moviewyrm/fedireads/broadcast.py
2020-02-15 13:01:42 -08:00

87 lines
2.8 KiB
Python

''' send out activitypub messages '''
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 json
import requests
from urllib.parse import urlparse
def get_recipients(user, post_privacy, direct_recipients=None):
''' deduplicated list of recipient inboxes '''
recipients = direct_recipients or []
if post_privacy == 'direct':
# all we care about is direct_recipients, not followers
return [u.inbox for u in recipients]
# load all the followers of the user who is sending the message
followers = user.followers.all()
if post_privacy == 'public':
# post to public shared inboxes
shared_inboxes = set(
u.shared_inbox for u in followers if u.shared_inbox
)
recipients += list(shared_inboxes)
recipients += [u.inbox for u in followers if not u.shared_inbox]
# TODO: direct to anyone who's mentioned
if post_privacy == 'followers':
# don't send it to the shared inboxes
inboxes = set(u.inbox for u in followers)
recipients += list(inboxes)
return recipients
def broadcast(sender, activity, recipients):
''' send out an event '''
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)
# TODO: raise an error if the user doesn't have a private key
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