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 #if defined(MBEDTLS_PLATFORM_C)
23 #include "mbedtls/platform.h"
24 #else
25 #include <stdio.h>
26 #include <stdlib.h>
27 #define mbedtls_printf printf
28 #define mbedtls_exit exit
29 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
30 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
31 #endif /* MBEDTLS_PLATFORM_C */
32
33 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_FS_IO)
34 #include "mbedtls/bignum.h"
35
36 #include <stdio.h>
37 #endif
38
39 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_FS_IO)
main(void)40 int main( void )
41 {
42 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_FS_IO not defined.\n");
43 mbedtls_exit( 0 );
44 }
45 #else
46
47
main(void)48 int main( void )
49 {
50 int ret = 1;
51 int exit_code = MBEDTLS_EXIT_FAILURE;
52 mbedtls_mpi E, P, Q, N, H, D, X, Y, Z;
53
54 mbedtls_mpi_init( &E ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &N );
55 mbedtls_mpi_init( &H ); mbedtls_mpi_init( &D ); mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
56 mbedtls_mpi_init( &Z );
57
58 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P, 10, "2789" ) );
59 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &Q, 10, "3203" ) );
60 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &E, 10, "257" ) );
61 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &N, &P, &Q ) );
62
63 mbedtls_printf( "\n Public key:\n\n" );
64 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " N = ", &N, 10, NULL ) );
65 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " E = ", &E, 10, NULL ) );
66
67 mbedtls_printf( "\n Private key:\n\n" );
68 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " P = ", &P, 10, NULL ) );
69 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Q = ", &Q, 10, NULL ) );
70
71 #if defined(MBEDTLS_GENPRIME)
72 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P, &P, 1 ) );
73 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q, &Q, 1 ) );
74 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P, &Q ) );
75 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &D, &E, &H ) );
76
77 mbedtls_mpi_write_file( " D = E^-1 mod (P-1)*(Q-1) = ",
78 &D, 10, NULL );
79 #else
80 mbedtls_printf("\nTest skipped (MBEDTLS_GENPRIME not defined).\n\n");
81 #endif
82 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &X, 10, "55555" ) );
83 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Y, &X, &E, &N, NULL ) );
84 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Z, &Y, &D, &N, NULL ) );
85
86 mbedtls_printf( "\n RSA operation:\n\n" );
87 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " X (plaintext) = ", &X, 10, NULL ) );
88 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Y (ciphertext) = X^E mod N = ", &Y, 10, NULL ) );
89 MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( " Z (decrypted) = Y^D mod N = ", &Z, 10, NULL ) );
90 mbedtls_printf( "\n" );
91
92 exit_code = MBEDTLS_EXIT_SUCCESS;
93
94 cleanup:
95 mbedtls_mpi_free( &E ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &N );
96 mbedtls_mpi_free( &H ); mbedtls_mpi_free( &D ); mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
97 mbedtls_mpi_free( &Z );
98
99 if( exit_code != MBEDTLS_EXIT_SUCCESS )
100 {
101 mbedtls_printf( "\nAn error occurred.\n" );
102 }
103
104 #if defined(_WIN32)
105 mbedtls_printf( " Press Enter to exit this program.\n" );
106 fflush( stdout ); getchar();
107 #endif
108
109 mbedtls_exit( exit_code );
110 }
111 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_FS_IO */
112