[nginx] SSL: explicit handling of empty names.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/cac82b9b3499
branches:  
changeset: 5669:cac82b9b3499
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Wed Apr 23 20:31:31 2014 +0400
description:
SSL: explicit handling of empty names.

X509_check_host() can't handle non null-terminated names with zero length,
so make sure to fail before calling it.

diffstat:

 src/event/ngx_event_openssl.c |  4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diffs (14 lines):

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -2504,6 +2504,10 @@ ngx_ssl_check_host(ngx_connection_t *c, 
 
     /* X509_check_host() is only available in OpenSSL 1.0.2+ */
 
+    if (name->len == 0) {
+        goto failed;
+    }
+
     if (X509_check_host(cert, name->data, name->len, 0) != 1) {
         ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
                        "X509_check_host(): no match");