97 mbedtls_entropy_context entropy;
98 mbedtls_ctr_drbg_context ctr_drbg;
99 unsigned char result[1024];
100 unsigned char buf[512];
101 const char *pers = "mbedtls_pk_decrypt";
102 ((void) argv);
103
104 mbedtls_pk_init( &pk );
105 mbedtls_entropy_init( &entropy );
106 mbedtls_ctr_drbg_init( &ctr_drbg );
107
108 memset(result, 0, sizeof( result ) );
109
110 if( argc != 2 )
111 {
112 mbedtls_printf( "usage: mbedtls_pk_decrypt <key_file>\n" );
113
114 #if defined(_WIN32)
115 mbedtls_printf( "\n" );
116 #endif
117
118 goto exit;
119 }
120
121 mbedtls_printf( "\n . Seeding the random number generator..." );
122 fflush( stdout );
123
124 if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
125 &entropy, (const unsigned char *) pers,
126 strlen( pers ) ) ) != 0 )
127 {
128 mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
129 -ret );
130 goto exit;
131 }
132
133 mbedtls_printf( "\n . Reading private key from '%s'", argv[1] );
134 fflush( stdout );
135
136 if( ( ret = mbedtls_pk_parse_keyfile( &pk, argv[1], "" ) ) != 0 )
137 {
138 mbedtls_printf( " failed\n ! mbedtls_pk_parse_keyfile returned -0x%04x\n", -ret );
139 goto exit;
140 }
141
142 /*
143 * Extract the RSA encrypted value from the text file
144 */
145 if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
146 {
147 mbedtls_printf( "\n ! Could not open %s\n\n", "result-enc.txt" );
148 ret = 1;
149 goto exit;
150 }
151
152 i = 0;
153 while( fscanf( f, "%02X", &c ) > 0 &&
154 i < (int) sizeof( buf ) )
155 {
156 buf[i++] = (unsigned char) c;
157 }
158
159 fclose( f );
160
161 /*
162 * Decrypt the encrypted RSA data and print the result.
163 */
164 mbedtls_printf( "\n . Decrypting the encrypted data" );
165 fflush( stdout );
166
167 if( ( ret = mbedtls_pk_decrypt( &pk, buf, i, result, &olen, sizeof(result),
168 mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
169 {
170 mbedtls_printf( " failed\n ! mbedtls_pk_decrypt returned -0x%04x\n",
171 -ret );
172 goto exit;
173 }
174
175 mbedtls_printf( "\n . OK\n\n" );
176
177 mbedtls_printf( "The decrypted result is: '%s'\n\n", result );
178
179 exit_code = MBEDTLS_EXIT_SUCCESS;
180
181 exit:
182
183 mbedtls_pk_free( &pk );
184 mbedtls_entropy_free( &entropy );
185 mbedtls_ctr_drbg_free( &ctr_drbg );
186
187 #if defined(MBEDTLS_ERROR_C)
188 if( exit_code != MBEDTLS_EXIT_SUCCESS )
189 {
190 mbedtls_strerror( ret, (char *) buf, sizeof( buf ) );
191 mbedtls_printf( " ! Last error was: %s\n", buf );
192 }
193 #endif
194
195 #if defined(_WIN32)
196 mbedtls_printf( " + Press Enter to exit this program.\n" );
197 fflush( stdout ); getchar();
198 #endif
199
200 mbedtls_exit( exit_code );
201 }
202 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
203 MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
204