From e2a39fbf7b1a90aee818790ad847c20f59351adc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Thu, 14 Jun 2018 12:21:37 +0200
Subject: [PATCH 1/7] vnc: Add anonymous TLS encryption support
Add support for encrypting the VNC connection using anonymous TLS. In
effect this means that the channel is encrypted using TLS but that no
authentication of the peers are done. This means the connection is still
vulnerable to man-in-the-middle attacks where an attacker proxies the
VNC connection.
---
meson.build | 1 +
src/grd-enums.h | 6 +
src/grd-session-vnc.c | 120 ++++-
src/grd-session-vnc.h | 17 +
src/grd-settings-user.c | 28 ++
src/grd-settings.c | 6 +
src/grd-settings.h | 4 +
src/grd-vnc-server.c | 47 ++
src/grd-vnc-tls.c | 444 ++++++++++++++++++
src/grd-vnc-tls.h | 28 ++
src/meson.build | 3 +
...nome.desktop.remote-desktop.gschema.xml.in | 10 +
12 files changed, 688 insertions(+), 26 deletions(-)
create mode 100644 src/grd-vnc-tls.c
create mode 100644 src/grd-vnc-tls.h
diff --git a/meson.build b/meson.build
index af607a47..a827c356 100644
--- a/meson.build
+++ b/meson.build
@@ -63,6 +63,7 @@ endif
if have_vnc
libvncclient_dep = dependency('libvncclient')
libvncserver_dep = dependency('libvncserver')
+ gnutls_dep = dependency('gnutls')
endif
prefix = get_option('prefix')
diff --git a/src/grd-enums.h b/src/grd-enums.h
index 44b181d6..de0d0f86 100644
--- a/src/grd-enums.h
+++ b/src/grd-enums.h
@@ -39,4 +39,10 @@ typedef enum
GRD_VNC_SCREEN_SHARE_MODE_EXTEND,
} GrdVncScreenShareMode;
+typedef enum
+{
+ GRD_VNC_ENCRYPTION_NONE = 1 << 0,
+ GRD_VNC_ENCRYPTION_TLS_ANON = 1 << 1,
+} GrdVncEncryption;
+
#endif /* GRD_ENUMS_H */
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index de1c26d7..a82952ae 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -45,7 +45,9 @@ struct _GrdSessionVnc
{
GrdSession parent;
+ GrdVncServer *vnc_server;
GSocketConnection *connection;
+ GList *socket_grabs;
GSource *source;
rfbScreenInfoPtr rfb_screen;
rfbClientPtr rfb_client;
@@ -588,6 +590,12 @@ check_rfb_password (rfbClientPtr rfb_client,
}
}
+int
+grd_session_vnc_get_fd (GrdSessionVnc *session_vnc)
+{
+ return session_vnc->rfb_screen->inetdSock;
+}
+
int
grd_session_vnc_get_stride_for_width (GrdSessionVnc *session_vnc,
int width)
@@ -595,6 +603,18 @@ grd_session_vnc_get_stride_for_width (GrdSessionVnc *session_vnc,
return width * BGRX_BYTES_PER_PIXEL;
}
+rfbClientPtr
+grd_session_vnc_get_rfb_client (GrdSessionVnc *session_vnc)
+{
+ return session_vnc->rfb_client;
+}
+
+GrdVncServer *
+grd_session_vnc_get_vnc_server (GrdSessionVnc *session_vnc)
+{
+ return session_vnc->vnc_server;
+}
+
static void
init_vnc_session (GrdSessionVnc *session_vnc)
{
@@ -669,44 +689,85 @@ init_vnc_session (GrdSessionVnc *session_vnc)
rfbProcessEvents (rfb_screen, 0);
}
+void
+grd_session_vnc_grab_socket (GrdSessionVnc *session_vnc,
+ GrdVncSocketGrabFunc grab_func)
+{
+ session_vnc->socket_grabs = g_list_prepend (session_vnc->socket_grabs,
+ grab_func);
+}
+
+void
+grd_session_vnc_ungrab_socket (GrdSessionVnc *session_vnc,
+ GrdVncSocketGrabFunc grab_func)
+{
+ session_vnc->socket_grabs = g_list_remove (session_vnc->socket_grabs,
+ grab_func);
+}
+
+static gboolean
+vnc_socket_grab_func (GrdSessionVnc *session_vnc,
+ GError **error)
+{
+ if (rfbIsActive (session_vnc->rfb_screen))
+ {
+ rfbProcessEvents (session_vnc->rfb_screen, 0);
+
+ if (session_vnc->pending_framebuffer_resize &&
+ session_vnc->rfb_client->preferredEncoding != -1)
+ {
+ resize_vnc_framebuffer (session_vnc,
+ session_vnc->pending_framebuffer_width,
+ session_vnc->pending_framebuffer_height);
+ session_vnc->pending_framebuffer_resize = FALSE;
+
+ /**
+ * This is a workaround. libvncserver is unable to handle clipboard
+ * changes early and either disconnects the client or crashes g-r-d
+ * if it receives rfbSendServerCutText too early altough the
+ * authentification process is already done.
+ * Doing this after resizing the framebuffer, seems to work fine,
+ * so enable the clipboard here and not when the remote desktop
+ * session proxy is acquired.
+ */
+ grd_clipboard_vnc_maybe_enable_clipboard (session_vnc->clipboard_vnc);
+ }
+ }
+
+ return TRUE;
+}
+
static gboolean
handle_socket_data (GSocket *socket,
GIOCondition condition,
gpointer user_data)
{
- GrdSessionVnc *session_vnc = user_data;
+ GrdSessionVnc *session_vnc = GRD_SESSION_VNC (user_data);
+ GrdSession *session = GRD_SESSION (session_vnc);
- if (condition & G_IO_IN)
+ if (condition & (G_IO_ERR | G_IO_HUP))
+ {
+ g_warning ("Client disconnected");
+
+ grd_session_stop (session);
+ }
+ else if (condition & G_IO_IN)
{
- if (rfbIsActive (session_vnc->rfb_screen))
+ GrdVncSocketGrabFunc grab_func;
+ g_autoptr (GError) error = NULL;
+
+ grab_func = g_list_first (session_vnc->socket_grabs)->data;
+ if (!grab_func (session_vnc, &error))
{
- rfbProcessEvents (session_vnc->rfb_screen, 0);
+ g_warning ("Error when reading socket: %s", error->message);
- if (session_vnc->pending_framebuffer_resize &&
- session_vnc->rfb_client->preferredEncoding != -1)
- {
- resize_vnc_framebuffer (session_vnc,
- session_vnc->pending_framebuffer_width,
- session_vnc->pending_framebuffer_height);
- session_vnc->pending_framebuffer_resize = FALSE;
-
- /**
- * This is a workaround. libvncserver is unable to handle clipboard
- * changes early and either disconnects the client or crashes g-r-d
- * if it receives rfbSendServerCutText too early altough the
- * authentification process is already done.
- * Doing this after resizing the framebuffer, seems to work fine,
- * so enable the clipboard here and not when the remote desktop
- * session proxy is acquired.
- */
- grd_clipboard_vnc_maybe_enable_clipboard (session_vnc->clipboard_vnc);
- }
+ grd_session_stop (session);
}
}
else
{
- g_debug ("Unhandled socket condition %d\n", condition);
- return G_SOURCE_REMOVE;
+ g_warning ("Unhandled socket condition %d\n", condition);
+ g_assert_not_reached ();
}
return G_SOURCE_CONTINUE;
@@ -719,7 +780,10 @@ grd_session_vnc_attach_source (GrdSessionVnc *session_vnc)
socket = g_socket_connection_get_socket (session_vnc->connection);
session_vnc->source = g_socket_create_source (socket,
- G_IO_IN | G_IO_PRI,
+ (G_IO_IN |
+ G_IO_PRI |
+ G_IO_ERR |
+ G_IO_HUP),
NULL);
g_source_set_callback (session_vnc->source,
(GSourceFunc) handle_socket_data,
@@ -750,11 +814,13 @@ grd_session_vnc_new (GrdVncServer *vnc_server,
"context", context,
NULL);
+ session_vnc->vnc_server = vnc_server;
session_vnc->connection = g_object_ref (connection);
settings = grd_context_get_settings (context);
session_vnc->screen_share_mode = grd_settings_get_vnc_screen_share_mode (settings);
+ grd_session_vnc_grab_socket (session_vnc, vnc_socket_grab_func);
grd_session_vnc_attach_source (session_vnc);
init_vnc_session (session_vnc);
@@ -769,6 +835,8 @@ grd_session_vnc_dispose (GObject *object)
g_assert (!session_vnc->rfb_screen);
+ g_clear_pointer (&session_vnc->socket_grabs, g_list_free);
+
g_clear_pointer (&session_vnc->pressed_keys, g_hash_table_unref);
G_OBJECT_CLASS (grd_session_vnc_parent_class)->dispose (object);
diff --git a/src/grd-session-vnc.h b/src/grd-session-vnc.h
index be79cf4a..ffc8d27a 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -37,6 +37,9 @@ G_DECLARE_FINAL_TYPE (GrdSessionVnc,
GRD, SESSION_VNC,
GrdSession)
+typedef gboolean (* GrdVncSocketGrabFunc) (GrdSessionVnc *session_vnc,
+ GError **error);
+
GrdSessionVnc *grd_session_vnc_new (GrdVncServer *vnc_server,
GSocketConnection *connection);
@@ -63,6 +66,20 @@ void grd_session_vnc_set_client_clipboard_text (GrdSessionVnc *session_vnc,
int grd_session_vnc_get_stride_for_width (GrdSessionVnc *session_vnc,
int width);
+int grd_session_vnc_get_fd (GrdSessionVnc *session_vnc);
+
+int grd_session_vnc_get_framebuffer_stride (GrdSessionVnc *session_vnc);
+
gboolean grd_session_vnc_is_client_gone (GrdSessionVnc *session_vnc);
+rfbClientPtr grd_session_vnc_get_rfb_client (GrdSessionVnc *session_vnc);
+
+void grd_session_vnc_grab_socket (GrdSessionVnc *session_vnc,
+ GrdVncSocketGrabFunc grab_func);
+
+void grd_session_vnc_ungrab_socket (GrdSessionVnc *session_vnc,
+ GrdVncSocketGrabFunc grab_func);
+
+GrdVncServer * grd_session_vnc_get_vnc_server (GrdSessionVnc *session_vnc);
+
#endif /* GRD_SESSION_VNC_H */
diff --git a/src/grd-settings-user.c b/src/grd-settings-user.c
index 42bf31dd..5f6a87dd 100644
--- a/src/grd-settings-user.c
+++ b/src/grd-settings-user.c
@@ -66,6 +66,7 @@ struct _GrdSettingsUser
gboolean view_only;
GrdVncScreenShareMode screen_share_mode;
GrdVncAuthMethod auth_method;
+ GrdVncEncryption encryption;
} vnc;
};
@@ -138,6 +139,13 @@ update_vnc_auth_method (GrdSettingsUser *settings)
"auth-method");
}
+static void
+update_vnc_encryption (GrdSettingsUser *settings)
+{
+ settings->vnc.encryption = g_settings_get_flags (settings->vnc.settings,
+ "encryption");
+}
+
static gboolean
grd_settings_user_is_rdp_enabled (GrdSettings *settings)
{
@@ -192,6 +200,12 @@ grd_settings_user_get_vnc_auth_method (GrdSettings *settings)
return GRD_SETTINGS_USER (settings)->vnc.auth_method;
}
+static GrdVncEncryption
+grd_settings_user_get_encryption (GrdSettings *settings)
+{
+ return GRD_SETTINGS_USER (settings)->vnc.encryption;
+}
+
GrdSettingsUser *
grd_settings_user_new (GrdContext *context)
{
@@ -273,6 +287,11 @@ on_vnc_settings_changed (GSettings *vnc_settings,
update_vnc_auth_method (settings);
g_signal_emit (settings, signals[VNC_AUTH_METHOD_CHANGED], 0);
}
+ else if (strcmp (key, "encryption") == 0)
+ {
+ update_vnc_encryption (settings);
+ g_signal_emit (settings, signals[VNC_ENCRYPTION_CHANGED], 0);
+ }
}
static void
@@ -294,6 +313,7 @@ grd_settings_user_init (GrdSettingsUser *settings)
update_vnc_view_only (settings);
update_vnc_screen_share_mode (settings);
update_vnc_auth_method (settings);
+ update_vnc_encryption (settings);
}
static void
@@ -313,6 +333,7 @@ grd_settings_user_class_init (GrdSettingsUserClass *klass)
settings_class->get_rdp_server_key = grd_settings_user_get_rdp_server_key;
settings_class->get_rdp_server_cert = grd_settings_user_get_rdp_server_cert;
settings_class->get_vnc_auth_method = grd_settings_user_get_vnc_auth_method;
+ settings_class->get_vnc_encryption = grd_settings_user_get_encryption;
signals[RDP_ENABLED_CHANGED] =
g_signal_new ("rdp-enabled-changed",
@@ -377,4 +398,11 @@ grd_settings_user_class_init (GrdSettingsUserClass *klass)
0,
NULL, NULL, NULL,
G_TYPE_NONE, 0);
+ signals[VNC_ENCRYPTION_CHANGED] =
+ g_signal_new ("vnc-encryption-changed",
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ 0,
+ NULL, NULL, NULL,
+ G_TYPE_NONE, 0);
}
diff --git a/src/grd-settings.c b/src/grd-settings.c
index 1cd4bea5..cd1dda1f 100644
--- a/src/grd-settings.c
+++ b/src/grd-settings.c
@@ -230,6 +230,12 @@ grd_settings_get_vnc_auth_method (GrdSettings *settings)
return GRD_SETTINGS_GET_CLASS (settings)->get_vnc_auth_method (settings);
}
+GrdVncEncryption
+grd_settings_get_vnc_encryption (GrdSettings *settings)
+{
+ return GRD_SETTINGS_GET_CLASS (settings)->get_vnc_encryption (settings);
+}
+
static void
grd_settings_finalize (GObject *object)
{
diff --git a/src/grd-settings.h b/src/grd-settings.h
index 9e36ff9d..51f0f1c3 100644
--- a/src/grd-settings.h
+++ b/src/grd-settings.h
@@ -56,6 +56,8 @@ struct _GrdSettingsClass
char * (* get_rdp_server_key) (GrdSettings *settings);
GrdVncAuthMethod (* get_vnc_auth_method) (GrdSettings *settings);
+
+ GrdVncEncryption (* get_vnc_encryption) (GrdSettings *settings);
};
int grd_settings_get_rdp_port (GrdSettings *settings);
@@ -94,4 +96,6 @@ char *grd_settings_get_rdp_server_key (GrdSettings *settings);
GrdVncAuthMethod grd_settings_get_vnc_auth_method (GrdSettings *settings);
+GrdVncEncryption grd_settings_get_vnc_encryption (GrdSettings *settings);
+
#endif /* GRD_SETTINGS_H */
diff --git a/src/grd-vnc-server.c b/src/grd-vnc-server.c
index 70efab12..9280dfb5 100644
--- a/src/grd-vnc-server.c
+++ b/src/grd-vnc-server.c
@@ -24,12 +24,14 @@
#include "grd-vnc-server.h"
+#include <rfb/rfb.h>
#include <gio/gio.h>
#include <rfb/rfb.h>
#include "grd-context.h"
#include "grd-debug.h"
#include "grd-session-vnc.h"
+#include "grd-vnc-tls.h"
enum
{
@@ -129,6 +131,43 @@ on_incoming (GSocketService *service,
return TRUE;
}
+static void
+sync_encryption_settings (GrdVncServer *vnc_server)
+{
+ GrdSettings *settings = grd_context_get_settings (vnc_server->context);
+ rfbSecurityHandler *tls_security_handler;
+ GrdVncEncryption encryption;
+
+ tls_security_handler = grd_vnc_tls_get_security_handler ();
+ encryption = grd_settings_get_vnc_encryption (settings);
+
+ if (encryption == (GRD_VNC_ENCRYPTION_NONE | GRD_VNC_ENCRYPTION_TLS_ANON))
+ {
+ rfbRegisterSecurityHandler (tls_security_handler);
+ rfbUnregisterChannelSecurityHandler (tls_security_handler);
+ }
+ else if (encryption == GRD_VNC_ENCRYPTION_NONE)
+ {
+ rfbUnregisterSecurityHandler (tls_security_handler);
+ rfbUnregisterChannelSecurityHandler (tls_security_handler);
+ }
+ else
+ {
+ if (encryption != GRD_VNC_ENCRYPTION_TLS_ANON)
+ g_warning ("Invalid VNC encryption setting, falling back to TLS-ANON");
+
+ rfbRegisterChannelSecurityHandler (tls_security_handler);
+ rfbUnregisterSecurityHandler (tls_security_handler);
+ }
+}
+
+static void
+on_vnc_encryption_changed (GrdSettings *settings,
+ GrdVncServer *vnc_server)
+{
+ sync_encryption_settings (vnc_server);
+}
+
gboolean
grd_vnc_server_start (GrdVncServer *vnc_server,
GError **error)
@@ -216,11 +255,19 @@ grd_vnc_server_dispose (GObject *object)
static void
grd_vnc_server_constructed (GObject *object)
{
+ GrdVncServer *vnc_server = GRD_VNC_SERVER (object);
+ GrdSettings *settings = grd_context_get_settings (vnc_server->context);
+
if (grd_get_debug_flags () & GRD_DEBUG_VNC)
rfbLogEnable (1);
else
rfbLogEnable (0);
+ g_signal_connect (settings, "vnc-encryption-changed",
+ G_CALLBACK (on_vnc_encryption_changed),
+ vnc_server);
+ sync_encryption_settings (vnc_server);
+
G_OBJECT_CLASS (grd_vnc_server_parent_class)->constructed (object);
}
diff --git a/src/grd-vnc-tls.c b/src/grd-vnc-tls.c
new file mode 100644
index 00000000..ec4758e0
--- /dev/null
+++ b/src/grd-vnc-tls.c
@@ -0,0 +1,444 @@
+/*
+ * Copyright (C) 2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "grd-vnc-tls.h"
+
+#include <errno.h>
+#include <glib.h>
+#include <gnutls/gnutls.h>
+#include <rfb/rfb.h>
+
+#include "grd-session-vnc.h"
+#include "grd-vnc-server.h"
+
+typedef struct _GrdVncTlsContext
+{
+ gnutls_anon_server_credentials_t anon_credentials;
+ gnutls_dh_params_t dh_params;
+} GrdVncTlsContext;
+
+typedef enum _GrdTlsHandshakeState
+{
+ GRD_TLS_HANDSHAKE_STATE_INIT,
+ GRD_TLS_HANDSHAKE_STATE_DURING,
+ GRD_TLS_HANDSHAKE_STATE_FINISHED
+} GrdTlsHandshakeState;
+
+typedef struct _GrdVncTlsSession
+{
+ GrdVncTlsContext *tls_context;
+
+ int fd;
+
+ gnutls_session_t tls_session;
+ GrdTlsHandshakeState handshake_state;
+
+ char *peek_buffer;
+ int peek_buffer_size;
+ int peek_buffer_len;
+} GrdVncTlsSession;
+
+static gboolean
+tls_handshake_grab_func (GrdSessionVnc *session_vnc,
+ GError **error);
+
+static GrdVncTlsContext *
+grd_vnc_tls_context_new (void)
+{
+ GrdVncTlsContext *tls_context;
+ const unsigned int dh_bits = 1024;
+
+ tls_context = g_new0 (GrdVncTlsContext, 1);
+
+ gnutls_global_init ();
+
+ gnutls_anon_allocate_server_credentials (&tls_context->anon_credentials);
+
+ gnutls_dh_params_init (&tls_context->dh_params);
+ gnutls_dh_params_generate2 (tls_context->dh_params, dh_bits);
+
+ gnutls_anon_set_server_dh_params (tls_context->anon_credentials,
+ tls_context->dh_params);
+
+ return tls_context;
+}
+
+static void
+grd_vnc_tls_context_free (GrdVncTlsContext *tls_context)
+{
+ gnutls_dh_params_deinit (tls_context->dh_params);
+ gnutls_anon_free_server_credentials (tls_context->anon_credentials);
+ gnutls_global_deinit ();
+}
+
+GrdVncTlsContext *
+ensure_tls_context (GrdVncServer *vnc_server)
+{
+ GrdVncTlsContext *tls_context;
+
+ tls_context = g_object_get_data (G_OBJECT (vnc_server), "vnc-tls-context");
+ if (!tls_context)
+ {
+ tls_context = grd_vnc_tls_context_new ();
+ g_object_set_data_full (G_OBJECT (vnc_server), "vnc-tls-context",
+ tls_context,
+ (GDestroyNotify) grd_vnc_tls_context_free);
+ }
+
+ return tls_context;
+}
+
+static gboolean
+perform_anon_tls_handshake (GrdVncTlsSession *tls_session,
+ GError **error)
+{
+ GrdVncTlsContext *tls_context = tls_session->tls_context;
+ const char kx_priority[] = "NORMAL:+ANON-DH";
+ int ret;
+
+ gnutls_init (&tls_session->tls_session, GNUTLS_SERVER | GNUTLS_NO_SIGNAL);
+
+ gnutls_set_default_priority (tls_session->tls_session);
+ gnutls_priority_set_direct (tls_session->tls_session, kx_priority, NULL);
+
+ gnutls_credentials_set (tls_session->tls_session,
+ GNUTLS_CRD_ANON,
+ tls_context->anon_credentials);
+ gnutls_transport_set_ptr (tls_session->tls_session,
+ GINT_TO_POINTER (tls_session->fd));
+
+ ret = gnutls_handshake (tls_session->tls_session);
+ if (ret != GNUTLS_E_SUCCESS && !gnutls_error_is_fatal (ret))
+ {
+ tls_session->handshake_state = GRD_TLS_HANDSHAKE_STATE_DURING;
+ return TRUE;
+ }
+
+ if (ret != GNUTLS_E_SUCCESS)
+ {
+ g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+ "%s", gnutls_strerror (ret));
+ gnutls_deinit (tls_session->tls_session);
+ tls_session->tls_session = NULL;
+ return FALSE;
+ }
+
+ tls_session->handshake_state = GRD_TLS_HANDSHAKE_STATE_FINISHED;
+ return TRUE;
+}
+
+static gboolean
+continue_tls_handshake (GrdVncTlsSession *tls_session,
+ GError **error)
+{
+ int ret;
+
+ ret = gnutls_handshake (tls_session->tls_session);
+ if (ret != GNUTLS_E_SUCCESS && !gnutls_error_is_fatal (ret))
+ return TRUE;
+
+ if (ret != GNUTLS_E_SUCCESS)
+ {
+ g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+ "%s", gnutls_strerror (ret));
+ gnutls_deinit (tls_session->tls_session);
+ tls_session->tls_session = NULL;
+ return FALSE;
+ }
+
+ tls_session->handshake_state = GRD_TLS_HANDSHAKE_STATE_FINISHED;
+ return TRUE;
+}
+
+static void
+grd_vnc_tls_session_free (GrdVncTlsSession *tls_session)
+{
+ g_clear_pointer (&tls_session->peek_buffer, g_free);
+ g_clear_pointer (&tls_session->tls_session, gnutls_deinit);
+ g_free (tls_session);
+}
+
+static GrdVncTlsSession *
+grd_vnc_tls_session_from_vnc_session (GrdSessionVnc *session_vnc)
+{
+ return g_object_get_data (G_OBJECT (session_vnc), "vnc-tls-session");
+}
+
+static int
+do_read (GrdVncTlsSession *tls_session,
+ char *buf,
+ int len)
+{
+ do
+ {
+ int ret;
+
+ ret = gnutls_record_recv (tls_session->tls_session, buf, len);
+ if (ret == GNUTLS_E_AGAIN ||
+ ret == GNUTLS_E_INTERRUPTED)
+ {
+ continue;
+ }
+ else if (ret < 0)
+ {
+ g_debug ("gnutls_record_recv failed: %s", gnutls_strerror (ret));
+ errno = EIO;
+ return -1;
+ }
+ else
+ {
+ return ret;
+ }
+ }
+ while (TRUE);
+}
+
+static int
+grd_vnc_tls_read_from_socket (rfbClientPtr rfb_client,
+ char *buf,
+ int len)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+ int to_read = len;
+ int len_read = 0;
+
+ if (to_read < tls_session->peek_buffer_len)
+ {
+ memcpy (buf, tls_session->peek_buffer, to_read);
+ memmove (buf,
+ tls_session->peek_buffer + to_read,
+ tls_session->peek_buffer_len - to_read);
+ len_read = to_read;
+ to_read = 0;
+ }
+ else
+ {
+ memcpy (buf,
+ tls_session->peek_buffer,
+ tls_session->peek_buffer_len);
+ to_read -= tls_session->peek_buffer_len;
+ len_read = tls_session->peek_buffer_len;
+
+ g_clear_pointer (&tls_session->peek_buffer,
+ g_free);
+ tls_session->peek_buffer_len = 0;
+ tls_session->peek_buffer_size = 0;
+ }
+
+ if (to_read > 0)
+ {
+ int ret;
+
+ ret = do_read (tls_session, buf + len_read, to_read);
+ if (ret == -1)
+ return -1;
+
+ len_read += ret;
+ }
+
+ return len_read;
+}
+
+static int
+grd_vnc_tls_peek_at_socket (rfbClientPtr rfb_client,
+ char *buf,
+ int len)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+ int peekable_len;
+
+ if (tls_session->peek_buffer_len < len)
+ {
+ int ret;
+
+ if (len > tls_session->peek_buffer_size)
+ {
+ tls_session->peek_buffer = g_renew (char,
+ tls_session->peek_buffer,
+ len);
+ tls_session->peek_buffer_size = len;
+ }
+
+ ret = do_read (tls_session,
+ tls_session->peek_buffer + tls_session->peek_buffer_len,
+ len - tls_session->peek_buffer_len);
+ if (ret == -1)
+ return -1;
+
+ tls_session->peek_buffer_len += ret;
+ }
+
+ peekable_len = MIN (len, tls_session->peek_buffer_len);
+ memcpy (buf, tls_session->peek_buffer, peekable_len);
+
+ return peekable_len;
+}
+
+static rfbBool
+grd_vnc_tls_has_pending_on_socket (rfbClientPtr rfb_client)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ if (tls_session->peek_buffer_len > 0)
+ return TRUE;
+
+ if (gnutls_record_check_pending (tls_session->tls_session) > 0)
+ return TRUE;
+
+ return FALSE;
+}
+
+static int
+grd_vnc_tls_write_to_socket (rfbClientPtr rfb_client,
+ const char *buf,
+ int len)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ do
+ {
+ int ret;
+
+ ret = gnutls_record_send (tls_session->tls_session, buf, len);
+ if (ret == GNUTLS_E_AGAIN ||
+ ret == GNUTLS_E_INTERRUPTED)
+ {
+ continue;
+ }
+ else if (ret < 0)
+ {
+ g_debug ("gnutls_record_send failed: %s", gnutls_strerror (ret));
+ errno = EIO;
+ return -1;
+ }
+ else
+ {
+ return ret;
+ }
+ }
+ while (TRUE);
+}
+
+static gboolean
+perform_handshake (GrdSessionVnc *session_vnc,
+ GError **error)
+{
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ switch (tls_session->handshake_state)
+ {
+ case GRD_TLS_HANDSHAKE_STATE_INIT:
+ if (!perform_anon_tls_handshake (tls_session, error))
+ return FALSE;
+ break;
+ case GRD_TLS_HANDSHAKE_STATE_DURING:
+ if (!continue_tls_handshake (tls_session, error))
+ return FALSE;
+ break;
+ case GRD_TLS_HANDSHAKE_STATE_FINISHED:
+ break;
+ }
+
+ switch (tls_session->handshake_state)
+ {
+ case GRD_TLS_HANDSHAKE_STATE_INIT:
+ break;
+ case GRD_TLS_HANDSHAKE_STATE_DURING:
+ break;
+ case GRD_TLS_HANDSHAKE_STATE_FINISHED:
+ grd_session_vnc_ungrab_socket (session_vnc, tls_handshake_grab_func);
+ rfbSendSecurityTypeList (grd_session_vnc_get_rfb_client (session_vnc),
+ RFB_SECURITY_TAG_CHANNEL);
+ break;
+ }
+
+ return TRUE;
+}
+
+static gboolean
+tls_handshake_grab_func (GrdSessionVnc *session_vnc,
+ GError **error)
+{
+ g_autoptr (GError) handshake_error = NULL;
+
+ if (!perform_handshake (session_vnc, &handshake_error))
+ {
+ g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+ "TLS handshake failed: %s", handshake_error->message);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static void
+rfb_tls_security_handler (rfbClientPtr rfb_client)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session;
+ g_autoptr(GError) error = NULL;
+
+ tls_session = grd_vnc_tls_session_from_vnc_session (session_vnc);
+ if (!tls_session)
+ {
+ GrdVncServer *vnc_server = grd_session_vnc_get_vnc_server (session_vnc);
+
+ tls_session = g_new0 (GrdVncTlsSession, 1);
+ tls_session->fd = grd_session_vnc_get_fd (session_vnc);
+ tls_session->tls_context = ensure_tls_context (vnc_server);
+ g_object_set_data_full (G_OBJECT (session_vnc), "vnc-tls-session",
+ tls_session,
+ (GDestroyNotify) grd_vnc_tls_session_free);
+
+ rfb_client->readFromSocket = grd_vnc_tls_read_from_socket;
+ rfb_client->peekAtSocket = grd_vnc_tls_peek_at_socket;
+ rfb_client->hasPendingOnSocket = grd_vnc_tls_has_pending_on_socket;
+ rfb_client->writeToSocket = grd_vnc_tls_write_to_socket;
+
+ grd_session_vnc_grab_socket (session_vnc, tls_handshake_grab_func);
+ }
+
+ if (!perform_handshake (session_vnc, &error))
+ {
+ g_warning ("TLS handshake failed: %s", error->message);
+ rfbCloseClient (rfb_client);
+ }
+}
+
+static rfbSecurityHandler anon_tls_security_handler = {
+ .type = rfbTLS,
+ .handler = rfb_tls_security_handler,
+ .securityTags = RFB_SECURITY_TAG_CHANNEL,
+};
+
+rfbSecurityHandler *
+grd_vnc_tls_get_security_handler (void)
+{
+ return &anon_tls_security_handler;
+}
diff --git a/src/grd-vnc-tls.h b/src/grd-vnc-tls.h
new file mode 100644
index 00000000..135ef8c7
--- /dev/null
+++ b/src/grd-vnc-tls.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#ifndef GRD_VNC_TLS_H
+#define GRD_VNC_TLS_H
+
+#include <rfb/rfb.h>
+
+rfbSecurityHandler * grd_vnc_tls_get_security_handler (void);
+
+#endif /* GRD_VNC_TLS_H */
diff --git a/src/meson.build b/src/meson.build
index ac07455b..654caccb 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -161,10 +161,13 @@ if have_vnc
'grd-vnc-pipewire-stream.h',
'grd-vnc-server.c',
'grd-vnc-server.h',
+ 'grd-vnc-tls.c',
+ 'grd-vnc-tls.h',
])
deps += [
libvncserver_dep,
+ gnutls_dep,
]
endif
diff --git a/src/org.gnome.desktop.remote-desktop.gschema.xml.in b/src/org.gnome.desktop.remote-desktop.gschema.xml.in
index 5b39a5de..c6dc2ab5 100644
--- a/src/org.gnome.desktop.remote-desktop.gschema.xml.in
+++ b/src/org.gnome.desktop.remote-desktop.gschema.xml.in
@@ -116,5 +116,15 @@
configuration updates.
</description>
</key>
+ <key name='encryption' flags='org.gnome.desktop.remote-desktop.GrdVncEncryption'>
+ <default>['tls-anon']</default>
+ <summary>Allowed encryption method to use</summary>
+ <description>
+ Allowed encryption methods. Includes the following:
+
+ * none - no encryption
+ * tls-anon - anonymous (unauthenticated) TLS
+ </description>
+ </key>
</schema>
</schemalist>
--
2.40.0
From e0192db09adddb551e4dbfeb17c281fb5815d7be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 11:02:09 +0100
Subject: [PATCH 2/7] session-vnc: Add paused/resumed signals
Paused is when the socket sourec is detached, and resumed when attached.
Meant to be used by the TLS channel security to a attach/detach
out-of-socket source.
---
src/grd-session-vnc.c | 72 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 65 insertions(+), 7 deletions(-)
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index a82952ae..1fd3b778 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -41,14 +41,27 @@
#define BGRX_SAMPLES_PER_PIXEL 3
#define BGRX_BYTES_PER_PIXEL 4
+enum
+{
+ PAUSED,
+ RESUMED,
+
+ N_SIGNALS
+};
+
+static guint signals[N_SIGNALS];
+
struct _GrdSessionVnc
{
GrdSession parent;
GrdVncServer *vnc_server;
GSocketConnection *connection;
+
GList *socket_grabs;
GSource *source;
+ gboolean is_paused;
+
rfbScreenInfoPtr rfb_screen;
rfbClientPtr rfb_client;
@@ -79,7 +92,7 @@ struct _GrdSessionVnc
G_DEFINE_TYPE (GrdSessionVnc, grd_session_vnc, GRD_TYPE_SESSION)
static void
-grd_session_vnc_detach_source (GrdSessionVnc *session_vnc);
+grd_session_vnc_pause (GrdSessionVnc *session_vnc);
static gboolean
close_session_idle (gpointer user_data);
@@ -246,7 +259,8 @@ handle_client_gone (rfbClientPtr rfb_client)
g_debug ("VNC client gone");
- grd_session_vnc_detach_source (session_vnc);
+ grd_session_vnc_pause (session_vnc);
+
maybe_queue_close_session_idle (session_vnc);
session_vnc->rfb_client = NULL;
}
@@ -315,7 +329,7 @@ handle_new_client (rfbClientPtr rfb_client)
session_vnc->prompt_cancellable,
prompt_response_callback,
session_vnc);
- grd_session_vnc_detach_source (session_vnc);
+ grd_session_vnc_pause (session_vnc);
return RFB_CLIENT_ON_HOLD;
case GRD_VNC_AUTH_METHOD_PASSWORD:
session_vnc->rfb_screen->passwordCheck = check_rfb_password;
@@ -581,7 +595,7 @@ check_rfb_password (rfbClientPtr rfb_client,
if (memcmp (challenge_encrypted, response_encrypted, len) == 0)
{
grd_session_start (GRD_SESSION (session_vnc));
- grd_session_vnc_detach_source (session_vnc);
+ grd_session_vnc_pause (session_vnc);
return TRUE;
}
else
@@ -801,6 +815,36 @@ grd_session_vnc_detach_source (GrdSessionVnc *session_vnc)
g_clear_pointer (&session_vnc->source, g_source_unref);
}
+gboolean
+grd_session_vnc_is_paused (GrdSessionVnc *session_vnc)
+{
+ return session_vnc->is_paused;
+}
+
+static void
+grd_session_vnc_pause (GrdSessionVnc *session_vnc)
+{
+ if (grd_session_vnc_is_paused (session_vnc))
+ return;
+
+ session_vnc->is_paused = TRUE;
+
+ grd_session_vnc_detach_source (session_vnc);
+ g_signal_emit (session_vnc, signals[PAUSED], 0);
+}
+
+static void
+grd_session_vnc_resume (GrdSessionVnc *session_vnc)
+{
+ if (!grd_session_vnc_is_paused (session_vnc))
+ return;
+
+ session_vnc->is_paused = FALSE;
+
+ grd_session_vnc_attach_source (session_vnc);
+ g_signal_emit (session_vnc, signals[RESUMED], 0);
+}
+
GrdSessionVnc *
grd_session_vnc_new (GrdVncServer *vnc_server,
GSocketConnection *connection)
@@ -822,6 +866,7 @@ grd_session_vnc_new (GrdVncServer *vnc_server,
grd_session_vnc_grab_socket (session_vnc, vnc_socket_grab_func);
grd_session_vnc_attach_source (session_vnc);
+ session_vnc->is_paused = FALSE;
init_vnc_session (session_vnc);
@@ -856,7 +901,7 @@ grd_session_vnc_stop (GrdSession *session)
g_clear_object (&session_vnc->stream);
}
- grd_session_vnc_detach_source (session_vnc);
+ grd_session_vnc_pause (session_vnc);
g_clear_object (&session_vnc->connection);
g_clear_object (&session_vnc->clipboard_vnc);
@@ -941,8 +986,8 @@ on_stream_ready (GrdStream *stream,
G_CALLBACK (on_pipewire_stream_closed),
session_vnc);
- if (!session_vnc->source)
- grd_session_vnc_attach_source (session_vnc);
+ if (grd_session_vnc_is_paused (session_vnc))
+ grd_session_vnc_resume (session_vnc);
}
static void
@@ -977,4 +1022,17 @@ grd_session_vnc_class_init (GrdSessionVncClass *klass)
session_class->remote_desktop_session_started =
grd_session_vnc_remote_desktop_session_started;
session_class->on_stream_created = grd_session_vnc_on_stream_created;
+
+ signals[PAUSED] = g_signal_new ("paused",
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ 0,
+ NULL, NULL, NULL,
+ G_TYPE_NONE, 0);
+ signals[RESUMED] = g_signal_new ("resumed",
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ 0,
+ NULL, NULL, NULL,
+ G_TYPE_NONE, 0);
}
--
2.40.0
From 9a36ce45052d05a0e0e4ab70beba704b321875a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 11:03:46 +0100
Subject: [PATCH 3/7] session-vnc: Add grd_session_vnc_dispatch() helper
To be used by the TLS channel security to dispatch when there is data
available that is not visible to the socket source.
---
src/grd-session-vnc.c | 26 ++++++++++++++++----------
src/grd-session-vnc.h | 2 ++
2 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index 1fd3b778..8366e661 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -751,6 +751,21 @@ vnc_socket_grab_func (GrdSessionVnc *session_vnc,
return TRUE;
}
+void
+grd_session_vnc_dispatch (GrdSessionVnc *session_vnc)
+{
+ GrdVncSocketGrabFunc grab_func;
+ g_autoptr (GError) error = NULL;
+
+ grab_func = g_list_first (session_vnc->socket_grabs)->data;
+ if (!grab_func (session_vnc, &error))
+ {
+ g_warning ("Error when reading socket: %s", error->message);
+
+ grd_session_stop (GRD_SESSION (session_vnc));
+ }
+}
+
static gboolean
handle_socket_data (GSocket *socket,
GIOCondition condition,
@@ -767,16 +782,7 @@ handle_socket_data (GSocket *socket,
}
else if (condition & G_IO_IN)
{
- GrdVncSocketGrabFunc grab_func;
- g_autoptr (GError) error = NULL;
-
- grab_func = g_list_first (session_vnc->socket_grabs)->data;
- if (!grab_func (session_vnc, &error))
- {
- g_warning ("Error when reading socket: %s", error->message);
-
- grd_session_stop (session);
- }
+ grd_session_vnc_dispatch (session_vnc);
}
else
{
diff --git a/src/grd-session-vnc.h b/src/grd-session-vnc.h
index ffc8d27a..a86d61d2 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -80,6 +80,8 @@ void grd_session_vnc_grab_socket (GrdSessionVnc *session_vnc,
void grd_session_vnc_ungrab_socket (GrdSessionVnc *session_vnc,
GrdVncSocketGrabFunc grab_func);
+void grd_session_vnc_dispatch (GrdSessionVnc *session_vnc);
+
GrdVncServer * grd_session_vnc_get_vnc_server (GrdSessionVnc *session_vnc);
#endif /* GRD_SESSION_VNC_H */
--
2.40.0
From 685f376a6b331d91e2bb34e8484682974db149a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 11:05:13 +0100
Subject: [PATCH 4/7] vnc/tls: Add some logging
Uses the log utility from libvncserver as it is related to the RFB
protocol rather than the session itself.
---
src/grd-vnc-tls.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/src/grd-vnc-tls.c b/src/grd-vnc-tls.c
index ec4758e0..ac6c35f6 100644
--- a/src/grd-vnc-tls.c
+++ b/src/grd-vnc-tls.c
@@ -67,6 +67,7 @@ grd_vnc_tls_context_new (void)
tls_context = g_new0 (GrdVncTlsContext, 1);
+ rfbLog ("TLS: Initializing gnutls context\n");
gnutls_global_init ();
gnutls_anon_allocate_server_credentials (&tls_context->anon_credentials);
@@ -127,6 +128,7 @@ perform_anon_tls_handshake (GrdVncTlsSession *tls_session,
ret = gnutls_handshake (tls_session->tls_session);
if (ret != GNUTLS_E_SUCCESS && !gnutls_error_is_fatal (ret))
{
+ rfbLog ("TLS: More handshake pending\n");
tls_session->handshake_state = GRD_TLS_HANDSHAKE_STATE_DURING;
return TRUE;
}
@@ -140,6 +142,8 @@ perform_anon_tls_handshake (GrdVncTlsSession *tls_session,
return FALSE;
}
+ rfbLog ("TLS: Handshake finished");
+
tls_session->handshake_state = GRD_TLS_HANDSHAKE_STATE_FINISHED;
return TRUE;
}
@@ -373,6 +377,7 @@ perform_handshake (GrdSessionVnc *session_vnc,
break;
case GRD_TLS_HANDSHAKE_STATE_FINISHED:
grd_session_vnc_ungrab_socket (session_vnc, tls_handshake_grab_func);
+ rfbLog ("TLS: Sending post-channel security security list\n");
rfbSendSecurityTypeList (grd_session_vnc_get_rfb_client (session_vnc),
RFB_SECURITY_TAG_CHANNEL);
break;
@@ -387,6 +392,7 @@ tls_handshake_grab_func (GrdSessionVnc *session_vnc,
{
g_autoptr (GError) handshake_error = NULL;
+ rfbLog ("TLS: Continuing handshake\n");
if (!perform_handshake (session_vnc, &handshake_error))
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
@@ -404,6 +410,8 @@ rfb_tls_security_handler (rfbClientPtr rfb_client)
GrdVncTlsSession *tls_session;
g_autoptr(GError) error = NULL;
+ rfbLog ("TLS: Setting up rfbClient for gnutls encrypted traffic\n");
+
tls_session = grd_vnc_tls_session_from_vnc_session (session_vnc);
if (!tls_session)
{
@@ -424,6 +432,7 @@ rfb_tls_security_handler (rfbClientPtr rfb_client)
grd_session_vnc_grab_socket (session_vnc, tls_handshake_grab_func);
}
+ rfbLog ("TLS: Performing handshake\n");
if (!perform_handshake (session_vnc, &error))
{
g_warning ("TLS handshake failed: %s", error->message);
--
2.40.0
From eebd752d3df83d6ae2df79782dbb8b4a80083608 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 11:07:40 +0100
Subject: [PATCH 5/7] vnc/tls: Dispatch also when data is pending outside of
the socket
gnutls may have data available in its buffers, and we have our own peek
buffer temporarly storing data later to be processed. This would missed
by the socket source, as it wouldn't get any notification about it from
epoll(). Deal with this by adding a custom source that dispatches as
long as there is data to read in those buffers.
---
src/grd-session-vnc.h | 2 +
src/grd-vnc-tls.c | 90 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 86 insertions(+), 6 deletions(-)
diff --git a/src/grd-session-vnc.h b/src/grd-session-vnc.h
index a86d61d2..5db388b0 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -80,6 +80,8 @@ void grd_session_vnc_grab_socket (GrdSessionVnc *session_vnc,
void grd_session_vnc_ungrab_socket (GrdSessionVnc *session_vnc,
GrdVncSocketGrabFunc grab_func);
+gboolean grd_session_vnc_is_paused (GrdSessionVnc *session_vnc);
+
void grd_session_vnc_dispatch (GrdSessionVnc *session_vnc);
GrdVncServer * grd_session_vnc_get_vnc_server (GrdSessionVnc *session_vnc);
diff --git a/src/grd-vnc-tls.c b/src/grd-vnc-tls.c
index ac6c35f6..312b6b92 100644
--- a/src/grd-vnc-tls.c
+++ b/src/grd-vnc-tls.c
@@ -41,6 +41,12 @@ typedef enum _GrdTlsHandshakeState
GRD_TLS_HANDSHAKE_STATE_FINISHED
} GrdTlsHandshakeState;
+typedef struct _PeekBufferSource
+{
+ GSource parent;
+ GrdSessionVnc *session_vnc;
+} PeekBufferSource;
+
typedef struct _GrdVncTlsSession
{
GrdVncTlsContext *tls_context;
@@ -53,6 +59,8 @@ typedef struct _GrdVncTlsSession
char *peek_buffer;
int peek_buffer_size;
int peek_buffer_len;
+
+ GSource *peek_buffer_source;
} GrdVncTlsSession;
static gboolean
@@ -299,13 +307,9 @@ grd_vnc_tls_peek_at_socket (rfbClientPtr rfb_client,
return peekable_len;
}
-static rfbBool
-grd_vnc_tls_has_pending_on_socket (rfbClientPtr rfb_client)
+static gboolean
+grd_vnc_tls_session_has_pending_data (GrdVncTlsSession *tls_session)
{
- GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
- GrdVncTlsSession *tls_session =
- grd_vnc_tls_session_from_vnc_session (session_vnc);
-
if (tls_session->peek_buffer_len > 0)
return TRUE;
@@ -315,6 +319,16 @@ grd_vnc_tls_has_pending_on_socket (rfbClientPtr rfb_client)
return FALSE;
}
+static rfbBool
+grd_vnc_tls_has_pending_on_socket (rfbClientPtr rfb_client)
+{
+ GrdSessionVnc *session_vnc = rfb_client->screen->screenData;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ return grd_vnc_tls_session_has_pending_data (tls_session);
+}
+
static int
grd_vnc_tls_write_to_socket (rfbClientPtr rfb_client,
const char *buf,
@@ -403,6 +417,62 @@ tls_handshake_grab_func (GrdSessionVnc *session_vnc,
return TRUE;
}
+static gboolean
+peek_buffer_source_prepare (GSource *source,
+ int *timeout)
+{
+ PeekBufferSource *psource = (PeekBufferSource *) source;
+ GrdSessionVnc *session_vnc = psource->session_vnc;
+ GrdVncTlsSession *tls_session =
+ grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ return grd_vnc_tls_session_has_pending_data (tls_session);
+}
+
+static gboolean
+peek_buffer_source_dispatch (GSource *source,
+ GSourceFunc callback,
+ gpointer user_data)
+{
+ PeekBufferSource *psource = (PeekBufferSource *) source;
+ GrdSessionVnc *session_vnc = psource->session_vnc;
+
+ grd_session_vnc_dispatch (session_vnc);
+
+ return G_SOURCE_CONTINUE;
+}
+
+static GSourceFuncs peek_buffer_source_funcs = {
+ .prepare = peek_buffer_source_prepare,
+ .dispatch = peek_buffer_source_dispatch,
+};
+
+static void
+attach_peek_buffer_source (GrdSessionVnc *session_vnc)
+{
+ GrdVncTlsSession *tls_session;
+
+ tls_session = grd_vnc_tls_session_from_vnc_session (session_vnc);
+ tls_session->peek_buffer_source = g_source_new (&peek_buffer_source_funcs,
+ sizeof (PeekBufferSource));
+ ((PeekBufferSource *) tls_session->peek_buffer_source)->session_vnc =
+ session_vnc;
+ g_source_set_priority (tls_session->peek_buffer_source,
+ G_PRIORITY_DEFAULT + 1);
+
+ g_source_attach (tls_session->peek_buffer_source, NULL);
+}
+
+static void
+detach_peek_buffer_source (GrdSessionVnc *session_vnc)
+{
+ GrdVncTlsSession *tls_session;
+
+ tls_session = grd_vnc_tls_session_from_vnc_session (session_vnc);
+
+ g_clear_pointer (&tls_session->peek_buffer_source, g_source_destroy);
+}
+
static void
rfb_tls_security_handler (rfbClientPtr rfb_client)
{
@@ -429,6 +499,14 @@ rfb_tls_security_handler (rfbClientPtr rfb_client)
rfb_client->hasPendingOnSocket = grd_vnc_tls_has_pending_on_socket;
rfb_client->writeToSocket = grd_vnc_tls_write_to_socket;
+ if (!grd_session_vnc_is_paused (session_vnc))
+ attach_peek_buffer_source (session_vnc);
+
+ g_signal_connect (session_vnc, "paused",
+ G_CALLBACK (detach_peek_buffer_source), NULL);
+ g_signal_connect (session_vnc, "resumed",
+ G_CALLBACK (attach_peek_buffer_source), NULL);
+
grd_session_vnc_grab_socket (session_vnc, tls_handshake_grab_func);
}
--
2.40.0
From 9f41a7aba0f24a3253a1483a290364e887345b42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 16:48:00 +0100
Subject: [PATCH 6/7] session-vnc: Set our own password handling function up
front
libvncserver decides whether to register a auth security handler
depending on whether the password data is set or not. When we use the
prompt auth method, we don't want to ask for password, so set the
password data to NULL.
Also, to be a bit more in control of the password mechanism, always set
the password function up front, instead of just when the client uses the
password prompt.
---
src/grd-session-vnc.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index 8366e661..baf7520c 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -97,11 +97,6 @@ grd_session_vnc_pause (GrdSessionVnc *session_vnc);
static gboolean
close_session_idle (gpointer user_data);
-static rfbBool
-check_rfb_password (rfbClientPtr rfb_client,
- const char *response_encrypted,
- int len);
-
static void
swap_uint8 (uint8_t *a,
uint8_t *b)
@@ -332,7 +327,6 @@ handle_new_client (rfbClientPtr rfb_client)
grd_session_vnc_pause (session_vnc);
return RFB_CLIENT_ON_HOLD;
case GRD_VNC_AUTH_METHOD_PASSWORD:
- session_vnc->rfb_screen->passwordCheck = check_rfb_password;
/*
* authPasswdData needs to be non NULL in libvncserver to trigger
* password authentication.
@@ -699,6 +693,8 @@ init_vnc_session (GrdSessionVnc *session_vnc)
session_vnc->monitor_config->connectors = connectors;
}
+ rfb_screen->passwordCheck = check_rfb_password;
+
rfbInitServer (rfb_screen);
rfbProcessEvents (rfb_screen, 0);
}
--
2.40.0
From ea9f0e491c6fd34cc6eda0104d017eba1a671023 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Mon, 12 Oct 2020 17:34:30 +0200
Subject: [PATCH 7/7] vnc: Copy pixels using the right destination stride
We're copying the pixels in a separate thread managed by PipeWire, and
in this thread, accessing the VNC framebuffer dimension and stride is
racy. Instead of fetching the dimension directly, pass the expected
width and get the stride it will eventually have.
Already before this patch, when the copied pixel end up on the main
thread and the dimension still doesn't match up, the frame will be
dropped.
---
src/grd-session-vnc.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/grd-session-vnc.h b/src/grd-session-vnc.h
index 5db388b0..c4f4e8d4 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -68,7 +68,8 @@ int grd_session_vnc_get_stride_for_width (GrdSessionVnc *session_vnc,
int grd_session_vnc_get_fd (GrdSessionVnc *session_vnc);
-int grd_session_vnc_get_framebuffer_stride (GrdSessionVnc *session_vnc);
+int grd_session_vnc_get_stride_for_width (GrdSessionVnc *session_vnc,
+ int width);
gboolean grd_session_vnc_is_client_gone (GrdSessionVnc *session_vnc);
--
2.40.0