diff options
Diffstat (limited to 'crypto/bn/old/bn_low.c')
| -rw-r--r-- | crypto/bn/old/bn_low.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/crypto/bn/old/bn_low.c b/crypto/bn/old/bn_low.c new file mode 100644 index 0000000000..217c8c2f96 --- /dev/null +++ b/crypto/bn/old/bn_low.c @@ -0,0 +1,201 @@ +/* crypto/bn/bn_mul.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" + +static int bn_mm_low(BIGNUM *m,BIGNUM *A,BIGNUM *B, int num, + BIGNUM *sk,BN_CTX *ctx); +int BN_mul_low(BIGNUM *r, BIGNUM *a, BIGNUM *b,int words); + +/* r must be different to a and b */ +int BN_mul_low(r, a, b, num) +BIGNUM *r; +BIGNUM *a; +BIGNUM *b; +int num; + { + BN_ULONG *ap,*bp,*rp; + BIGNUM *sk; + int j,i,n,ret; + int max,al,bl; + BN_CTX ctx; + + bn_check_top(a); + bn_check_top(b); + +#ifdef BN_MUL_DEBUG +printf("BN_mul_low(%d,%d,%d)\n",a->top,b->top,num); +#endif + + al=a->top; + bl=b->top; + if ((al == 0) || (bl == 0)) + { + r->top=0; + return(1); + } + + if ((bn_limit_bits_low > 0) && (num > bn_limit_num_low)) + { + n=BN_num_bits_word(num*2)-bn_limit_bits_low; + n*=2; + sk=(BIGNUM *)Malloc(sizeof(BIGNUM)*n); + memset(sk,0,sizeof(BIGNUM)*n); + memset(&ctx,0,sizeof(ctx)); + + ret=bn_mm_low(r,a,b,num,&(sk[0]),&ctx); + for (i=0; i<n; i+=2) + { + BN_clear_free(&sk[i]); + BN_clear_free(&sk[i+1]); + } + Free(sk); + return(ret); + } + + max=(al+bl); + if (bn_wexpand(r,max) == NULL) return(0); + r->neg=a->neg^b->neg; + ap=a->d; + bp=b->d; + rp=r->d; + r->top=(max > num)?num:max; + + rp[al]=bn_mul_words(rp,ap,al,*(bp++)); + rp++; + j=bl; + for (i=1; i<j; i++) + { + if (al >= num--) + { + al--; + if (al <= 0) break; + } + rp[al]=bn_mul_add_words(rp,ap,al,*(bp++)); + rp++; + } + + while ((r->top > 0) && (r->d[r->top-1] == 0)) + r->top--; + return(1); + } + + +#define t1 (sk[0]) +#define t2 (sk[1]) + +/* r must be different to a and b */ +int bn_mm_low(m, A, B, num, sk,ctx) +BIGNUM *m,*A,*B; +int num; +BIGNUM *sk; +BN_CTX *ctx; + { + int n; /* ,sqr=0; */ + int an,bn; + BIGNUM ah,al,bh,bl; + + bn_wexpand(m,num+3); + an=A->top; + bn=B->top; + +#ifdef BN_MUL_DEBUG +printf("bn_mm_low(%d,%d,%d)\n",A->top,B->top,num); +#endif + + n=(num+1)/2; + + BN_init(&ah); BN_init(&al); BN_init(&bh); BN_init(&bl); + + bn_set_low( &al,A,n); + bn_set_high(&ah,A,n); + bn_set_low( &bl,B,n); + bn_set_high(&bh,B,n); + + if (num <= (bn_limit_num_low+bn_limit_num_low)) + { + BN_mul(m,&al,&bl); + BN_mul_low(&t1,&al,&bh,n); + BN_mul_low(&t2,&ah,&bl,n); + } + else + { + bn_mm(m ,&al,&bl,&(sk[2]),ctx); + bn_mm_low(&t1,&al,&bh,n,&(sk[2]),ctx); + bn_mm_low(&t2,&ah,&bl,n,&(sk[2]),ctx); + } + + BN_add(&t1,&t1,&t2); + + /* We will now do an evil hack instead of + * BN_lshift(&t1,&t1,n*BN_BITS2); + * BN_add(m,m,&t1); + * BN_mask_bits(m,num*BN_BITS2); + */ + bn_set_high(&ah,m,n); ah.max=num+2; + BN_add(&ah,&ah,&t1); + m->top=num; + + m->neg=A->neg^B->neg; + return(1); + } + +#undef t1 (sk[0]) +#undef t2 (sk[1]) |