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)
25int 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
35int 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
140exit:
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