text: ﻿/* dh_asn1.c */
  /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   * project 2000.
   */
  /* ====================================================================
   * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer. 
   *
   * 2. 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.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    licensing@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED 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 OpenSSL PROJECT OR
   * ITS 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.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  
  #include <stdio.h>
  #include "cryptlib.h"
  #include <openssl/bn.h>
  #include <openssl/dh.h>
  #include <openssl/objects.h>
  #include <openssl/asn1t.h>
  
  /* Override the default free and new methods */
  static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  						void *exarg)
  {
  	if(operation == ASN1_OP_NEW_PRE) {
  		*pval = (ASN1_VALUE *)DH_new();
  		if(*pval) return 2;
  		return 0;
  	} else if(operation == ASN1_OP_FREE_PRE) {
  		DH_free((DH *)*pval);
  		*pval = NULL;
  		return 2;
  	}
  	return 1;
  }
  
  ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
  	ASN1_SIMPLE(DH, p, BIGNUM),
  	ASN1_SIMPLE(DH, g, BIGNUM),
  	ASN1_OPT(DH, length, ZLONG),
  } ASN1_SEQUENCE_END_cb(DH, DHparams)
  
  IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
  
  DH *DHparams_dup(DH *dh)
  	{
  	return ASN1_item_dup(ASN1_ITEM_rptr(DHparams), dh);
  	}
  