bookwyrm/fedireads/broadcast.py
2020-05-09 16:16:23 -07:00

102 lines
3.3 KiB
Python

''' send out activitypub messages '''
import json
from urllib.parse import urlparse
from base64 import b64encode
from Crypto.PublicKey import RSA
from Crypto.Signature import pkcs1_15
from Crypto.Hash import SHA256
from django.utils.http import http_date
import requests
from fedireads import models
from fedireads.tasks import app
def get_public_recipients(user, software=None):
''' everybody and their public inboxes '''
followers = user.followers.filter(local=False)
if software:
# TODO: eventually we may want to handle particular software differently
followers = followers.filter(fedireads_user=(software == 'fedireads'))
# we want shared inboxes when available
shared = followers.filter(
shared_inbox__isnull=False
).values_list('shared_inbox', flat=True).distinct()
# if a user doesn't have a shared inbox, we need their personal inbox
# iirc pixelfed doesn't have shared inboxes
inboxes = followers.filter(
shared_inbox__isnull=True
).values_list('inbox', flat=True)
return list(shared) + list(inboxes)
def broadcast(sender, activity, software=None, \
privacy='public', direct_recipients=None):
''' send out an event '''
# start with parsing the direct recipients
recipients = [u.inbox for u in direct_recipients or []]
# and then add any other recipients
# TODO: other kinds of privacy
if privacy == 'public':
recipients += get_public_recipients(sender, software=software)
broadcast_task.delay(sender.id, activity, recipients)
@app.task
def broadcast_task(sender_id, activity, recipients):
''' the celery task for broadcast '''
sender = models.User.objects.get(id=sender_id)
errors = []
for recipient in recipients:
try:
sign_and_send(sender, activity, recipient)
except requests.exceptions.HTTPError as e:
# TODO: maybe keep track of users who cause errors
errors.append({
'error': e,
'recipient': recipient,
'activity': activity,
})
return errors
def sign_and_send(sender, activity, destination):
''' crpyto whatever and http junk '''
inbox_parts = urlparse(destination)
now = http_date()
signature_headers = [
'(request-target): post %s' % inbox_parts.path,
'host: %s' % inbox_parts.netloc,
'date: %s' % now
]
message_to_sign = '\n'.join(signature_headers)
if not sender.private_key:
# this shouldn't happen. it would be bad if it happened.
raise ValueError('No private key found for sender')
signer = pkcs1_15.new(RSA.import_key(sender.private_key))
signed_message = signer.sign(SHA256.new(message_to_sign.encode('utf8')))
signature = {
'keyId': '%s#main-key' % sender.actor,
'algorithm': 'rsa-sha256',
'headers': '(request-target) host date',
'signature': b64encode(signed_message).decode('utf8'),
}
signature = ','.join('%s="%s"' % (k, v) for (k, v) in signature.items())
response = requests.post(
destination,
data=json.dumps(activity),
headers={
'Date': now,
'Signature': signature,
'Content-Type': 'application/activity+json; charset=utf-8',
},
)
if not response.ok:
response.raise_for_status()
return response