programs/pkey/mpi_demo.c

   1 /*
   2  *  Simple MPI demonstration program
   3  *
   4  *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
   5  *
   6  *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
   7  *
   8  *  All rights reserved.
   9  *
  10  *  Redistribution and use in source and binary forms, with or without
  11  *  modification, are permitted provided that the following conditions
  12  *  are met:
  13  *
  14  *    * Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *    * Redistributions in binary form must reproduce the above copyright
  17  *      notice, this list of conditions and the following disclaimer in the
  18  *      documentation and/or other materials provided with the distribution.
  19  *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
  20  *      may be used to endorse or promote products derived from this software
  21  *      without specific prior written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  26  *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 #ifndef _CRT_SECURE_NO_DEPRECATE
  37 #define _CRT_SECURE_NO_DEPRECATE 1
  38 #endif
  39
  40 #include <stdio.h>
  41
  42 #include "tropicssl/bignum.h"
  43
  44 int main(void)
  45 {
  46         mpi E, P, Q, N, H, D, X, Y, Z;
  47
  48         mpi_init(&E); mpi_init(&P); mpi_init(&Q); mpi_init(&N);
  49         mpi_init(&H); mpi_init(&D); mpi_init(&X); mpi_init(&Y);
  50         mpi_init(&Z);
  51
  52         mpi_read_string(&P, 10, "2789");
  53         mpi_read_string(&Q, 10, "3203");
  54         mpi_read_string(&E, 10, "257");
  55         mpi_mul_mpi(&N, &P, &Q);
  56
  57         printf("\n  Public key:\n\n");
  58         mpi_write_file("  N = ", &N, 10, NULL);
  59         mpi_write_file("  E = ", &E, 10, NULL);
  60
  61         printf("\n  Private key:\n\n");
  62         mpi_write_file("  P = ", &P, 10, NULL);
  63         mpi_write_file("  Q = ", &Q, 10, NULL);
  64
  65         mpi_sub_int(&P, &P, 1);
  66         mpi_sub_int(&Q, &Q, 1);
  67         mpi_mul_mpi(&H, &P, &Q);
  68         mpi_inv_mod(&D, &E, &H);
  69
  70         mpi_write_file("  D = E^-1 mod (P-1)*(Q-1) = ", &D, 10, NULL);
  71
  72         mpi_read_string(&X, 10, "55555");
  73         mpi_exp_mod(&Y, &X, &E, &N, NULL);
  74         mpi_exp_mod(&Z, &Y, &D, &N, NULL);
  75
  76         printf("\n  RSA operation:\n\n");
  77         mpi_write_file("  X (plaintext)  = ", &X, 10, NULL);
  78         mpi_write_file("  Y (ciphertext) = X^E mod N = ", &Y, 10, NULL);
  79         mpi_write_file("  Z (decrypted)  = Y^D mod N = ", &Z, 10, NULL);
  80         printf("\n");
  81
  82         mpi_free(&Z); mpi_free(&Y); mpi_free(&X); mpi_free(&D);
  83         mpi_free(&H); mpi_free(&N); mpi_free(&Q); mpi_free(&P);
  84         mpi_free(&E);
  85
  86 #ifdef WIN32
  87         printf("  Press Enter to exit this program.\n");
  88         fflush(stdout);
  89         getchar();
  90 #endif
  91
  92         return (0);
  93 }