rhodecode/tweens.py

# -*- coding: utf-8 -*-

# Copyright (C) 2010-2020 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# 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 Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/


import logging
from pyramid.httpexceptions import HTTPException, HTTPBadRequest

from rhodecode.lib.middleware.vcs import (
    detect_vcs_request, VCS_TYPE_KEY, VCS_TYPE_SKIP)


log = logging.getLogger(__name__)


def vcs_detection_tween_factory(handler, registry):

    def vcs_detection_tween(request):
        """
        Do detection of vcs type, and save results for other layers to re-use
        this information
        """
        vcs_server_enabled = request.registry.settings.get('vcs.server.enable')
        vcs_handler = vcs_server_enabled and detect_vcs_request(
            request.environ, request.registry.settings.get('vcs.backends'))

        if vcs_handler:
            # save detected VCS type for later re-use
            request.environ[VCS_TYPE_KEY] = vcs_handler.SCM
            request.vcs_call = vcs_handler.SCM

            log.debug('Processing request with `%s` handler', handler)
            return handler(request)

        # mark that we didn't detect an VCS, and we can skip detection later on
        request.environ[VCS_TYPE_KEY] = VCS_TYPE_SKIP

        log.debug('Processing request with `%s` handler', handler)
        return handler(request)

    return vcs_detection_tween


def junk_encoding_detector(request):
    """
    Detect bad encoded GET params, and fail immediately with BadRequest
    """

    try:
        request.GET.get("", None)
    except UnicodeDecodeError:
        raise HTTPBadRequest("Invalid bytes in query string.")


def bad_url_data_detector(request):
    """
    Detect invalid bytes in a path.
    """
    try:
        request.path_info
    except UnicodeDecodeError:
        raise HTTPBadRequest("Invalid bytes in URL.")


def junk_form_data_detector(request):
    """
    Detect bad encoded POST params, and fail immediately with BadRequest
    """

    if request.method == "POST":
        try:
            request.POST.get("", None)
        except ValueError:
            raise HTTPBadRequest("Invalid bytes in form data.")


def sanity_check_factory(handler, registry):
    def sanity_check(request):
        log.debug('Checking current URL sanity for bad data')
        try:
            junk_encoding_detector(request)
            bad_url_data_detector(request)
            junk_form_data_detector(request)
        except HTTPException as exc:
            return exc

        return handler(request)

    return sanity_check


def includeme(config):
    config.add_subscriber('rhodecode.subscribers.add_renderer_globals',
                          'pyramid.events.BeforeRender')
    config.add_subscriber('rhodecode.subscribers.set_user_lang',
                          'pyramid.events.NewRequest')
    config.add_subscriber('rhodecode.subscribers.add_localizer',
                          'pyramid.events.NewRequest')
    config.add_subscriber('rhodecode.subscribers.add_request_user_context',
                          'pyramid.events.ContextFound')
    config.add_tween('rhodecode.tweens.vcs_detection_tween_factory')
    config.add_tween('rhodecode.tweens.sanity_check_factory')

    # This needs to be the LAST item
    config.add_tween('rhodecode.lib.middleware.request_wrapper.RequestWrapperTween')
    log.debug('configured all tweens')