X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_shift.c;h=70f785ea185b8841e415d33b385bf96de95535be;hb=c237de058f91072b5d54ad9c570049c14df6957e;hp=61aae65a6bfce8f86f7e4b358ee54bf16f613baf;hpb=84c15db551ce1d167b901a3bde2b21880b084384;p=oweals%2Fopenssl.git

diff --git a/crypto/bn/bn_shift.c b/crypto/bn/bn_shift.c
index 61aae65a6b..70f785ea18 100644
--- a/crypto/bn/bn_shift.c
+++ b/crypto/bn/bn_shift.c
@@ -60,7 +60,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-int BN_lshift1(BIGNUM *r, BIGNUM *a)
+int BN_lshift1(BIGNUM *r, const BIGNUM *a)
 	{
 	register BN_ULONG *ap,*rp,t,c;
 	int i;
@@ -92,7 +92,7 @@ int BN_lshift1(BIGNUM *r, BIGNUM *a)
 	return(1);
 	}
 
-int BN_rshift1(BIGNUM *r, BIGNUM *a)
+int BN_rshift1(BIGNUM *r, const BIGNUM *a)
 	{
 	BN_ULONG *ap,*rp,t,c;
 	int i;
@@ -128,8 +128,8 @@ int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
 	BN_ULONG l;
 
 	r->neg=a->neg;
-	if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
 	nw=n/BN_BITS2;
+	if (bn_wexpand(r,a->top+nw+1) == NULL) return(0);
 	lb=n%BN_BITS2;
 	rb=BN_BITS2-lb;
 	f=a->d;
@@ -153,7 +153,7 @@ int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
 	return(1);
 	}
 
-int BN_rshift(BIGNUM *r, BIGNUM *a, int n)
+int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
 	{
 	int i,j,nw,lb,rb;
 	BN_ULONG *t,*f;
@@ -162,7 +162,7 @@ int BN_rshift(BIGNUM *r, BIGNUM *a, int n)
 	nw=n/BN_BITS2;
 	rb=n%BN_BITS2;
 	lb=BN_BITS2-rb;
-	if (nw > a->top)
+	if (nw > a->top || a->top == 0)
 		{
 		BN_zero(r);
 		return(1);
@@ -172,6 +172,11 @@ int BN_rshift(BIGNUM *r, BIGNUM *a, int n)
 		r->neg=a->neg;
 		if (bn_wexpand(r,a->top-nw+1) == NULL) return(0);
 		}
+	else
+		{
+		if (n == 0)
+			return 1; /* or the copying loop will go berserk */
+		}
 
 	f= &(a->d[nw]);
 	t=r->d;