/*
 *  Example RSA key generation program
 *
 *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
 *
 *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *  
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _CRT_SECURE_NO_DEPRECATE
#define _CRT_SECURE_NO_DEPRECATE 1
#endif

#include <stdio.h>

#include "polarssl/havege.h"
#include "polarssl/bignum.h"
#include "polarssl/x509.h"
#include "polarssl/rsa.h"

#define KEY_SIZE 2048
#define EXPONENT 65537

int main( void )
{
    int ret;
    rsa_context rsa;
    havege_state hs;
    FILE *fpub  = NULL;
    FILE *fpriv = NULL;
    x509_raw cert;

    printf( "\n  . Seeding the random number generator..." );
    fflush( stdout );

    havege_init( &hs );

    printf( " ok\n  . Generating the RSA key [ %d-bit ]...", KEY_SIZE );
    fflush( stdout );

    rsa_init( &rsa, RSA_PKCS_V15, 0, havege_rand, &hs );

    if( ( ret = rsa_gen_key( &rsa, KEY_SIZE, EXPONENT ) ) != 0 )
    {
        printf( " failed\n  ! rsa_gen_key returned %d\n\n", ret );
        goto exit;
    }

    printf( " ok\n  . Exporting the public  key in rsa_pub.txt...." );
    fflush( stdout );

    if( ( fpub = fopen( "rsa_pub.txt", "wb+" ) ) == NULL )
    {
        printf( " failed\n  ! could not open rsa_pub.txt for writing\n\n" );
        ret = 1;
        goto exit;
    }

    if( ( ret = mpi_write_file( "N = ", &rsa.N, 16, fpub ) ) != 0 ||
        ( ret = mpi_write_file( "E = ", &rsa.E, 16, fpub ) ) != 0 )
    {
        printf( " failed\n  ! mpi_write_file returned %d\n\n", ret );
        goto exit;
    }

    printf( " ok\n  . Exporting the private key in rsa_priv.txt..." );
    fflush( stdout );

    if( ( fpriv = fopen( "rsa_priv.txt", "wb+" ) ) == NULL )
    {
        printf( " failed\n  ! could not open rsa_priv.txt for writing\n" );
        ret = 1;
        goto exit;
    }

    if( ( ret = mpi_write_file( "N = " , &rsa.N , 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "E = " , &rsa.E , 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "D = " , &rsa.D , 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "P = " , &rsa.P , 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "Q = " , &rsa.Q , 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "DP = ", &rsa.DP, 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "DQ = ", &rsa.DQ, 16, fpriv ) ) != 0 ||
        ( ret = mpi_write_file( "QP = ", &rsa.QP, 16, fpriv ) ) != 0 )
    {
        printf( " failed\n  ! mpi_write_file returned %d\n\n", ret );
        goto exit;
    }
/*
    printf( " ok\n  . Generating the certificate..." );

    x509write_init_raw( &cert );
    x509write_add_pubkey( &cert, &rsa );
    x509write_add_subject( &cert, "CN='localhost'" );
    x509write_add_validity( &cert, "2007-09-06 17:00:32",
                                   "2010-09-06 17:00:32" );
    x509write_create_selfsign( &cert, &rsa );
    x509write_crtfile( &cert, "cert.der", X509_OUTPUT_DER );
    x509write_crtfile( &cert, "cert.pem", X509_OUTPUT_PEM );
    x509write_free_raw( &cert );
*/
    printf( " ok\n\n" );

exit:

    if( fpub  != NULL )
        fclose( fpub );

    if( fpriv != NULL )
        fclose( fpriv );

    rsa_free( &rsa );

#ifdef WIN32
    printf( "  Press Enter to exit this program.\n" );
    fflush( stdout ); getchar();
#endif

    return( ret );
}