Avoid undefined results when the parameter is out of range.

diff --git a/crypto/stack/stack.c b/crypto/stack/stack.c
index 02857f044664bf4ee34c21a6514855f9ee1ec718..7877b15a4f0b23fef32b870486804f3eaef240fa 100644 (file)
--- a/crypto/stack/stack.c
+++ b/crypto/stack/stack.c
@@ -304,7 +304,7 @@ int sk_num(const STACK *st)
 
 char *sk_value(const STACK *st, int i)
 {
-       if(st == NULL) return NULL;
+       if(!st || (i < 0) || (i >= st->num)) return NULL;
        return st->data[i];
 }