1/* 2 * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. 3 * 4 * The contents of this file constitute Original Code as defined in and are 5 * subject to the Apple Public Source License Version 1.2 (the 'License'). 6 * You may not use this file except in compliance with the License. Please obtain 7 * a copy of the License at http://www.apple.com/publicsource and read it before 8 * using this file. 9 * 10 * This Original Code and all software distributed under the License are 11 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS 12 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT 13 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 14 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the 15 * specific language governing rights and limitations under the License. 16 */ 17 18 19/* crypto/bn/bn_shift.c */ 20/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 21 * All rights reserved. 22 * 23 * This package is an SSL implementation written 24 * by Eric Young (eay@cryptsoft.com). 25 * The implementation was written so as to conform with Netscapes SSL. 26 * 27 * This library is free for commercial and non-commercial use as long as 28 * the following conditions are aheared to. The following conditions 29 * apply to all code found in this distribution, be it the RC4, RSA, 30 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 31 * included with this distribution is covered by the same copyright terms 32 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 33 * 34 * Copyright remains Eric Young's, and as such any Copyright notices in 35 * the code are not to be removed. 36 * If this package is used in a product, Eric Young should be given attribution 37 * as the author of the parts of the library used. 38 * This can be in the form of a textual message at program startup or 39 * in documentation (online or textual) provided with the package. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. All advertising materials mentioning features or use of this software 50 * must display the following acknowledgement: 51 * "This product includes cryptographic software written by 52 * Eric Young (eay@cryptsoft.com)" 53 * The word 'cryptographic' can be left out if the rouines from the library 54 * being used are not cryptographic related :-). 55 * 4. If you include any Windows specific code (or a derivative thereof) from 56 * the apps directory (application code) you must include an acknowledgement: 57 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 58 * 59 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * The licence and distribution terms for any publically available version or 72 * derivative of this code cannot be changed. i.e. this code cannot simply be 73 * copied and put under another distribution licence 74 * [including the GNU Public Licence.] 75 */ 76 77#include <stdio.h> 78#include "cryptlib.h" 79#include "bn_lcl.h" 80 81int BN_lshift1(BIGNUM *r, BIGNUM *a) 82 { 83 register BN_ULONG *ap,*rp,t,c; 84 int i; 85 86 if (r != a) 87 { 88 r->neg=a->neg; 89 if (bn_wexpand(r,a->top+1) == NULL) return(0); 90 r->top=a->top; 91 } 92 else 93 { 94 if (bn_wexpand(r,a->top+1) == NULL) return(0); 95 } 96 ap=a->d; 97 rp=r->d; 98 c=0; 99 for (i=0; i<a->top; i++) 100 { 101 t= *(ap++); 102 *(rp++)=((t<<1)|c)&BN_MASK2; 103 c=(t & BN_TBIT)?1:0; 104 } 105 if (c) 106 { 107 *rp=1; 108 r->top++; 109 } 110 return(1); 111 } 112 113int BN_rshift1(BIGNUM *r, BIGNUM *a) 114 { 115 BN_ULONG *ap,*rp,t,c; 116 int i; 117 118 if (BN_is_zero(a)) 119 { 120 BN_zero(r); 121 return(1); 122 } 123 if (a != r) 124 { 125 if (bn_wexpand(r,a->top) == NULL) return(0); 126 r->top=a->top; 127 r->neg=a->neg; 128 } 129 ap=a->d; 130 rp=r->d; 131 c=0; 132 for (i=a->top-1; i>=0; i--) 133 { 134 t=ap[i]; 135 rp[i]=((t>>1)&BN_MASK2)|c; 136 c=(t&1)?BN_TBIT:0; 137 } 138 bn_fix_top(r); 139 return(1); 140 } 141 142int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) 143 { 144 int i,nw,lb,rb; 145 BN_ULONG *t,*f; 146 BN_ULONG l; 147 148 r->neg=a->neg; 149 if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0); 150 nw=n/BN_BITS2; 151 lb=n%BN_BITS2; 152 rb=BN_BITS2-lb; 153 f=a->d; 154 t=r->d; 155 t[a->top+nw]=0; 156 if (lb == 0) 157 for (i=a->top-1; i>=0; i--) 158 t[nw+i]=f[i]; 159 else 160 for (i=a->top-1; i>=0; i--) 161 { 162 l=f[i]; 163 t[nw+i+1]|=(l>>rb)&BN_MASK2; 164 t[nw+i]=(l<<lb)&BN_MASK2; 165 } 166 memset(t,0,nw*sizeof(t[0])); 167/* for (i=0; i<nw; i++) 168 t[i]=0;*/ 169 r->top=a->top+nw+1; 170 bn_fix_top(r); 171 return(1); 172 } 173 174int BN_rshift(BIGNUM *r, BIGNUM *a, int n) 175 { 176 int i,j,nw,lb,rb; 177 BN_ULONG *t,*f; 178 BN_ULONG l,tmp; 179 180 nw=n/BN_BITS2; 181 rb=n%BN_BITS2; 182 lb=BN_BITS2-rb; 183 if (nw > a->top) 184 { 185 BN_zero(r); 186 return(1); 187 } 188 if (r != a) 189 { 190 r->neg=a->neg; 191 if (bn_wexpand(r,a->top-nw+1) == NULL) return(0); 192 } 193 194 f= &(a->d[nw]); 195 t=r->d; 196 j=a->top-nw; 197 r->top=j; 198 199 if (rb == 0) 200 { 201 for (i=j+1; i > 0; i--) 202 *(t++)= *(f++); 203 } 204 else 205 { 206 l= *(f++); 207 for (i=1; i<j; i++) 208 { 209 tmp =(l>>rb)&BN_MASK2; 210 l= *(f++); 211 *(t++) =(tmp|(l<<lb))&BN_MASK2; 212 } 213 *(t++) =(l>>rb)&BN_MASK2; 214 } 215 *t=0; 216 bn_fix_top(r); 217 return(1); 218 } 219