1 /*
2  *  Simple MPI demonstration program
3  *
4  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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  *  This file is part of mbed TLS (https://tls.mbed.org)
20  */
21 
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
24 #else
25 #include MBEDTLS_CONFIG_FILE
26 #endif
27 
28 #if defined(MBEDTLS_PLATFORM_C)
29 #include "mbedtls/platform.h"
30 #else
31 #include <stdio.h>
32 #include <stdlib.h>
33 #define mbedtls_printf          printf
34 #define mbedtls_exit            exit
35 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
36 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
37 #endif /* MBEDTLS_PLATFORM_C */
38 
39 #if defined(MBEDTLS_BIGNUM_C) && defined(MBEDTLS_FS_IO)
40 #include "mbedtls/bignum.h"
41 
42 #include <stdio.h>
43 #endif
44 
45 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_FS_IO)
main(void)46 int main( void )
47 {
48     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_FS_IO not defined.\n");
49     return( 0 );
50 }
51 #else
52 
53 #if defined(MBEDTLS_CHECK_PARAMS)
54 #include "mbedtls/platform_util.h"
mbedtls_param_failed(const char * failure_condition,const char * file,int line)55 void mbedtls_param_failed( const char *failure_condition,
56                            const char *file,
57                            int line )
58 {
59     mbedtls_printf( "%s:%i: Input param failed - %s\n",
60                     file, line, failure_condition );
61     mbedtls_exit( MBEDTLS_EXIT_FAILURE );
62 }
63 #endif
64 
main(void)65 int main( void )
66 {
67     int ret = 1;
68     int exit_code = MBEDTLS_EXIT_FAILURE;
69     mbedtls_mpi E, P, Q, N, H, D, X, Y, Z;
70 
71     mbedtls_mpi_init( &E ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &N );
72     mbedtls_mpi_init( &H ); mbedtls_mpi_init( &D ); mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
73     mbedtls_mpi_init( &Z );
74 
75     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P, 10, "2789" ) );
76     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &Q, 10, "3203" ) );
77     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &E, 10,  "257" ) );
78     MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &N, &P, &Q ) );
79 
80     mbedtls_printf( "\n  Public key:\n\n" );
81     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  N = ", &N, 10, NULL ) );
82     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  E = ", &E, 10, NULL ) );
83 
84     mbedtls_printf( "\n  Private key:\n\n" );
85     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  P = ", &P, 10, NULL ) );
86     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  Q = ", &Q, 10, NULL ) );
87 
88 #if defined(MBEDTLS_GENPRIME)
89     MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P, &P, 1 ) );
90     MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q, &Q, 1 ) );
91     MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P, &Q ) );
92     MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &D, &E, &H ) );
93 
94     mbedtls_mpi_write_file( "  D = E^-1 mod (P-1)*(Q-1) = ",
95                     &D, 10, NULL );
96 #else
97     mbedtls_printf("\nTest skipped (MBEDTLS_GENPRIME not defined).\n\n");
98 #endif
99     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &X, 10, "55555" ) );
100     MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Y, &X, &E, &N, NULL ) );
101     MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &Z, &Y, &D, &N, NULL ) );
102 
103     mbedtls_printf( "\n  RSA operation:\n\n" );
104     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  X (plaintext)  = ", &X, 10, NULL ) );
105     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  Y (ciphertext) = X^E mod N = ", &Y, 10, NULL ) );
106     MBEDTLS_MPI_CHK( mbedtls_mpi_write_file( "  Z (decrypted)  = Y^D mod N = ", &Z, 10, NULL ) );
107     mbedtls_printf( "\n" );
108 
109     exit_code = MBEDTLS_EXIT_SUCCESS;
110 
111 cleanup:
112     mbedtls_mpi_free( &E ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &N );
113     mbedtls_mpi_free( &H ); mbedtls_mpi_free( &D ); mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
114     mbedtls_mpi_free( &Z );
115 
116     if( exit_code != MBEDTLS_EXIT_SUCCESS )
117     {
118         mbedtls_printf( "\nAn error occurred.\n" );
119     }
120 
121 #if defined(_WIN32)
122     mbedtls_printf( "  Press Enter to exit this program.\n" );
123     fflush( stdout ); getchar();
124 #endif
125 
126     return( exit_code );
127 }
128 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_FS_IO */
129