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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 "internal.h"
+
+
+int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) {
+ int i, nw, lb, rb;
+ BN_ULONG *t, *f;
+ BN_ULONG l;
+
+ r->neg = a->neg;
+ nw = n / BN_BITS2;
+ if (bn_wexpand(r, a->top + nw + 1) == NULL) {
+ 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;
+ }
+ }
+ 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) == NULL) {
+ return 0;
+ }
+ r->top = a->top;
+ } else {
+ if (bn_wexpand(r, a->top + 1) == NULL) {
+ 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;
+
+ 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) == NULL) {
+ 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;
+ }
+ }
+
+ 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) == NULL) {
+ 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;
+
+ 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) == NULL) {
+ 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;
+}
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