X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mul.c;h=b848c8cc60f4d69ab60468c3090385318930a40a;hp=fd598b8b3d61fd1212890bcc583a1a98f3f2ce8f;hb=6343829a391df59e46e513c84b6264ee71ad9518;hpb=9cdf87f19431b32a50b12e468cf2a9557cfc3568

diff --git a/crypto/bn/bn_mul.c b/crypto/bn/bn_mul.c
index fd598b8b3d..b848c8cc60 100644
--- a/crypto/bn/bn_mul.c
+++ b/crypto/bn/bn_mul.c
@@ -66,7 +66,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-#if defined(OPENSSL_NO_ASM) || !(defined(__i386) || defined(__i386__))/* Assembler implementation exists only for x86 */
+#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
@@ -389,6 +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)
 	{
@@ -398,7 +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
@@ -545,16 +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,zero;
 	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)
 		{
@@ -655,14 +657,17 @@ 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]),
@@ -706,7 +711,7 @@ 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++;
@@ -964,7 +969,7 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 
 	if ((al == 0) || (bl == 0))
 		{
-		if (!BN_zero(r)) goto err;
+		BN_zero(r);
 		return(1);
 		}
 	top=al+bl;
@@ -1090,10 +1095,11 @@ 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);
 	}