Add zapfreestr() helper to k5-int.h

Since zapfree(str, strlen(str)) won't work for possibly-null values of
str, add a helper zapfreestr() which only calls strlen() if the string
value is non-null.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/include/k5-int.h b/src/include/k5-int.h
index d119d02be..670915d74 100644
--- a/src/include/k5-int.h
+++ b/src/include/k5-int.h
@@ -675,6 +675,16 @@ zapfree(void *ptr, size_t len)
     }
 }
 
+/* Convenience function: zap and free zero-terminated str if it is non-NULL. */
+static inline void
+zapfreestr(void *str)
+{
+    if (str != NULL) {
+        zap(str, strlen((char *)str));
+        free(str);
+    }
+}
+
 /*
  * Combine two keys (normally used by the hardware preauth mechanism)
  */