* [including the GNU Public Licence.]
*/
+#ifndef BN_DEBUG
+# undef NDEBUG /* avoid conflicting definitions */
+# define NDEBUG
+#endif
+
#include <stdio.h>
#include <assert.h>
#include "cryptlib.h"
#include "bn_lcl.h"
+#if defined(OPENSSL_NO_ASM) || !defined(OPENSSL_BN_ASM_PART_WORDS)
/* Here follows specialised variants of bn_add_words() and
bn_sub_words(). They have the property performing operations on
arrays of different sizes. The sizes of those arrays is expressed through
}
return c;
}
+#endif
BN_ULONG bn_add_part_words(BN_ULONG *r,
const BN_ULONG *a, const BN_ULONG *b,
* a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0])
* a[1]*b[1]
*/
+/* dnX may not be positive, but n2/2+dnX has to be */
void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
- BN_ULONG *t)
+ int dna, int dnb, BN_ULONG *t)
{
int n=n2/2,c1,c2;
+ int tna=n+dna, tnb=n+dnb;
unsigned int neg,zero;
BN_ULONG ln,lo,*p;
# ifdef BN_COUNT
- fprintf(stderr," bn_mul_recursive %d * %d\n",n2,n2);
+ fprintf(stderr," bn_mul_recursive %d%+d * %d%+d\n",n2,dna,n2,dnb);
# endif
# ifdef BN_MUL_COMBA
# if 0
return;
}
# endif
- if (n2 == 8)
+ /* Only call bn_mul_comba 8 if n2 == 8 and the
+ * two arrays are complete [steve]
+ */
+ if (n2 == 8 && dna == 0 && dnb == 0)
{
bn_mul_comba8(r,a,b);
return;
}
# endif /* BN_MUL_COMBA */
+ /* Else do normal multiply */
if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL)
{
- /* This should not happen */
- bn_mul_normal(r,a,n2,b,n2);
+ bn_mul_normal(r,a,n2+dna,b,n2+dnb);
+ if ((dna + dnb) < 0)
+ memset(&r[2*n2 + dna + dnb], 0,
+ sizeof(BN_ULONG) * -(dna + dnb));
return;
}
/* r=(a[0]-a[1])*(b[1]-b[0]) */
- c1=bn_cmp_words(a,&(a[n]),n);
- c2=bn_cmp_words(&(b[n]),b,n);
+ c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna);
+ c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n);
zero=neg=0;
switch (c1*3+c2)
{
case -4:
- bn_sub_words(t, &(a[n]),a, n); /* - */
- bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
+ bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */
+ bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */
break;
case -3:
zero=1;
break;
case -2:
- bn_sub_words(t, &(a[n]),a, n); /* - */
- bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */
+ bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */
+ bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */
neg=1;
break;
case -1:
zero=1;
break;
case 2:
- bn_sub_words(t, a, &(a[n]),n); /* + */
- bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
+ bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */
+ bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */
neg=1;
break;
case 3:
zero=1;
break;
case 4:
- bn_sub_words(t, a, &(a[n]),n);
- bn_sub_words(&(t[n]),&(b[n]),b, n);
+ bn_sub_part_words(t, a, &(a[n]),tna,n-tna);
+ bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n);
break;
}
# ifdef BN_MUL_COMBA
- if (n == 4)
+ if (n == 4 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba4 could take
+ extra args to do this well */
{
if (!zero)
bn_mul_comba4(&(t[n2]),t,&(t[n]));
bn_mul_comba4(r,a,b);
bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n]));
}
- else if (n == 8)
+ else if (n == 8 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba8 could
+ take extra args to do this
+ well */
{
if (!zero)
bn_mul_comba8(&(t[n2]),t,&(t[n]));
{
p= &(t[n2*2]);
if (!zero)
- bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
+ bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p);
else
memset(&(t[n2]),0,n2*sizeof(BN_ULONG));
- bn_mul_recursive(r,a,b,n,p);
- bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,p);
+ bn_mul_recursive(r,a,b,n,0,0,p);
+ bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,dna,dnb,p);
}
/* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
/* n+tn is the word length
* t needs to be n*4 is size, as does r */
-void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int tn,
- int n, BN_ULONG *t)
+/* tnX may not be negative but less than n */
+void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
+ int tna, int tnb, BN_ULONG *t)
{
int i,j,n2=n*2;
- unsigned int c1,c2,neg,zero;
+ int c1,c2,neg;
BN_ULONG ln,lo,*p;
# ifdef BN_COUNT
- fprintf(stderr," bn_mul_part_recursive (%d+%d) * (%d+%d)\n",
- tn, n,tn, n);
+ fprintf(stderr," bn_mul_part_recursive (%d%+d) * (%d%+d)\n",
+ n, tna, n, tnb);
# endif
if (n < 8)
{
- i=tn+n;
- bn_mul_normal(r,a,i,b,i);
+ bn_mul_normal(r,a,n+tna,b,n+tnb);
return;
}
/* r=(a[0]-a[1])*(b[1]-b[0]) */
- c1=bn_cmp_part_words(a,&(a[n]),tn,n-tn);
- c2=bn_cmp_part_words(&(b[n]),b,tn,tn-n);
- zero=neg=0;
+ c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna);
+ c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n);
+ neg=0;
switch (c1*3+c2)
{
case -4:
- bn_sub_part_words(t, &(a[n]),a, tn,tn-n); /* - */
- bn_sub_part_words(&(t[n]),b, &(b[n]),tn,n-tn); /* - */
+ bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */
+ bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */
break;
case -3:
- zero=1;
/* break; */
case -2:
- bn_sub_part_words(t, &(a[n]),a, tn,tn-n); /* - */
- bn_sub_part_words(&(t[n]),&(b[n]),b, tn,tn-n); /* + */
+ bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */
+ bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */
neg=1;
break;
case -1:
case 0:
case 1:
- zero=1;
/* break; */
case 2:
- bn_sub_part_words(t, a, &(a[n]),tn,n-tn); /* + */
- bn_sub_part_words(&(t[n]),b, &(b[n]),tn,n-tn); /* - */
+ bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */
+ bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */
neg=1;
break;
case 3:
- zero=1;
/* break; */
case 4:
- bn_sub_part_words(t, a, &(a[n]),tn,n-tn);
- bn_sub_part_words(&(t[n]),&(b[n]),b, tn,tn-n);
+ bn_sub_part_words(t, a, &(a[n]),tna,n-tna);
+ bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n);
break;
}
/* The zero case isn't yet implemented here. The speedup
{
bn_mul_comba8(&(t[n2]),t,&(t[n]));
bn_mul_comba8(r,a,b);
- bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
- memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2));
+ bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb);
+ memset(&(r[n2+tna+tnb]),0,sizeof(BN_ULONG)*(n2-tna-tnb));
}
else
{
p= &(t[n2*2]);
- bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
- bn_mul_recursive(r,a,b,n,p);
+ bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p);
+ bn_mul_recursive(r,a,b,n,0,0,p);
i=n/2;
/* If there is only a bottom half to the number,
* just do it */
- j=tn-i;
+ if (tna > tnb)
+ j = tna - i;
+ else
+ j = tnb - i;
if (j == 0)
{
- bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),i,p);
+ bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),
+ i,tna-i,tnb-i,p);
memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2-i*2));
}
else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */
{
bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]),
- j,i,p);
- memset(&(r[n2+tn*2]),0,
- sizeof(BN_ULONG)*(n2-tn*2));
+ i,tna-i,tnb-i,p);
+ memset(&(r[n2+tna+tnb]),0,
+ sizeof(BN_ULONG)*(n2-tna-tnb));
}
else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */
{
memset(&(r[n2]),0,sizeof(BN_ULONG)*n2);
- if (tn < BN_MUL_RECURSIVE_SIZE_NORMAL)
+ if (tna < BN_MUL_RECURSIVE_SIZE_NORMAL
+ && tnb < BN_MUL_RECURSIVE_SIZE_NORMAL)
{
- bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
+ bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb);
}
else
{
for (;;)
{
i/=2;
- if (i < tn)
+ /* these simplified conditions work
+ * exclusively because difference
+ * between tna and tnb is 1 or 0 */
+ if (i < tna || i < tnb)
{
bn_mul_part_recursive(&(r[n2]),
&(a[n]),&(b[n]),
- tn-i,i,p);
+ i,tna-i,tnb-i,p);
break;
}
- else if (i == tn)
+ else if (i == tna || i == tnb)
{
bn_mul_recursive(&(r[n2]),
&(a[n]),&(b[n]),
- i,p);
+ i,tna-i,tnb-i,p);
break;
}
}
/* The overflow will stop before we over write
* words we should not overwrite */
- if (ln < c1)
+ if (ln < (BN_ULONG)c1)
{
do {
p++;
fprintf(stderr," bn_mul_low_recursive %d * %d\n",n2,n2);
# endif
- bn_mul_recursive(r,a,b,n,&(t[0]));
+ bn_mul_recursive(r,a,b,n,0,0,&(t[0]));
if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL)
{
bn_mul_low_recursive(&(t[0]),&(a[0]),&(b[n]),n,&(t[n2]));
else
# endif
{
- bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,&(t[n2]));
- bn_mul_recursive(r,&(a[n]),&(b[n]),n,&(t[n2]));
+ bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,0,0,&(t[n2]));
+ bn_mul_recursive(r,&(a[n]),&(b[n]),n,0,0,&(t[n2]));
}
/* s0 == low(al*bl)
}
#endif /* BN_RECURSION */
-int BN_mul(BIGNUM *r, /* almost const */ const BIGNUM *a, /* almost const */ const BIGNUM *b, BN_CTX *ctx)
+int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
{
+ int ret=0;
int top,al,bl;
BIGNUM *rr;
- int ret = 0;
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
int i;
#endif
#ifdef BN_RECURSION
- BIGNUM *t;
- int j,k;
+ BIGNUM *t=NULL;
+ int j=0,k;
#endif
- BIGNUM *free_a = NULL, *free_b = NULL;
#ifdef BN_COUNT
fprintf(stderr,"BN_mul %d * %d\n",a->top,b->top);
#ifdef BN_RECURSION
if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL))
{
+ if (i >= -1 && i <= 1)
+ {
+ /* Find out the power of two lower or equal
+ to the longest of the two numbers */
+ if (i >= 0)
+ {
+ j = BN_num_bits_word((BN_ULONG)al);
+ }
+ if (i == -1)
+ {
+ j = BN_num_bits_word((BN_ULONG)bl);
+ }
+ j = 1<<(j-1);
+ assert(j <= al || j <= bl);
+ k = j+j;
+ t = BN_CTX_get(ctx);
+ if (t == NULL)
+ goto err;
+ if (al > j || bl > j)
+ {
+ if (bn_wexpand(t,k*4) == NULL) goto err;
+ if (bn_wexpand(rr,k*4) == NULL) goto err;
+ bn_mul_part_recursive(rr->d,a->d,b->d,
+ j,al-j,bl-j,t->d);
+ }
+ else /* al <= j || bl <= j */
+ {
+ if (bn_wexpand(t,k*2) == NULL) goto err;
+ if (bn_wexpand(rr,k*2) == NULL) goto err;
+ bn_mul_recursive(rr->d,a->d,b->d,
+ j,al-j,bl-j,t->d);
+ }
+ rr->top=top;
+ goto end;
+ }
+#if 0
if (i == 1 && !BN_get_flags(b,BN_FLG_STATIC_DATA))
{
BIGNUM *tmp_bn = (BIGNUM *)b;
- bn_wexpand(tmp_bn,al);
+ if (bn_wexpand(tmp_bn,al) == NULL) goto err;
tmp_bn->d[bl]=0;
bl++;
i--;
else if (i == -1 && !BN_get_flags(a,BN_FLG_STATIC_DATA))
{
BIGNUM *tmp_bn = (BIGNUM *)a;
- bn_wexpand(tmp_bn,bl);
+ if (bn_wexpand(tmp_bn,bl) == NULL) goto err;
tmp_bn->d[al]=0;
al++;
i++;
t = BN_CTX_get(ctx);
if (al == j) /* exact multiple */
{
- bn_wexpand(t,k*2);
- bn_wexpand(rr,k*2);
+ if (bn_wexpand(t,k*2) == NULL) goto err;
+ if (bn_wexpand(rr,k*2) == NULL) goto err;
bn_mul_recursive(rr->d,a->d,b->d,al,t->d);
}
else
{
- bn_wexpand(t,k*4);
- bn_wexpand(rr,k*4);
+ if (bn_wexpand(t,k*4) == NULL) goto err;
+ if (bn_wexpand(rr,k*4) == NULL) goto err;
bn_mul_part_recursive(rr->d,a->d,b->d,al-j,j,t->d);
}
rr->top=top;
goto end;
}
+#endif
}
#endif /* BN_RECURSION */
if (bn_wexpand(rr,top) == NULL) goto err;
#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
end:
#endif
- bn_fix_top(rr);
+ bn_correct_top(rr);
if (r != rr) BN_copy(r,rr);
ret=1;
err:
- if (free_a) BN_free(free_a);
- if (free_b) BN_free(free_b);
+ bn_check_top(r);
BN_CTX_end(ctx);
return(ret);
}
}
rr= &(r[na]);
- rr[0]=bn_mul_words(r,a,na,b[0]);
+ if (nb <= 0)
+ {
+ (void)bn_mul_words(r,a,na,0);
+ return;
+ }
+ else
+ rr[0]=bn_mul_words(r,a,na,b[0]);
for (;;)
{