Commit 75052806 authored by Philipp Hörist's avatar Philipp Hörist
Browse files

[omemo] Add file decryption

parent 65e2f437
# -*- coding: utf-8 -*-
#
# Copyright 2017 Philipp Hörist <philipp@hoerist.com>
#
# This file is part of Gajim-OMEMO plugin.
#
# The Gajim-OMEMO plugin 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.
#
# Gajim-OMEMO 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
# the Gajim-OMEMO plugin. If not, see <http://www.gnu.org/licenses/>.
#
import os
import hashlib
import logging
import socket
import threading
import platform
import subprocess
import binascii
from urllib.request import urlopen
from urllib.error import URLError
from urllib.parse import urlparse, urldefrag
from io import BufferedWriter, FileIO, BytesIO
from gi.repository import GLib
import gtkgui_helpers
from common import configpaths
from dialogs import ErrorDialog, YesNoDialog
if os.name == 'nt':
import certifi
log = logging.getLogger('gajim.plugin_system.omemo.filedecryption')
ERROR = False
try:
from cryptography.hazmat.primitives.ciphers import Cipher
from cryptography.hazmat.primitives.ciphers import algorithms
from cryptography.hazmat.primitives.ciphers.modes import GCM
from cryptography.hazmat.backends import default_backend
except ImportError:
log.exception('ImportError')
ERROR = True
DIRECTORY = os.path.join(configpaths.gajimpaths['MY_DATA'], 'downloads')
try:
if not os.path.exists(DIRECTORY):
os.makedirs(DIRECTORY)
except Exception:
ERROR = True
log.exception('Error')
class File:
def __init__(self, url):
self.url, self.fragment = urldefrag(url)
self.key = None
self.iv = None
self.filepath = None
self.filename = None
class FileDecryption:
def __init__(self, plugin):
self.plugin = plugin
self.window = None
def hyperlink_handler(self, url, kind, instance, window):
if ERROR or kind != 'url':
return
self.window = window
urlparts = urlparse(url)
file = File(urlparts.geturl())
if urlparts.scheme not in ["https"] or not urlparts.netloc:
log.info("Not accepting URL for decryption: %s", url)
return
if not self.is_encrypted(file):
log.info('Url not encrypted: %s', url)
return
self.create_paths(file)
if os.path.exists(file.filepath):
instance.plugin_modified = True
self.finished(file)
return
event = threading.Event()
progressbar = ProgressWindow(self.plugin, self.window, event)
thread = threading.Thread(target=Download,
args=(file, progressbar, self.window,
event, self))
thread.daemon = True
thread.start()
instance.plugin_modified = True
def is_encrypted(self, file):
if file.fragment:
try:
fragment = binascii.unhexlify(file.fragment)
file.key = fragment[16:]
file.iv = fragment[:16]
if len(file.key) == 32 and len(file.iv) == 16:
return True
except:
return False
return False
def create_paths(self, file):
file.filename = os.path.basename(file.url)
ext = os.path.splitext(file.filename)[1]
name = os.path.splitext(file.filename)[0]
urlhash = hashlib.sha1(file.url.encode('utf-8')).hexdigest()
newfilename = name + '_' + urlhash[:10] + ext
file.filepath = os.path.join(DIRECTORY, newfilename)
def finished(self, file):
question = 'Do you want to open %s' % file.filename
YesNoDialog('Open File', question,
transient_for=self.window,
on_response_yes=(self.open_file, file.filepath))
return False
def open_file(self, checked, path):
if platform.system() == "Windows":
os.startfile(path)
elif platform.system() == "Darwin":
subprocess.Popen(["open", path])
else:
subprocess.Popen(["xdg-open", path])
class Download:
def __init__(self, file, progressbar, window, event, base):
self.file = file
self.progressbar = progressbar
self.window = window
self.event = event
self.base = base
self.download()
def download(self):
GLib.idle_add(self.progressbar.set_text, 'Downloading...')
data = self.load_url()
if isinstance(data, str):
GLib.idle_add(self.progressbar.close_dialog)
GLib.idle_add(self.error, data)
return
GLib.idle_add(self.progressbar.set_text, 'Decrypting...')
decrypted_data = self.aes_decrypt(data)
GLib.idle_add(
self.progressbar.set_text, 'Writing file to harddisk...')
self.write_file(decrypted_data)
GLib.idle_add(self.progressbar.close_dialog)
GLib.idle_add(self.base.finished, self.file)
def load_url(self):
try:
stream = BytesIO()
if os.name == 'nt':
get_request = urlopen(
self.file.url, cafile=certifi.where(), timeout=30)
else:
get_request = urlopen(self.file.url, timeout=30)
size = get_request.info()['Content-Length']
if not size:
errormsg = 'Content-Length not found in header'
log.error(errormsg)
return errormsg
while True:
try:
if self.event.isSet():
raise UploadAbortedException
temp = get_request.read(10000)
GLib.idle_add(
self.progressbar.update_progress, len(temp), size)
except socket.timeout:
errormsg = 'Request timeout'
log.error(errormsg)
return errormsg
if temp:
stream.write(temp)
else:
return stream
except UploadAbortedException as error:
log.info('Upload Aborted')
errormsg = error
except URLError as error:
log.exception('URLError')
errormsg = error.reason
except Exception as error:
log.exception('Error')
errormsg = error
stream.close()
return str(errormsg)
def aes_decrypt(self, payload):
# Use AES128 GCM with the given key and iv to decrypt the payload.
payload = payload.getvalue()
data = payload[:-16]
tag = payload[-16:]
decryptor = Cipher(
algorithms.AES(self.file.key),
GCM(self.file.iv, tag=tag),
backend=default_backend()).decryptor()
return decryptor.update(data) + decryptor.finalize()
def write_file(self, data):
log.info('Writing data to %s', self.file.filepath)
try:
with BufferedWriter(FileIO(self.file.filepath, "wb")) as output:
output.write(data)
output.close()
except Exception:
log.exception('Failed to write file')
def error(self, error):
ErrorDialog(_('Error'), error, transient_for=self.window)
return False
class ProgressWindow:
def __init__(self, plugin, window, event):
self.plugin = plugin
self.event = event
self.xml = gtkgui_helpers.get_gtk_builder(
self.plugin.local_file_path('upload_progress_dialog.ui'))
self.dialog = self.xml.get_object('progress_dialog')
self.dialog.set_transient_for(window)
self.label = self.xml.get_object('label')
self.progressbar = self.xml.get_object('progressbar')
self.progressbar.set_text("")
self.dialog.show_all()
self.xml.connect_signals(self)
self.seen = 0
def set_text(self, text):
self.label.set_markup('<big>%s</big>' % text)
return False
def update_progress(self, seen, total):
self.seen += seen
pct = (self.seen / float(total)) * 100.0
self.progressbar.set_fraction(self.seen / float(total))
self.progressbar.set_text(str(int(pct)) + "%")
return False
def close_dialog(self, *args):
self.dialog.destroy()
return False
def on_destroy(self, *args):
self.event.set()
class UploadAbortedException(Exception):
def __str__(self):
return _('Upload Aborted')
......@@ -30,6 +30,7 @@ from plugins import GajimPlugin
from plugins.helpers import log_calls
from nbxmpp.simplexml import Node
from nbxmpp import NS_CORRECT, NS_ADDRESS
from .file_decryption import FileDecryption
from .xmpp import (
NS_NOTIFY, NS_OMEMO, NS_EME, BundleInformationAnnouncement,
......@@ -115,7 +116,9 @@ class OmemoPlugin(GajimPlugin):
self.gui_extension_points = {'chat_control': (self.connect_ui,
self.disconnect_ui),
'groupchat_control': (self.connect_ui,
self.disconnect_ui)}
self.disconnect_ui),
'hyperlink_handler': (self.file_decryption,
None)}
SUPPORTED_PERSONAL_USER_EVENTS.append(DevicelistPEP)
self.plugin = self
self.announced = []
......@@ -179,6 +182,9 @@ class OmemoPlugin(GajimPlugin):
'enable_esessions', False)
log.info(str(account) + " => Gajim E2E encryption disabled")
def file_decryption(self, url, kind, instance, window):
FileDecryption(self).hyperlink_handler(url, kind, instance, window)
@log_calls('OmemoPlugin')
def signed_in(self, event):
""" Method called on SignIn
......
<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.20.0 -->
<interface>
<requires lib="gtk+" version="3.0"/>
<object class="GtkDialog" id="progress_dialog">
<property name="can_focus">True</property>
<property name="title" translatable="yes">Download</property>
<property name="resizable">False</property>
<property name="window_position">center-on-parent</property>
<property name="destroy_with_parent">True</property>
<property name="icon_name">go-down</property>
<property name="type_hint">dialog</property>
<child internal-child="vbox">
<object class="GtkBox" id="dialog-vbox">
<property name="width_request">250</property>
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="spacing">6</property>
<child internal-child="action_area">
<object class="GtkButtonBox" id="dialog-action_area11">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="layout_style">end</property>
<child>
<object class="GtkAlignment" id="alignment3">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="top_padding">2</property>
<property name="bottom_padding">4</property>
<property name="right_padding">3</property>
<child>
<object class="GtkButton" id="close_button">
<property name="label">gtk-cancel</property>
<property name="visible">True</property>
<property name="can_focus">True</property>
<property name="can_default">True</property>
<property name="receives_default">False</property>
<property name="use_stock">True</property>
<signal name="clicked" handler="close_dialog" swapped="no"/>
<signal name="destroy" handler="on_destroy" swapped="no"/>
</object>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">2</property>
</packing>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">False</property>
<property name="pack_type">end</property>
<property name="position">0</property>
</packing>
</child>
<child>
<object class="GtkAlignment" id="alignment1">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="top_padding">8</property>
<property name="bottom_padding">4</property>
<property name="left_padding">8</property>
<property name="right_padding">8</property>
<child>
<object class="GtkLabel" id="label">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="use_markup">True</property>
</object>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
<child>
<object class="GtkAlignment" id="alignment2">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="top_padding">4</property>
<property name="bottom_padding">4</property>
<property name="left_padding">8</property>
<property name="right_padding">8</property>
<child>
<object class="GtkProgressBar" id="progressbar">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="pulse_step">0.10000000149</property>
<property name="show_text">True</property>
</object>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">2</property>
</packing>
</child>
</object>
</child>
</object>
</interface>
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