| 1 | /* crypto/bn/bn_mul.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 <string.h> |
| 61 | #include "bn_lcl.h" |
| 62 | |
| 63 | int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx) |
| 64 | { |
| 65 | int top,al,bl; |
| 66 | BIGNUM *rr; |
| 67 | int ret = 0; |
| 68 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 69 | int i; |
| 70 | #endif |
| 71 | #ifdef BN_RECURSION |
| 72 | BIGNUM *t; |
| 73 | int j,k; |
| 74 | #endif |
| 75 | |
| 76 | #ifdef BN_COUNT |
| 77 | printf("BN_mul %d * %d\n",a->top,b->top); |
| 78 | #endif |
| 79 | |
| 80 | bn_check_top(a); |
| 81 | bn_check_top(b); |
| 82 | bn_check_top(r); |
| 83 | |
| 84 | al=a->top; |
| 85 | bl=b->top; |
| 86 | |
| 87 | if ((al == 0) || (bl == 0)) |
| 88 | { |
| 89 | BN_zero(r); |
| 90 | return(1); |
| 91 | } |
| 92 | top=al+bl; |
| 93 | |
| 94 | BN_CTX_start(ctx); |
| 95 | if ((r == a) || (r == b)) |
| 96 | { |
| 97 | if ((rr = BN_CTX_get(ctx)) == NULL) goto err; |
| 98 | } |
| 99 | else |
| 100 | rr = r; |
| 101 | rr->neg=a->neg^b->neg; |
| 102 | |
| 103 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 104 | i = al-bl; |
| 105 | #endif |
| 106 | #ifdef BN_MUL_COMBA |
| 107 | if (i == 0) |
| 108 | { |
| 109 | # if 0 |
| 110 | if (al == 4) |
| 111 | { |
| 112 | if (bn_wexpand(rr,8) == NULL) goto err; |
| 113 | rr->top=8; |
| 114 | bn_mul_comba4(rr->d,a->d,b->d); |
| 115 | goto end; |
| 116 | } |
| 117 | # endif |
| 118 | if (al == 8) |
| 119 | { |
| 120 | if (bn_wexpand(rr,16) == NULL) goto err; |
| 121 | rr->top=16; |
| 122 | bn_mul_comba8(rr->d,a->d,b->d); |
| 123 | goto end; |
| 124 | } |
| 125 | } |
| 126 | #endif /* BN_MUL_COMBA */ |
| 127 | if (bn_wexpand(rr,top) == NULL) goto err; |
| 128 | rr->top=top; |
| 129 | bn_mul_normal(rr->d,a->d,al,b->d,bl); |
| 130 | |
| 131 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 132 | end: |
| 133 | #endif |
| 134 | bn_fix_top(rr); |
| 135 | if (r != rr) BN_copy(r,rr); |
| 136 | ret=1; |
| 137 | err: |
| 138 | BN_CTX_end(ctx); |
| 139 | return(ret); |
| 140 | } |
| 141 | |
| 142 | void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb) |
| 143 | { |
| 144 | BN_ULONG *rr; |
| 145 | |
| 146 | #ifdef BN_COUNT |
| 147 | printf(" bn_mul_normal %d * %d\n",na,nb); |
| 148 | #endif |
| 149 | |
| 150 | if (na < nb) |
| 151 | { |
| 152 | int itmp; |
| 153 | BN_ULONG *ltmp; |
| 154 | |
| 155 | itmp=na; na=nb; nb=itmp; |
| 156 | ltmp=a; a=b; b=ltmp; |
| 157 | |
| 158 | } |
| 159 | rr= &(r[na]); |
| 160 | rr[0]=bn_mul_words(r,a,na,b[0]); |
| 161 | |
| 162 | for (;;) |
| 163 | { |
| 164 | if (--nb <= 0) return; |
| 165 | rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]); |
| 166 | if (--nb <= 0) return; |
| 167 | rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]); |
| 168 | if (--nb <= 0) return; |
| 169 | rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]); |
| 170 | if (--nb <= 0) return; |
| 171 | rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]); |
| 172 | rr+=4; |
| 173 | r+=4; |
| 174 | b+=4; |
| 175 | } |
| 176 | } |
| 177 | |
