Fix segfault with empty fields as last in the config.

Reviewed-by: Tim Hudson <tjh@openssl.org>

ssl/ssl_conf.c

diff --git a/ssl/ssl_conf.c b/ssl/ssl_conf.c
index af88a47..354f218 100644
--- a/ssl/ssl_conf.c
+++ b/ssl/ssl_conf.c
@@ -167,6 +167,8 @@
      * len == -1 indicates not being called in list context, just for single
      * command line switches, so don't allow +, -.
      */
+    if (elem == NULL)
+        return 0;
     if (len != -1) {
         if (*elem == '+') {
             elem++;

ssl/t1_lib.c

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 8fb26a4..115aab5 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -596,6 +596,8 @@
     size_t i;
     int nid;
     char etmp[20];
+    if (elem == NULL)
+        return 0;
     if (narg->nidcnt == MAX_CURVELIST)
         return 0;
     if (len > (int)(sizeof(etmp) - 1))
@@ -4001,6 +4003,8 @@
     size_t i;
     char etmp[20], *p;
     int sig_alg, hash_alg;
+    if (elem == NULL)
+        return 0;
     if (sarg->sigalgcnt == MAX_SIGALGLEN)
         return 0;
     if (len > (int)(sizeof(etmp) - 1))