1 /* crypto/bn/bn_mul.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
63 int bn_mm(BIGNUM *m,BIGNUM *A,BIGNUM *B, BIGNUM *sk,BN_CTX *ctx);
65 /* r must be different to a and b */
82 if ((al == 0) || (bl == 0))
88 printf("BN_mul(%d,%d)\n",a->top,b->top);
92 if ( (bn_limit_bits > 0) &&
93 (bl > bn_limit_num) && (al > bn_limit_num))
95 n=(BN_num_bits_word(al|bl)-bn_limit_bits);
97 sk=(BIGNUM *)Malloc(sizeof(BIGNUM)*n);
98 memset(sk,0,sizeof(BIGNUM)*n);
99 memset(&ctx,0,sizeof(ctx));
101 ret=bn_mm(r,a,b,&(sk[0]),&ctx);
104 BN_clear_free(&sk[i]);
105 BN_clear_free(&sk[i+1]);
113 if (bn_wexpand(r,max) == NULL) return(0);
115 r->neg=a->neg^b->neg;
121 if ((al == bl) && (al == 8))
123 bn_mul_comba8(rp,ap,bp);
128 rp[al]=bn_mul_words(rp,ap,al,*(bp++));
132 rp[al]=bn_mul_add_words(rp,ap,al,*(bp++));
136 if ((max > 0) && (r->d[max-1] == 0)) r->top--;
145 /* r must be different to a and b */
146 int bn_mm(m, A, B, sk,ctx)
158 printf("bn_mm(%d,%d)\n",A->top,B->top);
164 /* Are going to now chop things into 'num' word chunks. */
171 bn_set_low (&al,A,n);
172 bn_set_high(&ah,A,n);
173 bn_set_low (&bl,B,n);
174 bn_set_high(&bh,B,n);
176 BN_sub(&ahal,&ah,&al);
177 BN_sub(&blbh,&bl,&bh);
179 if (num <= (bn_limit_num+bn_limit_num))
181 BN_mul(m,&ahal,&blbh);
184 BN_sqr(&ahal,&al,ctx);
185 BN_sqr(&blbh,&ah,ctx);
189 BN_mul(&ahal,&al,&bl);
190 BN_mul(&blbh,&ah,&bh);
195 bn_mm(m,&ahal,&blbh,&(sk[2]),ctx);
196 bn_mm(&ahal,&al,&bl,&(sk[2]),ctx);
197 bn_mm(&blbh,&ah,&bh,&(sk[2]),ctx);
203 BN_lshift(m,m,n*BN_BITS2);
204 BN_lshift(&blbh,&blbh,n*BN_BITS2*2);
209 m->neg=A->neg^B->neg;