AppleCSP/open_ssl/bn/bn_word.c

   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_word.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
  81 BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
  82         {
  83 #ifndef BN_LLONG
  84         BN_ULONG ret=0;
  85 #else
  86         BN_ULLONG ret=0;
  87 #endif
  88         int i;
  89
  90         w&=BN_MASK2;
  91         for (i=a->top-1; i>=0; i--)
  92                 {
  93 #ifndef BN_LLONG
  94                 ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w;
  95                 ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%w;
  96 #else
  97                 ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%
  98                         (BN_ULLONG)w);
  99 #endif
 100                 }
 101         return((BN_ULONG)ret);
 102         }
 103
 104 BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
 105         {
 106         BN_ULONG ret;
 107         int i;
 108
 109         if (a->top == 0) return(0);
 110         ret=0;
 111         w&=BN_MASK2;
 112         for (i=a->top-1; i>=0; i--)
 113                 {
 114                 BN_ULONG l,d;
 115
 116                 l=a->d[i];
 117                 d=bn_div_words(ret,l,w);
 118                 ret=(l-((d*w)&BN_MASK2))&BN_MASK2;
 119                 a->d[i]=d;
 120                 }
 121         if ((a->top > 0) && (a->d[a->top-1] == 0))
 122                 a->top--;
 123         return(ret);
 124         }
 125
 126 int BN_add_word(BIGNUM *a, BN_ULONG w)
 127         {
 128         BN_ULONG l;
 129         int i;
 130
 131         if (a->neg)
 132                 {
 133                 a->neg=0;
 134                 i=BN_sub_word(a,w);
 135                 if (!BN_is_zero(a))
 136                         a->neg=1;
 137                 return(i);
 138                 }
 139         w&=BN_MASK2;
 140         if (bn_wexpand(a,a->top+1) == NULL) return(0);
 141         i=0;
 142         for (;;)
 143                 {
 144                 l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
 145                 a->d[i]=l;
 146                 if (w > l)
 147                         w=1;
 148                 else
 149                         break;
 150                 i++;
 151                 }
 152         if (i >= a->top)
 153                 a->top++;
 154         return(1);
 155         }
 156
 157 int BN_sub_word(BIGNUM *a, BN_ULONG w)
 158         {
 159         int i;
 160
 161         if (a->neg)
 162                 {
 163                 a->neg=0;
 164                 i=BN_add_word(a,w);
 165                 a->neg=1;
 166                 return(i);
 167                 }
 168
 169         w&=BN_MASK2;
 170         if ((a->top == 1) && (a->d[0] < w))
 171                 {
 172                 a->d[0]=w-a->d[0];
 173                 a->neg=1;
 174                 return(1);
 175                 }
 176         i=0;
 177         for (;;)
 178                 {
 179                 if (a->d[i] >= w)
 180                         {
 181                         a->d[i]-=w;
 182                         break;
 183                         }
 184                 else
 185                         {
 186                         a->d[i]=(a->d[i]-w)&BN_MASK2;
 187                         i++;
 188                         w=1;
 189                         }
 190                 }
 191         if ((a->d[i] == 0) && (i == (a->top-1)))
 192                 a->top--;
 193         return(1);
 194         }
 195
 196 int BN_mul_word(BIGNUM *a, BN_ULONG w)
 197         {
 198         BN_ULONG ll;
 199
 200         w&=BN_MASK2;
 201         if (a->top)
 202                 {
 203                 ll=bn_mul_words(a->d,a->d,a->top,w);
 204                 if (ll)
 205                         {
 206                         if (bn_wexpand(a,a->top+1) == NULL) return(0);
 207                         a->d[a->top++]=ll;
 208                         }
 209                 }
 210         return(1);
 211         }
 212