React to Meek client binary not found

2 files changed, 26 insertions, 7 deletions

diff --git a/cli/onionshare_cli/meek.py b/cli/onionshare_cli/meek.py
index 675402d3..ff44cb13 100644
--- a/cli/onionshare_cli/meek.py
+++ b/cli/onionshare_cli/meek.py
@@ -72,6 +72,12 @@ class Meek(object):
                 queue.put(line)
             out.close()
 
+        # Abort early if we can't find the Meek client
+        # common.get_tor_paths() has already checked it's a file
+        # so just abort if it's a NoneType object
+        if self.meek_client_file_path is None:
+            raise MeekNotFound()
+
         # Start the Meek Client as a subprocess.
 
         if self.common.platform == "Windows":
@@ -179,3 +185,8 @@ class MeekNotRunning(Exception):
     We were unable to start Meek or obtain the port
     number it started on, in order to do domain fronting.
     """
+
+class MeekNotFound(Exception):
+    """
+    We were unable to find the Meek Client binary.
+    """
diff --git a/desktop/src/onionshare/moat_dialog.py b/desktop/src/onionshare/moat_dialog.py
index 9046c989..2821bb1e 100644
--- a/desktop/src/onionshare/moat_dialog.py
+++ b/desktop/src/onionshare/moat_dialog.py
@@ -26,7 +26,7 @@ import json
 
 from . import strings
 from .gui_common import GuiCommon
-from onionshare_cli.meek import MeekNotRunning
+from onionshare_cli.meek import MeekNotFound
 
 
 class MoatDialog(QtWidgets.QDialog):
@@ -234,12 +234,19 @@ class MoatThread(QtCore.QThread):
     def run(self):
 
         # Start Meek so that we can do domain fronting
-        self.meek.start()
+        try:
+            self.meek.start()
+        except MeekNotFound:
+            self.common.log("MoatThread", "run", f"Could not find the Meek Client")
+            self.bridgedb_error.emit()
+            return
 
         # We should only fetch bridges if we can domain front,
         # but we can override this in local-only mode.
         if not self.meek.meek_proxies and not self.common.gui.local_only:
-            self.common.log("MoatThread", "run", f"Could not identify meek proxies to make request")
+            self.common.log(
+                "MoatThread", "run", f"Could not identify meek proxies to make request"
+            )
             self.bridgedb_error.emit()
             return
 
@@ -256,15 +263,14 @@ class MoatThread(QtCore.QThread):
                         {
                             "version": "0.1.0",
                             "type": "client-transports",
-                            "supported": [
-                                "obfs4",
-                                "snowflake",
-                            ],
+                            "supported": ["obfs4", "snowflake"],
                         }
                     ]
                 },
             )
+
             self.meek.cleanup()
+
             if r.status_code != 200:
                 self.common.log("MoatThread", "run", f"status_code={r.status_code}")
                 self.bridgedb_error.emit()
@@ -317,7 +323,9 @@ class MoatThread(QtCore.QThread):
                     ]
                 },
             )
+
             self.meek.cleanup()
+
             if r.status_code != 200:
                 self.common.log("MoatThread", "run", f"status_code={r.status_code}")
                 self.bridgedb_error.emit()