2 * Example RSA key generation program
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
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
11 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 * This file is part of mbed TLS (https://tls.mbed.org)
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
25 #include MBEDTLS_CONFIG_FILE
28 #if defined(MBEDTLS_PLATFORM_C)
29 #include "mbedtls/platform.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 */
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"
53 #define EXPONENT 65537
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)
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");
67 #if defined(MBEDTLS_CHECK_PARAMS)
68 #include "mbedtls/platform_util.h"
69 void mbedtls_param_failed( const char *failure_condition,
73 mbedtls_printf( "%s:%i: Input param failed - %s\n",
74 file, line, failure_condition );
75 mbedtls_exit( MBEDTLS_EXIT_FAILURE );
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;
89 const char *pers = "rsa_genkey";
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 );
97 mbedtls_printf( "\n . Seeding the random number generator..." );
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 )
105 mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
109 mbedtls_printf( " ok\n . Generating the RSA key [ %d-bit ]...", KEY_SIZE );
112 if( ( ret = mbedtls_rsa_gen_key( &rsa, mbedtls_ctr_drbg_random, &ctr_drbg, KEY_SIZE,
115 mbedtls_printf( " failed\n ! mbedtls_rsa_gen_key returned %d\n\n", ret );
119 mbedtls_printf( " ok\n . Exporting the public key in rsa_pub.txt...." );
122 if( ( ret = mbedtls_rsa_export ( &rsa, &N, &P, &Q, &D, &E ) ) != 0 ||
123 ( ret = mbedtls_rsa_export_crt( &rsa, &DP, &DQ, &QP ) ) != 0 )
125 mbedtls_printf( " failed\n ! could not export RSA parameters\n\n" );
129 if( ( fpub = fopen( "rsa_pub.txt", "wb+" ) ) == NULL )
131 mbedtls_printf( " failed\n ! could not open rsa_pub.txt for writing\n\n" );
135 if( ( ret = mbedtls_mpi_write_file( "N = ", &N, 16, fpub ) ) != 0 ||
136 ( ret = mbedtls_mpi_write_file( "E = ", &E, 16, fpub ) ) != 0 )
138 mbedtls_printf( " failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret );
142 mbedtls_printf( " ok\n . Exporting the private key in rsa_priv.txt..." );
145 if( ( fpriv = fopen( "rsa_priv.txt", "wb+" ) ) == NULL )
147 mbedtls_printf( " failed\n ! could not open rsa_priv.txt for writing\n" );
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 )
160 mbedtls_printf( " failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret );
164 mbedtls_printf( " ok\n . Generating the certificate..." );
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 );
176 mbedtls_printf( " ok\n\n" );
178 exit_code = MBEDTLS_EXIT_SUCCESS;
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 );
196 mbedtls_printf( " Press Enter to exit this program.\n" );
197 fflush( stdout ); getchar();
202 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_RSA_C &&
203 MBEDTLS_GENPRIME && MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */