Move Censorship stuff into its own class. Early attempt at subprocessing out to meek (unfinished)

cli/onionshare_cli/censorship.py

@@ -0,0 +1,216 @@
+# -*- coding: utf-8 -*-
+"""
+OnionShare | https://onionshare.org/
+
+Copyright (C) 2014-2021 Micah Lee, et al. <micah@micahflee.com>
+
+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 3 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, see <http://www.gnu.org/licenses/>.
+"""
+import requests
+import subprocess
+
+
+class CensorshipCircumvention:
+    """
+    The CensorShipCircumvention object contains methods to detect
+    and offer solutions to censorship when connecting to Tor.
+    """
+
+    def __init__(self, common):
+
+        self.common = common
+        self.common.log("CensorshipCircumvention", "__init__")
+
+        get_tor_paths = self.common.get_tor_paths
+        (
+            self.tor_path,
+            self.tor_geo_ip_file_path,
+            self.tor_geo_ipv6_file_path,
+            self.obfs4proxy_file_path,
+            self.meek_client_file_path,
+        ) = get_tor_paths()
+
+        meek_url = "https://moat.torproject.org.global.prod.fastly.net/"
+        meek_front = "cdn.sstatic.net"
+        meek_env = {
+            "TOR_PT_MANAGED_TRANSPORT_VER": "1",
+            "TOR_PT_CLIENT_TRANSPORTS": "meek",
+        }
+
+        # @TODO detect the port from the subprocess output
+        meek_address = "127.0.0.1"
+        meek_port = "43533"  # hardcoded for testing
+        self.meek_proxies = {
+            "http": f"socks5h://{meek_address}:{meek_port}",
+            "https": f"socks5h://{meek_address}:{meek_port}",
+        }
+
+        # Start the Meek Client as a subprocess.
+        # This will be used to do domain fronting to the Tor
+        # Moat API endpoints for censorship circumvention as
+        # well as BridgeDB lookups.
+
+        if self.common.platform == "Windows":
+            # In Windows, hide console window when opening tor.exe subprocess
+            startupinfo = subprocess.STARTUPINFO()
+            startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
+            self.meek_proc = subprocess.Popen(
+                [self.meek_client_file_path, "--url", meek_url, "--front", meek_front],
+                stdout=subprocess.PIPE,
+                startupinfo=startupinfo,
+                bufsize=1,
+                env=meek_env,
+                text=True,
+            )
+        else:
+            self.meek_proc = subprocess.Popen(
+                [self.meek_client_file_path, "--url", meek_url, "--front", meek_front],
+                stdout=subprocess.PIPE,
+                bufsize=1,
+                env=meek_env,
+                text=True,
+            )
+
+            # if "CMETHOD meek socks5" in line:
+            #    self.meek_host = (line.split(" ")[3].split(":")[0])
+            #    self.meek_port = (line.split(" ")[3].split(":")[1])
+            #    self.common.log("CensorshipCircumvention", "__init__", f"Meek host is {self.meek_host}")
+            #    self.common.log("CensorshipCircumvention", "__init__", f"Meek port is {self.meek_port}")
+
+    def censorship_obtain_map(self, country=False):
+        """
+        Retrieves the Circumvention map from Tor Project and store it
+        locally for further look-ups if required.
+
+        Optionally pass a country code in order to get recommended settings
+        just for that country.
+
+        Note that this API endpoint doesn't return actual bridges,
+        it just returns the recommended bridge type countries.
+        """
+        endpoint = "https://bridges.torproject.org/moat/circumvention/map"
+        data = {}
+        if country:
+            data = {"country": country}
+
+        r = requests.post(
+            endpoint,
+            json=data,
+            headers={"Content-Type": "application/vnd.api+json"},
+            proxies=self.meek_proxies,
+        )
+        if r.status_code != 200:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_map",
+                f"status_code={r.status_code}",
+            )
+            return False
+
+        result = r.json()
+
+        if "errors" in result:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_map",
+                f"errors={result['errors']}",
+            )
+            return False
+
+        return result
+
+    def censorship_obtain_settings(self, country=False, transports=False):
+        """
+        Retrieves the Circumvention Settings from Tor Project, which
+        will return recommended settings based on the country code of
+        the requesting IP.
+
+        Optionally, a country code can be specified in order to override
+        the IP detection.
+
+        Optionally, a list of transports can be specified in order to
+        return recommended settings for just that transport type.
+        """
+        endpoint = "https://bridges.torproject.org/moat/circumvention/settings"
+        data = {}
+        if country:
+            data = {"country": country}
+        if transports:
+            data.append({"transports": transports})
+        r = requests.post(
+            endpoint,
+            json=data,
+            headers={"Content-Type": "application/vnd.api+json"},
+            proxies=self.meek_proxies,
+        )
+        if r.status_code != 200:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_settings",
+                f"status_code={r.status_code}",
+            )
+            return False
+
+        result = r.json()
+
+        if "errors" in result:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_settings",
+                f"errors={result['errors']}",
+            )
+            return False
+
+        # There are no settings - perhaps this country doesn't require censorship circumvention?
+        # This is not really an error, so we can just check if False and assume direct Tor
+        # connection will work.
+        if not "settings" in result:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_settings",
+                "No settings found for this country",
+            )
+            return False
+
+        return result
+
+    def censorship_obtain_builtin_bridges(self):
+        """
+        Retrieves the list of built-in bridges from the Tor Project.
+        """
+        endpoint = "https://bridges.torproject.org/moat/circumvention/builtin"
+        r = requests.post(
+            endpoint,
+            headers={"Content-Type": "application/vnd.api+json"},
+            proxies=self.meek_proxies,
+        )
+        if r.status_code != 200:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_builtin_bridges",
+                f"status_code={r.status_code}",
+            )
+            return False
+
+        result = r.json()
+
+        if "errors" in result:
+            self.common.log(
+                "CensorshipCircumvention",
+                "censorship_obtain_builtin_bridges",
+                f"errors={result['errors']}",
+            )
+            return False
+
+        return result