Add gnubby authentication to remoting host

remoting/tools/me2me_virtual_host.py

Index: remoting/tools/me2me_virtual_host.py
diff --git a/remoting/tools/me2me_virtual_host.py b/remoting/tools/me2me_virtual_host.py
index c1eaa99b7cb9a59de5b2b79660e60c7014f5e7dd..ad322d4f1b1d417e145cd45977068fc676ad0b09 100755
--- a/remoting/tools/me2me_virtual_host.py
+++ b/remoting/tools/me2me_virtual_host.py
@@ -192,6 +192,7 @@ class Desktop:
     self.pulseaudio_pipe = None
     self.server_supports_exact_resize = False
     self.host_ready = False
+    self.ssh_auth_sockname = None
     g_desktops.append(self)
 
   @staticmethod
@@ -292,6 +293,10 @@ class Desktop:
 
     return True
 
+  def _setup_gnubby(self):
+    self.ssh_auth_sockname = ("/tmp/chromoting.%s.ssh_auth_sock" %
+                              os.environ["USER"])
+
   def _launch_x_server(self, extra_x_args):
     x_auth_file = os.path.expanduser("~/.Xauthority")
     self.child_env["XAUTHORITY"] = x_auth_file
@@ -349,6 +354,10 @@ class Desktop:
     chrome_profile = os.path.join(CONFIG_DIR, "chrome-profile")
     self.child_env["CHROME_USER_DATA_DIR"] = chrome_profile
 
+    # Set SSH_AUTH_SOCK to the file name to listen on.
+    if self.ssh_auth_sockname:
+      self.child_env["SSH_AUTH_SOCK"] = self.ssh_auth_sockname
+
     # Wait for X to be active.
     for _test in range(5):
       proc = subprocess.Popen("xdpyinfo", env=self.child_env, stdout=devnull)
@@ -421,6 +430,7 @@ class Desktop:
   def launch_session(self, x_args):
     self._init_child_env()
     self._setup_pulseaudio()
+    self._setup_gnubby()
     self._launch_x_server(x_args)
     self._launch_x_session()
 
@@ -431,6 +441,8 @@ class Desktop:
       args.append("--audio-pipe-name=%s" % self.pulseaudio_pipe)
     if self.server_supports_exact_resize:
       args.append("--server-supports-exact-resize")
+    if self.ssh_auth_sockname:
+      args.append("--ssh-auth-sockname=%s" % self.ssh_auth_sockname)
 
     # Have the host process use SIGUSR1 to signal a successful start.
     def sigusr1_handler(signum, frame):