VarRSACipherText.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: VarRSACipherText.cc,v 1.3 2004/05/19 15:56:48 mmarsh Exp $
//
// $Log: VarRSACipherText.cc,v $
// Revision 1.3  2004/05/19 15:56:48  mmarsh
// *** empty log message ***
//
// Revision 1.2  2003/11/04 22:31:48  mmarsh
// *** empty log message ***
//
//

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

using namespace CODEX_Ciphers;

void
VarRSACipherText::operator=( const VarRSACipherText& aOther )
{
   m_initialized = aOther.m_initialized;
   m_c1          = aOther.m_c1;
   m_c2          = aOther.m_c2;
}

bool
VarRSACipherText::operator==( const VarRSACipherText& aOther ) const
{
   if ( m_c1 != aOther.m_c1 ) return false;
   if ( m_c2 != aOther.m_c2 ) return false;
   return true;
}

bool
VarRSACipherText::operator!=( const VarRSACipherText& aOther ) const
{
   return ! ( *this == aOther );
}

VarRSABlindCipherText*
VarRSACipherText::blind( const RSACipherText& aOther,
                         const CODEX_ASN1::BigNumber& modulus ) const
{
   VarRSABlindCipherText* retVal = 0;
   // The notation is somewhat historical.
   const BIGNUM * kbn = m_c1.value();
   const BIGNUM * b = aOther.value();
   const BIGNUM * n = modulus.value();
   BIGNUM * bk = 0;
   BN_CTX * ctx = 0;
   try
   {
      ctx = BN_CTX_new();
      if ( 0 == ctx )
      {
         throw CODEX_Exceptions::BignumContextException( __FILE__ , __LINE__ );
      }
      bk = BN_new();
      if ( 0 == bk )
      {
         throw CODEX_Exceptions::BignumNullException( __FILE__ , __LINE__ );
      }
      if ( ! BN_mod_mul( bk, b, kbn, n, ctx ) )
      {
         throw CODEX_Exceptions::BignumModMulException( __FILE__ , __LINE__ );
      }
      retVal = new VarRSABlindCipherText( bk, m_c2 );
      bk = 0;
      BN_CTX_free( ctx );
      ctx = 0;
      return retVal;
   }
   catch ( ... )
   {
      if ( 0 != ctx ) BN_CTX_free( ctx );
      if ( 0 != bk ) BN_free( bk );
      throw;
   }
}

int
VarRSACipherText::marshal( unsigned char ** pp ) const
{
   int r=0;
   int ret=0;
   unsigned char * p;

   ret += m_c1.marshal(0);
   ret += m_c2.marshal(0);
   M_ASN1_I2D_seq_total();
   m_c1.marshal(&p);
   m_c2.marshal(&p);
   M_ASN1_I2D_finish();
}

void*
VarRSACipherText::unmarshal( void* bogus, unsigned char ** pp, long length )
{
   if ( m_initialized )
   {
      return NULL;
   }
   if ( (NULL == pp) || (NULL == *pp) )
   {
      return NULL;
   }
   ASN1_CTX c;
   c.pp = pp;
   c.q = *pp;
   c.error = ERR_R_NESTED_ASN1_ERROR;
   int i;

   M_ASN1_D2I_Init();
   M_ASN1_D2I_start_sequence();
   M_ASN1_D2I_get(i, m_c1.unmarshal);
   M_ASN1_D2I_get(i, m_c2.unmarshal);
   if ( !asn1_Finish(&c) )
   {
      return NULL;
   }
   *pp=c.p;
   m_initialized = true;
   return this;
  err: // needed by ASN.1 macros
   return NULL;
}

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