rdesktop/crypto/bn_shift.c

/* crypto/bn/bn_shift.c */
/* 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 <stdio.h>
#include "bn_lcl.h"

#if 0
int BN_lshift1(BIGNUM *r, BIGNUM *a)
        {
        register 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_rshift1(BIGNUM *r, BIGNUM *a)
        {
        BN_ULONG *ap,*rp,t,c;
        int i;

        if (BN_is_zero(a))
                {
                BN_zero(r);
                return(1);
                }
        if (a != r)
                {
                if (bn_wexpand(r,a->top) == NULL) return(0);
                r->top=a->top;
                r->neg=a->neg;
                }
        ap=a->d;
        rp=r->d;
        c=0;
        for (i=a->top-1; i>=0; i--)
                {
                t=ap[i];
                rp[i]=((t>>1)&BN_MASK2)|c;
                c=(t&1)?BN_TBIT:0;
                }
        bn_fix_top(r);
        return(1);
        }
#endif

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;
        if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
        nw=n/BN_BITS2;
        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]));
/*      for (i=0; i<nw; i++)
                t[i]=0;*/
        r->top=a->top+nw+1;
        bn_fix_top(r);
        return(1);
        }

int BN_rshift(BIGNUM *r, 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);
                }
        if (r != a)
                {
                r->neg=a->neg;
                if (bn_wexpand(r,a->top-nw+1) == 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=j;

        if (rb == 0)
                {
                for (i=j+1; i > 0; i--)
                        *(t++)= *(f++);
                }
        else
                {
                l= *(f++);
                for (i=1; i<j; i++)
                        {
                        tmp =(l>>rb)&BN_MASK2;
                        l= *(f++);
                        *(t++) =(tmp|(l<<lb))&BN_MASK2;
                        }
                *(t++) =(l>>rb)&BN_MASK2;
                }
        *t=0;
        bn_fix_top(r);
        return(1);
        }
1	matty	32	/* crypto/bn/bn_shift.c */
2			/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3			* All rights reserved.
4			*
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.
8			*
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).
15			*
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.
22			*
23			* Redistribution and use in source and binary forms, with or without
24			* modification, are permitted provided that the following conditions
25			* are met:
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)"
40			*
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
51			* SUCH DAMAGE.
52			*
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.]
57			*/
58
59			#include <stdio.h>
60			#include "bn_lcl.h"
61
62			#if 0
63			int BN_lshift1(BIGNUM r, BIGNUM a)
64			{
65			register BN_ULONG ap,rp,t,c;
66			int i;
67
68			if (r != a)
69			{
70			r->neg=a->neg;
71			if (bn_wexpand(r,a->top+1) == NULL) return(0);
72			r->top=a->top;
73			}
74			else
75			{
76			if (bn_wexpand(r,a->top+1) == NULL) return(0);
77			}
78			ap=a->d;
79			rp=r->d;
80			c=0;
81			for (i=0; i<a->top; i++)
82			{
83			t= *(ap++);
84			*(rp++)=((t<<1)\|c)&BN_MASK2;
85			c=(t & BN_TBIT)?1:0;
86			}
87			if (c)
88			{
89			*rp=1;
90			r->top++;
91			}
92			return(1);
93			}
94
95			int BN_rshift1(BIGNUM r, BIGNUM a)
96			{
97			BN_ULONG ap,rp,t,c;
98			int i;
99
100			if (BN_is_zero(a))
101			{
102			BN_zero(r);
103			return(1);
104			}
105			if (a != r)
106			{
107			if (bn_wexpand(r,a->top) == NULL) return(0);
108			r->top=a->top;
109			r->neg=a->neg;
110			}
111			ap=a->d;
112			rp=r->d;
113			c=0;
114			for (i=a->top-1; i>=0; i--)
115			{
116			t=ap[i];
117			rp[i]=((t>>1)&BN_MASK2)\|c;
118			c=(t&1)?BN_TBIT:0;
119			}
120			bn_fix_top(r);
121			return(1);
122			}
123			#endif
124
125			int BN_lshift(BIGNUM r, const BIGNUM a, int n)
126			{
127			int i,nw,lb,rb;
128			BN_ULONG t,f;
129			BN_ULONG l;
130
131			r->neg=a->neg;
132			if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
133			nw=n/BN_BITS2;
134			lb=n%BN_BITS2;
135			rb=BN_BITS2-lb;
136			f=a->d;
137			t=r->d;
138			t[a->top+nw]=0;
139			if (lb == 0)
140			for (i=a->top-1; i>=0; i--)
141			t[nw+i]=f[i];
142			else
143			for (i=a->top-1; i>=0; i--)
144			{
145			l=f[i];
146			t[nw+i+1]\|=(l>>rb)&BN_MASK2;
147			t[nw+i]=(l<<lb)&BN_MASK2;
148			}
149			memset(t,0,nw*sizeof(t[0]));
150			/* for (i=0; i<nw; i++)
151			t[i]=0;*/
152			r->top=a->top+nw+1;
153			bn_fix_top(r);
154			return(1);
155			}
156
157			int BN_rshift(BIGNUM r, BIGNUM a, int n)
158			{
159			int i,j,nw,lb,rb;
160			BN_ULONG t,f;
161			BN_ULONG l,tmp;
162
163			nw=n/BN_BITS2;
164			rb=n%BN_BITS2;
165			lb=BN_BITS2-rb;
166			if (nw > a->top \|\| a->top == 0)
167			{
168			BN_zero(r);
169			return(1);
170			}
171			if (r != a)
172			{
173			r->neg=a->neg;
174			if (bn_wexpand(r,a->top-nw+1) == NULL) return(0);
175			}
176			else
177			{
178			if (n == 0)
179			return 1; /* or the copying loop will go berserk */
180			}
181
182			f= &(a->d[nw]);
183			t=r->d;
184			j=a->top-nw;
185			r->top=j;
186
187			if (rb == 0)
188			{
189			for (i=j+1; i > 0; i--)
190			(t++)= (f++);
191			}
192			else
193			{
194			l= *(f++);
195			for (i=1; i<j; i++)
196			{
197			tmp =(l>>rb)&BN_MASK2;
198			l= *(f++);
199			*(t++) =(tmp\|(l<<lb))&BN_MASK2;
200			}
201			*(t++) =(l>>rb)&BN_MASK2;
202			}
203			*t=0;
204			bn_fix_top(r);
205			return(1);
206			}