Differential D9035 Diff 29587 profiles/views/webhooks.py

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profiles/views/webhooks.py

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				"""Implement webhook handlers."""
				from typing import Any, Dict
				import hashlib
				import hmac
				import json
				import logging
				import requests

				from django.conf import settings
				from django.core.exceptions import ObjectDoesNotExist
				from django.http import HttpResponse, HttpResponseBadRequest
				from django.http.request import HttpRequest
				from django.views.decorators.csrf import csrf_exempt
				from django.views.decorators.http import require_POST

				from profiles.blender_id import BIDSession
				from profiles.queries import set_groups

				bid = BIDSession()


				logger = logging.getLogger(__name__)
				WEBHOOK_MAX_BODY_SIZE = 1024 * 10 # 10 kB is large enough


				sybrenUnsubmitted Done Inline Actions Return type declaration & docstring are missing. sybren: Return type declaration & docstring are missing.
				sybrenUnsubmitted Done Inline Actions This function is doing too many things at once, better to split it up into a few smaller functions. sybren: This function is doing too many things at once, better to split it up into a few smaller…
				@csrf_exempt
				@require_POST
				def user_modified_webhook(request: HttpRequest) -> HttpResponse:
				"""
				Handle user modified request sent by Blender ID.

				Payload is expected to have the following format:
				{
				"avatar_changed": false,
				"email": "newmail@example.com",
				"full_name": "John Doe",
				"id": 2,
				sybrenUnsubmitted Not Done Inline Actions You're careful here with the length check, which is nice. An extra layer of carefulness could be added by using `body = request.body[:content_length+1]`. That way you read at most only a byte too many, avoiding DoS attacks. sybren: You're careful here with the length check, which is nice. An extra layer of carefulness could…
				raillaAuthorUnsubmitted Done Inline Actions This is a copypaste from Blender Cloud's code. I think this shouldn't be here at all, and should instead be handled by the webserver (e.g. nginx), not the application. railla: This is a copypaste from Blender Cloud's code. I think this shouldn't be here at all, and…
				"old_email": "mail@example.com",
				"roles": ["role1", "role2"],
				}
				"""
				hmac_secret = settings.BLENDER_ID['WEBHOOK_USER_MODIFIED_SECRET']
				sybrenUnsubmitted Done Inline Actions If the secret is going to be encoded anyway, why not store it in the config file as bytes? sybren: If the secret is going to be encoded anyway, why not store it in the config file as bytes?

				# Check the content type
				if request.content_type != 'application/json':
				logger.info(f'unexpected content type {request.content_type}')
				return HttpResponseBadRequest('Unsupported Content-Type')

				# Check the length of the body
				content_length = int(request.headers['CONTENT_LENGTH'])
				if content_length > WEBHOOK_MAX_BODY_SIZE:
				return HttpResponse('Payload Too Large', status=413)
				body = request.body
				if len(body) != content_length:
				return HttpResponseBadRequest("Content-Length header doesn't match content")

				# Validate the request
				mac = hmac.new(hmac_secret, body, hashlib.sha256)
				req_hmac = request.headers.get('X-Webhook-HMAC', '')
				our_hmac = mac.hexdigest()
				if not hmac.compare_digest(req_hmac, our_hmac):
				logger.info(f'Invalid HMAC {req_hmac}, expected {our_hmac}')
				return HttpResponseBadRequest('Invalid HMAC')

				try:
				payload = json.loads(body)
				# TODO(anna) validate the payload
				logger.info('payload: %s', payload)
				except json.JSONDecodeError:
				logger.exception('Malformed JSON received')
				return HttpResponseBadRequest('Malformed JSON')
				sybrenUnsubmitted Done Inline Actions What if the response is something else? sybren: What if the response is something else?

				# TODO(anna) move to a background task
				handle_user_modified(payload)

				sybrenUnsubmitted Not Done Inline Actions What if there is already a user with that username? sybren: What if there is already a user with that username?
				return HttpResponse(status=204)

				sybrenUnsubmitted Not Done Inline Actions What if there is already a user with that email address? sybren: What if there is already a user with that email address?

				def handle_user_modified(payload: Dict[Any, Any]) -> None:
				"""Handle payload of a user modified webhook, updating User and Profile when necessary."""
				oauth_user_id = str(payload['id'])
				try:
				oauth_user_info = bid.get_oauth_user_info(oauth_user_id)
				except ObjectDoesNotExist:
				logger.error(f'Cannot update profile: no OAuth info found for ID {oauth_user_id}')
				return

				user = oauth_user_info.user
				profile = user.profile

				# FIXME(anna) payload doesn't have username/nickname in it
				try:
				user_info = bid.get_user_info(oauth_user_id)
				if user_info['nickname'] != user.username:
				# TODO(anna) handle duplicate usernames
				user.username = user_info['nickname']
				user.save()
				except requests.HTTPError:
				sybrenUnsubmitted Not Done Inline Actions This is doing quite a few DB queries. It'll probably be simpler to get all the groups in the same query that fetches the user (with `select_related()`), then use sets to compute the differences. sybren: This is doing quite a few DB queries. It'll probably be simpler to get all the groups in the…
				raillaAuthorUnsubmitted Done Inline Actions Updated the code to use `select_related('user')` and a bulk query for adding to groups, same a with removing from groups. railla: Updated the code to use `select_related('user')` and a bulk query for adding to groups, same a…
				logger.exception(f'Unable to update username for {profile}')

				if payload['email'] != user.email:
				# TODO(anna) handle duplicate emails
				user.email = payload['email']
				user.save()

				if payload['full_name'] != profile.full_name:
				profile.full_name = payload['full_name']
				profile.save()
				if payload.get('avatar_changed') or not profile.avatar.name:
				profile.copy_avatar_from_blender_id()

				# Sync roles to groups
				group_names = payload.get('roles') or []
				set_groups(user, group_names=group_names)