TLS support for VNC Websockets

Added TLS support to the VNC QEMU Websockets implementation.
VNC-TLS needs to be enabled for this feature to be used.

The required certificates are specified as in case of VNC-TLS
with the VNC parameter "x509=<path>".

If the server certificate isn't signed by a rooth authority it needs to
be manually imported in the browser because at least in case of Firefox
and Chrome there is no user dialog, the connection just gets canceled.

As a side note VEncrypt over Websocket doesn't work atm because TLS can't
be stacked in the current implementation. (It also didn't work before)
Nevertheless to my knowledge there is no HTML 5 VNC client which supports
it and the Websocket connection can be encrypted with regular TLS now so
it should be fine for most use cases.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366727581-5772-1-git-send-email-thardeck@suse.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 39 insertions, 22 deletions

diff --git a/ui/vnc-tls.c b/ui/vnc-tls.c
index 8d4cc8e..50275de 100644
--- a/ui/vnc-tls.c
+++ b/ui/vnc-tls.c
@@ -334,29 +334,38 @@ static int vnc_set_gnutls_priority(gnutls_session_t s, int x509)
 
 int vnc_tls_client_setup(struct VncState *vs,
                          int needX509Creds) {
+    VncStateTLS *tls;
 
     VNC_DEBUG("Do TLS setup\n");
+#ifdef CONFIG_VNC_WS
+    if (vs->websocket) {
+        tls = &vs->ws_tls;
+    } else
+#endif /* CONFIG_VNC_WS */
+    {
+        tls = &vs->tls;
+    }
     if (vnc_tls_initialize() < 0) {
         VNC_DEBUG("Failed to init TLS\n");
         vnc_client_error(vs);
         return -1;
     }
-    if (vs->tls.session == NULL) {
-        if (gnutls_init(&vs->tls.session, GNUTLS_SERVER) < 0) {
+    if (tls->session == NULL) {
+        if (gnutls_init(&tls->session, GNUTLS_SERVER) < 0) {
             vnc_client_error(vs);
             return -1;
         }
 
-        if (gnutls_set_default_priority(vs->tls.session) < 0) {
-            gnutls_deinit(vs->tls.session);
-            vs->tls.session = NULL;
+        if (gnutls_set_default_priority(tls->session) < 0) {
+            gnutls_deinit(tls->session);
+            tls->session = NULL;
             vnc_client_error(vs);
             return -1;
         }
 
-        if (vnc_set_gnutls_priority(vs->tls.session, needX509Creds) < 0) {
-            gnutls_deinit(vs->tls.session);
-            vs->tls.session = NULL;
+        if (vnc_set_gnutls_priority(tls->session, needX509Creds) < 0) {
+            gnutls_deinit(tls->session);
+            tls->session = NULL;
             vnc_client_error(vs);
             return -1;
         }
@@ -364,43 +373,43 @@ int vnc_tls_client_setup(struct VncState *vs,
         if (needX509Creds) {
             gnutls_certificate_server_credentials x509_cred = vnc_tls_initialize_x509_cred(vs->vd);
             if (!x509_cred) {
-                gnutls_deinit(vs->tls.session);
-                vs->tls.session = NULL;
+                gnutls_deinit(tls->session);
+                tls->session = NULL;
                 vnc_client_error(vs);
                 return -1;
             }
-            if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) {
-                gnutls_deinit(vs->tls.session);
-                vs->tls.session = NULL;
+            if (gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) {
+                gnutls_deinit(tls->session);
+                tls->session = NULL;
                 gnutls_certificate_free_credentials(x509_cred);
                 vnc_client_error(vs);
                 return -1;
             }
             if (vs->vd->tls.x509verify) {
                 VNC_DEBUG("Requesting a client certificate\n");
-                gnutls_certificate_server_set_request (vs->tls.session, GNUTLS_CERT_REQUEST);
+                gnutls_certificate_server_set_request (tls->session, GNUTLS_CERT_REQUEST);
             }
 
         } else {
             gnutls_anon_server_credentials_t anon_cred = vnc_tls_initialize_anon_cred();
             if (!anon_cred) {
-                gnutls_deinit(vs->tls.session);
-                vs->tls.session = NULL;
+                gnutls_deinit(tls->session);
+                tls->session = NULL;
                 vnc_client_error(vs);
                 return -1;
             }
-            if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_ANON, anon_cred) < 0) {
-                gnutls_deinit(vs->tls.session);
-                vs->tls.session = NULL;
+            if (gnutls_credentials_set(tls->session, GNUTLS_CRD_ANON, anon_cred) < 0) {
+                gnutls_deinit(tls->session);
+                tls->session = NULL;
                 gnutls_anon_free_server_credentials(anon_cred);
                 vnc_client_error(vs);
                 return -1;
             }
         }
 
-        gnutls_transport_set_ptr(vs->tls.session, (gnutls_transport_ptr_t)vs);
-        gnutls_transport_set_push_function(vs->tls.session, vnc_tls_push);
-        gnutls_transport_set_pull_function(vs->tls.session, vnc_tls_pull);
+        gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr_t)vs);
+        gnutls_transport_set_push_function(tls->session, vnc_tls_push);
+        gnutls_transport_set_pull_function(tls->session, vnc_tls_pull);
     }
     return 0;
 }
@@ -414,6 +423,14 @@ void vnc_tls_client_cleanup(struct VncState *vs)
     }
     vs->tls.wiremode = VNC_WIREMODE_CLEAR;
     g_free(vs->tls.dname);
+#ifdef CONFIG_VNC_WS
+    if (vs->ws_tls.session) {
+        gnutls_deinit(vs->ws_tls.session);
+        vs->ws_tls.session = NULL;
+    }
+    vs->ws_tls.wiremode = VNC_WIREMODE_CLEAR;
+    g_free(vs->ws_tls.dname);
+#endif /* CONFIG_VNC_WS */
 }