Avoid possible NULL deref in openssl(1) s_server.

Fixes Coverity issue 78873.

ok miod@

1 files changed, 5 insertions, 2 deletions

diff --git a/src/usr.bin/openssl/s_server.c b/src/usr.bin/openssl/s_server.c
index 2422642989..317b1a849f 100644
--- a/src/usr.bin/openssl/s_server.c
+++ b/src/usr.bin/openssl/s_server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s_server.c,v 1.13 2015/07/17 16:09:46 doug Exp $ */
+/* $OpenBSD: s_server.c,v 1.14 2015/07/20 18:31:01 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1132,7 +1132,10 @@ bad:
 
                 if (ctx2) {
                         if (!dhfile) {
-                                DH *dh2 = load_dh_param(s_cert_file2);
+                                DH *dh2 = NULL;
+
+                                if (s_cert_file2 != NULL)
+                                        dh2 = load_dh_param(s_cert_file2);
                                 if (dh2 != NULL) {
                                         BIO_printf(bio_s_out, "Setting temp DH parameters\n");
                                         (void) BIO_flush(bio_s_out);