1 /*
2  *  Example RSA key generation program
3  *
4  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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  *  This file is part of mbed TLS (https://tls.mbed.org)
20  */
21 
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
24 #else
25 #include MBEDTLS_CONFIG_FILE
26 #endif
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_printf          printf
34 #define mbedtls_exit            exit
35 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
36 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
37 #endif /* MBEDTLS_PLATFORM_C */
38 
39 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_ENTROPY_C) && \
40     defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME) && \
41     defined(MBEDTLS_FS_IO) && defined(MBEDTLS_CTR_DRBG_C)
42 #include "mbedtls/entropy.h"
43 #include "mbedtls/ctr_drbg.h"
44 #include "mbedtls/bignum.h"
45 #include "mbedtls/x509.h"
46 #include "mbedtls/rsa.h"
47 
48 #include <stdio.h>
49 #include <string.h>
50 #endif
51 
52 #define KEY_SIZE 2048
53 #define EXPONENT 65537
54 
55 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) ||   \
56     !defined(MBEDTLS_RSA_C) || !defined(MBEDTLS_GENPRIME) ||      \
57     !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_CTR_DRBG_C)
main(void)58 int main( void )
59 {
60     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or "
61            "MBEDTLS_RSA_C and/or MBEDTLS_GENPRIME and/or "
62            "MBEDTLS_FS_IO and/or MBEDTLS_CTR_DRBG_C not defined.\n");
63     return( 0 );
64 }
65 #else
66 
67 #if defined(MBEDTLS_CHECK_PARAMS)
68 #include "mbedtls/platform_util.h"
mbedtls_param_failed(const char * failure_condition,const char * file,int line)69 void mbedtls_param_failed( const char *failure_condition,
70                            const char *file,
71                            int line )
72 {
73     mbedtls_printf( "%s:%i: Input param failed - %s\n",
74                     file, line, failure_condition );
75     mbedtls_exit( MBEDTLS_EXIT_FAILURE );
76 }
77 #endif
78 
main(void)79 int main( void )
80 {
81     int ret = 1;
82     int exit_code = MBEDTLS_EXIT_FAILURE;
83     mbedtls_rsa_context rsa;
84     mbedtls_entropy_context entropy;
85     mbedtls_ctr_drbg_context ctr_drbg;
86     mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
87     FILE *fpub  = NULL;
88     FILE *fpriv = NULL;
89     const char *pers = "rsa_genkey";
90 
91     mbedtls_ctr_drbg_init( &ctr_drbg );
92     mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
93     mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
94     mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP );
95     mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP );
96 
97     mbedtls_printf( "\n  . Seeding the random number generator..." );
98     fflush( stdout );
99 
100     mbedtls_entropy_init( &entropy );
101     if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
102                                (const unsigned char *) pers,
103                                strlen( pers ) ) ) != 0 )
104     {
105         mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned %d\n", ret );
106         goto exit;
107     }
108 
109     mbedtls_printf( " ok\n  . Generating the RSA key [ %d-bit ]...", KEY_SIZE );
110     fflush( stdout );
111 
112     if( ( ret = mbedtls_rsa_gen_key( &rsa, mbedtls_ctr_drbg_random, &ctr_drbg, KEY_SIZE,
113                                      EXPONENT ) ) != 0 )
114     {
115         mbedtls_printf( " failed\n  ! mbedtls_rsa_gen_key returned %d\n\n", ret );
116         goto exit;
117     }
118 
119     mbedtls_printf( " ok\n  . Exporting the public  key in rsa_pub.txt...." );
120     fflush( stdout );
121 
122     if( ( ret = mbedtls_rsa_export    ( &rsa, &N, &P, &Q, &D, &E ) ) != 0 ||
123         ( ret = mbedtls_rsa_export_crt( &rsa, &DP, &DQ, &QP ) )      != 0 )
124     {
125         mbedtls_printf( " failed\n  ! could not export RSA parameters\n\n" );
126         goto exit;
127     }
128 
129     if( ( fpub = fopen( "rsa_pub.txt", "wb+" ) ) == NULL )
130     {
131         mbedtls_printf( " failed\n  ! could not open rsa_pub.txt for writing\n\n" );
132         goto exit;
133     }
134 
135     if( ( ret = mbedtls_mpi_write_file( "N = ", &N, 16, fpub ) ) != 0 ||
136         ( ret = mbedtls_mpi_write_file( "E = ", &E, 16, fpub ) ) != 0 )
137     {
138         mbedtls_printf( " failed\n  ! mbedtls_mpi_write_file returned %d\n\n", ret );
139         goto exit;
140     }
141 
142     mbedtls_printf( " ok\n  . Exporting the private key in rsa_priv.txt..." );
143     fflush( stdout );
144 
145     if( ( fpriv = fopen( "rsa_priv.txt", "wb+" ) ) == NULL )
146     {
147         mbedtls_printf( " failed\n  ! could not open rsa_priv.txt for writing\n" );
148         goto exit;
149     }
150 
151     if( ( ret = mbedtls_mpi_write_file( "N = " , &N , 16, fpriv ) ) != 0 ||
152         ( ret = mbedtls_mpi_write_file( "E = " , &E , 16, fpriv ) ) != 0 ||
153         ( ret = mbedtls_mpi_write_file( "D = " , &D , 16, fpriv ) ) != 0 ||
154         ( ret = mbedtls_mpi_write_file( "P = " , &P , 16, fpriv ) ) != 0 ||
155         ( ret = mbedtls_mpi_write_file( "Q = " , &Q , 16, fpriv ) ) != 0 ||
156         ( ret = mbedtls_mpi_write_file( "DP = ", &DP, 16, fpriv ) ) != 0 ||
157         ( ret = mbedtls_mpi_write_file( "DQ = ", &DQ, 16, fpriv ) ) != 0 ||
158         ( ret = mbedtls_mpi_write_file( "QP = ", &QP, 16, fpriv ) ) != 0 )
159     {
160         mbedtls_printf( " failed\n  ! mbedtls_mpi_write_file returned %d\n\n", ret );
161         goto exit;
162     }
163 /*
164     mbedtls_printf( " ok\n  . Generating the certificate..." );
165 
166     x509write_init_raw( &cert );
167     x509write_add_pubkey( &cert, &rsa );
168     x509write_add_subject( &cert, "CN='localhost'" );
169     x509write_add_validity( &cert, "2007-09-06 17:00:32",
170                                    "2010-09-06 17:00:32" );
171     x509write_create_selfsign( &cert, &rsa );
172     x509write_crtfile( &cert, "cert.der", X509_OUTPUT_DER );
173     x509write_crtfile( &cert, "cert.pem", X509_OUTPUT_PEM );
174     x509write_free_raw( &cert );
175 */
176     mbedtls_printf( " ok\n\n" );
177 
178     exit_code = MBEDTLS_EXIT_SUCCESS;
179 
180 exit:
181 
182     if( fpub  != NULL )
183         fclose( fpub );
184 
185     if( fpriv != NULL )
186         fclose( fpriv );
187 
188     mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
189     mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP );
190     mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP );
191     mbedtls_rsa_free( &rsa );
192     mbedtls_ctr_drbg_free( &ctr_drbg );
193     mbedtls_entropy_free( &entropy );
194 
195 #if defined(_WIN32)
196     mbedtls_printf( "  Press Enter to exit this program.\n" );
197     fflush( stdout ); getchar();
198 #endif
199 
200     return( exit_code );
201 }
202 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_RSA_C &&
203           MBEDTLS_GENPRIME && MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */
204