392 lines
10 KiB
C
Executable File
392 lines
10 KiB
C
Executable File
#include "bn.h"
|
|
|
|
#ifndef WITH_LIBCRYPTO
|
|
//FIXME Not checked on threadsafety yet; after checking please remove this line
|
|
/* crypto/bn/bn_div.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 license 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 license
|
|
* [including the GNU Public License.]
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include "openssl_mods.h"
|
|
#include "bn_lcl.h"
|
|
|
|
/* The old slow way */
|
|
#if 0
|
|
int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
|
|
BN_CTX *ctx)
|
|
{
|
|
int i, nm, nd;
|
|
int ret = 0;
|
|
BIGNUM *D;
|
|
|
|
bn_check_top(m);
|
|
bn_check_top(d);
|
|
if(BN_is_zero(d))
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
if(BN_ucmp(m, d) < 0)
|
|
{
|
|
if(rem != NULL)
|
|
{
|
|
if(BN_copy(rem, m) == NULL) { return (0); }
|
|
}
|
|
if(dv != NULL) { BN_zero(dv); }
|
|
return (1);
|
|
}
|
|
|
|
BN_CTX_start(ctx);
|
|
D = BN_CTX_get(ctx);
|
|
if(dv == NULL) { dv = BN_CTX_get(ctx); }
|
|
if(rem == NULL) { rem = BN_CTX_get(ctx); }
|
|
if(D == NULL || dv == NULL || rem == NULL)
|
|
{ goto end; }
|
|
|
|
nd = BN_num_bits(d);
|
|
nm = BN_num_bits(m);
|
|
if(BN_copy(D, d) == NULL) { goto end; }
|
|
if(BN_copy(rem, m) == NULL) { goto end; }
|
|
|
|
/* The next 2 are needed so we can do a dv->d[0]|=1 later
|
|
* since BN_lshift1 will only work once there is a value :-) */
|
|
BN_zero(dv);
|
|
bn_wexpand(dv, 1);
|
|
dv->top = 1;
|
|
|
|
if(!BN_lshift(D, D, nm - nd)) { goto end; }
|
|
for(i = nm - nd; i >= 0; i--)
|
|
{
|
|
if(!BN_lshift1(dv, dv)) { goto end; }
|
|
if(BN_ucmp(rem, D) >= 0)
|
|
{
|
|
dv->d[0] |= 1;
|
|
if(!BN_usub(rem, rem, D)) { goto end; }
|
|
}
|
|
/* CAN IMPROVE (and have now :=) */
|
|
if(!BN_rshift1(D, D)) { goto end; }
|
|
}
|
|
rem->neg = BN_is_zero(rem) ? 0 : m->neg;
|
|
dv->neg = m->neg ^ d->neg;
|
|
ret = 1;
|
|
end:
|
|
BN_CTX_end(ctx);
|
|
return (ret);
|
|
}
|
|
|
|
#else
|
|
|
|
#if !defined(NO_ASM) && !defined(NO_INLINE_ASM) && !defined(PEDANTIC) && !defined(BN_DIV3W)
|
|
# if defined(__GNUC__) && __GNUC__>=2
|
|
# if defined(__i386) || defined (__i386__)
|
|
/*
|
|
* There were two reasons for implementing this template:
|
|
* - GNU C generates a call to a function (__udivdi3 to be exact)
|
|
* in reply to ((((BN_ULLONG)n0)<<BN_BITS2)|n1)/d0 (I fail to
|
|
* understand why...);
|
|
* - divl doesn't only calculate quotient, but also leaves
|
|
* remainder in %edx which we can definitely use here:-)
|
|
*
|
|
* <appro@fy.chalmers.se>
|
|
*/
|
|
# define bn_div_words(n0,n1,d0) \
|
|
({ __asm__ volatile ( \
|
|
"divl %4" \
|
|
: "=a"(q), "=d"(rem) \
|
|
: "a"(n1), "d"(n0), "g"(d0) \
|
|
: "cc"); \
|
|
q; \
|
|
})
|
|
# define REMAINDER_IS_ALREADY_CALCULATED
|
|
# endif /* __<cpu> */
|
|
# endif /* __GNUC__ */
|
|
#endif /* NO_ASM */
|
|
|
|
int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
|
|
BN_CTX *ctx)
|
|
{
|
|
int norm_shift, i, j, loop;
|
|
BIGNUM *tmp, wnum, *snum, *sdiv, *res;
|
|
BN_ULONG *resp, *wnump;
|
|
BN_ULONG d0, d1;
|
|
int num_n, div_n;
|
|
|
|
bn_check_top(num);
|
|
bn_check_top(divisor);
|
|
|
|
if(BN_is_zero(divisor))
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
if(BN_ucmp(num, divisor) < 0)
|
|
{
|
|
if(rm != NULL)
|
|
{
|
|
if(BN_copy(rm, num) == NULL) { return (0); }
|
|
}
|
|
if(dv != NULL) { BN_zero(dv); }
|
|
return (1);
|
|
}
|
|
|
|
BN_CTX_start(ctx);
|
|
tmp = BN_CTX_get(ctx);
|
|
snum = BN_CTX_get(ctx);
|
|
sdiv = BN_CTX_get(ctx);
|
|
if(dv == NULL)
|
|
{ res = BN_CTX_get(ctx); }
|
|
else { res = dv; }
|
|
if(sdiv == NULL || res == NULL) { goto err; }
|
|
tmp->neg = 0;
|
|
|
|
/* First we normalise the numbers */
|
|
norm_shift = BN_BITS2 - ((BN_num_bits(divisor)) % BN_BITS2);
|
|
BN_lshift(sdiv, divisor, norm_shift);
|
|
sdiv->neg = 0;
|
|
norm_shift += BN_BITS2;
|
|
BN_lshift(snum, num, norm_shift);
|
|
snum->neg = 0;
|
|
div_n = sdiv->top;
|
|
num_n = snum->top;
|
|
loop = num_n - div_n;
|
|
|
|
/* Lets setup a 'window' into snum
|
|
* This is the part that corresponds to the current
|
|
* 'area' being divided */
|
|
BN_init(&wnum);
|
|
wnum.d = &(snum->d[loop]);
|
|
wnum.top = div_n;
|
|
wnum.dmax = snum->dmax + 1; /* a bit of a lie */
|
|
|
|
/* Get the top 2 words of sdiv */
|
|
/* i=sdiv->top; */
|
|
d0 = sdiv->d[div_n - 1];
|
|
d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];
|
|
|
|
/* pointer to the 'top' of snum */
|
|
wnump = &(snum->d[num_n - 1]);
|
|
|
|
/* Setup to 'res' */
|
|
res->neg = (num->neg ^ divisor->neg);
|
|
if(!bn_wexpand(res, (loop + 1))) { goto err; }
|
|
res->top = loop;
|
|
resp = &(res->d[loop - 1]);
|
|
|
|
/* space for temp */
|
|
if(!bn_wexpand(tmp, (div_n + 1))) { goto err; }
|
|
|
|
if(BN_ucmp(&wnum, sdiv) >= 0)
|
|
{
|
|
if(!BN_usub(&wnum, &wnum, sdiv)) { goto err; }
|
|
*resp = 1;
|
|
res->d[res->top - 1] = 1;
|
|
}
|
|
else
|
|
{ res->top--; }
|
|
resp--;
|
|
|
|
for(i = 0; i < loop - 1; i++)
|
|
{
|
|
BN_ULONG q, l0;
|
|
#if defined(BN_DIV3W) && !defined(NO_ASM)
|
|
BN_ULONG bn_div_3_words(BN_ULONG *, BN_ULONG, BN_ULONG);
|
|
q = bn_div_3_words(wnump, d1, d0);
|
|
#else
|
|
BN_ULONG n0, n1, rem = 0;
|
|
|
|
n0 = wnump[0];
|
|
n1 = wnump[-1];
|
|
if(n0 == d0)
|
|
{ q = BN_MASK2; }
|
|
else /* n0 < d0 */
|
|
{
|
|
#ifdef BN_LLONG
|
|
BN_ULLONG t2;
|
|
|
|
#if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)
|
|
q = (BN_ULONG)(((((BN_ULLONG)n0) << BN_BITS2) | n1) / d0);
|
|
#else
|
|
q = bn_div_words(n0, n1, d0);
|
|
#endif
|
|
|
|
#ifndef REMAINDER_IS_ALREADY_CALCULATED
|
|
/*
|
|
* rem doesn't have to be BN_ULLONG. The least we
|
|
* know it's less that d0, isn't it?
|
|
*/
|
|
rem = (n1 - q * d0)&BN_MASK2;
|
|
#endif
|
|
t2 = (BN_ULLONG)d1 * q;
|
|
|
|
for(;;)
|
|
{
|
|
if(t2 <= ((((BN_ULLONG)rem) << BN_BITS2) | wnump[-2]))
|
|
{ break; }
|
|
q--;
|
|
rem += d0;
|
|
if(rem < d0) { break; } /* don't let rem overflow */
|
|
t2 -= d1;
|
|
}
|
|
#else /* !BN_LLONG */
|
|
BN_ULONG t2l, t2h, ql, qh;
|
|
|
|
q = bn_div_words(n0, n1, d0);
|
|
#ifndef REMAINDER_IS_ALREADY_CALCULATED
|
|
rem = (n1 - q * d0)&BN_MASK2;
|
|
#endif
|
|
|
|
#ifdef BN_UMULT_HIGH
|
|
t2l = d1 * q;
|
|
t2h = BN_UMULT_HIGH(d1, q);
|
|
#else
|
|
t2l = LBITS(d1);
|
|
t2h = HBITS(d1);
|
|
ql = LBITS(q);
|
|
qh = HBITS(q);
|
|
mul64(t2l, t2h, ql, qh); /* t2=(BN_ULLONG)d1*q; */
|
|
#endif
|
|
|
|
for(;;)
|
|
{
|
|
if((t2h < rem) ||
|
|
((t2h == rem) && (t2l <= wnump[-2])))
|
|
{ break; }
|
|
q--;
|
|
rem += d0;
|
|
if(rem < d0) { break; } /* don't let rem overflow */
|
|
if(t2l < d1) { t2h--; }
|
|
t2l -= d1;
|
|
}
|
|
#endif /* !BN_LLONG */
|
|
}
|
|
#endif /* !BN_DIV3W */
|
|
|
|
l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);
|
|
wnum.d--;
|
|
wnum.top++;
|
|
tmp->d[div_n] = l0;
|
|
for(j = div_n + 1; j > 0; j--)
|
|
if(tmp->d[j - 1]) { break; }
|
|
tmp->top = j;
|
|
|
|
j = wnum.top;
|
|
BN_sub(&wnum, &wnum, tmp);
|
|
|
|
snum->top = snum->top + wnum.top - j;
|
|
|
|
if(wnum.neg)
|
|
{
|
|
q--;
|
|
j = wnum.top;
|
|
BN_add(&wnum, &wnum, sdiv);
|
|
snum->top += wnum.top - j;
|
|
}
|
|
*(resp--) = q;
|
|
wnump--;
|
|
}
|
|
if(rm != NULL)
|
|
{
|
|
BN_rshift(rm, snum, norm_shift);
|
|
rm->neg = num->neg;
|
|
}
|
|
BN_CTX_end(ctx);
|
|
return (1);
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
return (0);
|
|
}
|
|
|
|
#endif
|
|
|
|
/* rem != m */
|
|
int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
|
|
{
|
|
#if 0 /* The old slow way */
|
|
int i, nm, nd;
|
|
BIGNUM *dv;
|
|
|
|
if(BN_ucmp(m, d) < 0)
|
|
{ return ((BN_copy(rem, m) == NULL) ? 0 : 1); }
|
|
|
|
BN_CTX_start(ctx);
|
|
dv = BN_CTX_get(ctx);
|
|
|
|
if(!BN_copy(rem, m)) { goto err; }
|
|
|
|
nm = BN_num_bits(rem);
|
|
nd = BN_num_bits(d);
|
|
if(!BN_lshift(dv, d, nm - nd)) { goto err; }
|
|
for(i = nm - nd; i >= 0; i--)
|
|
{
|
|
if(BN_cmp(rem, dv) >= 0)
|
|
{
|
|
if(!BN_sub(rem, rem, dv)) { goto err; }
|
|
}
|
|
if(!BN_rshift1(dv, dv)) { goto err; }
|
|
}
|
|
BN_CTX_end(ctx);
|
|
return (1);
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
return (0);
|
|
#else
|
|
return (BN_div(NULL, rem, m, d, ctx));
|
|
#endif
|
|
}
|
|
|
|
#endif
|