1 /*
2 * Public key-based simple decryption program
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 #if !defined(MBEDTLS_CONFIG_FILE)
21 #include "mbedtls/config.h"
22 #else
23 #include MBEDTLS_CONFIG_FILE
24 #endif
25
26 #if defined(MBEDTLS_PLATFORM_C)
27 #include "mbedtls/platform.h"
28 #else
29 #include <stdio.h>
30 #include <stdlib.h>
31 #define mbedtls_printf printf
32 #define mbedtls_exit exit
33 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
34 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
35 #endif /* MBEDTLS_PLATFORM_C */
36
37 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_PK_PARSE_C) && \
38 defined(MBEDTLS_FS_IO) && defined(MBEDTLS_ENTROPY_C) && \
39 defined(MBEDTLS_CTR_DRBG_C)
40 #include "mbedtls/error.h"
41 #include "mbedtls/pk.h"
42 #include "mbedtls/entropy.h"
43 #include "mbedtls/ctr_drbg.h"
44
45 #include <stdio.h>
46 #include <string.h>
47 #endif
48
49 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_PK_PARSE_C) || \
50 !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
51 !defined(MBEDTLS_CTR_DRBG_C)
main(void)52 int main( void )
53 {
54 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_PK_PARSE_C and/or "
55 "MBEDTLS_FS_IO and/or MBEDTLS_ENTROPY_C and/or "
56 "MBEDTLS_CTR_DRBG_C 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 FILE *f;
65 int ret = 1;
66 unsigned c;
67 int exit_code = MBEDTLS_EXIT_FAILURE;
68 size_t i, olen = 0;
69 mbedtls_pk_context pk;
70 mbedtls_entropy_context entropy;
71 mbedtls_ctr_drbg_context ctr_drbg;
72 unsigned char result[1024];
73 unsigned char buf[512];
74 const char *pers = "mbedtls_pk_decrypt";
75 ((void) argv);
76
77 mbedtls_pk_init( &pk );
78 mbedtls_entropy_init( &entropy );
79 mbedtls_ctr_drbg_init( &ctr_drbg );
80
81 memset(result, 0, sizeof( result ) );
82
83 if( argc != 2 )
84 {
85 mbedtls_printf( "usage: mbedtls_pk_decrypt <key_file>\n" );
86
87 #if defined(_WIN32)
88 mbedtls_printf( "\n" );
89 #endif
90
91 goto exit;
92 }
93
94 mbedtls_printf( "\n . Seeding the random number generator..." );
95 fflush( stdout );
96
97 if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
98 &entropy, (const unsigned char *) pers,
99 strlen( pers ) ) ) != 0 )
100 {
101 mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
102 (unsigned int) -ret );
103 goto exit;
104 }
105
106 mbedtls_printf( "\n . Reading private key from '%s'", argv[1] );
107 fflush( stdout );
108
109 if( ( ret = mbedtls_pk_parse_keyfile( &pk, argv[1], "" ) ) != 0 )
110 {
111 mbedtls_printf( " failed\n ! mbedtls_pk_parse_keyfile returned -0x%04x\n", (unsigned int) -ret );
112 goto exit;
113 }
114
115 /*
116 * Extract the RSA encrypted value from the text file
117 */
118 if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
119 {
120 mbedtls_printf( "\n ! Could not open %s\n\n", "result-enc.txt" );
121 ret = 1;
122 goto exit;
123 }
124
125 i = 0;
126 while( fscanf( f, "%02X", (unsigned int*) &c ) > 0 &&
127 i < (int) sizeof( buf ) )
128 {
129 buf[i++] = (unsigned char) c;
130 }
131
132 fclose( f );
133
134 /*
135 * Decrypt the encrypted RSA data and print the result.
136 */
137 mbedtls_printf( "\n . Decrypting the encrypted data" );
138 fflush( stdout );
139
140 if( ( ret = mbedtls_pk_decrypt( &pk, buf, i, result, &olen, sizeof(result),
141 mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
142 {
143 mbedtls_printf( " failed\n ! mbedtls_pk_decrypt returned -0x%04x\n",
144 (unsigned int) -ret );
145 goto exit;
146 }
147
148 mbedtls_printf( "\n . OK\n\n" );
149
150 mbedtls_printf( "The decrypted result is: '%s'\n\n", result );
151
152 exit_code = MBEDTLS_EXIT_SUCCESS;
153
154 exit:
155
156 mbedtls_pk_free( &pk );
157 mbedtls_entropy_free( &entropy );
158 mbedtls_ctr_drbg_free( &ctr_drbg );
159
160 #if defined(MBEDTLS_ERROR_C)
161 if( exit_code != MBEDTLS_EXIT_SUCCESS )
162 {
163 mbedtls_strerror( ret, (char *) buf, sizeof( buf ) );
164 mbedtls_printf( " ! Last error was: %s\n", buf );
165 }
166 #endif
167
168 #if defined(_WIN32)
169 mbedtls_printf( " + Press Enter to exit this program.\n" );
170 fflush( stdout ); getchar();
171 #endif
172
173 mbedtls_exit( exit_code );
174 }
175 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
176 MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
177
