# -*- 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 logging
import os
import queue
import requests
from distutils.version import LooseVersion as Version
import flask
from flask import (
Flask,
request,
render_template,
abort,
make_response,
send_file,
__version__ as flask_version,
)
from flask_httpauth import HTTPBasicAuth
from flask_socketio import SocketIO
from .share_mode import ShareModeWeb
from .receive_mode import ReceiveModeWeb, ReceiveModeWSGIMiddleware, ReceiveModeRequest
from .website_mode import WebsiteModeWeb
from .chat_mode import ChatModeWeb
# Stub out flask's show_server_banner function, to avoiding showing warnings that
# are not applicable to OnionShare
def stubbed_show_server_banner(env, debug, app_import_path, eager_loading):
pass
try:
flask.cli.show_server_banner = stubbed_show_server_banner
except:
pass
class Web:
"""
The Web object is the OnionShare web server, powered by flask
"""
REQUEST_LOAD = 0
REQUEST_STARTED = 1
REQUEST_PROGRESS = 2
REQUEST_CANCELED = 3
REQUEST_RATE_LIMIT = 4
REQUEST_UPLOAD_FILE_RENAMED = 5
REQUEST_UPLOAD_SET_DIR = 6
REQUEST_UPLOAD_FINISHED = 7
REQUEST_UPLOAD_CANCELED = 8
REQUEST_INDIVIDUAL_FILE_STARTED = 9
REQUEST_INDIVIDUAL_FILE_PROGRESS = 10
REQUEST_INDIVIDUAL_FILE_CANCELED = 11
REQUEST_ERROR_DATA_DIR_CANNOT_CREATE = 12
REQUEST_OTHER = 13
REQUEST_INVALID_PASSWORD = 14
def __init__(self, common, is_gui, mode_settings, mode="share"):
self.common = common
self.common.log("Web", "__init__", f"is_gui={is_gui}, mode={mode}")
self.settings = mode_settings
# The flask app
self.app = Flask(
__name__,
static_folder=self.common.get_resource_path("static"),
static_url_path=f"/static_{self.common.random_string(16)}", # randomize static_url_path to avoid making /static unusable
template_folder=self.common.get_resource_path("templates"),
)
self.app.secret_key = self.common.random_string(8)
self.generate_static_url_path()
self.auth = HTTPBasicAuth()
self.auth.error_handler(self.error401)
# Verbose mode?
if self.common.verbose:
self.verbose_mode()
# Are we running in GUI mode?
self.is_gui = is_gui
# If the user stops the server while a transfer is in progress, it should
# immediately stop the transfer. In order to make it thread-safe, stop_q
# is a queue. If anything is in it, then the user stopped the server
self.stop_q = queue.Queue()
# Are we using receive mode?
self.mode = mode
if self.mode == "receive":
# Use custom WSGI middleware, to modify environ
self.app.wsgi_app = ReceiveModeWSGIMiddleware(self.app.wsgi_app, self)
# Use a custom Request class to track upload progress
self.app.request_class = ReceiveModeRequest
# Starting in Flask 0.11, render_template_string autoescapes template variables
# by default. To prevent content injection through template variables in
# earlier versions of Flask, we force autoescaping in the Jinja2 template
# engine if we detect a Flask version with insecure default behavior.
if Version(flask_version) < Version("0.11"):
# Monkey-patch in the fix from https://github.com/pallets/flask/commit/99c99c4c16b1327288fd76c44bc8635a1de452bc
Flask.select_jinja_autoescape = self._safe_select_jinja_autoescape
self.security_headers = [
("X-Frame-Options", "DENY"),
("X-Xss-Protection", "1; mode=block"),
("X-Content-Type-Options", "nosniff"),
("Referrer-Policy", "no-referrer"),
("Server", "OnionShare"),
]
self.q = queue.Queue()
self.password = None
self.reset_invalid_passwords()
self.done = False
# shutting down the server only works within the context of flask, so the easiest way to do it is over http
self.shutdown_password = self.common.random_string(16)
# Keep track if the server is running
self.running = False
# Define the web app routes
self.define_common_routes()
# Create the mode web object, which defines its own routes
self.share_mode = None
self.receive_mode = None
self.website_mode = None
self.chat_mode = None
if self.mode == "share":
self.share_mode = ShareModeWeb(self.common, self)
elif self.mode == "receive":
self.receive_mode = ReceiveModeWeb(self.common, self)
elif self.mode == "website":
self.website_mode = WebsiteModeWeb(self.common, self)
elif self.mode == "chat":
self.socketio = SocketIO()
self.socketio.init_app(self.app)
self.chat_mode = ChatModeWeb(self.common, self)
def get_mode(self):
if self.mode == "share":
return self.share_mode
elif self.mode == "receive":
return self.receive_mode
elif self.mode == "website":
return self.website_mode
elif self.mode == "chat":
return self.chat_mode
else:
return None
def generate_static_url_path(self):
# The static URL path has a 128-bit random number in it to avoid having name
# collisions with files that might be getting shared
self.static_url_path = f"/static_{self.common.random_string(16)}"
self.common.log(
"Web",
"generate_static_url_path",
f"new static_url_path is {self.static_url_path}",
)
# Update the flask route to handle the new static URL path
self.app.static_url_path = self.static_url_path
self.app.add_url_rule(
self.static_url_path + "/<path:filename>",
endpoint="static",
view_func=self.app.send_static_file,
)
def define_common_routes(self):
"""
Common web app routes between all modes.
"""
@self.auth.get_password
def get_pw(username):
if username == "onionshare":
return self.password
else:
return None
@self.app.before_request
def conditional_auth_check():
# Allow static files without basic authentication
if request.path.startswith(self.static_url_path + "/"):
return None
# If public mode is disabled, require authentication
if not self.settings.get("general", "public"):
@self.auth.login_required
def _check_login():
return None
return _check_login()
@self.app.errorhandler(404)
def not_found(e):
mode = self.get_mode()
history_id = mode.cur_history_id
mode.cur_history_id += 1
return self.error404(history_id)
@self.app.route("/<password_candidate>/shutdown")
def shutdown(password_candidate):
"""
Stop the flask web server, from the context of an http request.
"""
if password_candidate == self.shutdown_password:
self.force_shutdown()
return ""
abort(404)
if self.mode != "website":
@self.app.route("/favicon.ico")
def favicon():
return send_file(
f"{self.common.get_resource_path('static')}/img/favicon.ico"
)
def error401(self):
auth = request.authorization
if auth:
if (
auth["username"] == "onionshare"
and auth["password"] not in self.invalid_passwords
):
print(f"Invalid password guess: {auth['password']}")
self.add_request(Web.REQUEST_INVALID_PASSWORD, data=auth["password"])
self.invalid_passwords.append(auth["password"])
self.invalid_passwords_count += 1
if self.invalid_passwords_count == 20:
self.add_request(Web.REQUEST_RATE_LIMIT)
self.force_shutdown()
print(
"Someone has made too many wrong attempts to guess your password, so OnionShare has stopped the server. Start sharing again and send the recipient a new address to share."
)
r = make_response(
render_template("401.html", static_url_path=self.static_url_path), 401
)
return self.add_security_headers(r)
def error403(self):
self.add_request(Web.REQUEST_OTHER, request.path)
r = make_response(
render_template("403.html", static_url_path=self.static_url_path), 403
)
return self.add_security_headers(r)
def error404(self, history_id):
self.add_request(
self.REQUEST_INDIVIDUAL_FILE_STARTED,
request.path,
{"id": history_id, "status_code": 404},
)
self.add_request(Web.REQUEST_OTHER, request.path)
r = make_response(
render_template("404.html", static_url_path=self.static_url_path), 404
)
return self.add_security_headers(r)
def error405(self, history_id):
self.add_request(
self.REQUEST_INDIVIDUAL_FILE_STARTED,
request.path,
{"id": history_id, "status_code": 405},
)
self.add_request(Web.REQUEST_OTHER, request.path)
r = make_response(
render_template("405.html", static_url_path=self.static_url_path), 405
)
return self.add_security_headers(r)
def add_security_headers(self, r):
"""
Add security headers to a request
"""
for header, value in self.security_headers:
r.headers.set(header, value)
# Set a CSP header unless in website mode and the user has disabled it
if not self.settings.get("website", "disable_csp") or self.mode != "website":
r.headers.set(
"Content-Security-Policy",
"default-src 'self'; style-src 'self'; script-src 'self'; img-src 'self' data:;",
)
return r
def _safe_select_jinja_autoescape(self, filename):
if filename is None:
return True
return filename.endswith((".html", ".htm", ".xml", ".xhtml"))
def add_request(self, request_type, path=None, data=None):
"""
Add a request to the queue, to communicate with the GUI.
"""
self.q.put({"type": request_type, "path": path, "data": data})
def generate_password(self, saved_password=None):
self.common.log("Web", "generate_password", f"saved_password={saved_password}")
if saved_password != None and saved_password != "":
self.password = saved_password
self.common.log(
"Web",
"generate_password",
f'saved_password sent, so password is: "{self.password}"',
)
else:
self.password = self.common.build_password()
self.common.log(
"Web", "generate_password", f'built random password: "{self.password}"'
)
def verbose_mode(self):
"""
Turn on verbose mode, which will log flask errors to a file.
"""
flask_log_filename = os.path.join(self.common.build_data_dir(), "flask.log")
log_handler = logging.FileHandler(flask_log_filename)
log_handler.setLevel(logging.WARNING)
self.app.logger.addHandler(log_handler)
def reset_invalid_passwords(self):
self.invalid_passwords_count = 0
self.invalid_passwords = []
def force_shutdown(self):
"""
Stop the flask web server, from the context of the flask app.
"""
# Shutdown the flask service
try:
func = request.environ.get("werkzeug.server.shutdown")
if func is None:
raise RuntimeError("Not running with the Werkzeug Server")
func()
except:
pass
self.running = False
def start(self, port):
"""
Start the flask web server.
"""
self.common.log("Web", "start", f"port={port}")
# Make sure the stop_q is empty when starting a new server
while not self.stop_q.empty():
try:
self.stop_q.get(block=False)
except queue.Empty:
pass
# In Whonix, listen on 0.0.0.0 instead of 127.0.0.1 (#220)
if os.path.exists("/usr/share/anon-ws-base-files/workstation"):
host = "0.0.0.0"
else:
host = "127.0.0.1"
self.running = True
if self.mode == "chat":
self.socketio.run(self.app, host=host, port=port)
else:
self.app.run(host=host, port=port, threaded=True)
def stop(self, port):
"""
Stop the flask web server by loading /shutdown.
"""
self.common.log("Web", "stop", "stopping server")
# Let the mode know that the user stopped the server
self.stop_q.put(True)
# To stop flask, load http://shutdown:[shutdown_password]@127.0.0.1/[shutdown_password]/shutdown
# (We're putting the shutdown_password in the path as well to make routing simpler)
if self.running:
if self.password:
requests.get(
f"http://127.0.0.1:{port}/{self.shutdown_password}/shutdown",
auth=requests.auth.HTTPBasicAuth("onionshare", self.password),
)
else:
requests.get(
f"http://127.0.0.1:{port}/{self.shutdown_password}/shutdown"
)
# Reset any password that was in use
self.password = None