FreedomBox/plinth/modules/tor/tor.py

#
# This file is part of Plinth.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#

"""
Plinth module for configuring Tor
"""

import augeas
from django import forms
from django.contrib import messages
from django.template.response import TemplateResponse
from gettext import gettext as _

from plinth import actions
from plinth import action_utils
from plinth import cfg
from plinth import package

APT_SOURCES_URI_PATH = '/files/etc/apt/sources.list/*/uri'
APT_TOR_PREFIX = 'tor+'


class TorForm(forms.Form):  # pylint: disable=W0232
    """Tor configuration form"""
    enabled = forms.BooleanField(
        label=_('Enable Tor'),
        required=False)
    hs_enabled = forms.BooleanField(
        label=_('Enable Tor Hidden Service'),
        required=False,
        help_text=_('A hidden service will allow FreedomBox to provide '
                    'selected services (such as ownCloud or Chat) without '
                    'revealing its location.'))
    apt_transport_tor_enabled = forms.BooleanField(
        label=_('Download software packages over Tor'),
        required=False,
        help_text=_('When enabled, Debian packages will be downloaded over '
                    'the Tor network for software installs and upgrades. This '
                    'adds a degree of privacy to your software downloads.'))


def init():
    """Initialize the Tor module."""
    menu = cfg.main_menu.get('apps:index')
    menu.add_urlname(_('Anonymity Network (Tor)'), 'glyphicon-eye-close',
                     'tor:index', 100)


def on_install():
    """Setup Tor configuration as soon as it is installed."""
    actions.superuser_run('tor', ['setup'])
    actions.superuser_run('tor', ['enable-apt-transport-tor'])


@package.required(['tor', 'obfsproxy', 'torsocks', 'apt-transport-tor'],
                  on_install=on_install)
def index(request):
    """Service the index page"""
    status = get_status()

    form = None

    if request.method == 'POST':
        form = TorForm(request.POST, prefix='tor')
        # pylint: disable=E1101
        if form.is_valid():
            _apply_changes(request, status, form.cleaned_data)
            status = get_status()
            form = TorForm(initial=status, prefix='tor')
    else:
        form = TorForm(initial=status, prefix='tor')

    return TemplateResponse(request, 'tor.html',
                            {'title': _('Tor Control Panel'),
                             'status': status,
                             'form': form})


def get_status():
    """Return the current status"""
    output = actions.superuser_run('tor', ['get-ports'])
    port_info = output.split('\n')
    ports = {}
    for line in port_info:
        try:
            (key, val) = line.split()
            ports[key] = val
        except ValueError:
            continue

    output = actions.superuser_run('tor', ['get-hs'])
    output = output.strip()
    if output == '':
        hs_enabled = False
        hs_hostname = 'Not Configured'
        hs_ports = ''
    elif output == 'error':
        hs_enabled = False
        hs_hostname = 'Not available (Run Tor at least once)'
        hs_ports = ''
    else:
        hs_enabled = True
        hs_info = output.split()
        hs_hostname = hs_info[0]
        hs_ports = hs_info[1]

    apt_transport_tor_enabled = False
    aug = augeas.Augeas()
    for uri_path in aug.match(APT_SOURCES_URI_PATH):
        if aug.get(uri_path).startswith(APT_TOR_PREFIX):
            apt_transport_tor_enabled = True
            break

    return {'enabled': action_utils.service_is_enabled('tor'),
            'is_running': action_utils.service_is_running('tor'),
            'ports': ports,
            'hs_enabled': hs_enabled,
            'hs_hostname': hs_hostname,
            'hs_ports': hs_ports,
            'apt_transport_tor_enabled': apt_transport_tor_enabled}


def _apply_changes(request, old_status, new_status):
    """Apply the changes."""
    if old_status['enabled'] == new_status['enabled'] and \
       old_status['hs_enabled'] == new_status['hs_enabled'] and \
       old_status['apt_transport_tor_enabled'] == \
       new_status['apt_transport_tor_enabled']:
        messages.info(request, _('Setting unchanged'))
        return

    if old_status['enabled'] != new_status['enabled']:
        if new_status['enabled']:
            messages.success(request, _('Tor enabled'))
            actions.superuser_run('tor', ['enable'])
        else:
            messages.success(request, _('Tor disabled'))
            actions.superuser_run('tor', ['disable'])

    if old_status['hs_enabled'] != new_status['hs_enabled']:
        if new_status['hs_enabled']:
            messages.success(request, _('Tor hidden service enabled'))
            actions.superuser_run('tor', ['enable-hs'])
        else:
            messages.success(request, _('Tor hidden service disabled'))
            actions.superuser_run('tor', ['disable-hs'])

    if old_status['apt_transport_tor_enabled'] != \
       new_status['apt_transport_tor_enabled']:
        if new_status['apt_transport_tor_enabled']:
            messages.success(request, _('Enabled package download over Tor'))
            actions.superuser_run('tor', ['enable-apt-transport-tor'])
        else:
            messages.success(request, _('Disabled package download over Tor'))
            actions.superuser_run('tor', ['disable-apt-transport-tor'])