rsa_encrypt.c (4232B)
1 /* 2 * RSA simple data encryption 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_RSA_C) && \ 13 defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_FS_IO) && \ 14 defined(MBEDTLS_CTR_DRBG_C) 15 #include "mbedtls/rsa.h" 16 #include "mbedtls/entropy.h" 17 #include "mbedtls/ctr_drbg.h" 18 19 #include <string.h> 20 #endif 21 22 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) || \ 23 !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_FS_IO) || \ 24 !defined(MBEDTLS_CTR_DRBG_C) 25 int main(void) 26 { 27 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or " 28 "MBEDTLS_ENTROPY_C and/or MBEDTLS_FS_IO and/or " 29 "MBEDTLS_CTR_DRBG_C not defined.\n"); 30 mbedtls_exit(0); 31 } 32 #else 33 34 35 int main(int argc, char *argv[]) 36 { 37 FILE *f; 38 int ret = 1; 39 int exit_code = MBEDTLS_EXIT_FAILURE; 40 size_t i; 41 mbedtls_rsa_context rsa; 42 mbedtls_entropy_context entropy; 43 mbedtls_ctr_drbg_context ctr_drbg; 44 unsigned char input[1024]; 45 unsigned char buf[512]; 46 const char *pers = "rsa_encrypt"; 47 mbedtls_mpi N, E; 48 49 if (argc != 2) { 50 mbedtls_printf("usage: rsa_encrypt <string of max 100 characters>\n"); 51 52 #if defined(_WIN32) 53 mbedtls_printf("\n"); 54 #endif 55 56 mbedtls_exit(exit_code); 57 } 58 59 mbedtls_printf("\n . Seeding the random number generator..."); 60 fflush(stdout); 61 62 mbedtls_mpi_init(&N); mbedtls_mpi_init(&E); 63 mbedtls_rsa_init(&rsa); 64 mbedtls_ctr_drbg_init(&ctr_drbg); 65 mbedtls_entropy_init(&entropy); 66 67 ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, 68 &entropy, (const unsigned char *) pers, 69 strlen(pers)); 70 if (ret != 0) { 71 mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d\n", 72 ret); 73 goto exit; 74 } 75 76 mbedtls_printf("\n . Reading public key from rsa_pub.txt"); 77 fflush(stdout); 78 79 if ((f = fopen("rsa_pub.txt", "rb")) == NULL) { 80 mbedtls_printf(" failed\n ! Could not open rsa_pub.txt\n" \ 81 " ! Please run rsa_genkey first\n\n"); 82 goto exit; 83 } 84 85 if ((ret = mbedtls_mpi_read_file(&N, 16, f)) != 0 || 86 (ret = mbedtls_mpi_read_file(&E, 16, f)) != 0) { 87 mbedtls_printf(" failed\n ! mbedtls_mpi_read_file returned %d\n\n", 88 ret); 89 fclose(f); 90 goto exit; 91 } 92 fclose(f); 93 94 if ((ret = mbedtls_rsa_import(&rsa, &N, NULL, NULL, NULL, &E)) != 0) { 95 mbedtls_printf(" failed\n ! mbedtls_rsa_import returned %d\n\n", 96 ret); 97 goto exit; 98 } 99 100 if (strlen(argv[1]) > 100) { 101 mbedtls_printf(" Input data larger than 100 characters.\n\n"); 102 goto exit; 103 } 104 105 memcpy(input, argv[1], strlen(argv[1])); 106 107 /* 108 * Calculate the RSA encryption of the hash. 109 */ 110 mbedtls_printf("\n . Generating the RSA encrypted value"); 111 fflush(stdout); 112 113 ret = mbedtls_rsa_pkcs1_encrypt(&rsa, mbedtls_ctr_drbg_random, 114 &ctr_drbg, strlen(argv[1]), input, buf); 115 if (ret != 0) { 116 mbedtls_printf(" failed\n ! mbedtls_rsa_pkcs1_encrypt returned %d\n\n", 117 ret); 118 goto exit; 119 } 120 121 /* 122 * Write the signature into result-enc.txt 123 */ 124 if ((f = fopen("result-enc.txt", "wb+")) == NULL) { 125 mbedtls_printf(" failed\n ! Could not create %s\n\n", "result-enc.txt"); 126 goto exit; 127 } 128 129 for (i = 0; i < mbedtls_rsa_get_len(&rsa); i++) { 130 mbedtls_fprintf(f, "%02X%s", buf[i], 131 (i + 1) % 16 == 0 ? "\r\n" : " "); 132 } 133 134 fclose(f); 135 136 mbedtls_printf("\n . Done (created \"%s\")\n\n", "result-enc.txt"); 137 138 exit_code = MBEDTLS_EXIT_SUCCESS; 139 140 exit: 141 mbedtls_mpi_free(&N); mbedtls_mpi_free(&E); 142 mbedtls_ctr_drbg_free(&ctr_drbg); 143 mbedtls_entropy_free(&entropy); 144 mbedtls_rsa_free(&rsa); 145 146 mbedtls_exit(exit_code); 147 } 148 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_ENTROPY_C && 149 MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */