1
/* crypto/bn/bn_shift.c */
2
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5
* This package is an SSL implementation written
6
* by Eric Young (eay@cryptsoft.com).
7
* The implementation was written so as to conform with Netscapes SSL.
9
* This library is free for commercial and non-commercial use as long as
10
* the following conditions are aheared to. The following conditions
11
* apply to all code found in this distribution, be it the RC4, RSA,
12
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
13
* included with this distribution is covered by the same copyright terms
14
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
16
* Copyright remains Eric Young's, and as such any Copyright notices in
17
* the code are not to be removed.
18
* If this package is used in a product, Eric Young should be given attribution
19
* as the author of the parts of the library used.
20
* This can be in the form of a textual message at program startup or
21
* in documentation (online or textual) provided with the package.
23
* Redistribution and use in source and binary forms, with or without
24
* modification, are permitted provided that the following conditions
26
* 1. Redistributions of source code must retain the copyright
27
* notice, this list of conditions and the following disclaimer.
28
* 2. Redistributions in binary form must reproduce the above copyright
29
* notice, this list of conditions and the following disclaimer in the
30
* documentation and/or other materials provided with the distribution.
31
* 3. All advertising materials mentioning features or use of this software
32
* must display the following acknowledgement:
33
* "This product includes cryptographic software written by
34
* Eric Young (eay@cryptsoft.com)"
35
* The word 'cryptographic' can be left out if the rouines from the library
36
* being used are not cryptographic related :-).
37
* 4. If you include any Windows specific code (or a derivative thereof) from
38
* the apps directory (application code) you must include an acknowledgement:
39
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53
* The licence and distribution terms for any publically available version or
54
* derivative of this code cannot be changed. i.e. this code cannot simply be
55
* copied and put under another distribution licence
56
* [including the GNU Public Licence.]
63
int BN_lshift1(BIGNUM *r, BIGNUM *a)
65
register BN_ULONG *ap,*rp,t,c;
71
if (bn_wexpand(r,a->top+1) == NULL) return(0);
76
if (bn_wexpand(r,a->top+1) == NULL) return(0);
81
for (i=0; i<a->top; i++)
84
*(rp++)=((t<<1)|c)&BN_MASK2;
95
int BN_rshift1(BIGNUM *r, BIGNUM *a)
107
if (bn_wexpand(r,a->top) == NULL) return(0);
114
for (i=a->top-1; i>=0; i--)
117
rp[i]=((t>>1)&BN_MASK2)|c;
125
int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
132
if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
140
for (i=a->top-1; i>=0; i--)
143
for (i=a->top-1; i>=0; i--)
146
t[nw+i+1]|=(l>>rb)&BN_MASK2;
147
t[nw+i]=(l<<lb)&BN_MASK2;
149
memset(t,0,nw*sizeof(t[0]));
150
/* for (i=0; i<nw; i++)
157
int BN_rshift(BIGNUM *r, BIGNUM *a, int n)
166
if (nw > a->top || a->top == 0)
174
if (bn_wexpand(r,a->top-nw+1) == NULL) return(0);
179
return 1; /* or the copying loop will go berserk */
189
for (i=j+1; i > 0; i--)
197
tmp =(l>>rb)&BN_MASK2;
199
*(t++) =(tmp|(l<<lb))&BN_MASK2;
201
*(t++) =(l>>rb)&BN_MASK2;