rsa_genkey.c (4763B)
1 /* 2 * Example RSA key generation program 3 * 4 * Copyright The Mbed TLS Contributors 5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 6 */ 7 8 #include "mbedtls/build_info.h" 9 10 #include "mbedtls/platform.h" 11 12 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_ENTROPY_C) && \ 13 defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME) && \ 14 defined(MBEDTLS_FS_IO) && defined(MBEDTLS_CTR_DRBG_C) 15 #include "mbedtls/entropy.h" 16 #include "mbedtls/ctr_drbg.h" 17 #include "mbedtls/bignum.h" 18 #include "mbedtls/rsa.h" 19 20 #include <stdio.h> 21 #include <string.h> 22 #endif 23 24 #define KEY_SIZE 2048 25 #define EXPONENT 65537 26 27 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) || \ 28 !defined(MBEDTLS_RSA_C) || !defined(MBEDTLS_GENPRIME) || \ 29 !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_CTR_DRBG_C) 30 int main(void) 31 { 32 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or " 33 "MBEDTLS_RSA_C and/or MBEDTLS_GENPRIME and/or " 34 "MBEDTLS_FS_IO and/or MBEDTLS_CTR_DRBG_C not defined.\n"); 35 mbedtls_exit(0); 36 } 37 #else 38 39 40 int main(void) 41 { 42 int ret = 1; 43 int exit_code = MBEDTLS_EXIT_FAILURE; 44 mbedtls_rsa_context rsa; 45 mbedtls_entropy_context entropy; 46 mbedtls_ctr_drbg_context ctr_drbg; 47 mbedtls_mpi N, P, Q, D, E, DP, DQ, QP; 48 FILE *fpub = NULL; 49 FILE *fpriv = NULL; 50 const char *pers = "rsa_genkey"; 51 52 mbedtls_ctr_drbg_init(&ctr_drbg); 53 mbedtls_rsa_init(&rsa); 54 mbedtls_mpi_init(&N); mbedtls_mpi_init(&P); mbedtls_mpi_init(&Q); 55 mbedtls_mpi_init(&D); mbedtls_mpi_init(&E); mbedtls_mpi_init(&DP); 56 mbedtls_mpi_init(&DQ); mbedtls_mpi_init(&QP); 57 58 mbedtls_printf("\n . Seeding the random number generator..."); 59 fflush(stdout); 60 61 mbedtls_entropy_init(&entropy); 62 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, 63 (const unsigned char *) pers, 64 strlen(pers))) != 0) { 65 mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret); 66 goto exit; 67 } 68 69 mbedtls_printf(" ok\n . Generating the RSA key [ %d-bit ]...", KEY_SIZE); 70 fflush(stdout); 71 72 if ((ret = mbedtls_rsa_gen_key(&rsa, mbedtls_ctr_drbg_random, &ctr_drbg, KEY_SIZE, 73 EXPONENT)) != 0) { 74 mbedtls_printf(" failed\n ! mbedtls_rsa_gen_key returned %d\n\n", ret); 75 goto exit; 76 } 77 78 mbedtls_printf(" ok\n . Exporting the public key in rsa_pub.txt...."); 79 fflush(stdout); 80 81 if ((ret = mbedtls_rsa_export(&rsa, &N, &P, &Q, &D, &E)) != 0 || 82 (ret = mbedtls_rsa_export_crt(&rsa, &DP, &DQ, &QP)) != 0) { 83 mbedtls_printf(" failed\n ! could not export RSA parameters\n\n"); 84 goto exit; 85 } 86 87 if ((fpub = fopen("rsa_pub.txt", "wb+")) == NULL) { 88 mbedtls_printf(" failed\n ! could not open rsa_pub.txt for writing\n\n"); 89 goto exit; 90 } 91 92 if ((ret = mbedtls_mpi_write_file("N = ", &N, 16, fpub)) != 0 || 93 (ret = mbedtls_mpi_write_file("E = ", &E, 16, fpub)) != 0) { 94 mbedtls_printf(" failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret); 95 goto exit; 96 } 97 98 mbedtls_printf(" ok\n . Exporting the private key in rsa_priv.txt..."); 99 fflush(stdout); 100 101 if ((fpriv = fopen("rsa_priv.txt", "wb+")) == NULL) { 102 mbedtls_printf(" failed\n ! could not open rsa_priv.txt for writing\n"); 103 goto exit; 104 } 105 106 if ((ret = mbedtls_mpi_write_file("N = ", &N, 16, fpriv)) != 0 || 107 (ret = mbedtls_mpi_write_file("E = ", &E, 16, fpriv)) != 0 || 108 (ret = mbedtls_mpi_write_file("D = ", &D, 16, fpriv)) != 0 || 109 (ret = mbedtls_mpi_write_file("P = ", &P, 16, fpriv)) != 0 || 110 (ret = mbedtls_mpi_write_file("Q = ", &Q, 16, fpriv)) != 0 || 111 (ret = mbedtls_mpi_write_file("DP = ", &DP, 16, fpriv)) != 0 || 112 (ret = mbedtls_mpi_write_file("DQ = ", &DQ, 16, fpriv)) != 0 || 113 (ret = mbedtls_mpi_write_file("QP = ", &QP, 16, fpriv)) != 0) { 114 mbedtls_printf(" failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret); 115 goto exit; 116 } 117 mbedtls_printf(" ok\n\n"); 118 119 exit_code = MBEDTLS_EXIT_SUCCESS; 120 121 exit: 122 123 if (fpub != NULL) { 124 fclose(fpub); 125 } 126 127 if (fpriv != NULL) { 128 fclose(fpriv); 129 } 130 131 mbedtls_mpi_free(&N); mbedtls_mpi_free(&P); mbedtls_mpi_free(&Q); 132 mbedtls_mpi_free(&D); mbedtls_mpi_free(&E); mbedtls_mpi_free(&DP); 133 mbedtls_mpi_free(&DQ); mbedtls_mpi_free(&QP); 134 mbedtls_rsa_free(&rsa); 135 mbedtls_ctr_drbg_free(&ctr_drbg); 136 mbedtls_entropy_free(&entropy); 137 138 mbedtls_exit(exit_code); 139 } 140 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_RSA_C && 141 MBEDTLS_GENPRIME && MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */