polarssl: check us->notify_verify_error for NULL before calling it

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/ustream-polarssl.c b/ustream-polarssl.c
index ef8360a..e5c8455 100644 (file)
--- a/ustream-polarssl.c
+++ b/ustream-polarssl.c
@@ -200,7 +200,8 @@ static void ustream_ssl_verify_cert(struct ustream_ssl *us)
                msg = "unknown error";
 
        if (r) {
-               us->notify_verify_error(us, r, msg);
+               if (us->notify_verify_error)
+                       us->notify_verify_error(us, r, msg);
                return;
        }