text: /* crypto/ecdsa/ecs_lib.c */
  /* ====================================================================
   * Copyright (c) 1998-2005 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
   *    openssl-core@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 "ecs_locl.h"
  #ifdef OPENSSL_SYS_WINDOWS
  #include <string.h>
  #endif
  #ifndef OPENSSL_NO_ENGINE
  #include <openssl/engine.h>
  #endif
  #include <openssl/err.h>
  #include <openssl/bn.h>
  
  const char ECDSA_version[]="ECDSA" OPENSSL_VERSION_PTEXT;
  
  static const ECDSA_METHOD *default_ECDSA_method = NULL;
  
  static void *ecdsa_data_new(void);
  static void *ecdsa_data_dup(void *);
  static void  ecdsa_data_free(void *);
  
  void ECDSA_set_default_method(const ECDSA_METHOD *meth)
  {
  	default_ECDSA_method = meth;
  }
  
  const ECDSA_METHOD *ECDSA_get_default_method(void)
  {
  	if(!default_ECDSA_method) 
  		default_ECDSA_method = ECDSA_OpenSSL();
  	return default_ECDSA_method;
  }
  
  int ECDSA_set_method(EC_KEY *eckey, const ECDSA_METHOD *meth)
  {
  	ECDSA_DATA *ecdsa;
  
  	ecdsa = ecdsa_check(eckey);
  
  	if (ecdsa == NULL)
  		return 0;
  
  #ifndef OPENSSL_NO_ENGINE
  	if (ecdsa->engine)
  	{
  		ENGINE_finish(ecdsa->engine);
  		ecdsa->engine = NULL;
  	}
  #endif
          ecdsa->meth = meth;
  
          return 1;
  }
  
  static ECDSA_DATA *ECDSA_DATA_new_method(ENGINE *engine)
  {
  	ECDSA_DATA *ret;
  
  	ret=(ECDSA_DATA *)OPENSSL_malloc(sizeof(ECDSA_DATA));
  	if (ret == NULL)
  	{
  		ECDSAerr(ECDSA_F_ECDSA_DATA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  		return(NULL);
  	}
  
  	ret->init = NULL;
  
  	ret->meth = ECDSA_get_default_method();
  	ret->engine = engine;
  #ifndef OPENSSL_NO_ENGINE
  	if (!ret->engine)
  		ret->engine = ENGINE_get_default_ECDSA();
  	if (ret->engine)
  	{
  		ret->meth = ENGINE_get_ECDSA(ret->engine);
  		if (!ret->meth)
  		{
  			ECDSAerr(ECDSA_F_ECDSA_DATA_NEW_METHOD, ERR_R_ENGINE_LIB);
  			ENGINE_finish(ret->engine);
  			OPENSSL_free(ret);
  			return NULL;
  		}
  	}
  #endif
  
  	ret->flags = ret->meth->flags;
  	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_ECDSA, ret, &ret->ex_data);
  #if 0
  	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
  	{
  		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ECDSA, ret, &ret->ex_data);
  		OPENSSL_free(ret);
  		ret=NULL;
  	}
  #endif	
  	return(ret);
  }
  
  static void *ecdsa_data_new(void)
  {
  	return (void *)ECDSA_DATA_new_method(NULL);
  }
  
  static void *ecdsa_data_dup(void *data)
  {
  	ECDSA_DATA *r = (ECDSA_DATA *)data;
  
  	/* XXX: dummy operation */
  	if (r == NULL)
  		return NULL;
  
  	return ecdsa_data_new();
  }
  
  static void ecdsa_data_free(void *data)
  {
  	ECDSA_DATA *r = (ECDSA_DATA *)data;
  
  #ifndef OPENSSL_NO_ENGINE
  	if (r->engine)
  		ENGINE_finish(r->engine);
  #endif
  	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ECDSA, r, &r->ex_data);
  
  	OPENSSL_cleanse((void *)r, sizeof(ECDSA_DATA));
  
  	OPENSSL_free(r);
  }
  
  ECDSA_DATA *ecdsa_check(EC_KEY *key)
  {
  	ECDSA_DATA *ecdsa_data;
   
  	void *data = EC_KEY_get_key_method_data(key, ecdsa_data_dup,
  					ecdsa_data_free, ecdsa_data_free);
  	if (data == NULL)
  	{
  		ecdsa_data = (ECDSA_DATA *)ecdsa_data_new();
  		if (ecdsa_data == NULL)
  			return NULL;
  		EC_KEY_insert_key_method_data(key, (void *)ecdsa_data,
  			ecdsa_data_dup, ecdsa_data_free, ecdsa_data_free);
  	}
  	else
  		ecdsa_data = (ECDSA_DATA *)data;
  	
  
  	return ecdsa_data;
  }
  
  int ECDSA_size(const EC_KEY *r)
  {
  	int ret,i;
  	ASN1_INTEGER bs;
  	BIGNUM	*order=NULL;
  	unsigned char buf[4];
  	const EC_GROUP *group;
  
  	if (r == NULL)
  		return 0;
  	group = EC_KEY_get0_group(r);
  	if (group == NULL)
  		return 0;
  
  	if ((order = BN_new()) == NULL) return 0;
  	if (!EC_GROUP_get_order(group,order,NULL))
  	{
  		BN_clear_free(order);
  		return 0;
  	} 
  	i=BN_num_bits(order);
  	bs.length=(i+7)/8;
  	bs.data=buf;
  	bs.type=V_ASN1_INTEGER;
  	/* If the top bit is set the asn1 encoding is 1 larger. */
  	buf[0]=0xff;	
  
  	i=i2d_ASN1_INTEGER(&bs,NULL);
  	i+=i; /* r and s */
  	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
  	BN_clear_free(order);
  	return(ret);
  }
  
  
  int ECDSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
  	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
  {
  	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ECDSA, argl, argp,
  				new_func, dup_func, free_func);
  }
  
  int ECDSA_set_ex_data(EC_KEY *d, int idx, void *arg)
  {
  	ECDSA_DATA *ecdsa;
  	ecdsa = ecdsa_check(d);
  	if (ecdsa == NULL)
  		return 0;
  	return(CRYPTO_set_ex_data(&ecdsa->ex_data,idx,arg));
  }
  
  void *ECDSA_get_ex_data(EC_KEY *d, int idx)
  {
  	ECDSA_DATA *ecdsa;
  	ecdsa = ecdsa_check(d);
  	if (ecdsa == NULL)
  		return NULL;
  	return(CRYPTO_get_ex_data(&ecdsa->ex_data,idx));
  }
  