programs/pkey/dh_genprime.c

   1 /*
   2  *  Diffie-Hellman-Merkle key exchange (prime generation)
   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 #include "tropicssl/config.h"
  44 #include "tropicssl/havege.h"
  45
  46 /*
  47  * Note: G = 4 is always a quadratic residue mod P,
  48  * so it is a generator of order Q (with P = 2*Q+1).
  49  */
  50 #define DH_P_SIZE 1024
  51 #define GENERATOR "4"
  52
  53 int main(void)
  54 {
  55         int ret = 1;
  56
  57 #if defined(TROPICSSL_GENPRIME)
  58         mpi G, P, Q;
  59         havege_state hs;
  60         FILE *fout;
  61
  62         mpi_init(&G, &P, &Q, NULL);
  63         mpi_read_string(&G, 10, GENERATOR);
  64
  65         printf("\n  . Seeding the random number generator...");
  66         fflush(stdout);
  67
  68         havege_init(&hs);
  69
  70         printf(" ok\n  . Generating the modulus, please wait...");
  71         fflush(stdout);
  72
  73         /*
  74          * This can take a long time...
  75          */
  76         if ((ret = mpi_gen_prime(&P, DH_P_SIZE, 1, havege_rand, &hs)) != 0) {
  77                 printf(" failed\n  ! mpi_gen_prime returned %d\n\n", ret);
  78                 goto exit;
  79         }
  80
  81         printf(" ok\n  . Verifying that Q = (P-1)/2 is prime...");
  82         fflush(stdout);
  83
  84         if ((ret = mpi_sub_int(&Q, &P, 1)) != 0) {
  85                 printf(" failed\n  ! mpi_sub_int returned %d\n\n", ret);
  86                 goto exit;
  87         }
  88
  89         if ((ret = mpi_div_int(&Q, NULL, &Q, 2)) != 0) {
  90                 printf(" failed\n  ! mpi_div_int returned %d\n\n", ret);
  91                 goto exit;
  92         }
  93
  94         if ((ret = mpi_is_prime(&Q, havege_rand, &hs)) != 0) {
  95                 printf(" failed\n  ! mpi_is_prime returned %d\n\n", ret);
  96                 goto exit;
  97         }
  98
  99         printf(" ok\n  . Exporting the value in dh_prime.txt...");
 100         fflush(stdout);
 101
 102         if ((fout = fopen("dh_prime.txt", "wb+")) == NULL) {
 103                 ret = 1;
 104                 printf(" failed\n  ! Could not create dh_prime.txt\n\n");
 105                 goto exit;
 106         }
 107
 108         if ((ret = mpi_write_file("P = ", &P, 16, fout) != 0) ||
 109             (ret = mpi_write_file("G = ", &G, 16, fout) != 0)) {
 110                 printf(" failed\n  ! mpi_write_file returned %d\n\n", ret);
 111                 goto exit;
 112         }
 113
 114         printf(" ok\n\n");
 115         fclose(fout);
 116
 117 exit:
 118
 119         mpi_free(&Q, &P, &G, NULL);
 120 #else
 121         printf("\n  ! Prime-number generation is not available.\n\n");
 122 #endif
 123
 124 #ifdef WIN32
 125         printf("  Press Enter to exit this program.\n");
 126         fflush(stdout);
 127         getchar();
 128 #endif
 129
 130         return (ret);
 131 }