1 files changed, 5 insertions, 0 deletions

diff --git a/src/lib/libcrypto/bn/bn_shift.c b/src/lib/libcrypto/bn/bn_shift.c
index 0883247384..c2608f9f4a 100644
--- a/src/lib/libcrypto/bn/bn_shift.c
+++ b/src/lib/libcrypto/bn/bn_shift.c
@@ -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;