-/* crypto/bn/bn_add.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
+/*
+ * Copyright 1995-2016 The OpenSSL Project Authors. 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.]
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
/* r can == a or b */
int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
- const BIGNUM *tmp;
int a_neg = a->neg, ret;
bn_check_top(a);
if (a_neg ^ b->neg) {
/* only one is negative */
if (a_neg) {
+ const BIGNUM *tmp;
+
tmp = a;
a = b;
b = tmp;
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a))
- return (0);
+ return 0;
r->neg = 1;
} else {
if (!BN_usub(r, a, b))
- return (0);
+ return 0;
r->neg = 0;
}
- return (1);
+ return 1;
}
ret = BN_uadd(r, a, b);
int max, min, dif;
const BN_ULONG *ap, *bp;
BN_ULONG *rp, carry, t1, t2;
- const BIGNUM *tmp;
bn_check_top(a);
bn_check_top(b);
if (a->top < b->top) {
+ const BIGNUM *tmp;
+
tmp = a;
a = b;
b = tmp;
carry = bn_add_words(rp, ap, bp, min);
rp += min;
ap += min;
- bp += min;
-
- if (carry) {
- while (dif) {
- dif--;
- t1 = *(ap++);
- t2 = (t1 + 1) & BN_MASK2;
- *(rp++) = t2;
- if (t2) {
- carry = 0;
- break;
- }
- }
- if (carry) {
- /* carry != 0 => dif == 0 */
- *rp = 1;
- r->top++;
- }
+
+ while (dif) {
+ dif--;
+ t1 = *(ap++);
+ t2 = (t1 + carry) & BN_MASK2;
+ *(rp++) = t2;
+ carry &= (t2 == 0);
}
- if (dif && rp != ap)
- while (dif--)
- /* copy remaining words if ap != rp */
- *(rp++) = *(ap++);
+ *rp = carry;
+ r->top += carry;
+
r->neg = 0;
bn_check_top(r);
return 1;
int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
int max, min, dif;
- register BN_ULONG t1, t2, *rp;
- register const BN_ULONG *ap, *bp;
- int i, carry;
+ BN_ULONG t1, t2, borrow, *rp;
+ const BN_ULONG *ap, *bp;
bn_check_top(a);
bn_check_top(b);
if (dif < 0) { /* hmm... should not be happening */
BNerr(BN_F_BN_USUB, BN_R_ARG2_LT_ARG3);
- return (0);
+ return 0;
}
if (bn_wexpand(r, max) == NULL)
- return (0);
+ return 0;
ap = a->d;
bp = b->d;
rp = r->d;
-#if 1
- carry = 0;
- for (i = min; i != 0; i--) {
- t1 = *(ap++);
- t2 = *(bp++);
- if (carry) {
- carry = (t1 <= t2);
- t1 = (t1 - t2 - 1) & BN_MASK2;
- } else {
- carry = (t1 < t2);
- t1 = (t1 - t2) & BN_MASK2;
- }
- *(rp++) = t1 & BN_MASK2;
- }
-#else
- carry = bn_sub_words(rp, ap, bp, min);
+ borrow = bn_sub_words(rp, ap, bp, min);
ap += min;
- bp += min;
rp += min;
-#endif
- if (carry) { /* subtracted */
- if (!dif)
- /* error: a < b */
- return 0;
- while (dif) {
- dif--;
- t1 = *(ap++);
- t2 = (t1 - 1) & BN_MASK2;
- *(rp++) = t2;
- if (t1)
- break;
- }
+
+ while (dif) {
+ dif--;
+ t1 = *(ap++);
+ t2 = (t1 - borrow) & BN_MASK2;
+ *(rp++) = t2;
+ borrow &= (t1 == 0);
}
- memcpy(rp, ap, sizeof(*rp) * dif);
r->top = max;
r->neg = 0;
bn_correct_top(r);
- return (1);
+ return 1;
}
int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
int max;
int add = 0, neg = 0;
- const BIGNUM *tmp;
bn_check_top(a);
bn_check_top(b);
*/
if (a->neg) {
if (b->neg) {
+ const BIGNUM *tmp;
+
tmp = a;
a = b;
b = tmp;
if (add) {
if (!BN_uadd(r, a, b))
- return (0);
+ return 0;
r->neg = neg;
- return (1);
+ return 1;
}
/* We are actually doing a - b :-) */
max = (a->top > b->top) ? a->top : b->top;
if (bn_wexpand(r, max) == NULL)
- return (0);
+ return 0;
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a))
- return (0);
+ return 0;
r->neg = 1;
} else {
if (!BN_usub(r, a, b))
- return (0);
+ return 0;
r->neg = 0;
}
bn_check_top(r);
- return (1);
+ return 1;
}