-/* crypto/bn/bn_word.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 <stdio.h>
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
- {
+{
#ifndef BN_LLONG
- BN_ULONG ret=0;
+ BN_ULONG ret = 0;
#else
- BN_ULLONG ret=0;
+ BN_ULLONG ret = 0;
#endif
- int i;
+ int i;
- if (w == 0)
- return (BN_ULONG)-1;
+ if (w == 0)
+ return (BN_ULONG)-1;
- bn_check_top(a);
- 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;
+ /*
+ * If |w| is too long and we don't have BN_ULLONG then we need to fall
+ * back to using BN_div_word
+ */
+ if (w > ((BN_ULONG)1 << BN_BITS4)) {
+ BIGNUM *tmp = BN_dup(a);
+ if (tmp == NULL)
+ return (BN_ULONG)-1;
+
+ ret = BN_div_word(tmp, w);
+ BN_free(tmp);
+
+ return ret;
+ }
+#endif
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+ for (i = a->top - 1; i >= 0; i--) {
+#ifndef BN_LLONG
+ /*
+ * We can assume here that | w <= ((BN_ULONG)1 << BN_BITS4) | and so
+ * | ret < ((BN_ULONG)1 << BN_BITS4) | and therefore the shifts here are
+ * safe and will not overflow
+ */
+ 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);
+ ret = (BN_ULLONG) (((ret << (BN_ULLONG) BN_BITS2) | a->d[i]) %
+ (BN_ULLONG) w);
#endif
- }
- return((BN_ULONG)ret);
- }
+ }
+ return ((BN_ULONG)ret);
+}
BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
- {
- BN_ULONG ret = 0;
- int i, j;
-
- bn_check_top(a);
- w &= BN_MASK2;
-
- if (!w)
- /* actually this an error (division by zero) */
- return (BN_ULONG)-1;
- if (a->top == 0)
- return 0;
-
- /* normalize input (so bn_div_words doesn't complain) */
- j = BN_BITS2 - BN_num_bits_word(w);
- w <<= j;
- if (!BN_lshift(a, a, j))
- return (BN_ULONG)-1;
-
- 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--;
- ret >>= j;
- bn_check_top(a);
- return(ret);
- }
+{
+ BN_ULONG ret = 0;
+ int i, j;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ if (!w)
+ /* actually this an error (division by zero) */
+ return (BN_ULONG)-1;
+ if (a->top == 0)
+ return 0;
+
+ /* normalize input (so bn_div_words doesn't complain) */
+ j = BN_BITS2 - BN_num_bits_word(w);
+ w <<= j;
+ if (!BN_lshift(a, a, j))
+ return (BN_ULONG)-1;
+
+ 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--;
+ ret >>= j;
+ if (!a->top)
+ a->neg = 0; /* don't allow negative zero */
+ bn_check_top(a);
+ return (ret);
+}
int BN_add_word(BIGNUM *a, BN_ULONG w)
- {
- BN_ULONG l;
- int i;
-
- bn_check_top(a);
- w &= BN_MASK2;
-
- /* degenerate case: w is zero */
- if (!w) return 1;
- /* degenerate case: a is zero */
- if(BN_is_zero(a)) return BN_set_word(a, w);
- /* handle 'a' when negative */
- if (a->neg)
- {
- a->neg=0;
- i=BN_sub_word(a,w);
- if (!BN_is_zero(a))
- a->neg=!(a->neg);
- return(i);
- }
- for (i=0;w!=0 && i<a->top;i++)
- {
- a->d[i] = l = (a->d[i]+w)&BN_MASK2;
- w = (w>l)?1:0;
- }
- if (w && i==a->top)
- {
- if (bn_wexpand(a,a->top+1) == NULL) return 0;
- a->top++;
- a->d[i]=w;
- }
- bn_check_top(a);
- return(1);
- }
+{
+ BN_ULONG l;
+ int i;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ /* degenerate case: w is zero */
+ if (!w)
+ return 1;
+ /* degenerate case: a is zero */
+ if (BN_is_zero(a))
+ return BN_set_word(a, w);
+ /* handle 'a' when negative */
+ if (a->neg) {
+ a->neg = 0;
+ i = BN_sub_word(a, w);
+ if (!BN_is_zero(a))
+ a->neg = !(a->neg);
+ return (i);
+ }
+ for (i = 0; w != 0 && i < a->top; i++) {
+ a->d[i] = l = (a->d[i] + w) & BN_MASK2;
+ w = (w > l) ? 1 : 0;
+ }
+ if (w && i == a->top) {
+ if (bn_wexpand(a, a->top + 1) == NULL)
+ return 0;
+ a->top++;
+ a->d[i] = w;
+ }
+ bn_check_top(a);
+ return (1);
+}
int BN_sub_word(BIGNUM *a, BN_ULONG w)
- {
- int i;
-
- bn_check_top(a);
- w &= BN_MASK2;
-
- /* degenerate case: w is zero */
- if (!w) return 1;
- /* degenerate case: a is zero */
- if(BN_is_zero(a))
- {
- i = BN_set_word(a,w);
- if (i != 0)
- BN_set_negative(a, 1);
- return i;
- }
- /* handle 'a' when negative */
- if (a->neg)
- {
- a->neg=0;
- i=BN_add_word(a,w);
- a->neg=1;
- return(i);
- }
-
- 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--;
- bn_check_top(a);
- return(1);
- }
+{
+ int i;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ /* degenerate case: w is zero */
+ if (!w)
+ return 1;
+ /* degenerate case: a is zero */
+ if (BN_is_zero(a)) {
+ i = BN_set_word(a, w);
+ if (i != 0)
+ BN_set_negative(a, 1);
+ return i;
+ }
+ /* handle 'a' when negative */
+ if (a->neg) {
+ a->neg = 0;
+ i = BN_add_word(a, w);
+ a->neg = 1;
+ return (i);
+ }
+
+ 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--;
+ bn_check_top(a);
+ return (1);
+}
int BN_mul_word(BIGNUM *a, BN_ULONG w)
- {
- BN_ULONG ll;
-
- bn_check_top(a);
- w&=BN_MASK2;
- if (a->top)
- {
- if (w == 0)
- BN_zero(a);
- else
- {
- 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;
- }
- }
- }
- bn_check_top(a);
- return(1);
- }
-
+{
+ BN_ULONG ll;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+ if (a->top) {
+ if (w == 0)
+ BN_zero(a);
+ else {
+ 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;
+ }
+ }
+ }
+ bn_check_top(a);
+ return (1);
+}
projects / openssl.git / blobdiff