openssl/crypto/bn/stuff/wei_mulw.c
1998-12-21 10:52:47 +00:00

411 lines
7.1 KiB
C

/* crypto/bn/wei_mulw.c */
#include <stdio.h>
#include "cryptlib.h"
#include "bn.h"
#include "bn_lcl.h"
BN_ULONG bn_add_word(BN_ULONG *a,BN_ULONG c,int num);
BN_ULONG bn_add_words(BN_ULONG *ret,BN_ULONG *a,BN_ULONG *b,int num);
BN_ULONG bn_sub_words(BN_ULONG *ret,BN_ULONG *a,BN_ULONG *b,int num);
void BN_mul_4words(BN_ULONG *ret,BN_ULONG a0,BN_ULONG a1,
BN_ULONG b0,BN_ULONG b1);
void pr(a,n,s)
BN_ULONG *a;
int n;
{
while (n--)
fprintf(stdout,"%02X",a[n]);
fprintf(stdout,"%s",s);
}
BN_ULONG bn_add_word(a,w,num)
BN_ULONG *a;
BN_ULONG w;
int num;
{
BN_ULONG t;
#ifdef DEBUG
{ BN_ULONG *aa=a; int i; for (i=num; i>0; i--) fprintf(stdout,"%02X",aa[i-1]);
fprintf(stdout," + %X - ",w); i=num;
#endif
loop:
t= *a;
t=(t+w)&BN_MASK2;
*(a++)=t;
w=(t < w);
if (w && --num) goto loop;
#ifdef DEBUG
for (; i>0; i--) fprintf(stdout,"%02X",aa[i-1]);
fprintf(stdout,"\n");
}
#endif
return(w);
}
BN_ULONG bn_add_words(r,a,b,num)
BN_ULONG *r;
BN_ULONG *a;
BN_ULONG *b;
int num;
{
#if defined(BN_LLONG)
BN_ULLONG t;
BN_ULONG c=0;
int i;
if (num&1) abort();
for (i=0; i<num; i+=2)
{
t=(BN_ULLONG)a[i]+b[i]+c;
r[i+0]=L(t);
t=(BN_ULLONG) H(t)+a[i+1]+b[i+1];
r[i+1]=L(t);
c=H(t);
}
return(c);
#else
BN_ULONG c=0,t1,t2;
for ( ; num; num--)
{
t1= *(a++);
t2= *(b++);
if (c)
{
c=(t2 >= ((~t1)&BN_MASK2));
(*r++)=(t1+t2+1)&BN_MASK2;
}
else
{
t2=(t1+t2)&BN_MASK2;
c=(t2 < t1);
(*r++)=t2;
}
}
return(c);
#endif
}
BN_ULONG bn_sub_words(r,a,b,num)
BN_ULONG *r;
BN_ULONG *a;
BN_ULONG *b;
int num;
{
#if defined(BN_LLONG)
BN_ULLONG t;
BN_ULONG c=0;
int i;
if (num&1) abort();
for (i=0; i<num; i+=2)
{
t=(BN_ULLONG)a[i]-b[i]-c;
r[i+0]=L(t);
t=(BN_ULLONG)a[i+1]-b[i+1]-(0-H(t))&BN_MASK2;
r[i+1]=L(t);
c=H(t);
}
return(c);
#else
BN_ULONG c=0,t1,t2;
for ( ; num; num--)
{
t1= *(a++);
t2= *(b++);
if (c)
{
c=(t1 <= t2);
t1=(t1-t2-1);
}
else
{
c=(t1 < t2);
t1=(t1-t2);
}
(*r++)=t1&BN_MASK2;
}
return(c);
#endif
}
/* ret[3,2,1,0] = a1,a0 * b1,b0 */
void BN_mul_4words(ret,a0,a1,b0,b1)
BN_ULONG *ret;
BN_ULONG a0,a1,b0,b1;
{
BN_ULONG s,u;
BN_ULLONG fix,a0b0,a1b1,tmp;
if (a1 >= a0)
{
s=(a1-a0);
u=(b0-b1);
fix=(BN_ULLONG)s*u;
if (b0 >= b1) s=0;
}
else
{
BN_ULONG u;
if (b0 > b1)
{
s=(b0-b1);
u=(a1-a0);
fix=(BN_ULLONG)s*u;
}
else
{
u=(a0-a1);
s=(b1-b0);
fix=(BN_ULLONG)s*u;
s=0;
}
}
a0b0=(BN_ULLONG)a0*b0;
ret[0]=L(a0b0);
a1b1=(BN_ULLONG)a1*b1;
tmp=(BN_ULLONG) H(a0b0) + L(a0b0) + L(fix) + L(a1b1);
ret[1]=L(tmp);
tmp=(BN_ULLONG) a1b1 + H(tmp) + H(a0b0) + H(fix) + H(a1b1) - s;
ret[2]=L(tmp);
ret[3]=H(tmp);
}
/* ret[3,2,1,0] += a1,a0 * b1,b0 */
BN_ULONG BN_mul_add_4words(ret,a0,a1,b0,b1)
BN_ULONG *ret;
BN_ULONG a0,a1,b0,b1;
{
BN_ULONG s,u;
BN_ULLONG fix,a0b0,a1b1,tmp;
#ifdef DEBUG
fprintf(stdout,"%02X%02X%02X%02X",ret[3],ret[2],ret[1],ret[0]);
fprintf(stdout," + ( %02X%02X * %02X%02X ) - ",a1,a0,b1,b0);
#endif
if (a1 >= a0)
{
s=(a1-a0);
u=(b0-b1);
fix=(BN_ULLONG)s*u;
if (b0 >= b1) s=0;
}
else
{
if (b0 > b1)
{
s=(b0-b1);
u=(a1-a0);
fix=(BN_ULLONG)s*u;
}
else
{
u=(a0-a1);
s=(b1-b0);
fix=(BN_ULLONG)s*u;
s=0;
}
}
a0b0=(BN_ULLONG)a0*b0;
tmp=a0b0+ret[0];
ret[0]=L(tmp);
a1b1=(BN_ULLONG)a1*b1;
tmp=(BN_ULLONG) H(tmp) + L(a0b0) + L(fix) + L(a1b1) + ret[1];
ret[1]=L(tmp);
tmp=(BN_ULLONG) H(tmp) + L(a1b1) + H(a0b0) +
H(fix) + H(a1b1) -s + ret[2];
ret[2]=L(tmp);
tmp=(BN_ULLONG) H(tmp) + H(a1b1) + ret[3];
ret[3]=L(tmp);
#ifdef DEBUG
fprintf(stdout,"%02X%02X%02X%02X%02X\n",H(tmp),ret[3],ret[2],ret[1],ret[0]);
#endif
return(H(tmp));
}
/* ret[3,2,1,0] += a1,a0 * a1,a0 */
void BN_sqr_4words(ret,a0,a1)
BN_ULONG *ret;
BN_ULONG a0,a1;
{
BN_ULONG s,u;
BN_ULLONG tmp,tmp2;
tmp=(BN_ULLONG)a0*a0;
ret[0]=L(tmp);
tmp2=(BN_ULLONG)a0*a1;
tmp=(BN_ULLONG)H(tmp)+L(tmp2)*2;
ret[1]=L(tmp);
tmp=(BN_ULLONG)a1*a1+H(tmp)+H(tmp2)*2;
ret[2]=L(tmp);
ret[3]=L(tmp);
}
#define N0 (0)
#define N1 (half)
#define N2 (num)
#define N3 (num+half)
#define word_cmp(r,a,b,num) \
{ \
int n=num; \
\
(r)=0; \
while (n--) \
{ \
if ((a)[(n)] > (b)[(n)]) \
{ (r)=1; break; } \
else if ((a)[(n)] < (b)[(n)]) \
{ (r)= -1; break; } \
} \
}
/* (a->top == b->top) && (a->top >= 2) && !(a->top & 1) */
void bn_recursize_mul(r,t,a,b,num)
BN_ULONG *r,*t,*a,*b;
int num;
{
if ((num < 2) || (num&1))
abort();
/* fprintf(stderr,"num=%d half=%d\n",num,num/2);*/
if (num == 2)
BN_mul_4words(r,a[0],a[1],b[0],b[1]);
else if (num == 4)
{
BN_ULONG c,tmp;
BN_mul_4words(&(r[0]),a[0],a[1],b[0],b[1]);
BN_mul_4words(&(r[4]),a[2],a[3],b[2],b[3]);
c =BN_mul_add_4words(&(r[2]),a[0],a[1],b[2],b[3]);
c+=BN_mul_add_4words(&(r[2]),a[2],a[3],b[0],b[1]);
bn_add_word(&(r[6]),c,2);
}
else
{
int half=num/2;
int carry,cmp_a,cmp_b;
word_cmp(cmp_a,&(a[0]),&(a[half]),half);
word_cmp(cmp_b,&(b[0]),&(b[half]),half);
switch (cmp_a*2+cmp_a+cmp_b)
{
case -4:
bn_sub_words(&(t[N0]),&(a[N1]),&(a[N0]),half);
bn_sub_words(&(t[N1]),&(b[N0]),&(b[N1]),half);
bn_recursize_mul(&(r[N1]),&(t[N2]),
&(t[N0]),&(t[N1]),half);
bn_sub_words(&(r[N2]),&(r[N2]),&(t[N0]),half);
carry= -1;
break;
case -2:
bn_sub_words(&(t[N0]),&(a[N1]),&(a[N0]),half);
bn_sub_words(&(t[N1]),&(b[N0]),&(b[N1]),half);
bn_recursize_mul(&(r[N1]),&(t[N2]),
&(t[N0]),&(t[N1]),half);
carry=0;
break;
case 2:
bn_sub_words(&(t[N0]),&(a[N0]),&(a[N1]),half);
bn_sub_words(&(t[N1]),&(b[N1]),&(b[N0]),half);
bn_recursize_mul(&(r[N1]),&(t[N2]),
&(t[N0]),&(t[N1]),half);
carry=0;
break;
case 4:
bn_sub_words(&(t[N0]),&(a[N1]),&(a[N0]),half);
bn_sub_words(&(t[N1]),&(b[N0]),&(b[N1]),half);
bn_recursize_mul(&(r[N1]),&(t[N2]),
&(t[N0]),&(t[N1]),half);
bn_sub_words(&(r[N2]),&(r[N2]),&(t[N1]),half);
carry= -1;
break;
default:
memset(&(r[N1]),0,sizeof(BN_ULONG)*num);
break;
}
bn_recursize_mul(&(t[N0]),&(t[N2]),&(a[N0]),&(b[N0]),half);
#ifdef DEBUG
pr(a,half," * ");
pr(b,half," - ");
pr(t,num," - 0\n");
#endif
memcpy(&(r[N0]),&(t[N0]),half*sizeof(BN_ULONG));
if (bn_add_words(&(r[N1]),&(r[N1]),&(t[N1]),half))
{ bn_add_word(&(t[N1]),1,half); }
carry+=bn_add_words(&(r[N1]),&(r[N1]),&(t[N0]),num);
bn_recursize_mul(&(t[N0]),&(t[N2]),&(a[N1]),&(b[N1]),half);
carry+=bn_add_words(&(r[N1]),&(r[N1]),&(t[N0]),num);
carry+=bn_add_words(&(r[N2]),&(r[N2]),&(t[N0]),half);
memcpy(&(r[N3]),&(t[N1]),half*sizeof(BN_ULONG));
bn_add_word(&(r[N3]),carry,half);
}
}
main()
{
BIGNUM *a,*b,*r,*t;
int i,j;
a=BN_new();
b=BN_new();
r=BN_new();
t=BN_new();
#define BITS 1024
bn_expand(r,BITS*2);
bn_expand(t,BITS*2);
fprintf(stdout,"obase=16\n");
fprintf(stdout,"ibase=16\n");
for (i=0; i<10; i++)
{
BN_rand(a,BITS,0,0);
BN_rand(b,BITS,0,0);
r->top=(BITS*2)/BN_BITS2;
memset(r->d,0,sizeof(r->top)*sizeof(BN_ULONG));
memset(t->d,0,sizeof(r->top)*sizeof(BN_ULONG));
for (j=0; j<1000; j++)
{
/* BN_mul(r,a,b); /**/
bn_recursize_mul(r->d,t->d,a->d,b->d,a->top); /**/
}
BN_print(stdout,a); fprintf(stdout," * ");
BN_print(stdout,b); fprintf(stdout," - ");
BN_print(stdout,r); fprintf(stdout,"\n");
}
}