sedi-relay/relay/actor.py

294 lines
8.4 KiB
Python

import aiohttp
import aiohttp.web
import asyncio
import logging
import uuid
import re
import simplejson as json
import cgi
from urllib.parse import urlsplit
from Crypto.PublicKey import RSA
from .database import DATABASE
from .http_debug import http_debug
from cachetools import LFUCache
# generate actor keys if not present
if "actorKeys" not in DATABASE:
logging.info("No actor keys present, generating 4096-bit RSA keypair.")
privkey = RSA.generate(4096)
pubkey = privkey.publickey()
DATABASE["actorKeys"] = {
"publicKey": pubkey.exportKey('PEM'),
"privateKey": privkey.exportKey('PEM')
}
PRIVKEY = RSA.importKey(DATABASE["actorKeys"]["privateKey"])
PUBKEY = PRIVKEY.publickey()
from . import app, CONFIG
from .remote_actor import fetch_actor
AP_CONFIG = CONFIG.get('ap', {'host': 'localhost','blocked_instances':[]})
CACHE_SIZE = CONFIG.get('cache-size', 16384)
CACHE = LFUCache(CACHE_SIZE)
async def actor(request):
data = {
"@context": "https://www.w3.org/ns/activitystreams",
"endpoints": {
"sharedInbox": "https://{}/inbox".format(request.host)
},
"followers": "https://{}/followers".format(request.host),
"following": "https://{}/following".format(request.host),
"inbox": "https://{}/inbox".format(request.host),
"name": "ActivityRelay",
"type": "Application",
"id": "https://{}/actor".format(request.host),
"publicKey": {
"id": "https://{}/actor#main-key".format(request.host),
"owner": "https://{}/actor".format(request.host),
"publicKeyPem": DATABASE["actorKeys"]["publicKey"]
},
"summary": "ActivityRelay bot",
"preferredUsername": "relay",
"url": "https://{}/actor".format(request.host)
}
return aiohttp.web.json_response(data)
app.router.add_get('/actor', actor)
from .http_signatures import sign_headers
get_actor_inbox = lambda actor: actor.get('endpoints', {}).get('sharedInbox', actor['inbox'])
async def push_message_to_actor(actor, message, our_key_id):
inbox = get_actor_inbox(actor)
url = urlsplit(inbox)
# XXX: Digest
data = json.dumps(message)
headers = {
'(request-target)': 'post {}'.format(url.path),
'Content-Length': str(len(data)),
'Content-Type': 'application/activity+json',
'User-Agent': 'ActivityRelay'
}
headers['signature'] = sign_headers(headers, PRIVKEY, our_key_id)
headers.pop('(request-target)')
logging.debug('%r >> %r', inbox, message)
try:
async with aiohttp.ClientSession(trace_configs=[http_debug()]) as session:
async with session.post(inbox, data=data, headers=headers) as resp:
if resp.status == 202:
return
resp_payload = await resp.text()
logging.debug('%r >> resp %r', inbox, resp_payload)
except Exception as e:
logging.info('Caught %r while pushing to %r.', e, inbox)
async def follow_remote_actor(actor_uri):
actor = await fetch_actor(actor_uri)
if not actor:
logging.info('failed to fetch actor at: %r', actor_uri)
return
logging.info('following: %r', actor_uri)
message = {
"@context": "https://www.w3.org/ns/activitystreams",
"type": "Follow",
"to": [actor['id']],
"object": actor['id'],
"id": "https://{}/activities/{}".format(AP_CONFIG['host'], uuid.uuid4()),
"actor": "https://{}/actor".format(AP_CONFIG['host'])
}
await push_message_to_actor(actor, message, "https://{}/actor#main-key".format(AP_CONFIG['host']))
async def unfollow_remote_actor(actor_uri):
actor = await fetch_actor(actor_uri)
if not actor:
logging.info('failed to fetch actor at: %r', actor_uri)
return
logging.info('unfollowing: %r', actor_uri)
message = {
"@context": "https://www.w3.org/ns/activitystreams",
"type": "Undo",
"to": [actor['id']],
"object": {
"type": "Follow",
"object": actor_uri,
"actor": actor['id'],
"id": "https://{}/activities/{}".format(AP_CONFIG['host'], uuid.uuid4())
},
"id": "https://{}/activities/{}".format(AP_CONFIG['host'], uuid.uuid4()),
"actor": "https://{}/actor".format(AP_CONFIG['host'])
}
await push_message_to_actor(actor, message, "https://{}/actor#main-key".format(AP_CONFIG['host']))
tag_re = re.compile(r'(<!--.*?-->|<[^>]*>)')
def strip_html(data):
no_tags = tag_re.sub('', data)
return cgi.escape(no_tags)
def distill_inboxes(actor, object_id):
global DATABASE
origin_hostname = urlsplit(object_id).hostname
inbox = get_actor_inbox(actor)
targets = [target for target in DATABASE.get('relay-list', []) if target != inbox]
targets = [target for target in targets if urlsplit(target).hostname != origin_hostname]
assert inbox not in targets
return targets
def distill_object_id(activity):
logging.debug('>> determining object ID for %r', activity['object'])
obj = activity['object']
if isinstance(obj, str):
return obj
return obj['id']
async def handle_relay(actor, data, request):
global CACHE
object_id = distill_object_id(data)
if object_id in CACHE:
logging.debug('>> already relayed %r as %r', object_id, CACHE[object_id])
return
# don't relay mastodon announces -- causes LRP fake direction issues
if data['type'] == 'Announce' and len(data.get('cc', [])) > 0:
return
activity_id = "https://{}/activities/{}".format(request.host, uuid.uuid4())
message = {
"@context": "https://www.w3.org/ns/activitystreams",
"type": "Announce",
"to": ["https://{}/actor/followers".format(request.host)],
"actor": "https://{}/actor".format(request.host),
"object": object_id,
"id": activity_id
}
logging.debug('>> relay: %r', message)
inboxes = distill_inboxes(actor, object_id)
futures = [push_message_to_actor({'inbox': inbox}, message, 'https://{}/actor#main-key'.format(request.host)) for inbox in inboxes]
asyncio.ensure_future(asyncio.gather(*futures))
CACHE[object_id] = activity_id
async def handle_follow(actor, data, request):
global DATABASE
following = DATABASE.get('relay-list', [])
inbox = get_actor_inbox(actor)
if urlsplit(inbox).hostname in AP_CONFIG['blocked_instances']:
return
if inbox not in following:
following += [inbox]
DATABASE['relay-list'] = following
if data['object'].endswith('/actor'):
asyncio.ensure_future(follow_remote_actor(actor['id']))
message = {
"@context": "https://www.w3.org/ns/activitystreams",
"type": "Accept",
"to": [actor["id"]],
"actor": "https://{}/actor".format(request.host),
# this is wrong per litepub, but mastodon < 2.4 is not compliant with that profile.
"object": {
"type": "Follow",
"id": data["id"],
"object": "https://{}/actor".format(request.host),
"actor": actor["id"]
},
"id": "https://{}/activities/{}".format(request.host, uuid.uuid4()),
}
asyncio.ensure_future(push_message_to_actor(actor, message, 'https://{}/actor#main-key'.format(request.host)))
async def handle_undo(actor, data, request):
global DATABASE
child = data['object']
if child['type'] == 'Follow':
following = DATABASE.get('relay-list', [])
inbox = get_actor_inbox(actor)
if inbox in following:
following.remove(inbox)
DATABASE['relay-list'] = following
if child['object'].endswith('/actor'):
await unfollow_remote_actor(actor['id'])
processors = {
'Announce': handle_relay,
'Create': handle_relay,
'Follow': handle_follow,
'Undo': handle_undo
}
async def inbox(request):
data = await request.json()
if 'actor' not in data or not request['validated']:
raise aiohttp.web.HTTPUnauthorized(body='access denied', content_type='text/plain')
actor = await fetch_actor(data["actor"])
actor_uri = 'https://{}/actor'.format(request.host)
logging.debug(">> payload %r", data)
processor = processors.get(data['type'], None)
if processor:
await processor(actor, data, request)
return aiohttp.web.Response(body=b'{}', content_type='application/activity+json')
app.router.add_post('/inbox', inbox)