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/* 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 <openssl/bn.h>
#include <string.h>
#include <openssl/err.h>
#include "internal.h"
int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) {
int i, nw, lb, rb;
BN_ULONG *t, *f;
BN_ULONG l;
if (n < 0) {
OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
return 0;
}
r->neg = a->neg;
nw = n / BN_BITS2;
if (!bn_wexpand(r, a->top + nw + 1)) {
return 0;
}
lb = n % BN_BITS2;
rb = BN_BITS2 - lb;
f = a->d;
t = r->d;
t[a->top + nw] = 0;
if (lb == 0) {
for (i = a->top - 1; i >= 0; i--) {
t[nw + i] = f[i];
}
} else {
for (i = a->top - 1; i >= 0; i--) {
l = f[i];
t[nw + i + 1] |= (l >> rb) & BN_MASK2;
t[nw + i] = (l << lb) & BN_MASK2;
}
}
OPENSSL_memset(t, 0, nw * sizeof(t[0]));
r->top = a->top + nw + 1;
bn_correct_top(r);
return 1;
}
int BN_lshift1(BIGNUM *r, const BIGNUM *a) {
BN_ULONG *ap, *rp, t, c;
int i;
if (r != a) {
r->neg = a->neg;
if (!bn_wexpand(r, a->top + 1)) {
return 0;
}
r->top = a->top;
} else {
if (!bn_wexpand(r, a->top + 1)) {
return 0;
}
}
ap = a->d;
rp = r->d;
c = 0;
for (i = 0; i < a->top; i++) {
t = *(ap++);
*(rp++) = ((t << 1) | c) & BN_MASK2;
c = (t & BN_TBIT) ? 1 : 0;
}
if (c) {
*rp = 1;
r->top++;
}
return 1;
}
int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) {
int i, j, nw, lb, rb;
BN_ULONG *t, *f;
BN_ULONG l, tmp;
if (n < 0) {
OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
return 0;
}
nw = n / BN_BITS2;
rb = n % BN_BITS2;
lb = BN_BITS2 - rb;
if (nw >= a->top || a->top == 0) {
BN_zero(r);
return 1;
}
i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2;
if (r != a) {
r->neg = a->neg;
if (!bn_wexpand(r, i)) {
return 0;
}
} else {
if (n == 0) {
return 1; // or the copying loop will go berserk
}
}
f = &(a->d[nw]);
t = r->d;
j = a->top - nw;
r->top = i;
if (rb == 0) {
for (i = j; i != 0; i--) {
*(t++) = *(f++);
}
} else {
l = *(f++);
for (i = j - 1; i != 0; i--) {
tmp = (l >> rb) & BN_MASK2;
l = *(f++);
*(t++) = (tmp | (l << lb)) & BN_MASK2;
}
if ((l = (l >> rb) & BN_MASK2)) {
*(t) = l;
}
}
if (r->top == 0) {
r->neg = 0;
}
return 1;
}
int BN_rshift1(BIGNUM *r, const BIGNUM *a) {
BN_ULONG *ap, *rp, t, c;
int i, j;
if (BN_is_zero(a)) {
BN_zero(r);
return 1;
}
i = a->top;
ap = a->d;
j = i - (ap[i - 1] == 1);
if (a != r) {
if (!bn_wexpand(r, j)) {
return 0;
}
r->neg = a->neg;
}
rp = r->d;
t = ap[--i];
c = (t & 1) ? BN_TBIT : 0;
if (t >>= 1) {
rp[i] = t;
}
while (i > 0) {
t = ap[--i];
rp[i] = ((t >> 1) & BN_MASK2) | c;
c = (t & 1) ? BN_TBIT : 0;
}
r->top = j;
if (r->top == 0) {
r->neg = 0;
}
return 1;
}
int BN_set_bit(BIGNUM *a, int n) {
int i, j, k;
if (n < 0) {
return 0;
}
i = n / BN_BITS2;
j = n % BN_BITS2;
if (a->top <= i) {
if (!bn_wexpand(a, i + 1)) {
return 0;
}
for (k = a->top; k < i + 1; k++) {
a->d[k] = 0;
}
a->top = i + 1;
}
a->d[i] |= (((BN_ULONG)1) << j);
return 1;
}
int BN_clear_bit(BIGNUM *a, int n) {
int i, j;
if (n < 0) {
return 0;
}
i = n / BN_BITS2;
j = n % BN_BITS2;
if (a->top <= i) {
return 0;
}
a->d[i] &= (~(((BN_ULONG)1) << j));
bn_correct_top(a);
return 1;
}
int BN_is_bit_set(const BIGNUM *a, int n) {
int i, j;
if (n < 0) {
return 0;
}
i = n / BN_BITS2;
j = n % BN_BITS2;
if (a->top <= i) {
return 0;
}
return (a->d[i]>>j)&1;
}
int BN_mask_bits(BIGNUM *a, int n) {
int b, w;
if (n < 0) {
return 0;
}
w = n / BN_BITS2;
b = n % BN_BITS2;
if (w >= a->top) {
return 0;
}
if (b == 0) {
a->top = w;
} else {
a->top = w + 1;
a->d[w] &= ~(BN_MASK2 << b);
}
bn_correct_top(a);
return 1;
}