bookwyrm/fedireads/incoming.py
2020-02-10 20:22:36 -08:00

335 lines
10 KiB
Python

''' handles all of the activity coming in to the server '''
from base64 import b64decode
from Crypto.PublicKey import RSA
from Crypto.Signature import pkcs1_15
from Crypto.Hash import SHA256
from django.http import HttpResponse, HttpResponseBadRequest, \
HttpResponseNotFound, JsonResponse
from django.views.decorators.csrf import csrf_exempt
import json
import requests
from uuid import uuid4
from fedireads import models
from fedireads.api import get_or_create_remote_user
from fedireads.openlibrary import get_or_create_book
from fedireads.settings import DOMAIN
# TODO: this should probably live somewhere else
class HttpResponseUnauthorized(HttpResponse):
''' http response for authentication failure '''
status_code = 401
def webfinger(request):
''' allow other servers to ask about a user '''
resource = request.GET.get('resource')
if not resource and not resource.startswith('acct:'):
return HttpResponseBadRequest()
ap_id = resource.replace('acct:', '')
user = models.User.objects.filter(username=ap_id).first()
if not user:
return HttpResponseNotFound('No account found')
return JsonResponse({
'subject': 'acct:%s' % (user.username),
'links': [
{
'rel': 'self',
'type': 'application/activity+json',
'href': user.actor
}
]
})
@csrf_exempt
def shared_inbox(request):
''' incoming activitypub events '''
# TODO: should this be functionally different from the non-shared inbox??
if request.method == 'GET':
return HttpResponseNotFound()
try:
activity = json.loads(request.body)
except json.decoder.JSONDecodeError:
return HttpResponseBadRequest
# verify rsa signature
signature_header = request.headers['Signature'].split(',')
signature_dict = {}
for pair in signature_header:
k, v = pair.split('=', 1)
v = v.replace('"', '')
signature_dict[k] = v
key_id = signature_dict['keyId']
headers = signature_dict['headers']
signature = b64decode(signature_dict['signature'])
response = requests.get(
key_id,
headers={'Accept': 'application/activity+json'}
)
if not response.ok:
return HttpResponseUnauthorized()
actor = response.json()
key = RSA.import_key(actor['publicKey']['publicKeyPem'])
comparison_string = []
for signed_header_name in headers.split(' '):
if signed_header_name == '(request-target)':
comparison_string.append('(request-target): post %s' % request.path)
else:
comparison_string.append('%s: %s' % (
signed_header_name,
request.headers[signed_header_name]
))
comparison_string = '\n'.join(comparison_string)
signer = pkcs1_15.new(key)
digest = SHA256.new()
digest.update(comparison_string.encode())
try:
signer.verify(digest, signature)
except ValueError:
return HttpResponseUnauthorized()
if activity['type'] == 'Add':
return handle_incoming_shelve(activity)
if activity['type'] == 'Follow':
return handle_incoming_follow(activity)
if activity['type'] == 'Create':
return handle_incoming_create(activity)
return HttpResponseNotFound()
@csrf_exempt
def inbox(request, username):
''' incoming activitypub events '''
# TODO: should do some kind of checking if the user accepts
# this action from the sender probably? idk
# but this will just throw an error if the user doesn't exist I guess
models.User.objects.get(localname=username)
return shared_inbox(request)
@csrf_exempt
def get_actor(request, username):
''' return an activitypub actor object '''
if request.method != 'GET':
return HttpResponseBadRequest()
user = models.User.objects.get(localname=username)
return JsonResponse({
'@context': [
'https://www.w3.org/ns/activitystreams',
'https://w3id.org/security/v1'
],
'id': user.actor,
'type': 'Person',
'preferredUsername': user.localname,
'name': user.name,
'inbox': user.inbox,
'followers': '%s/followers' % user.actor,
'following': '%s/following' % user.actor,
'summary': user.summary,
'publicKey': {
'id': '%s/#main-key' % user.actor,
'owner': user.actor,
'publicKeyPem': user.public_key,
},
'endpoints': {
'sharedInbox': user.shared_inbox,
}
})
@csrf_exempt
def get_followers(request, username):
''' return a list of followers for an actor '''
if request.method != 'GET':
return HttpResponseBadRequest()
user = models.User.objects.get(localname=username)
followers = user.followers
return format_follow_info(user, request.GET.get('page'), followers)
@csrf_exempt
def get_following(request, username):
''' return a list of following for an actor '''
if request.method != 'GET':
return HttpResponseBadRequest()
user = models.User.objects.get(localname=username)
following = models.User.objects.filter(followers=user)
return format_follow_info(user, request.GET.get('page'), following)
def format_follow_info(user, page, follow_queryset):
''' create the activitypub json for followers/following '''
id_slug = '%s/following' % user.actor
if page:
return JsonResponse(get_follow_page(follow_queryset, id_slug, page))
count = follow_queryset.count()
return JsonResponse({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': id_slug,
'type': 'OrderedCollection',
'totalItems': count,
'first': '%s?page=1' % id_slug,
})
def get_follow_page(user_list, id_slug, page):
''' format a list of followers/following '''
page = int(page)
page_length = 10
start = (page - 1) * page_length
end = start + page_length
follower_page = user_list.all()[start:end]
data = {
'@context': 'https://www.w3.org/ns/activitystreams',
'id': '%s?page=%d' % (id_slug, page),
'type': 'OrderedCollectionPage',
'totalItems': user_list.count(),
'partOf': id_slug,
'orderedItems': [u.actor for u in follower_page],
}
if end <= user_list.count():
# there are still more pages
data['next'] = '%s?page=%d' % (id_slug, page + 1)
if start > 0:
data['prev'] = '%s?page=%d' % (id_slug, page - 1)
return data
def handle_incoming_shelve(activity):
''' receiving an Add activity (to shelve a book) '''
# TODO what happens here? If it's a remote over, then I think
# I should save both the activity and the ShelfBook entry. But
# I'll do that later.
uuid = activity['id']
models.ShelveActivity.objects.get(uuid=uuid)
'''
book_id = activity['object']['url']
book = openlibrary.get_or_create_book(book_id)
user_ap_id = activity['actor'].replace('https//:', '')
user = models.User.objects.get(actor=user_ap_id)
if not user or not user.local:
return HttpResponseBadRequest()
shelf = models.Shelf.objects.get(activitypub_id=activity['target']['id'])
models.ShelfBook(
shelf=shelf,
book=book,
added_by=user,
).save()
'''
return HttpResponse()
def handle_incoming_follow(activity):
'''
{
"@context": "https://www.w3.org/ns/activitystreams",
"id": "https://friend.camp/768222ce-a1c7-479c-a544-c93b8b67fb54",
"type": "Follow",
"actor": "https://friend.camp/users/tripofmice",
"object": "https://ff2cb3e9.ngrok.io/api/u/mouse"
}
'''
# figure out who they want to follow
to_follow = models.User.objects.get(actor=activity['object'])
# figure out who they are
user = get_or_create_remote_user(activity['actor'])
to_follow.followers.add(user)
# verify uuid and accept the request
models.FollowActivity(
uuid=activity['id'],
user=user,
followed=to_follow,
content=activity,
activity_type='Follow',
)
uuid = uuid4()
# TODO does this need to be signed?
return JsonResponse({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': 'https://%s/%s' % (DOMAIN, uuid),
'type': 'Accept',
'actor': user.actor,
'object': activity,
})
def handle_incoming_create(activity):
''' someone did something, good on them '''
user = get_or_create_remote_user(activity['actor'])
uuid = activity['id']
# if it's an article and in reply to a book, we have a review
if activity['object']['type'] == 'Article' and \
'inReplyTo' in activity['object']:
possible_book = activity['object']['inReplyTo']
try:
# TODO idk about this error handling, should probs be more granular
book = get_or_create_book(possible_book)
models.Review(
uuid=uuid,
user=user,
content=activity,
activity_type='Article',
book=book,
name=activity['object']['name'],
rating=activity['object']['rating'],
review_content=activity['objet']['content'],
).save()
return HttpResponse()
except KeyError:
pass
models.Activity(
uuid=uuid,
user=user,
content=activity,
activity_type=activity['object']['type']
)
return HttpResponse()
def handle_incoming_accept(activity):
''' someone is accepting a follow request '''
# our local user
user = models.User.objects.get(actor=activity['actor'])
# the person our local user wants to follow, who said yes
followed = get_or_create_remote_user(activity['object']['actor'])
# save this relationship in the db
followed.followers.add(user)
# save the activity record
models.FollowActivity(
uuid=activity['id'],
user=user,
followed=followed,
content=activity,
).save()
return HttpResponse()
def handle_response(response):
''' hopefully it's an accept from our follow request '''
try:
activity = response.json()
except ValueError:
return
if activity['type'] == 'Accept':
handle_incoming_accept(activity)