crypto/bn/bn_word.c

   1 /* crypto/bn/bn_word.c */
   2 /* Copyright (C) 1995-1997 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 "cryptlib.h"
  61 #include "bn_lcl.h"
  62
  63 BN_ULONG BN_mod_word(a, w)
  64 BIGNUM *a;
  65 unsigned long w;
  66         {
  67 #ifndef BN_LLONG
  68         BN_ULONG ret=0;
  69 #else
  70         BN_ULLONG ret=0;
  71 #endif
  72         int i;
  73
  74         for (i=a->top-1; i>=0; i--)
  75                 {
  76 #ifndef BN_LLONG
  77                 ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(int)w;
  78                 ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(int)w;
  79 #else
  80                 ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%
  81                         (BN_ULLONG)w);
  82 #endif
  83                 }
  84         return((BN_ULONG)ret);
  85         }
  86
  87 BN_ULONG BN_div_word(a, w)
  88 BIGNUM *a;
  89 unsigned long w;
  90         {
  91         BN_ULONG ret;
  92         int i;
  93
  94         if (a->top == 0) return(0);
  95         ret=0;
  96         for (i=a->top-1; i>=0; i--)
  97                 {
  98 #ifndef BN_LLONG
  99                 ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(int)w;
 100                 ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(int)w;
 101 #else
 102                 BN_ULLONG ll;
 103
 104                 ll=((BN_ULLONG)ret<<(BN_ULONG)BN_BITS2)|a->d[i];
 105                 a->d[i]=(BN_ULONG)(ll/w);
 106                 ret=(BN_ULONG)(ll%w);
 107 #endif
 108                 }
 109         if (a->d[a->top-1] == 0)
 110                 a->top--;
 111         return(ret);
 112         }
 113
 114 int BN_add_word(a, w)
 115 BIGNUM *a;
 116 unsigned long w;
 117         {
 118         BN_ULONG l;
 119         int i;
 120
 121         if (bn_expand(a,a->top*BN_BITS2+1) == NULL) return(0);
 122         i=0;
 123         for (;;)
 124                 {
 125                 l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
 126                 a->d[i]=l;
 127                 if (w > l)
 128                         w=1;
 129                 else
 130                         break;
 131                 i++;
 132                 }
 133         if (i >= a->top)
 134                 a->top++;
 135         return(1);
 136         }
 137
 138 #ifdef undef
 139 BN_ULONG *BN_mod_inverse_word(a)
 140 BN_ULONG a;
 141         {
 142         BN_ULONG A,B,X,Y,M,D,R,RET,T;
 143         int sign,hight=1;
 144
 145         X=0;
 146         Y=1;
 147         A=0;
 148         B=a;
 149         sign=1;
 150
 151         while (B != 0)
 152                 {
 153
 154 #endif
 155