/* * Example RSA key generation program * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include <stdio.h> #include <stdlib.h> #define mbedtls_printf printf #define mbedtls_exit exit #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE #endif /* MBEDTLS_PLATFORM_C */ #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_ENTROPY_C) && \ defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME) && \ defined(MBEDTLS_FS_IO) && defined(MBEDTLS_CTR_DRBG_C) #include "mbedtls/entropy.h" #include "mbedtls/ctr_drbg.h" #include "mbedtls/bignum.h" #include "mbedtls/rsa.h" #include <stdio.h> #include <string.h> #endif #define KEY_SIZE 2048 #define EXPONENT 65537 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) || \ !defined(MBEDTLS_RSA_C) || !defined(MBEDTLS_GENPRIME) || \ !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_CTR_DRBG_C) int main( void ) { mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or " "MBEDTLS_RSA_C and/or MBEDTLS_GENPRIME and/or " "MBEDTLS_FS_IO and/or MBEDTLS_CTR_DRBG_C not defined.\n"); mbedtls_exit( 0 ); } #else int main( void ) { int ret = 1; int exit_code = MBEDTLS_EXIT_FAILURE; mbedtls_rsa_context rsa; mbedtls_entropy_context entropy; mbedtls_ctr_drbg_context ctr_drbg; mbedtls_mpi N, P, Q, D, E, DP, DQ, QP; FILE *fpub = NULL; FILE *fpriv = NULL; const char *pers = "rsa_genkey"; mbedtls_ctr_drbg_init( &ctr_drbg ); mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 ); mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP ); mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP ); mbedtls_printf( "\n . Seeding the random number generator..." ); fflush( stdout ); mbedtls_entropy_init( &entropy ); if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy, (const unsigned char *) pers, strlen( pers ) ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret ); goto exit; } mbedtls_printf( " ok\n . Generating the RSA key [ %d-bit ]...", KEY_SIZE ); fflush( stdout ); if( ( ret = mbedtls_rsa_gen_key( &rsa, mbedtls_ctr_drbg_random, &ctr_drbg, KEY_SIZE, EXPONENT ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_rsa_gen_key returned %d\n\n", ret ); goto exit; } mbedtls_printf( " ok\n . Exporting the public key in rsa_pub.txt...." ); fflush( stdout ); if( ( ret = mbedtls_rsa_export ( &rsa, &N, &P, &Q, &D, &E ) ) != 0 || ( ret = mbedtls_rsa_export_crt( &rsa, &DP, &DQ, &QP ) ) != 0 ) { mbedtls_printf( " failed\n ! could not export RSA parameters\n\n" ); goto exit; } if( ( fpub = fopen( "rsa_pub.txt", "wb+" ) ) == NULL ) { mbedtls_printf( " failed\n ! could not open rsa_pub.txt for writing\n\n" ); goto exit; } if( ( ret = mbedtls_mpi_write_file( "N = ", &N, 16, fpub ) ) != 0 || ( ret = mbedtls_mpi_write_file( "E = ", &E, 16, fpub ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret ); goto exit; } mbedtls_printf( " ok\n . Exporting the private key in rsa_priv.txt..." ); fflush( stdout ); if( ( fpriv = fopen( "rsa_priv.txt", "wb+" ) ) == NULL ) { mbedtls_printf( " failed\n ! could not open rsa_priv.txt for writing\n" ); goto exit; } if( ( ret = mbedtls_mpi_write_file( "N = " , &N , 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "E = " , &E , 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "D = " , &D , 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "P = " , &P , 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "Q = " , &Q , 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "DP = ", &DP, 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "DQ = ", &DQ, 16, fpriv ) ) != 0 || ( ret = mbedtls_mpi_write_file( "QP = ", &QP, 16, fpriv ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret ); goto exit; } mbedtls_printf( " ok\n\n" ); exit_code = MBEDTLS_EXIT_SUCCESS; exit: if( fpub != NULL ) fclose( fpub ); if( fpriv != NULL ) fclose( fpriv ); mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP ); mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP ); mbedtls_rsa_free( &rsa ); mbedtls_ctr_drbg_free( &ctr_drbg ); mbedtls_entropy_free( &entropy ); #if defined(_WIN32) mbedtls_printf( " Press Enter to exit this program.\n" ); fflush( stdout ); getchar(); #endif mbedtls_exit( exit_code ); } #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_RSA_C && MBEDTLS_GENPRIME && MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */