RSAKeyPairGenerator.cc

/*
 * Copyright 2003 Michael A. Marsh, Cornell University. All rights reserved.
 * This software is released under the modified BSD license.
 * See the file LICENSE in the top-level directory for details.
 */
//
// $Id: RSAKeyPairGenerator.cc,v 1.3 2004/05/19 15:56:47 mmarsh Exp $
//
// $Log: RSAKeyPairGenerator.cc,v $
// Revision 1.3  2004/05/19 15:56:47  mmarsh
// *** empty log message ***
//
// Revision 1.2  2003/11/04 22:31:47  mmarsh
// *** empty log message ***
//
//

#include "RSA.h"
#include "CODEX_Exceptions/BignumExceptions.h"

using namespace CODEX_Ciphers;
using namespace CODEX_Exceptions;
using CODEX_ASN1::BigNumber;
using CODEX_ASN1::SecureBigNumber;

void
RSAKeyPairGenerator::operator()( RSAPublicKey*& pubKey,
                                 RSAPrivateKey*& privKey )
{
   BN_CTX * ctx = NULL;
   BIGNUM * p = NULL;
   BIGNUM * q = NULL;
   BIGNUM * n = NULL;
   BIGNUM * e = NULL;
   BIGNUM * p1 = NULL;
   BIGNUM * q1 = NULL;
   BIGNUM * phi = NULL;
   BIGNUM * d = NULL;

   try
   {
      ctx = BN_CTX_new();
      if ( NULL == ctx )
      {
         throw BignumContextException( __FILE__ , __LINE__ );
      }

      // generate a safe prime
      p = BN_new();
      if ( NULL == p )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( NULL == BN_generate_prime( p, m_numBits, 1,
                                      NULL, NULL, NULL, NULL ) )
      {
         throw BignumGeneratePrimeException( __FILE__ , __LINE__ );
      }

      // generate a safe prime
      q = BN_new();
      if ( NULL == q )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( NULL == BN_generate_prime( q, m_numBits, 1,
                                      NULL, NULL, NULL, NULL ) )
      {
         throw BignumGeneratePrimeException( __FILE__ , __LINE__ );
      }

      n = BN_new();
      if ( NULL == n )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_mul( n, p, q, ctx ) )
      {
         throw BignumMulException( __FILE__ , __LINE__ );
      }

      p1 = BN_new();
      if ( NULL == p1 )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_sub( p1, p, BN_value_one() ) )
      {
         throw BignumSubException( __FILE__ , __LINE__ );
      }

      q1 = BN_new();
      if ( NULL == q1 )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_sub( q1, q, BN_value_one() ) )
      {
         throw BignumSubException( __FILE__ , __LINE__ );
      }

      phi = BN_new();
      if ( NULL == phi )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_mul( phi, p1, q1, ctx ) )
      {
         throw BignumMulException( __FILE__ , __LINE__ );
      }

      e = BN_new();
      if ( NULL == e )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_set_word( e, 65537 ) ) // 2^16 + 2^0
      {
         throw BignumSetWordException( __FILE__ , __LINE__ );
      }

      d = BN_new();
      if ( NULL == d )
      {
         throw BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_mod_inverse( d, e, phi, ctx ) )
      {
         throw BignumModInverseException( __FILE__ , __LINE__ );
      }

      // We need to duplicate n in one of the constructors.
      pubKey = new RSAPublicKey( BN_dup(n), e );
      privKey = new RSAPrivateKey( p, q, d, n, phi );

      if ( NULL != ctx ) BN_CTX_free( ctx );
      if ( NULL != p1 ) BN_clear_free( p1 );
      if ( NULL != q1 ) BN_clear_free( q1 );
   }
   catch ( ... )
   {
      if ( NULL != ctx ) BN_CTX_free( ctx );
      if ( NULL != p ) BN_clear_free( p );
      if ( NULL != q ) BN_clear_free( q );
      if ( NULL != n ) BN_free( n );
      if ( NULL != e ) BN_free( e );
      if ( NULL != p1 ) BN_clear_free( p1 );
      if ( NULL != q1 ) BN_clear_free( q1 );
      if ( NULL != phi ) BN_clear_free( phi );
      if ( NULL != d ) BN_clear_free( d );
      throw;
   }
}

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