]>
Commit | Line | Data |
---|---|---|
58964a49 RE |
1 | /* crypto/bn/bn_m.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 "cryptlib.h" | |
61 | #include "bn_lcl.h" | |
62 | #include "stack.h" | |
63 | ||
64 | int limit=16; | |
65 | ||
66 | typedef struct bn_pool_st | |
67 | { | |
68 | int used; | |
69 | int tos; | |
70 | STACK *sk; | |
71 | } BN_POOL; | |
72 | ||
6b691a5c | 73 | BIGNUM *BN_POOL_push(BN_POOL *bp) |
58964a49 RE |
74 | { |
75 | BIGNUM *ret; | |
76 | ||
77 | if (bp->used >= bp->tos) | |
78 | { | |
79 | ret=BN_new(); | |
80 | sk_push(bp->sk,(char *)ret); | |
81 | bp->tos++; | |
82 | bp->used++; | |
83 | } | |
84 | else | |
85 | { | |
86 | ret=(BIGNUM *)sk_value(bp->sk,bp->used); | |
87 | bp->used++; | |
88 | } | |
89 | return(ret); | |
90 | } | |
91 | ||
6b691a5c | 92 | void BN_POOL_pop(BN_POOL *bp, int num) |
58964a49 RE |
93 | { |
94 | bp->used-=num; | |
95 | } | |
96 | ||
6b691a5c | 97 | int BN_m(BIGNUM *r, BIGNUM *a, BIGNUM *b) |
58964a49 RE |
98 | { |
99 | static BN_POOL bp; | |
100 | static init=1; | |
101 | ||
102 | if (init) | |
103 | { | |
104 | bp.used=0; | |
105 | bp.tos=0; | |
106 | bp.sk=sk_new_null(); | |
107 | init=0; | |
108 | } | |
109 | return(BN_mm(r,a,b,&bp)); | |
110 | } | |
111 | ||
112 | /* r must be different to a and b */ | |
6b691a5c | 113 | int BN_mm(BIGNUM *m, BIGNUM *A, BIGNUM *B, BN_POOL *bp) |
58964a49 RE |
114 | { |
115 | int i,num; | |
116 | int an,bn; | |
117 | BIGNUM *a,*b,*c,*d,*ac,*bd; | |
118 | ||
119 | an=A->top; | |
120 | bn=B->top; | |
121 | if ((an <= limit) || (bn <= limit)) | |
122 | { | |
123 | return(BN_mul(m,A,B)); | |
124 | } | |
125 | ||
126 | a=BN_POOL_push(bp); | |
127 | b=BN_POOL_push(bp); | |
128 | c=BN_POOL_push(bp); | |
129 | d=BN_POOL_push(bp); | |
130 | ac=BN_POOL_push(bp); | |
131 | bd=BN_POOL_push(bp); | |
132 | ||
133 | num=(an <= bn)?an:bn; | |
134 | num=1<<(BN_num_bits_word(num-1)-1); | |
135 | ||
136 | /* Are going to now chop things into 'num' word chunks. */ | |
137 | num*=BN_BITS2; | |
138 | ||
139 | BN_copy(a,A); | |
140 | BN_mask_bits(a,num); | |
141 | BN_rshift(b,A,num); | |
142 | ||
143 | BN_copy(c,B); | |
144 | BN_mask_bits(c,num); | |
145 | BN_rshift(d,B,num); | |
146 | ||
147 | BN_sub(ac ,b,a); | |
148 | BN_sub(bd,c,d); | |
149 | BN_mm(m,ac,bd,bp); | |
150 | BN_mm(ac,a,c,bp); | |
151 | BN_mm(bd,b,d,bp); | |
152 | ||
153 | BN_add(m,m,ac); | |
154 | BN_add(m,m,bd); | |
155 | BN_lshift(m,m,num); | |
156 | BN_lshift(bd,bd,num*2); | |
157 | ||
158 | BN_add(m,m,ac); | |
159 | BN_add(m,m,bd); | |
160 | BN_POOL_pop(bp,6); | |
161 | return(1); | |
162 | } | |
163 |