1 /*
2 * Simple MPI demonstration 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_FS_IO)
13 #include "mbedtls/bignum.h"
14
15 #include <stdio.h>
16 #endif
17
18 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_FS_IO)
main(void)19 int main(void)
20 {
21 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_FS_IO not defined.\n");
22 mbedtls_exit(0);
23 }
24 #else
25
26
main(void)27 int main(void)
28 {
29 int ret = 1;
30 int exit_code = MBEDTLS_EXIT_FAILURE;
31 mbedtls_mpi E, P, Q, N, H, D, X, Y, Z;
32
33 mbedtls_mpi_init(&E); mbedtls_mpi_init(&P); mbedtls_mpi_init(&Q); mbedtls_mpi_init(&N);
34 mbedtls_mpi_init(&H); mbedtls_mpi_init(&D); mbedtls_mpi_init(&X); mbedtls_mpi_init(&Y);
35 mbedtls_mpi_init(&Z);
36
37 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&P, 10, "2789"));
38 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&Q, 10, "3203"));
39 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&E, 10, "257"));
40 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&N, &P, &Q));
41
42 mbedtls_printf("\n Public key:\n\n");
43 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" N = ", &N, 10, NULL));
44 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" E = ", &E, 10, NULL));
45
46 mbedtls_printf("\n Private key:\n\n");
47 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" P = ", &P, 10, NULL));
48 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Q = ", &Q, 10, NULL));
49
50 #if defined(MBEDTLS_GENPRIME)
51 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&P, &P, 1));
52 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&Q, &Q, 1));
53 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&H, &P, &Q));
54 MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&D, &E, &H));
55
56 mbedtls_mpi_write_file(" D = E^-1 mod (P-1)*(Q-1) = ",
57 &D, 10, NULL);
58 #else
59 mbedtls_printf("\nTest skipped (MBEDTLS_GENPRIME not defined).\n\n");
60 #endif
61 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&X, 10, "55555"));
62 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&Y, &X, &E, &N, NULL));
63 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&Z, &Y, &D, &N, NULL));
64
65 mbedtls_printf("\n RSA operation:\n\n");
66 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" X (plaintext) = ", &X, 10, NULL));
67 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Y (ciphertext) = X^E mod N = ", &Y, 10, NULL));
68 MBEDTLS_MPI_CHK(mbedtls_mpi_write_file(" Z (decrypted) = Y^D mod N = ", &Z, 10, NULL));
69 mbedtls_printf("\n");
70
71 exit_code = MBEDTLS_EXIT_SUCCESS;
72
73 cleanup:
74 mbedtls_mpi_free(&E); mbedtls_mpi_free(&P); mbedtls_mpi_free(&Q); mbedtls_mpi_free(&N);
75 mbedtls_mpi_free(&H); mbedtls_mpi_free(&D); mbedtls_mpi_free(&X); mbedtls_mpi_free(&Y);
76 mbedtls_mpi_free(&Z);
77
78 if (exit_code != MBEDTLS_EXIT_SUCCESS) {
79 mbedtls_printf("\nAn error occurred.\n");
80 }
81
82 mbedtls_exit(exit_code);
83 }
84 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_FS_IO */
85
