zulip/zerver/lib/rest.py

125 lines
5.6 KiB
Python

from __future__ import absolute_import
from typing import Any, Dict
from django.utils.module_loading import import_string
from django.utils.translation import ugettext as _
from django.views.decorators.csrf import csrf_exempt, csrf_protect
from zerver.decorator import authenticated_json_view, authenticated_rest_api_view, \
process_as_post
from zerver.lib.response import json_method_not_allowed, json_unauthorized
from django.http import HttpRequest, HttpResponse, HttpResponseRedirect
from django.conf import settings
METHODS = ('GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'PATCH')
FLAGS = ('override_api_url_scheme')
@csrf_exempt
def rest_dispatch(request, **kwargs):
# type: (HttpRequest, **Any) -> HttpResponse
"""Dispatch to a REST API endpoint.
Unauthenticated endpoints should not use this, as authentication is verified
in the following ways:
* for paths beginning with /api, HTTP Basic auth
* for paths beginning with /json (used by the web client), the session token
This calls the function named in kwargs[request.method], if that request
method is supported, and after wrapping that function to:
* protect against CSRF (if the user is already authenticated through
a Django session)
* authenticate via an API key (otherwise)
* coerce PUT/PATCH/DELETE into having POST-like semantics for
retrieving variables
Any keyword args that are *not* HTTP methods are passed through to the
target function.
Never make a urls.py pattern put user input into a variable called GET, POST,
etc, as that is where we route HTTP verbs to target functions.
"""
supported_methods = {} # type: Dict[str, Any]
# duplicate kwargs so we can mutate the original as we go
for arg in list(kwargs):
if arg in METHODS:
supported_methods[arg] = kwargs[arg]
del kwargs[arg]
if request.method == 'OPTIONS':
response = HttpResponse(status=204) # No content
response['Allow'] = ', '.join(supported_methods.keys())
response['Content-Length'] = "0"
return response
# Override requested method if magic method=??? parameter exists
method_to_use = request.method
if request.POST and 'method' in request.POST:
method_to_use = request.POST['method']
if method_to_use == "SOCKET" and "zulip.emulated_method" in request.META:
method_to_use = request.META["zulip.emulated_method"]
if method_to_use in supported_methods:
entry = supported_methods[method_to_use]
if isinstance(entry, tuple):
target_function, view_flags = entry
target_function = import_string(target_function)
else:
target_function = import_string(supported_methods[method_to_use])
view_flags = set()
# Set request._query for update_activity_user(), which is called
# by some of the later wrappers.
request._query = target_function.__name__
# We want to support authentication by both cookies (web client)
# and API keys (API clients). In the former case, we want to
# do a check to ensure that CSRF etc is honored, but in the latter
# we can skip all of that.
#
# Security implications of this portion of the code are minimal,
# as we should worst-case fail closed if we miscategorise a request.
# for some special views (e.g. serving a file that has been
# uploaded), we support using the same url for web and API clients.
if ('override_api_url_scheme' in view_flags
and request.META.get('HTTP_AUTHORIZATION', None) is not None):
# This request API based authentication.
target_function = authenticated_rest_api_view()(target_function)
# /json views (web client) validate with a session token (cookie)
elif not request.path.startswith("/api") and request.user.is_authenticated():
# Authenticated via sessions framework, only CSRF check needed
target_function = csrf_protect(authenticated_json_view(target_function))
# most clients (mobile, bots, etc) use HTTP Basic Auth and REST calls, where instead of
# username:password, we use email:apiKey
elif request.META.get('HTTP_AUTHORIZATION', None):
# Wrap function with decorator to authenticate the user before
# proceeding
target_function = authenticated_rest_api_view()(target_function)
# Pick a way to tell user they're not authed based on how the request was made
else:
# If this looks like a request from a top-level page in a
# browser, send the user to the login page
if 'text/html' in request.META.get('HTTP_ACCEPT', ''):
return HttpResponseRedirect('%s/?next=%s' % (settings.HOME_NOT_LOGGED_IN, request.path))
# Ask for basic auth (email:apiKey)
elif request.path.startswith("/api"):
return json_unauthorized(_("Not logged in: API authentication or user session required"))
# Session cookie expired, notify the client
else:
return json_unauthorized(_("Not logged in: API authentication or user session required"),
www_authenticate='session')
if request.method not in ["GET", "POST"]:
# process_as_post needs to be the outer decorator, because
# otherwise we might access and thus cache a value for
# request.REQUEST.
target_function = process_as_post(target_function)
return target_function(request, **kwargs)
return json_method_not_allowed(list(supported_methods.keys()))