[thirdparty/openssl.git] / crypto / bn / bn_word.c

/* crypto/bn/bn_word.c */
/* Copyright (C) 1995-1998 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_ULONG BN_mod_word(a, w)
BIGNUM *a;
BN_ULONG w;
	{
#ifndef BN_LLONG
	BN_ULONG ret=0;
#else
	BN_ULLONG ret=0;
#endif
	int i;

	w&=BN_MASK2;
	for (i=a->top-1; i>=0; i--)
		{
#ifndef BN_LLONG
		ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w;
		ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%w;
#else
		ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%
			(BN_ULLONG)w);
#endif
		}
	return((BN_ULONG)ret);
	}

BN_ULONG BN_div_word(a, w)
BIGNUM *a;
BN_ULONG w;
	{
	BN_ULONG ret;
	int i;

	if (a->top == 0) return(0);
	ret=0;
	w&=BN_MASK2;
	for (i=a->top-1; i>=0; i--)
		{
		BN_ULONG l,d;
		
		l=a->d[i];
		d=bn_div_words(ret,l,w);
		ret=(l-((d*w)&BN_MASK2))&BN_MASK2;
		a->d[i]=d;
		}
	if ((a->top > 0) && (a->d[a->top-1] == 0))
		a->top--;
	return(ret);
	}

int BN_add_word(a, w)
BIGNUM *a;
BN_ULONG w;
	{
	BN_ULONG l;
	int i;

	if (a->neg)
		{
		a->neg=0;
		i=BN_sub_word(a,w);
		if (!BN_is_zero(a))
			a->neg=1;
		return(i);
		}
	w&=BN_MASK2;
	if (bn_wexpand(a,a->top+1) == NULL) return(0);
	i=0;
	for (;;)
		{
		l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
		a->d[i]=l;
		if (w > l)
			w=1;
		else
			break;
		i++;
		}
	if (i >= a->top)
		a->top++;
	return(1);
	}

int BN_sub_word(a, w)
BIGNUM *a;
BN_ULONG w;
	{
	int i;

	if (a->neg)
		{
		a->neg=0;
		i=BN_add_word(a,w);
		a->neg=1;
		return(i);
		}

	w&=BN_MASK2;
	if ((a->top == 1) && (a->d[0] < w))
		{
		a->d[0]=w-a->d[0];
		a->neg=1;
		return(1);
		}
	i=0;
	for (;;)
		{
		if (a->d[i] >= w)
			{
			a->d[i]-=w;
			break;
			}
		else
			{
			a->d[i]=(a->d[i]-w)&BN_MASK2;
			i++;
			w=1;
			}
		}
	if ((a->d[i] == 0) && (i == (a->top-1)))
		a->top--;
	return(1);
	}

int BN_mul_word(a,w)
BIGNUM *a;
BN_ULONG w;
	{
	BN_ULONG ll;

	w&=BN_MASK2;
	if (a->top)
		{
		ll=bn_mul_words(a->d,a->d,a->top,w);
		if (ll)
			{
			if (bn_wexpand(a,a->top+1) == NULL) return(0);
			a->d[a->top++]=ll;
			}
		}
	return(1);
	}
Commit	Line	Data
d02b48c6	1	/* crypto/bn/bn_word.c */
58964a49	2	/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
d02b48c6 RE	3	* All rights reserved.
	4	*
	5	* This package is an SSL implementation written
	6	* by Eric Young (eay@cryptsoft.com).
	7	* The implementation was written so as to conform with Netscapes SSL.
	8	*
	9	* This library is free for commercial and non-commercial use as long as
	10	* the following conditions are aheared to. The following conditions
	11	* apply to all code found in this distribution, be it the RC4, RSA,
	12	* lhash, DES, etc., code; not just the SSL code. The SSL documentation
	13	* included with this distribution is covered by the same copyright terms
	14	* except that the holder is Tim Hudson (tjh@cryptsoft.com).
	15	*
	16	* Copyright remains Eric Young's, and as such any Copyright notices in
	17	* the code are not to be removed.
	18	* If this package is used in a product, Eric Young should be given attribution
	19	* as the author of the parts of the library used.
	20	* This can be in the form of a textual message at program startup or
	21	* in documentation (online or textual) provided with the package.
	22	*
	23	* Redistribution and use in source and binary forms, with or without
	24	* modification, are permitted provided that the following conditions
	25	* are met:
	26	* 1. Redistributions of source code must retain the copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* 2. Redistributions in binary form must reproduce the above copyright
	29	* notice, this list of conditions and the following disclaimer in the
	30	* documentation and/or other materials provided with the distribution.
	31	* 3. All advertising materials mentioning features or use of this software
	32	* must display the following acknowledgement:
	33	* "This product includes cryptographic software written by
	34	* Eric Young (eay@cryptsoft.com)"
	35	* The word 'cryptographic' can be left out if the rouines from the library
	36	* being used are not cryptographic related :-).
	37	* 4. If you include any Windows specific code (or a derivative thereof) from
	38	* the apps directory (application code) you must include an acknowledgement:
	39	* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
	40	*
	41	* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
	42	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	43	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	44	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	45	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	46	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	47	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	49	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	50	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	51	* SUCH DAMAGE.
	52	*
	53	* The licence and distribution terms for any publically available version or
	54	* derivative of this code cannot be changed. i.e. this code cannot simply be
	55	* copied and put under another distribution licence
	56	* [including the GNU Public Licence.]
	57	*/
	58
	59	#include <stdio.h>
	60	#include "cryptlib.h"
	61	#include "bn_lcl.h"
	62
	63	BN_ULONG BN_mod_word(a, w)
	64	BIGNUM *a;
dfeab068	65	BN_ULONG w;
d02b48c6 RE	66	{
	67	#ifndef BN_LLONG
	68	BN_ULONG ret=0;
	69	#else
	70	BN_ULLONG ret=0;
	71	#endif
	72	int i;
	73
58964a49	74	w&=BN_MASK2;
d02b48c6 RE	75	for (i=a->top-1; i>=0; i--)
	76	{
	77	#ifndef BN_LLONG
dfeab068 RE	78	ret=((ret<<BN_BITS4)\|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w;
dfeab068 RE	79	ret=((ret<<BN_BITS4)\|(a->d[i]&BN_MASK2l))%w;
d02b48c6 RE	80	#else
	81	ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)\|a->d[i])%
	82	(BN_ULLONG)w);
	83	#endif
	84	}
	85	return((BN_ULONG)ret);
	86	}
	87
	88	BN_ULONG BN_div_word(a, w)
	89	BIGNUM *a;
dfeab068	90	BN_ULONG w;
d02b48c6 RE	91	{
	92	BN_ULONG ret;
	93	int i;
	94
	95	if (a->top == 0) return(0);
	96	ret=0;
58964a49	97	w&=BN_MASK2;
d02b48c6 RE	98	for (i=a->top-1; i>=0; i--)
d02b48c6 RE	99	{
58964a49 RE	100	BN_ULONG l,d;
	101
	102	l=a->d[i];
dfeab068	103	d=bn_div_words(ret,l,w);
58964a49 RE	104	ret=(l-((d*w)&BN_MASK2))&BN_MASK2;
58964a49 RE	105	a->d[i]=d;
d02b48c6	106	}
dfeab068	107	if ((a->top > 0) && (a->d[a->top-1] == 0))
d02b48c6 RE	108	a->top--;
	109	return(ret);
	110	}
	111
	112	int BN_add_word(a, w)
	113	BIGNUM *a;
dfeab068	114	BN_ULONG w;
d02b48c6 RE	115	{
	116	BN_ULONG l;
	117	int i;
	118
58964a49 RE	119	if (a->neg)
	120	{
	121	a->neg=0;
	122	i=BN_sub_word(a,w);
	123	if (!BN_is_zero(a))
	124	a->neg=1;
	125	return(i);
	126	}
	127	w&=BN_MASK2;
	128	if (bn_wexpand(a,a->top+1) == NULL) return(0);
d02b48c6 RE	129	i=0;
	130	for (;;)
	131	{
	132	l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
	133	a->d[i]=l;
	134	if (w > l)
	135	w=1;
	136	else
	137	break;
	138	i++;
	139	}
	140	if (i >= a->top)
	141	a->top++;
	142	return(1);
	143	}
	144
58964a49 RE	145	int BN_sub_word(a, w)
58964a49 RE	146	BIGNUM *a;
dfeab068	147	BN_ULONG w;
d02b48c6	148	{
58964a49	149	int i;
d02b48c6	150
58964a49 RE	151	if (a->neg)
	152	{
	153	a->neg=0;
	154	i=BN_add_word(a,w);
	155	a->neg=1;
	156	return(i);
	157	}
d02b48c6	158
58964a49 RE	159	w&=BN_MASK2;
	160	if ((a->top == 1) && (a->d[0] < w))
	161	{
	162	a->d[0]=w-a->d[0];
	163	a->neg=1;
	164	return(1);
	165	}
	166	i=0;
	167	for (;;)
d02b48c6	168	{
58964a49 RE	169	if (a->d[i] >= w)
	170	{
	171	a->d[i]-=w;
	172	break;
	173	}
	174	else
	175	{
	176	a->d[i]=(a->d[i]-w)&BN_MASK2;
	177	i++;
	178	w=1;
	179	}
	180	}
	181	if ((a->d[i] == 0) && (i == (a->top-1)))
	182	a->top--;
	183	return(1);
	184	}
d02b48c6	185
58964a49 RE	186	int BN_mul_word(a,w)
58964a49 RE	187	BIGNUM *a;
dfeab068	188	BN_ULONG w;
58964a49 RE	189	{
	190	BN_ULONG ll;
	191
	192	w&=BN_MASK2;
	193	if (a->top)
	194	{
	195	ll=bn_mul_words(a->d,a->d,a->top,w);
	196	if (ll)
	197	{
	198	if (bn_wexpand(a,a->top+1) == NULL) return(0);
	199	a->d[a->top++]=ll;
	200	}
	201	}
dfeab068	202	return(1);
58964a49	203	}
d02b48c6	204