1 /*
2 * Simple MPI demonstration program
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 #include "mbedtls/build_info.h"
21
22 #include "mbedtls/platform.h"
23
24 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_FS_IO)
25 #include "mbedtls/bignum.h"
26
27 #include <stdio.h>
28 #endif
29
30 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_FS_IO)
main(void)31 int main( void )
32 {
33 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_FS_IO not defined.\n");
34 mbedtls_exit( 0 );
35 }
36 #else
37
38
main(void)39 int main( void )
40 {
41 int ret = 1;
42 int exit_code = MBEDTLS_EXIT_FAILURE;
43 mbedtls_mpi E, P, Q, N, H, D, X, Y, Z;
44
45 mbedtls_mpi_init( &E ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &N );
46 mbedtls_mpi_init( &H ); mbedtls_mpi_init( &D ); mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
47 mbedtls_mpi_init( &Z );
48
49 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P, 10, "2789" ) );
50 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &Q, 10, "3203" ) );
51 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &E, 10, "257" ) );
52 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &N, &P, &Q ) );
53
54 mbedtls_printf( "\n Public key:\n\n" );
55 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " N = ", &N, 10, NULL ) );
56 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " E = ", &E, 10, NULL ) );
57
58 mbedtls_printf( "\n Private key:\n\n" );
59 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " P = ", &P, 10, NULL ) );
60 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Q = ", &Q, 10, NULL ) );
61
62 #if defined(MBEDTLS_GENPRIME)
63 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P, &P, 1 ) );
64 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q, &Q, 1 ) );
65 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P, &Q ) );
66 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &D, &E, &H ) );
67
68 mbedtls_mpi_write_file( " D = E^-1 mod (P-1)*(Q-1) = ",
69 &D, 10, NULL );
70 #else
71 mbedtls_printf("\nTest skipped (MBEDTLS_GENPRIME not defined).\n\n");
72 #endif
73 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &X, 10, "55555" ) );
74 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Y, &X, &E, &N, NULL ) );
75 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Z, &Y, &D, &N, NULL ) );
76
77 mbedtls_printf( "\n RSA operation:\n\n" );
78 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " X (plaintext) = ", &X, 10, NULL ) );
79 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Y (ciphertext) = X^E mod N = ", &Y, 10, NULL ) );
80 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Z (decrypted) = Y^D mod N = ", &Z, 10, NULL ) );
81 mbedtls_printf( "\n" );
82
83 exit_code = MBEDTLS_EXIT_SUCCESS;
84
85 cleanup:
86 mbedtls_mpi_free( &E ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &N );
87 mbedtls_mpi_free( &H ); mbedtls_mpi_free( &D ); mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
88 mbedtls_mpi_free( &Z );
89
90 if( exit_code != MBEDTLS_EXIT_SUCCESS )
91 {
92 mbedtls_printf( "\nAn error occurred.\n" );
93 }
94
95 mbedtls_exit( exit_code );
96 }
97 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_FS_IO */
98
