bn_shift.c

RMI的处理器au1200系列所用的BOOTLOAD,包括SD卡启动USB启动硬盘启动网络启动,并初始化硬件的所有参数,支持内核调试.

/* crypto/bn/bn_shift.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * 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 ([e-mail]).
 * 
 * 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 ([e-mail])"
 *    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 ([e-mail])"
 * 
 * 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"

int BN_lshift1(BIGNUM * r, BIGNUM * a)
{
    register BN_ULONG *ap, *rp, t, c;
    int i;

    if (r != a) {
	r->neg = a->neg;
	if (bn_wexpand(r, a->top + 1) == NULL)
	    return (0);
	r->top = a->top;
    } else {
	if (bn_wexpand(r, a->top + 1) == NULL)
	    return (0);
    }
    ap = a->d;
    rp = r->d;
    c = 0;
    for (i = 0; i < a->top; i++) {
	t = *(ap++);
	*(rp++) = ((t << 1) | c) & BN_MASK2;
	c = (t & BN_TBIT) ? 1 : 0;
    }
    if (c) {
	*rp = 1;
	r->top++;
    }
    return (1);
}

int BN_rshift1(BIGNUM * r, BIGNUM * a)
{
    BN_ULONG *ap, *rp, t, c;
    int i;

    if (BN_is_zero(a)) {
	BN_zero(r);
	return (1);
    }
    if (a != r) {
	if (bn_wexpand(r, a->top) == NULL)
	    return (0);
	r->top = a->top;
	r->neg = a->neg;
    }
    ap = a->d;
    rp = r->d;
    c = 0;
    for (i = a->top - 1; i >= 0; i--) {
	t = ap[i];
	rp[i] = ((t >> 1) & BN_MASK2) | c;
	c = (t & 1) ? BN_TBIT : 0;
    }
    bn_fix_top(r);
    return (1);
}

int BN_lshift(BIGNUM * r, const BIGNUM * a, int n)
{
    int i, nw, lb, rb;
    BN_ULONG *t, *f;
    BN_ULONG l;

    r->neg = a->neg;
    if (bn_wexpand(r, a->top + (n / BN_BITS2) + 1) == NULL)
	return (0);
    nw = n / BN_BITS2;
    lb = n % BN_BITS2;
    rb = BN_BITS2 - lb;
    f = a->d;
    t = r->d;
    t[a->top + nw] = 0;
    if (lb == 0)
	for (i = a->top - 1; i >= 0; i--)
	    t[nw + i] = f[i];
    else
	for (i = a->top - 1; i >= 0; i--) {
	    l = f[i];
	    t[nw + i + 1] |= (l >> rb) & BN_MASK2;
	    t[nw + i] = (l << lb) & BN_MASK2;
	}
    memset(t, 0, nw * sizeof(t[0]));
/*	for (i=0; i<nw; i++)
		t[i]=0;*/
    r->top = a->top + nw + 1;
    bn_fix_top(r);
    return (1);
}

int BN_rshift(BIGNUM * r, BIGNUM * a, int n)
{
    int i, j, nw, lb, rb;
    BN_ULONG *t, *f;
    BN_ULONG l, tmp;

    nw = n / BN_BITS2;
    rb = n % BN_BITS2;
    lb = BN_BITS2 - rb;
    if (nw > a->top || a->top == 0) {
	BN_zero(r);
	return (1);
    }
    if (r != a) {
	r->neg = a->neg;
	if (bn_wexpand(r, a->top - nw + 1) == NULL)
	    return (0);
    } else {
	if (n == 0)
	    return 1;		/* or the copying loop will go berserk */
    }

    f = &(a->d[nw]);
    t = r->d;
    j = a->top - nw;
    r->top = j;

    if (rb == 0) {
	for (i = j + 1; i > 0; i--)
	    *(t++) = *(f++);
    } else {
	l = *(f++);
	for (i = 1; i < j; i++) {
	    tmp = (l >> rb) & BN_MASK2;
	    l = *(f++);
	    *(t++) = (tmp | (l << lb)) & BN_MASK2;
	}
	*(t++) = (l >> rb) & BN_MASK2;
    }
    *t = 0;
    bn_fix_top(r);
    return (1);
}