+++ /dev/null
-/* crypto/bn/bn_recp.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"
-
-void BN_RECP_CTX_init(BN_RECP_CTX *recp)
- {
- BN_init(&(recp->N));
- BN_init(&(recp->Nr));
- recp->num_bits=0;
- recp->flags=0;
- }
-
-BN_RECP_CTX *BN_RECP_CTX_new(void)
- {
- BN_RECP_CTX *ret;
-
- if ((ret=(BN_RECP_CTX *)OPENSSL_malloc(sizeof(BN_RECP_CTX))) == NULL)
- return(NULL);
-
- BN_RECP_CTX_init(ret);
- ret->flags=BN_FLG_MALLOCED;
- return(ret);
- }
-
-void BN_RECP_CTX_free(BN_RECP_CTX *recp)
- {
- if(recp == NULL)
- return;
-
- BN_free(&(recp->N));
- BN_free(&(recp->Nr));
- if (recp->flags & BN_FLG_MALLOCED)
- OPENSSL_free(recp);
- }
-
-int BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx)
- {
- if (!BN_copy(&(recp->N),d)) return 0;
- if (!BN_zero(&(recp->Nr))) return 0;
- recp->num_bits=BN_num_bits(d);
- recp->shift=0;
- return(1);
- }
-
-int BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
- BN_RECP_CTX *recp, BN_CTX *ctx)
- {
- int ret=0;
- BIGNUM *a;
- const BIGNUM *ca;
-
- BN_CTX_start(ctx);
- if ((a = BN_CTX_get(ctx)) == NULL) goto err;
- if (y != NULL)
- {
- if (x == y)
- { if (!BN_sqr(a,x,ctx)) goto err; }
- else
- { if (!BN_mul(a,x,y,ctx)) goto err; }
- ca = a;
- }
- else
- ca=x; /* Just do the mod */
-
- ret = BN_div_recp(NULL,r,ca,recp,ctx);
-err:
- BN_CTX_end(ctx);
- return(ret);
- }
-
-int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
- BN_RECP_CTX *recp, BN_CTX *ctx)
- {
- int i,j,ret=0;
- BIGNUM *a,*b,*d,*r;
-
- BN_CTX_start(ctx);
- a=BN_CTX_get(ctx);
- b=BN_CTX_get(ctx);
- if (dv != NULL)
- d=dv;
- else
- d=BN_CTX_get(ctx);
- if (rem != NULL)
- r=rem;
- else
- r=BN_CTX_get(ctx);
- if (a == NULL || b == NULL || d == NULL || r == NULL) goto err;
-
- if (BN_ucmp(m,&(recp->N)) < 0)
- {
- if (!BN_zero(d)) return 0;
- if (!BN_copy(r,m)) return 0;
- BN_CTX_end(ctx);
- return(1);
- }
-
- /* We want the remainder
- * Given input of ABCDEF / ab
- * we need multiply ABCDEF by 3 digests of the reciprocal of ab
- *
- */
-
- /* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */
- i=BN_num_bits(m);
- j=recp->num_bits<<1;
- if (j>i) i=j;
-
- /* Nr := round(2^i / N) */
- if (i != recp->shift)
- recp->shift=BN_reciprocal(&(recp->Nr),&(recp->N),
- i,ctx); /* BN_reciprocal returns i, or -1 for an error */
- if (recp->shift == -1) goto err;
-
- /* d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
- * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
- * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
- * = |m/N|
- */
- if (!BN_rshift(a,m,recp->num_bits)) goto err;
- if (!BN_mul(b,a,&(recp->Nr),ctx)) goto err;
- if (!BN_rshift(d,b,i-recp->num_bits)) goto err;
- d->neg=0;
-
- if (!BN_mul(b,&(recp->N),d,ctx)) goto err;
- if (!BN_usub(r,m,b)) goto err;
- r->neg=0;
-
-#if 1
- j=0;
- while (BN_ucmp(r,&(recp->N)) >= 0)
- {
- if (j++ > 2)
- {
- BNerr(BN_F_BN_MOD_MUL_RECIPROCAL,BN_R_BAD_RECIPROCAL);
- goto err;
- }
- if (!BN_usub(r,r,&(recp->N))) goto err;
- if (!BN_add_word(d,1)) goto err;
- }
-#endif
-
- r->neg=BN_is_zero(r)?0:m->neg;
- d->neg=m->neg^recp->N.neg;
- ret=1;
-err:
- BN_CTX_end(ctx);
- return(ret);
- }
-
-/* len is the expected size of the result
- * We actually calculate with an extra word of precision, so
- * we can do faster division if the remainder is not required.
- */
-/* r := 2^len / m */
-int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
- {
- int ret= -1;
- BIGNUM t;
-
- BN_init(&t);
-
- if (!BN_zero(&t)) goto err;
- if (!BN_set_bit(&t,len)) goto err;
-
- if (!BN_div(r,NULL,&t,m,ctx)) goto err;
-
- ret=len;
-err:
- BN_free(&t);
- return(ret);
- }
projects / bcm963xx.git / blobdiff