diff options
Diffstat (limited to 'crypto/bn/bn_m.c')
| -rw-r--r-- | crypto/bn/bn_m.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/crypto/bn/bn_m.c b/crypto/bn/bn_m.c new file mode 100644 index 0000000000..5166daaeec --- /dev/null +++ b/crypto/bn/bn_m.c @@ -0,0 +1,169 @@ +/* crypto/bn/bn_m.c */ +/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) + * All rights reserved. + * + * This package is an SSL implementation written + * by Eric Young (eay@cryptsoft.com). + * The implementation was written so as to conform with Netscapes SSL. + * + * This library is free for commercial and non-commercial use as long as + * the following conditions are aheared to. The following conditions + * apply to all code found in this distribution, be it the RC4, RSA, + * lhash, DES, etc., code; not just the SSL code. The SSL documentation + * included with this distribution is covered by the same copyright terms + * except that the holder is Tim Hudson (tjh@cryptsoft.com). + * + * Copyright remains Eric Young's, and as such any Copyright notices in + * the code are not to be removed. + * If this package is used in a product, Eric Young should be given attribution + * as the author of the parts of the library used. + * This can be in the form of a textual message at program startup or + * in documentation (online or textual) provided with the package. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * "This product includes cryptographic software written by + * Eric Young (eay@cryptsoft.com)" + * The word 'cryptographic' can be left out if the rouines from the library + * being used are not cryptographic related :-). + * 4. If you include any Windows specific code (or a derivative thereof) from + * the apps directory (application code) you must include an acknowledgement: + * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" + * + * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * The licence and distribution terms for any publically available version or + * derivative of this code cannot be changed. i.e. this code cannot simply be + * copied and put under another distribution licence + * [including the GNU Public Licence.] + */ + +#include <stdio.h> +#include "cryptlib.h" +#include "bn_lcl.h" +#include "stack.h" + +int limit=16; + +typedef struct bn_pool_st + { + int used; + int tos; + STACK *sk; + } BN_POOL; + +BIGNUM *BN_POOL_push(bp) +BN_POOL *bp; + { + BIGNUM *ret; + + if (bp->used >= bp->tos) + { + ret=BN_new(); + sk_push(bp->sk,(char *)ret); + bp->tos++; + bp->used++; + } + else + { + ret=(BIGNUM *)sk_value(bp->sk,bp->used); + bp->used++; + } + return(ret); + } + +void BN_POOL_pop(bp,num) +BN_POOL *bp; +int num; + { + bp->used-=num; + } + +int BN_m(r,a,b) +BIGNUM *r,*a,*b; + { + static BN_POOL bp; + static init=1; + + if (init) + { + bp.used=0; + bp.tos=0; + bp.sk=sk_new_null(); + init=0; + } + return(BN_mm(r,a,b,&bp)); + } + +/* r must be different to a and b */ +int BN_mm(m, A, B, bp) +BIGNUM *m,*A,*B; +BN_POOL *bp; + { + int i,num; + int an,bn; + BIGNUM *a,*b,*c,*d,*ac,*bd; + + an=A->top; + bn=B->top; + if ((an <= limit) || (bn <= limit)) + { + return(BN_mul(m,A,B)); + } + + a=BN_POOL_push(bp); + b=BN_POOL_push(bp); + c=BN_POOL_push(bp); + d=BN_POOL_push(bp); + ac=BN_POOL_push(bp); + bd=BN_POOL_push(bp); + + num=(an <= bn)?an:bn; + num=1<<(BN_num_bits_word(num-1)-1); + + /* Are going to now chop things into 'num' word chunks. */ + num*=BN_BITS2; + + BN_copy(a,A); + BN_mask_bits(a,num); + BN_rshift(b,A,num); + + BN_copy(c,B); + BN_mask_bits(c,num); + BN_rshift(d,B,num); + + BN_sub(ac ,b,a); + BN_sub(bd,c,d); + BN_mm(m,ac,bd,bp); + BN_mm(ac,a,c,bp); + BN_mm(bd,b,d,bp); + + BN_add(m,m,ac); + BN_add(m,m,bd); + BN_lshift(m,m,num); + BN_lshift(bd,bd,num*2); + + BN_add(m,m,ac); + BN_add(m,m,bd); + BN_POOL_pop(bp,6); + return(1); + } + |