__init__.py

# -*- coding: utf8 -*-
# This file is part of PYBOSSA.
#
# Copyright (C) 2018 Scifabric LTD.
#
# PYBOSSA 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.
#
# PYBOSSA 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 PYBOSSA.  If not, see <http://www.gnu.org/licenses/>.

import inspect
from flask import abort
from flask_login import current_user
from pybossa.core import announcement_repo, task_repo, project_repo, result_repo
from pybossa.core import project_stats_repo
from pybossa.auth.errcodes import *

import jwt
from flask import jsonify
from jwt import exceptions

import project
import projectstats
import task
import taskrun
import category
import user
import token
import announcement
import blogpost
import auditlog
import webhook
import result
import helpingmaterial

assert project
assert projectstats
assert task
assert taskrun
assert category
assert user
assert token
assert announcement
assert blogpost
assert auditlog
assert webhook
assert result


_actions = ['create', 'read', 'update', 'delete']
_auth_classes = {'project': project.ProjectAuth,
                 'projectstats': projectstats.ProjectStatsAuth,
                 'auditlog': auditlog.AuditlogAuth,
                 'announcement': announcement.AnnouncementAuth,
                 'blogpost': blogpost.BlogpostAuth,
                 'category': category.CategoryAuth,
                 'task': task.TaskAuth,
                 'taskrun': taskrun.TaskRunAuth,
                 'token': token.TokenAuth,
                 'user': user.UserAuth,
                 'webhook': webhook.WebhookAuth,
                 'result': result.ResultAuth,
                 'helpingmaterial': helpingmaterial.HelpingMaterialAuth}


def is_authorized(user, action, resource, **kwargs):
    is_class = inspect.isclass(resource)
    name = resource.__name__ if is_class else resource.__class__.__name__
    if resource == 'token':
        name = resource
    resource = None if is_class else resource
    auth = _authorizer_for(name.lower())
    actions = _actions + auth.specific_actions
    assert action in actions, "%s is not a valid action" % action
    return auth.can(user, action, resource, **kwargs)


def ensure_authorized_to(action, resource, **kwargs):
    authorized = is_authorized(current_user, action, resource, **kwargs)
    if authorized is False:
        if current_user.is_anonymous():
            raise abort(401)
        else:
            raise abort(403)
    return authorized


def _authorizer_for(resource_name):
    kwargs = {}
    if resource_name in ('project', 'taskrun'):
        kwargs.update({'task_repo': task_repo})
    if resource_name in ('auditlog', 'blogpost', 'task',
                         'taskrun', 'webhook', 'result',
                         'helpingmaterial'):
        kwargs.update({'project_repo': project_repo})
    if resource_name in ('project', 'task', 'taskrun'):
        kwargs.update({'result_repo': result_repo})
    return _auth_classes[resource_name](**kwargs)


def handle_error(error):
    """Return authentication error in JSON."""
    resp = jsonify(error)
    resp.status_code = 401
    return resp


def jwt_authorize_project(project, payload):
    """Authorize the project for the payload."""
    try:
        if payload is None:
            return handle_error(INVALID_HEADER_MISSING)
        parts = payload.split()

        if parts[0].lower() != 'bearer':
            return handle_error(INVALID_HEADER_BEARER)
        elif len(parts) == 1:
            return handle_error(INVALID_HEADER_TOKEN)
        elif len(parts) > 2:
            return handle_error(INVALID_HEADER_BEARER_TOKEN)

        data = jwt.decode(parts[1],
                          project.secret_key,
                          'H256')
        if (data['project_id'] == project.id
            and data['short_name'] == project.short_name):
            return True
        else:
            return handle_error(WRONG_PROJECT_SIGNATURE)
    except exceptions.DecodeError:
        return handle_error(DECODE_ERROR_SIGNATURE)