SSL: server name callback changed to return SSL_TLSEXT_ERR_OK.

OpenSSL 1.1.1 does not save server name to the session if server name
callback returns anything but SSL_TLSEXT_ERR_OK, thus breaking
the $ssl_server_name variable in resumed sessions.

Since $ssl_server_name can be used even if we've selected the default
server and there are no other servers, it looks like the only viable
solution is to always return SSL_TLSEXT_ERR_OK regardless of the actual
result.

To fix things in the stream module as well, added a dummy server name
callback which always returns SSL_TLSEXT_ERR_OK.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
index 9266e99aa..b099a805a 100644
--- a/src/stream/ngx_stream_ssl_module.c
+++ b/src/stream/ngx_stream_ssl_module.c
@@ -22,6 +22,9 @@ static ngx_int_t ngx_stream_ssl_handler(ngx_stream_session_t *s);
 static ngx_int_t ngx_stream_ssl_init_connection(ngx_ssl_t *ssl,
     ngx_connection_t *c);
 static void ngx_stream_ssl_handshake_handler(ngx_connection_t *c);
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+int ngx_stream_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg);
+#endif
 #ifdef SSL_R_CERT_CB_ERROR
 static int ngx_stream_ssl_certificate(ngx_ssl_conn_t *ssl_conn, void *arg);
 #endif
@@ -414,6 +417,17 @@ ngx_stream_ssl_handshake_handler(ngx_connection_t *c)
 }
 
 
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+
+int
+ngx_stream_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg)
+{
+    return SSL_TLSEXT_ERR_OK;
+}
+
+#endif
+
+
 #ifdef SSL_R_CERT_CB_ERROR
 
 int
@@ -682,6 +696,11 @@ ngx_stream_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
     cln->handler = ngx_ssl_cleanup_ctx;
     cln->data = &conf->ssl;
 
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+    SSL_CTX_set_tlsext_servername_callback(conf->ssl.ctx,
+                                           ngx_stream_ssl_servername);
+#endif
+
     if (ngx_stream_ssl_compile_certificates(cf, conf) != NGX_OK) {
         return NGX_CONF_ERROR;
     }