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)
main(void)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
main(int argc,char * argv[])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 */
150
