1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
58 #include "internal/cryptlib.h"
61 int BN_lshift1(BIGNUM *r, const BIGNUM *a)
63 register BN_ULONG *ap, *rp, t, c;
71 if (bn_wexpand(r, a->top + 1) == NULL)
75 if (bn_wexpand(r, a->top + 1) == NULL)
81 for (i = 0; i < a->top; i++) {
83 *(rp++) = ((t << 1) | c) & BN_MASK2;
84 c = (t & BN_TBIT) ? 1 : 0;
94 int BN_rshift1(BIGNUM *r, const BIGNUM *a)
96 BN_ULONG *ap, *rp, t, c;
108 j = i - (ap[i - 1] == 1);
110 if (bn_wexpand(r, j) == NULL)
116 c = (t & 1) ? BN_TBIT : 0;
121 rp[i] = ((t >> 1) & BN_MASK2) | c;
122 c = (t & 1) ? BN_TBIT : 0;
129 int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
139 BNerr(BN_F_BN_LSHIFT, BN_R_INVALID_SHIFT);
145 if (bn_wexpand(r, a->top + nw + 1) == NULL)
153 for (i = a->top - 1; i >= 0; i--)
156 for (i = a->top - 1; i >= 0; i--) {
158 t[nw + i + 1] |= (l >> rb) & BN_MASK2;
159 t[nw + i] = (l << lb) & BN_MASK2;
161 memset(t, 0, sizeof(*t) * nw);
162 r->top = a->top + nw + 1;
168 int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
170 int i, j, nw, lb, rb;
178 BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT);
185 if (nw >= a->top || a->top == 0) {
189 i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2;
192 if (bn_wexpand(r, i) == NULL)
196 return 1; /* or the copying loop will go berserk */
205 for (i = j; i != 0; i--)
209 for (i = j - 1; i != 0; i--) {
210 tmp = (l >> rb) & BN_MASK2;
212 *(t++) = (tmp | (l << lb)) & BN_MASK2;
214 if ((l = (l >> rb) & BN_MASK2))