X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_div.c;h=ac1a09615a30d170924f6055b1bb07108967d83d;hb=6f9079fd505c28961049a732e33e662530bdad21;hp=c3772c243be575d8c321bc4f22fe3bc215008d59;hpb=2d978cbd30f60f9e9ddaf743d818ef66ec217f47;p=oweals%2Fopenssl.git

diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c
index c3772c243b..ac1a09615a 100644
--- a/crypto/bn/bn_div.c
+++ b/crypto/bn/bn_div.c
@@ -61,6 +61,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
+
 /* The old slow way */
 #if 0
 int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
@@ -126,9 +127,10 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 
 #else
 
-#if !defined(NO_ASM) && !defined(NO_INLINE_ASM) && !defined(PEDANTIC) && !defined(BN_DIV3W)
+#if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) \
+    && !defined(PEDANTIC) && !defined(BN_DIV3W)
 # if defined(__GNUC__) && __GNUC__>=2
-#  if defined(__i386)
+#  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)
@@ -150,8 +152,16 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 #  define REMAINDER_IS_ALREADY_CALCULATED
 #  endif /* __<cpu> */
 # endif /* __GNUC__ */
-#endif /* NO_ASM */
+#endif /* OPENSSL_NO_ASM */
+
 
+/* BN_div computes  dv := num / divisor,  rounding towards zero, and sets up
+ * rm  such that  dv*divisor + rm = num  holds.
+ * Thus:
+ *     dv->neg == num->neg ^ divisor->neg  (unless the result is zero)
+ *     rm->neg == num->neg                 (unless the remainder is zero)
+ * If 'dv' or 'rm' is NULL, the respective value is not returned.
+ */
 int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
 	   BN_CTX *ctx)
 	{
@@ -180,13 +190,13 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
 
 	BN_CTX_start(ctx);
 	tmp=BN_CTX_get(ctx);
-	tmp->neg=0;
 	snum=BN_CTX_get(ctx);
 	sdiv=BN_CTX_get(ctx);
 	if (dv == NULL)
 		res=BN_CTX_get(ctx);
 	else	res=dv;
-	if (res == NULL) goto err;
+	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);
@@ -232,12 +242,15 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
 		}
 	else
 		res->top--;
+	if (res->top == 0)
+		res->neg = 0;
 	resp--;
 
 	for (i=0; i<loop-1; i++)
 		{
 		BN_ULONG q,l0;
-#ifdef BN_DIV3W
+#if defined(BN_DIV3W) && !defined(OPENSSL_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;
@@ -330,8 +343,13 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
 		}
 	if (rm != NULL)
 		{
+		/* Keep a copy of the neg flag in num because if rm==num
+		 * BN_rshift() will overwrite it.
+		 */
+		int neg = num->neg;
 		BN_rshift(rm,snum,norm_shift);
-		rm->neg=num->neg;
+		if (!BN_is_zero(rm))
+			rm->neg = neg;
 		}
 	BN_CTX_end(ctx);
 	return(1);
@@ -341,40 +359,3 @@ err:
 	}
 
 #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
-	}
-