128 lines
3.3 KiB
C
128 lines
3.3 KiB
C
/*
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* Diffie-Hellman-Merkle key exchange (prime generation)
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*
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* Copyright (C) 2006-2010, Brainspark B.V.
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*
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* This file is part of PolarSSL (http://www.polarssl.org)
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* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef _CRT_SECURE_NO_DEPRECATE
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#define _CRT_SECURE_NO_DEPRECATE 1
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#endif
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#include <stdio.h>
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#include "polarssl/bignum.h"
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#include "polarssl/config.h"
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#include "polarssl/havege.h"
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/*
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* Note: G = 4 is always a quadratic residue mod P,
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* so it is a generator of order Q (with P = 2*Q+1).
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*/
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#define DH_P_SIZE 1024
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#define GENERATOR "4"
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int main( void )
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{
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int ret = 1;
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#if defined(POLARSSL_GENPRIME)
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mpi G, P, Q;
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havege_state hs;
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FILE *fout;
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mpi_init( &G, &P, &Q, NULL );
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mpi_read_string( &G, 10, GENERATOR );
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printf( "\n . Seeding the random number generator..." );
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fflush( stdout );
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havege_init( &hs );
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printf( " ok\n . Generating the modulus, please wait..." );
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fflush( stdout );
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/*
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* This can take a long time...
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*/
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if( ( ret = mpi_gen_prime( &P, DH_P_SIZE, 1,
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havege_rand, &hs ) ) != 0 )
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{
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printf( " failed\n ! mpi_gen_prime returned %d\n\n", ret );
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goto exit;
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}
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printf( " ok\n . Verifying that Q = (P-1)/2 is prime..." );
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fflush( stdout );
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if( ( ret = mpi_sub_int( &Q, &P, 1 ) ) != 0 )
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{
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printf( " failed\n ! mpi_sub_int returned %d\n\n", ret );
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goto exit;
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}
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if( ( ret = mpi_div_int( &Q, NULL, &Q, 2 ) ) != 0 )
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{
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printf( " failed\n ! mpi_div_int returned %d\n\n", ret );
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goto exit;
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}
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if( ( ret = mpi_is_prime( &Q, havege_rand, &hs ) ) != 0 )
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{
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printf( " failed\n ! mpi_is_prime returned %d\n\n", ret );
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goto exit;
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}
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printf( " ok\n . Exporting the value in dh_prime.txt..." );
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fflush( stdout );
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if( ( fout = fopen( "dh_prime.txt", "wb+" ) ) == NULL )
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{
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ret = 1;
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printf( " failed\n ! Could not create dh_prime.txt\n\n" );
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goto exit;
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}
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if( ( ret = mpi_write_file( "P = ", &P, 16, fout ) != 0 ) ||
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( ret = mpi_write_file( "G = ", &G, 16, fout ) != 0 ) )
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{
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printf( " failed\n ! mpi_write_file returned %d\n\n", ret );
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goto exit;
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}
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printf( " ok\n\n" );
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fclose( fout );
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exit:
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mpi_free( &Q, &P, &G, NULL );
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#else
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printf( "\n ! Prime-number generation is not available.\n\n" );
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#endif
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#ifdef WIN32
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printf( " Press Enter to exit this program.\n" );
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fflush( stdout ); getchar();
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#endif
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return( ret );
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}
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