Make tls_config_parse_protocols() work correctly when passed a NULL pointer

for a protocol string.

Issue found by semarie@, who also provided the diff.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/lib/libtls/tls_config.c b/src/lib/libtls/tls_config.c
index 777dfc52f0..e2e3f4abaa 100644
--- a/src/lib/libtls/tls_config.c
+++ b/src/lib/libtls/tls_config.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_config.c,v 1.44 2017/09/25 18:07:03 jsing Exp $ */
+/* $OpenBSD: tls_config.c,v 1.45 2017/12/09 16:46:08 jsing Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -311,8 +311,10 @@ tls_config_parse_protocols(uint32_t *protocols, const char *protostr)
         char *s, *p, *q;
         int negate;
 
-        if (protostr == NULL)
-                return TLS_PROTOCOLS_DEFAULT;
+        if (protostr == NULL) {
+                *protocols = TLS_PROTOCOLS_DEFAULT;
+                return (0);
+        }
 
         if ((s = strdup(protostr)) == NULL)
                 return (-1);