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gnome-remote-desktop/SOURCES/anon-tls-support.patch
CentOS Sources 9ea614af72 import gnome-remote-desktop-0.1.8-3.el8
2021-09-09 17:48:43 +00:00

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From 10843a1f3edffbb475c01835451d39ebe6153e44 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 | 98 +++-
src/grd-session-vnc.h | 15 +
src/grd-settings.c | 28 ++
src/grd-settings.h | 2 +
src/grd-vnc-server.c | 45 ++
src/grd-vnc-tls.c | 444 ++++++++++++++++++
src/grd-vnc-tls.h | 28 ++
src/meson.build | 5 +-
...nome.desktop.remote-desktop.gschema.xml.in | 10 +
11 files changed, 666 insertions(+), 16 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 1c96849..a24acfd 100644
--- a/meson.build
+++ b/meson.build
@@ -15,6 +15,7 @@ libvncserver_dep = dependency('libvncserver')
libvncclient_dep = dependency('libvncclient')
libsecret_dep = dependency('libsecret-1')
libnotify_dep = dependency('libnotify')
+gnutls_dep = dependency('gnutls')
cdata = configuration_data()
cdata.set_quoted('GETTEXT_PACKAGE', 'gnome-remote-desktop')
diff --git a/src/grd-enums.h b/src/grd-enums.h
index ffab821..4333863 100644
--- a/src/grd-enums.h
+++ b/src/grd-enums.h
@@ -27,4 +27,10 @@ typedef enum
GRD_VNC_AUTH_METHOD_PASSWORD
} GrdVncAuthMethod;
+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 1f3f0e2..0cc2ea2 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -44,7 +44,9 @@ struct _GrdSessionVnc
{
GrdSession parent;
+ GrdVncServer *vnc_server;
GSocketConnection *connection;
+ GList *socket_grabs;
GSource *source;
rfbScreenInfoPtr rfb_screen;
rfbClientPtr rfb_client;
@@ -505,12 +507,30 @@ 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_framebuffer_stride (GrdSessionVnc *session_vnc)
{
return session_vnc->rfb_screen->paddedWidthInBytes;
}
+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)
{
@@ -551,33 +571,74 @@ 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;
+ }
+ }
+
+ 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;
- }
+ 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;
@@ -590,7 +651,10 @@ 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,
@@ -616,8 +680,10 @@ grd_session_vnc_new (GrdVncServer *vnc_server,
"context", context,
NULL);
+ session_vnc->vnc_server = vnc_server;
session_vnc->connection = g_object_ref (connection);
+ grd_session_vnc_grab_socket (session_vnc, vnc_socket_grab_func);
grd_session_vnc_attach_source (session_vnc);
init_vnc_session (session_vnc);
@@ -632,6 +698,8 @@ 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 14b5d12..46a8579 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -36,6 +36,9 @@ 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);
@@ -53,6 +56,18 @@ void grd_session_vnc_move_cursor (GrdSessionVnc *session_vnc,
int x,
int y);
+int grd_session_vnc_get_fd (GrdSessionVnc *session_vnc);
+
int grd_session_vnc_get_framebuffer_stride (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.c b/src/grd-settings.c
index bdf8211..7324310 100644
--- a/src/grd-settings.c
+++ b/src/grd-settings.c
@@ -48,6 +48,7 @@ struct _GrdSettings
gboolean view_only;
GrdVncAuthMethod auth_method;
int port;
+ GrdVncEncryption encryption;
} vnc;
};
@@ -120,6 +121,12 @@ grd_settings_get_vnc_auth_method (GrdSettings *settings)
return settings->vnc.auth_method;
}
+GrdVncEncryption
+grd_settings_get_vnc_encryption (GrdSettings *settings)
+{
+ return settings->vnc.encryption;
+}
+
static void
update_vnc_view_only (GrdSettings *settings)
{
@@ -134,6 +141,13 @@ update_vnc_auth_method (GrdSettings *settings)
"auth-method");
}
+static void
+update_vnc_encryption (GrdSettings *settings)
+{
+ settings->vnc.encryption = g_settings_get_flags (settings->vnc.settings,
+ "encryption");
+}
+
static void
on_vnc_settings_changed (GSettings *vnc_settings,
const char *key,
@@ -149,6 +163,11 @@ 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
@@ -172,6 +191,8 @@ grd_settings_init (GrdSettings *settings)
update_vnc_auth_method (settings);
settings->vnc.port = GRD_VNC_SERVER_PORT;
+
+ update_vnc_encryption (settings);
}
static void
@@ -195,4 +216,11 @@ grd_settings_class_init (GrdSettingsClass *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.h b/src/grd-settings.h
index e4e0c09..0575ec1 100644
--- a/src/grd-settings.h
+++ b/src/grd-settings.h
@@ -45,4 +45,6 @@ gboolean grd_settings_get_vnc_view_only (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 a6d95cb..f9c68db 100644
--- a/src/grd-vnc-server.c
+++ b/src/grd-vnc-server.c
@@ -24,11 +24,13 @@
#include "grd-vnc-server.h"
+#include <rfb/rfb.h>
#include <gio/gio.h>
#include <rfb/rfb.h>
#include "grd-context.h"
#include "grd-session-vnc.h"
+#include "grd-vnc-tls.h"
enum
@@ -130,6 +132,43 @@ 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)
@@ -220,12 +259,18 @@ 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_context_get_debug_flags (vnc_server->context) & 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 0000000..ec4758e
--- /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 0000000..135ef8c
--- /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 0f76fab..9d2f1ce 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -21,6 +21,8 @@ daemon_sources = files([
'grd-vnc-pipewire-stream.h',
'grd-vnc-server.c',
'grd-vnc-server.h',
+ 'grd-vnc-tls.c',
+ 'grd-vnc-tls.h',
])
gen_daemon_sources = []
@@ -51,7 +53,8 @@ executable('gnome-remote-desktop-daemon',
pipewire_dep,
libvncserver_dep,
libsecret_dep,
- libnotify_dep],
+ libnotify_dep,
+ gnutls_dep],
include_directories: [configinc],
install: true,
install_dir: libexecdir)
diff --git a/src/org.gnome.desktop.remote-desktop.gschema.xml.in b/src/org.gnome.desktop.remote-desktop.gschema.xml.in
index a5c2022..846e65b 100644
--- a/src/org.gnome.desktop.remote-desktop.gschema.xml.in
+++ b/src/org.gnome.desktop.remote-desktop.gschema.xml.in
@@ -23,5 +23,15 @@
* password - by requiring the remote client to provide a known password
</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>
--
2.26.2
From aa54aeb43938250a4d27a99e62eb5628d3b55076 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 0cc2ea2..076e25f 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -40,14 +40,27 @@
#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;
@@ -73,7 +86,7 @@ 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);
@@ -212,7 +225,8 @@ 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);
}
@@ -280,7 +294,7 @@ 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;
@@ -498,7 +512,7 @@ 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
@@ -668,6 +682,36 @@ grd_session_vnc_detach_source (GrdSessionVnc *session_vnc)
g_clear_pointer (&session_vnc->source, g_source_destroy);
}
+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)
@@ -685,6 +729,7 @@ 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);
@@ -714,7 +759,7 @@ grd_session_vnc_stop (GrdSession *session)
g_clear_object (&session_vnc->pipewire_stream);
- grd_session_vnc_detach_source (session_vnc);
+ grd_session_vnc_pause (session_vnc);
g_clear_object (&session_vnc->connection);
g_clear_pointer (&session_vnc->rfb_screen->frameBuffer, g_free);
@@ -770,8 +815,8 @@ grd_session_vnc_stream_ready (GrdSession *session,
G_CALLBACK (on_pipwire_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
@@ -790,4 +835,17 @@ grd_session_vnc_class_init (GrdSessionVncClass *klass)
session_class->stop = grd_session_vnc_stop;
session_class->stream_ready = grd_session_vnc_stream_ready;
+
+ 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);
}
--
2.26.2
From ed3d72cb8d08192831397903f0ba92f439751988 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 076e25f..8b8ce1b 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -622,6 +622,21 @@ 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,
@@ -638,16 +653,7 @@ 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 46a8579..910b00c 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -68,6 +68,8 @@ 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 */
--
2.26.2
From 44e6bec84a86064a7b3abbcbbcd07ebb525aca9f 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 ec4758e..ac6c35f 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);
--
2.26.2
From fc07db3b6fafec47e02ff81f0f893dcaf64ba988 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 | 92 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 88 insertions(+), 6 deletions(-)
diff --git a/src/grd-session-vnc.h b/src/grd-session-vnc.h
index 910b00c..294860e 100644
--- a/src/grd-session-vnc.h
+++ b/src/grd-session-vnc.h
@@ -68,6 +68,8 @@ 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 ac6c35f..8f65225 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
@@ -296,16 +304,14 @@ grd_vnc_tls_peek_at_socket (rfbClientPtr rfb_client,
peekable_len = MIN (len, tls_session->peek_buffer_len);
memcpy (buf, tls_session->peek_buffer, peekable_len);
+ fprintf(stderr, ":::: %s:%d %s() - peeked %d bytes, can peek %d bytes\n", __FILE__, __LINE__, __func__,
+ peekable_len, tls_session->peek_buffer_len);
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 +321,16 @@ 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 +419,62 @@ 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 +501,14 @@ 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);
}
--
2.26.2
From c582baab12c1e2dd2b512329da42880c40993df6 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 8b8ce1b..a93a2e3 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -91,11 +91,6 @@ 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)
@@ -297,7 +292,6 @@ 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.
@@ -581,6 +575,8 @@ init_vnc_session (GrdSessionVnc *session_vnc)
rfb_screen->frameBuffer = g_malloc0 (screen_width * screen_height * 4);
memset (rfb_screen->frameBuffer, 0x1f, screen_width * screen_height * 4);
+ rfb_screen->passwordCheck = check_rfb_password;
+
rfbInitServer (rfb_screen);
rfbProcessEvents (rfb_screen, 0);
}
--
2.26.2
From b7fc232ee5272b430f28c33ebaacd501ff63a4dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 27 Nov 2019 16:53:42 +0100
Subject: [PATCH 7/7] vnc: Unregister previously set security handlers on init
When we're starting a session, we're going to handle a new client
connection. However, any previous client that was ever run on in a
previous session would still have their "security handler" registered,
as such is a global permanent change in libvncserver right now.
To work around this, unregister all primary security handler (i.e.
'none' and 'password') when initializing the RFB screen. We'll set up
the preferred one when handling the new client.
---
src/grd-session-vnc.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index a93a2e3..9fcbb69 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -555,6 +555,12 @@ init_vnc_session (GrdSessionVnc *session_vnc)
8, 3, 4);
session_vnc->rfb_screen = rfb_screen;
+ /*
+ * Unregister whatever security handler was used the last time; we'll set
+ * up new ones when authorizing the new client anyway.
+ */
+ rfbUnregisterPrimarySecurityHandlers ();
+
update_server_format (session_vnc);
socket = g_socket_connection_get_socket (session_vnc->connection);
--
2.26.2
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