X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mul.c;h=12e5be80eb2b442db28f6b1955c0d583bb91bb83;hp=eb5d5256137ea5861f3cf71d2f07ae83b75afbe9;hb=46bf83f07ae1ba7fda435c90af93960e77159f4b;hpb=90e7ce363ae8278bb4ac647739c89a43ed341e34

diff --git a/crypto/bn/bn_mul.c b/crypto/bn/bn_mul.c
index eb5d525613..12e5be80eb 100644
--- a/crypto/bn/bn_mul.c
+++ b/crypto/bn/bn_mul.c
@@ -66,6 +66,7 @@
 #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
@@ -201,6 +202,7 @@ BN_ULONG bn_sub_part_words(BN_ULONG *r,
 		}
 	return c;
 	}
+#endif
 
 BN_ULONG bn_add_part_words(BN_ULONG *r,
 	const BN_ULONG *a, const BN_ULONG *b,
@@ -387,6 +389,7 @@ BN_ULONG bn_add_part_words(BN_ULONG *r,
  * 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,
 	int dna, int dnb, BN_ULONG *t)
 	{
@@ -396,7 +399,7 @@ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
 	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
@@ -406,16 +409,22 @@ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
 		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]) */
@@ -456,7 +465,8 @@ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
 		}
 
 # 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]));
@@ -466,7 +476,9 @@ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
 		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]));
@@ -534,16 +546,17 @@ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
 
 /* n+tn is the word length
  * t needs to be n*4 is size, as does r */
+/* 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",
-		tna, n, tnb, n);
+	fprintf(stderr," bn_mul_part_recursive (%d%+d) * (%d%+d)\n",
+		n, tna, n, tnb);
 # endif
 	if (n < 8)
 		{
@@ -554,7 +567,7 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
 	/* r=(a[0]-a[1])*(b[1]-b[0]) */
 	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;
+	neg=0;
 	switch (c1*3+c2)
 		{
 	case -4:
@@ -562,7 +575,6 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int 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,      tna,tna-n); /* - */
@@ -572,7 +584,6 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
 	case -1:
 	case 0:
 	case 1:
-		zero=1;
 		/* break; */
 	case 2:
 		bn_sub_part_words(t,      a,      &(a[n]),tna,n-tna); /* + */
@@ -580,7 +591,6 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
 		neg=1;
 		break;
 	case 3:
-		zero=1;
 		/* break; */
 	case 4:
 		bn_sub_part_words(t,      a,      &(a[n]),tna,n-tna);
@@ -644,14 +654,17 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
 				for (;;)
 					{
 					i/=2;
-					if (i < tna && i < tnb)
+					/* 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]),
 							i,tna-i,tnb-i,p);
 						break;
 						}
-					else if (i <= tna && i <= tnb)
+					else if (i == tna || i == tnb)
 						{
 						bn_mul_recursive(&(r[n2]),
 							&(a[n]),&(b[n]),
@@ -695,7 +708,7 @@ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
 
 		/* The overflow will stop before we over write
 		 * words we should not overwrite */
-		if (ln < c1)
+		if (ln < (BN_ULONG)c1)
 			{
 			do	{
 				p++;
@@ -936,8 +949,8 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 	int i;
 #endif
 #ifdef BN_RECURSION
-	BIGNUM *t;
-	int j,k;
+	BIGNUM *t=NULL;
+	int j=0,k;
 #endif
 
 #ifdef BN_COUNT
@@ -996,7 +1009,6 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 		{
 		if (i >= -1 && i <= 1)
 			{
-			int sav_j =0;
 			/* Find out the power of two lower or equal
 			   to the longest of the two numbers */
 			if (i >= 0)
@@ -1007,22 +1019,23 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 				{
 				j = BN_num_bits_word((BN_ULONG)bl);
 				}
-			sav_j = j;
 			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)
 				{
-				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,
 					j,al-j,bl-j,t->d);
 				}
 			else	/* al <= j || bl <= j */
 				{
-				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,
 					j,al-j,bl-j,t->d);
 				}
@@ -1033,7 +1046,7 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 		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--;
@@ -1041,7 +1054,7 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 		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++;
@@ -1056,14 +1069,14 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 			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;
@@ -1079,10 +1092,11 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 #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:
+	bn_check_top(r);
 	BN_CTX_end(ctx);
 	return(ret);
 	}
@@ -1105,7 +1119,13 @@ void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb)
 
 		}
 	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 (;;)
 		{