/* crypto/bn/bn_bld.c */
/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "cryptlib.h"
#include "bn_lcl.h"

BN_BL_CTX *BN_BL_CTX_new()
	{
	BN_BL_CTX *ret;

	if ((ret=(BN_BL_CTX *)Malloc(sizeof(BN_BL_CTX))) == NULL)
		{
		BNerr(BN_F_BN_BL_CTX_NEW,ERR_R_MALLOC_FAILURE);
		return(NULL);
		}
	if ((ret->num=BN_new()) == NULL) goto err;
	if ((ret->mod=BN_new()) == NULL) goto err;
	ret->inum=NULL;
	ret->count=16;
	ret->count=1;
	return(ret);
	}

int BN_BL_CTX_Init(a,mod)
BN_BL_CTX *a;
BIGNUM *mod;
	{
	int i;
	BN_CTX *ctx;

	if ((ctx=BN_CTX_new()) == NULL) goto m_err;

	if (BN_copy(a->mod,mod) == NULL) goto err;
	i=BN_num_bits(mod);
	if (!BN_rand(a->num,i,1,0)) goto err;
	
	if (a->inum != NULL) BN_clear_free(a->inum);
	a->inum=BN_mod_inverse(a->num,a->mod,ctx)
	ret->count=16;
	return(1);
m_err:
	BNerr(BN_F_BN_BL_CTX_INIT,ERR_R_MALLOC_FAILURE);
err:
	return(0);
	}

BN_BL_CTX *BN_BL_CTX_Update(a)
BN_BL_CTX *a;
	{
	BN_CTX *ctx;
	BN_BL_CTX *new;

	if (--a->count > 0)
		return(1);

	new=BN_BL_CTX_new();
	/* set/get lock */
	if ((ctx=BN_CTX_new()) == NULL)
		return(NULL);
	new->inum=BN_new();

	BN_mod_mul(new->num,a->num,a->num,a->mod,ctx);
	BN_mod_mul(new->inum,a->inum,a->inum,a->mod,ctx);
	BN_copy(new->mod,a->mod);
	BN_BL_CTX_free(a);
	return(new);
	}

void BN_BL_CTX_free(a)
BN_BL_CTX *a;
	{
	int i;

	if (a == NULL) return;

	i=CRYPTO_add(&a->references,-1,CRYPTO_LOCK_RSA);
	if (i > 0) return;
#ifdef REF_CHECK
	if (i < 0)
		{
		fprintf(stderr,"BN_BL_CTX_free, bad reference count\n");
		abort();
		}
#endif
	if (a->num == NULL) BN_clear_free(a->num);
	if (a->inum == NULL) BN_clear_free(a->inum);
	if (a->mod == NULL) BN_clear_free(a->mod);
	}