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bridgy-fed/activitypub.py

1070 wiersze
40 KiB
Python
Czysty Bezpośredni odnośnik Wina Historia

"""ActivityPub protocol implementation."""
from base64 import b64encode
from hashlib import sha256
import itertools
import logging
import re
from urllib.parse import quote_plus, urljoin, urlparse
from flask import abort, g, redirect, request
from google.cloud import ndb
from google.cloud.ndb.query import FilterNode, OR, Query
from granary import as1, as2
from httpsig import HeaderVerifier
from httpsig.requests_auth import HTTPSignatureAuth
from httpsig.utils import parse_signature_header
from oauth_dropins.webutil import appengine_info, flask_util, util
from oauth_dropins.webutil.util import fragmentless, json_dumps, json_loads
import requests
from werkzeug.exceptions import BadGateway
from flask_app import app, cache
import common
from common import (
add,
CACHE_TIME,
CONTENT_TYPE_HTML,
DOMAINS,
DOMAIN_RE,
error,
host_url,
LOCAL_DOMAINS,
PRIMARY_DOMAIN,
redirect_wrap,
subdomain_wrap,
unwrap,
)
from models import fetch_objects, Follower, Object, PROTOCOLS, User
from protocol import Protocol
import webfinger
logger = logging.getLogger(__name__)
CONNEG_HEADERS_AS2_HTML = {
'Accept': f'{as2.CONNEG_HEADERS["Accept"]}, {CONTENT_TYPE_HTML}; q=0.5'
}
HTTP_SIG_HEADERS = ('Date', 'Host', 'Digest', '(request-target)')
SECURITY_CONTEXT = 'https://w3id.org/security/v1'
# https://seb.jambor.dev/posts/understanding-activitypub-part-4-threads/#the-instance-actor
_INSTANCE_ACTOR = None
# populated in User.status
WEB_OPT_OUT_DOMAINS = None
FEDI_URL_RE = re.compile(r'https://[^/]+/(@|users/)([^/@]+)(@[^/@]+)?(/(?:statuses/)?[0-9]+)?')
def instance_actor():
global _INSTANCE_ACTOR
if _INSTANCE_ACTOR is None:
import web
_INSTANCE_ACTOR = web.Web.get_or_create(PRIMARY_DOMAIN)
return _INSTANCE_ACTOR
class ActivityPub(User, Protocol):
"""ActivityPub protocol class.
Key id is AP/AS2 actor id URL. (*Not* fediverse/WebFinger @-@ handle!)
"""
ABBREV = 'ap'
PHRASE = 'the fediverse'
LOGO_HTML = '<img src="/static/fediverse_logo.svg">'
CONTENT_TYPE = as2.CONTENT_TYPE_LD_PROFILE
HAS_FOLLOW_ACCEPTS = True
def _pre_put_hook(self):
"""Validate id, require URL, don't allow Bridgy Fed domains.
TODO: normalize scheme and domain to lower case. Add that to
:class:`oauth_dropins.webutil.util.UrlCanonicalizer`\?
"""
super()._pre_put_hook()
id = self.key.id()
assert id
assert util.is_web(id), f'{id} is not a URL'
domain = util.domain_from_link(id)
assert domain, 'missing domain'
assert not self.is_blocklisted(domain), f'{id} is a blocked domain'
def web_url(self):
"""Returns this user's web URL aka web_url, eg ``https://foo.com/``."""
if self.obj and self.obj.as1:
url = as1.get_url(self.obj.as1)
if url:
return url
return self.key.id()
@ndb.ComputedProperty
def handle(self):
"""Returns this user's ActivityPub address, eg ``@user@foo.com``."""
if self.obj and self.obj.as1:
addr = as2.address(self.convert(self.obj, from_user=self))
if addr:
return addr
return as2.address(self.key.id())
@ndb.ComputedProperty
def status(self):
"""Override :meth:`Model.status` and include Web opted out domains."""
global WEB_OPT_OUT_DOMAINS
if WEB_OPT_OUT_DOMAINS is None:
WEB_OPT_OUT_DOMAINS = {
key.id() for key in Query(
'MagicKey',
filters=FilterNode('manual_opt_out', '=', True)
).fetch(keys_only=True)
}
logger.info(f'Loaded {len(WEB_OPT_OUT_DOMAINS)} manually opted out Web users')
status = super().status
if status:
return status
return util.domain_or_parent_in(util.domain_from_link(self.key.id()),
WEB_OPT_OUT_DOMAINS)
@classmethod
def owns_id(cls, id):
"""Returns None if ``id`` is an http(s) URL, False otherwise.
All AP ids are http(s) URLs, but not all http(s) URLs are AP ids.
https://www.w3.org/TR/activitypub/#obj-id
I used to include a heuristic here that no actor is the root path on its
host, which was nice because it let us assume that home pages are Web
users without making any network requests...but then I inevitably ran
into AP actors that _are_ the root path, eg microblog.pub sites like
https://bw3.dev/ .
https://docs.microblog.pub/user_guide.html#activitypub
"""
if util.is_web(id) and not cls.is_blocklisted(id):
return None
return False
@classmethod
def owns_handle(cls, handle):
"""Returns True if handle is a WebFinger ``@-@`` handle, False otherwise.
Example: ``@user@instance.com``. The leading ``@`` is optional.
https://datatracker.ietf.org/doc/html/rfc7033#section-3.1
https://datatracker.ietf.org/doc/html/rfc7033#section-4.5
"""
parts = handle.lstrip('@').split('@')
if len(parts) != 2:
return False
user, domain = parts
return user and domain and not cls.is_blocklisted(domain)
@classmethod
def handle_to_id(cls, handle):
"""Looks in the datastore first, then queries WebFinger."""
assert cls.owns_handle(handle)
if not handle.startswith('@'):
handle = '@' + handle
user = ActivityPub.query(OR(ActivityPub.handle == handle,
ActivityPub.readable_id == handle),
).get()
if user:
return user.key.id()
return webfinger.fetch_actor_url(handle)
@classmethod
def target_for(cls, obj, shared=False):
"""Returns ``obj``'s or its author's/actor's inbox, if available."""
if not obj.as1:
return None
if obj.type not in as1.ACTOR_TYPES:
for field in 'actor', 'author', 'attributedTo':
inner_obj = as1.get_object(obj.as1, field)
inner_id = inner_obj.get('id') or as1.get_url(inner_obj)
if (not inner_id
or inner_id == obj.as1.get('id')
or (obj.key and inner_id == obj.key.id())):
continue
# TODO: need a "soft" kwarg for load to suppress errors?
actor = cls.load(inner_id)
if actor and actor.as1:
target = cls.target_for(actor)
if target:
logger.info(f'Target for {obj.key} via {inner_id} is {target}')
return target
logger.info(f'{obj.key} type {obj.type} is not an actor and has no author or actor with inbox')
actor = ActivityPub.convert(obj)
if shared:
shared_inbox = actor.get('endpoints', {}).get('sharedInbox')
if shared_inbox:
return shared_inbox
return actor.get('publicInbox') or actor.get('inbox')
@classmethod
def send(to_cls, obj, url, from_user=None, orig_obj=None):
"""Delivers an activity to an inbox URL.
If ``obj.recipient_obj`` is set, it's interpreted as the receiving actor
who we're delivering to and its id is populated into ``cc``.
"""
if to_cls.is_blocklisted(url):
logger.info(f'Skipping sending to blocklisted {url}')
return False
orig_obj = to_cls.convert(orig_obj, from_user=from_user)
activity = to_cls.convert(obj, from_user=from_user, orig_obj=orig_obj)
return signed_post(url, data=activity, from_user=from_user).ok
@classmethod
def fetch(cls, obj, **kwargs):
"""Tries to fetch an AS2 object.
Assumes ``obj.id`` is a URL. Any fragment at the end is stripped before
loading. This is currently underspecified and somewhat inconsistent
across AP implementations:
* https://socialhub.activitypub.rocks/t/problems-posting-to-mastodon-inbox/801/11
* https://socialhub.activitypub.rocks/t/problems-posting-to-mastodon-inbox/801/23
* https://socialhub.activitypub.rocks/t/s2s-create-activity/1647/5
* https://github.com/mastodon/mastodon/issues/13879 (open!)
* https://github.com/w3c/activitypub/issues/224
Uses HTTP content negotiation via the ``Content-Type`` header. If the
url is HTML and it has a ``rel-alternate`` link with an AS2 content
type, fetches and returns that URL.
Includes an HTTP Signature with the request.
* https://w3c.github.io/activitypub/#authorization
* https://tools.ietf.org/html/draft-cavage-http-signatures-07
* https://github.com/mastodon/mastodon/pull/11269
Mastodon requires this signature if ``AUTHORIZED_FETCH`` aka secure mode
is on: https://docs.joinmastodon.org/admin/config/#authorized_fetch
Signs the request with the current user's key. If not provided, defaults to
using @snarfed.org@snarfed.org's key.
See :meth:`protocol.Protocol.fetch` for more details.
Args:
obj (models.Object): with the id to fetch. Fills data into the as2
property.
kwargs: ignored
Returns:
bool: True if the object was fetched and populated successfully,
False otherwise
Raises:
requests.HTTPError:
werkzeug.exceptions.HTTPException: will have an additional
``requests_response`` attribute with the last
:class:`requests.Response` we received.
"""
url = obj.key.id()
if not util.is_web(url):
logger.info(f'{url} is not a URL')
return False
resp = None
def _error(extra_msg=None):
msg = f"Couldn't fetch {url} as ActivityStreams 2"
if extra_msg:
msg += ': ' + extra_msg
logger.warning(msg)
# protocol.for_id depends on us raising this when an AP network
# fetch fails. if we change that, update for_id too!
err = BadGateway(msg)
err.requests_response = resp
raise err
def _get(url, headers):
"""Returns None if we fetched and populated, resp otherwise."""
nonlocal resp
try:
resp = signed_get(url, headers=headers, gateway=True)
except BadGateway as e:
# ugh, this is ugly, should be something structured
if '406 Client Error' in str(e):
return
raise
if not resp.content:
_error('empty response')
elif common.content_type(resp) in as2.CONTENT_TYPES:
try:
return resp.json()
except requests.JSONDecodeError:
_error("Couldn't decode as JSON")
obj.as2 = _get(url, CONNEG_HEADERS_AS2_HTML)
if obj.as2:
return True
elif not resp:
return False
# look in HTML to find AS2 link
if common.content_type(resp) != 'text/html':
logger.info('no AS2 available')
return False
parsed = util.parse_html(resp)
link = parsed.find('link', rel=('alternate', 'self'), type=(
as2.CONTENT_TYPE, as2.CONTENT_TYPE_LD))
if not (link and link['href']):
logger.info('no AS2 available')
return False
obj.as2 = _get(link['href'], as2.CONNEG_HEADERS)
if obj.as2:
return True
return False
@classmethod
def convert(cls, obj, orig_obj=None, from_user=None):
"""Convert a :class:`models.Object` to AS2.
Args:
obj (models.Object)
orig_obj (dict): AS2 object, optional. The target of activity's
``inReplyTo`` or ``Like``/``Announce``/etc object, if any. Passed
through to :func:`postprocess_as2`.
from_user (models.User): user (actor) this activity/object is from
Returns:
dict: AS2 JSON
"""
if not obj or not obj.as1:
return {}
from_proto = PROTOCOLS.get(obj.source_protocol)
user_id = from_user.key.id() if from_user and from_user.key else None
# TODO: uncomment
# if from_proto and not common.is_enabled(cls, from_proto, handle_or_id=user_id):
# error(f'{cls.LABEL} <=> {from_proto.LABEL} not enabled')
if obj.as2:
return {
# add back @context since we strip it when we store Objects
'@context': [as2.CONTEXT, SECURITY_CONTEXT],
**obj.as2,
}
translated = cls.translate_ids(obj.as1)
# compact actors to just string id for compatibility, since many other
# AP implementations choke on objects.
# https://github.com/snarfed/bridgy-fed/issues/658
#
# TODO: expand this to general purpose compact() function and use
# elsewhere, eg in models.resolve_id
for o in translated, as1.get_object(translated):
for field in 'actor', 'attributedTo', 'author':
actors = as1.get_objects(o, field)
ids = [a['id'] for a in actors if a.get('id')]
o[field] = ids[0] if len(ids) == 1 else ids
converted = as2.from_as1(translated)
if obj.source_protocol in ('ap', 'activitypub'):
return converted
# special cases where obj or obj['object'] or obj['object']['object']
# are an actor
if from_user:
if as1.object_type(obj.as1) in as1.ACTOR_TYPES:
return postprocess_as2_actor(converted, user=from_user)
inner_obj = as1.get_object(obj.as1)
if as1.object_type(inner_obj) in as1.ACTOR_TYPES:
converted['object'] = postprocess_as2_actor(converted['object'],
user=from_user)
# eg Accept of a Follow
if from_user.is_web_url(as1.get_object(inner_obj).get('id')):
converted['object']['object'] = from_user.id_as(ActivityPub)
# convert!
return postprocess_as2(converted, orig_obj=orig_obj)
@classmethod
def verify_signature(cls, activity):
"""Verifies the current request's HTTP Signature.
Raises :class:`werkzeug.exceptions.HTTPError` if the signature is
missing or invalid, otherwise does nothing and returns the id of the
actor whose key signed the request.
Logs details of the result.
Args:
activity (dict): AS2 activity
Returns:
str: signing AP actor id
"""
headers = dict(request.headers) # copy so we can modify below
sig = headers.get('Signature')
if not sig:
if appengine_info.DEBUG:
logger.info('No HTTP Signature, allowing due to DEBUG=true')
return
error('No HTTP Signature', status=401)
logger.info('Verifying HTTP Signature')
# logger.info(f'Headers: {json_dumps(headers, indent=2)}')
# parse_signature_header lower-cases all keys
sig_fields = parse_signature_header(sig)
keyId = fragmentless(sig_fields.get('keyid'))
if not keyId:
error('HTTP Signature missing keyId', status=401)
# TODO: right now, assume hs2019 is rsa-sha256. the real answer is...
# ...complicated and unclear. 🤷
# https://github.com/snarfed/bridgy-fed/issues/430#issuecomment-1510462267
# https://arewehs2019yet.vpzom.click/
# https://socialhub.activitypub.rocks/t/state-of-http-signatures/754/23
# https://socialhub.activitypub.rocks/t/http-signatures-libraray/2087/2
# https://github.com/mastodon/mastodon/pull/14556
if sig_fields.get('algorithm') == 'hs2019':
headers['Signature'] = headers['Signature'].replace(
'algorithm="hs2019"', 'algorithm=rsa-sha256')
digest = headers.get('Digest') or ''
if not digest:
error('Missing Digest header, required for HTTP Signature', status=401)
expected = b64encode(sha256(request.data).digest()).decode()
if digest.removeprefix('SHA-256=').removeprefix('sha-256=') != expected:
error('Invalid Digest header, required for HTTP Signature', status=401)
try:
key_actor = cls.load(keyId)
except BadGateway:
obj_id = as1.get_object(activity).get('id')
if (activity.get('type') == 'Delete' and obj_id
and keyId == fragmentless(obj_id)):
logger.info('Object/actor being deleted is also keyId')
key_actor = Object.get_or_create(
id=keyId, source_protocol='activitypub', deleted=True)
key_actor.put()
else:
raise
if key_actor and key_actor.deleted:
abort(202, f'Ignoring, signer {keyId} is already deleted')
elif not key_actor or not key_actor.as1:
error(f"Couldn't load {keyId} to verify signature", status=401)
# don't ActivityPub.convert since we don't want to postprocess_as2
key = as2.from_as1(key_actor.as1).get('publicKey', {}).get('publicKeyPem')
if not key:
error(f'No public key for {keyId}', status=401)
# can't use request.full_path because it includes a trailing ? even if
# it wasn't in the request. https://github.com/pallets/flask/issues/2867
path_query = request.url.removeprefix(request.host_url.rstrip('/'))
logger.info(f'Verifying signature for {path_query} with key {key}')
try:
verified = HeaderVerifier(headers, key,
required_headers=['Digest'],
method=request.method,
path=path_query,
sign_header='signature',
).verify()
except BaseException as e:
error(f'HTTP Signature verification failed: {e}', status=401)
if verified:
logger.info('HTTP Signature verified!')
else:
error('HTTP Signature verification failed', status=401)
return keyId
def signed_get(url, from_user=None, **kwargs):
return signed_request(util.requests_get, url, from_user=from_user, **kwargs)
def signed_post(url, from_user, **kwargs):
assert from_user
return signed_request(util.requests_post, url, from_user=from_user, **kwargs)
def signed_request(fn, url, data=None, headers=None, from_user=None, **kwargs):
"""Wraps ``requests.*`` and adds HTTP Signature.
Args:
fn (callable): :func:`util.requests_get` or :func:`util.requests_post`
url (str):
data (dict): optional AS2 object
from_user (models.User): user to sign request as; optional. If not
provided, uses the default user ``@snarfed.org@snarfed.org``.
kwargs: passed through to requests
Returns:
requests.Response:
"""
if headers is None:
headers = {}
# prepare HTTP Signature and headers
if not from_user or isinstance(from_user, ActivityPub):
# ActivityPub users are remote, so we don't have their keys
from_user = instance_actor()
if data:
logger.info(f'Sending AS2 object: {json_dumps(data, indent=2)}')
data = json_dumps(data).encode()
headers = {
**headers,
# required for HTTP Signature
# https://tools.ietf.org/html/draft-cavage-http-signatures-07#section-2.1.3
'Date': util.now().strftime('%a, %d %b %Y %H:%M:%S GMT'),
# required by Mastodon
# https://github.com/tootsuite/mastodon/pull/14556#issuecomment-674077648
'Host': util.domain_from_link(url, minimize=False),
'Content-Type': as2.CONTENT_TYPE_LD_PROFILE,
# required for HTTP Signature and Mastodon
'Digest': f'SHA-256={b64encode(sha256(data or b"").digest()).decode()}',
}
logger.info(f"Signing with {from_user.key}'s key")
# (request-target) is a special HTTP Signatures header that some fediverse
# implementations require, eg Peertube.
# https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12#section-2.3
# https://www.w3.org/wiki/SocialCG/ActivityPub/Authentication_Authorization#Signing_requests_using_HTTP_Signatures
# https://docs.joinmastodon.org/spec/security/#http
key_id = f'{from_user.id_as(ActivityPub)}#key'
auth = HTTPSignatureAuth(secret=from_user.private_pem(), key_id=key_id,
algorithm='rsa-sha256', sign_header='signature',
headers=HTTP_SIG_HEADERS)
# make HTTP request
kwargs.setdefault('gateway', True)
resp = fn(url, data=data, auth=auth, headers=headers, allow_redirects=False,
**kwargs)
logger.info(f'Got {resp.status_code} headers: {resp.headers}')
# handle GET redirects manually so that we generate a new HTTP signature
if resp.is_redirect and fn == util.requests_get:
new_url = urljoin(url, resp.headers['Location'])
return signed_request(fn, new_url, data=data, headers=headers,
**kwargs)
type = common.content_type(resp)
if (type and type != 'text/html' and
(type.startswith('text/') or type.endswith('+json')
or type.endswith('/json'))):
logger.info(resp.text)
return resp
def postprocess_as2(activity, orig_obj=None, wrap=True):
"""Prepare an AS2 object to be served or sent via ActivityPub.
Args:
activity (dict): AS2 object or activity
orig_obj (dict): AS2 object, optional. The target of activity's
``inReplyTo`` or ``Like``/``Announce``/etc object, if any.
wrap (bool): whether to wrap ``id``, ``url``, ``object``, ``actor``, and
``attributedTo``
"""
if not activity or isinstance(activity, str):
return redirect_wrap(activity) if wrap else activity
elif activity.keys() == {'id'}:
return redirect_wrap(activity['id']) if wrap else activity['id']
type = activity.get('type')
# inReplyTo: singly valued, prefer id over url
# TODO: ignore orig_obj, do for all inReplyTo
orig_id = orig_obj.get('id') if orig_obj else None
in_reply_to = activity.get('inReplyTo')
if in_reply_to:
if orig_id:
activity['inReplyTo'] = orig_id
elif isinstance(in_reply_to, list):
if len(in_reply_to) > 1:
logger.warning(
"AS2 doesn't support multiple inReplyTo URLs! "
f'Only using the first: {in_reply_to[0]}')
activity['inReplyTo'] = in_reply_to[0]
# Mastodon evidently requires a Mention tag for replies to generate a
# notification to the original post's author. not required for likes,
# reposts, etc. details:
# https://github.com/snarfed/bridgy-fed/issues/34
if orig_obj:
for to in (util.get_list(orig_obj, 'attributedTo') +
util.get_list(orig_obj, 'author') +
util.get_list(orig_obj, 'actor')):
if isinstance(to, dict):
to = util.get_first(to, 'url') or to.get('id')
if to:
add(activity.setdefault('tag', []), {
'type': 'Mention',
'href': to,
})
# activity objects (for Like, Announce, etc): prefer id over url
obj = as1.get_object(activity)
id = obj.get('id')
if orig_id and type in as2.TYPES_WITH_OBJECT:
# inline most objects as bare string ids, not composite objects, for interop
activity['object'] = orig_id
elif not id:
obj['id'] = util.get_first(obj, 'url')
# id is required for most things. default to url if it's not set.
if not activity.get('id'):
activity['id'] = util.get_first(activity, 'url')
if wrap:
activity['id'] = redirect_wrap(activity.get('id'))
activity['url'] = [redirect_wrap(u) for u in util.get_list(activity, 'url')]
if len(activity['url']) == 1:
activity['url'] = activity['url'][0]
# TODO: find a better way to check this, sometimes or always?
# removed for now since it fires on posts without u-id or u-url, eg
# https://chrisbeckstrom.com/2018/12/27/32551/
# assert activity.get('id') or (isinstance(obj, dict) and obj.get('id'))
# copy image(s) into attachment(s). may be Mastodon-specific.
# https://github.com/snarfed/bridgy-fed/issues/33#issuecomment-440965618
obj_or_activity = obj if obj.keys() > set(['id']) else activity
imgs = util.get_list(obj_or_activity, 'image')
atts = obj_or_activity.setdefault('attachment', [])
if imgs:
atts.extend(img for img in imgs if img not in atts)
# cc target's author(s), recipients, mentions
# https://www.w3.org/TR/activitystreams-vocabulary/#audienceTargeting
# https://w3c.github.io/activitypub/#delivery
# https://docs.joinmastodon.org/spec/activitypub/#Mention
obj_or_activity.setdefault('cc', [])
tags = util.get_list(activity, 'tag') + util.get_list(obj, 'tag')
for tag in tags:
href = tag.get('href')
if (href and tag.get('type') == 'Mention'
and not ActivityPub.is_blocklisted(href)):
add(obj_or_activity['cc'], href)
if orig_obj and type in as2.TYPE_TO_VERB:
for field in 'actor', 'attributedTo', 'to', 'cc':
for recip in as1.get_objects(orig_obj, field):
add(obj_or_activity['cc'], util.get_url(recip) or recip.get('id'))
# to public, since Mastodon interprets to public as public, cc public as unlisted:
# https://socialhub.activitypub.rocks/t/visibility-to-cc-mapping/284
# https://wordsmith.social/falkreon/securing-activitypub
to = activity.setdefault('to', [])
add(to, as2.PUBLIC_AUDIENCE)
# hashtags. Mastodon requires:
# * type: Hashtag
# * name starts with #
# * href is set to a valid, fully qualified URL
#
# If content has an <a> tag with a fully qualified URL and the hashtag name
# (with leading #) as its text, Mastodon will rewrite its href to the local
# instance's search for that hashtag. If content doesn't have a link for a
# given hashtag, Mastodon won't add one, but that hashtag will still be
# indexed in search.
#
# https://docs.joinmastodon.org/spec/activitypub/#properties-used
# https://github.com/snarfed/bridgy-fed/issues/45
for tag in tags:
name = tag.get('name')
if name and tag.get('type', 'Tag') == 'Tag':
tag['type'] = 'Hashtag'
tag.setdefault('href', common.host_url(
f'hashtag/{quote_plus(name.removeprefix("#"))}'))
if not name.startswith('#'):
tag['name'] = f'#{name}'
# language, in contentMap
# https://github.com/snarfed/bridgy-fed/issues/681
if content := obj_or_activity.get('content'):
obj_or_activity.setdefault('contentMap', {'en': content})
activity['object'] = [
postprocess_as2(o, orig_obj=orig_obj,
wrap=wrap and type in ('Create', 'Update', 'Delete'))
for o in as1.get_objects(activity)]
if len(activity['object']) == 1:
activity['object'] = activity['object'][0]
return util.trim_nulls(activity)
def postprocess_as2_actor(actor, user):
"""Prepare an AS2 actor object to be served or sent via ActivityPub.
Modifies actor in place.
Args:
actor (dict): AS2 actor object
user (models.User): current user
Returns:
actor dict
"""
if not actor:
return actor
assert isinstance(actor, dict)
assert user
url = user.web_url()
urls = [u for u in util.get_list(actor, 'url') if u and not u.startswith('acct:')]
if not urls and url:
urls = [url]
if urls:
urls[0] = redirect_wrap(urls[0])
id = actor.get('id')
user_id = user.key.id()
if not id or user.is_web_url(id) or unwrap(id) in (user_id, f'www.{user_id}'):
id = actor['id'] = user.id_as(ActivityPub)
actor['url'] = urls[0] if len(urls) == 1 else urls
# required by ActivityPub
# https://www.w3.org/TR/activitypub/#actor-objects
actor.setdefault('inbox', id + '/inbox')
actor.setdefault('outbox', id + '/outbox')
# For web, this has to be domain for Mastodon etc interop! It seems like it
# should be the custom username from the acct: u-url in their h-card, but
# that breaks Mastodon's Webfinger discovery.
# Background:
# https://docs.joinmastodon.org/spec/activitypub/#properties-used-1
# https://docs.joinmastodon.org/spec/webfinger/#mastodons-requirements-for-webfinger
# https://github.com/snarfed/bridgy-fed/issues/302#issuecomment-1324305460
# https://github.com/snarfed/bridgy-fed/issues/77
if user.LABEL == 'web':
actor['preferredUsername'] = user.key.id()
else:
handle = user.handle_as(ActivityPub)
if handle:
actor['preferredUsername'] = handle.strip('@').split('@')[0]
# Override the label for their home page to be "Web site"
for att in util.get_list(actor, 'attachment'):
if att.get('type') == 'PropertyValue':
val = att.get('value', '')
link = util.parse_html(val).find('a')
if url and url.rstrip('/') in [val.rstrip('/'),
link.get('href').rstrip('/')]:
att['name'] = 'Web site'
# required by pixelfed. https://github.com/snarfed/bridgy-fed/issues/39
actor.setdefault('summary', '')
if not actor.get('publicKey') and not isinstance(user, ActivityPub):
# underspecified, inferred from this issue and Mastodon's implementation:
# https://github.com/w3c/activitypub/issues/203#issuecomment-297553229
# https://github.com/tootsuite/mastodon/blob/bc2c263504e584e154384ecc2d804aeb1afb1ba3/app/services/activitypub/process_account_service.rb#L77
actor.update({
'publicKey': {
'id': f'{id}#key',
'owner': id,
'publicKeyPem': user.public_pem().decode(),
},
'@context': (util.get_list(actor, '@context') + [SECURITY_CONTEXT]),
})
if (user.key.id() not in DOMAINS
and (not user.direct
# Web users only
or (user.LABEL == 'web'
and not getattr(user, 'last_webmention_in', 'unset')
and not getattr(user, 'has_redirects', None)))):
actor['type'] = 'Application'
disclaimer = f'[<a href="https://{PRIMARY_DOMAIN}{user.user_page_path()}">bridged</a> from <a href="{user.web_url()}">{user.handle_or_id()}</a> by <a href="https://{PRIMARY_DOMAIN}/">Bridgy Fed</a>]'
if not actor['summary'].endswith(disclaimer):
if actor['summary']:
actor['summary'] += '<br><br>'
actor['summary'] += disclaimer
return actor
# source protocol in subdomain.
# WARNING: the user page handler in pages.py overrides this for fediverse
# addresses with leading @ character. be careful when changing this route!
@app.get(f'/ap/<handle_or_id>')
# source protocol in path; primarily for backcompat
@app.get(f'/ap/web/<handle_or_id>')
# special case Web users without /ap/web/ prefix, for backward compatibility
@app.get(f'/<regex("{DOMAIN_RE}"):handle_or_id>')
@flask_util.cached(cache, CACHE_TIME)
def actor(handle_or_id):
"""Serves a user's AS2 actor from the datastore."""
cls = Protocol.for_request(fed='web')
if not cls:
error(f"Couldn't determine protocol", status=404)
elif not common.is_enabled(cls, ActivityPub, handle_or_id=handle_or_id):
error(f'{cls.LABEL} <=> activitypub not enabled')
elif cls.LABEL == 'web' and request.path.startswith('/ap/'):
# we started out with web users' AP ids as fed.brid.gy/[domain], so we
# need to preserve those for backward compatibility
return redirect(subdomain_wrap(None, f'/{handle_or_id}'), code=301)
if cls.owns_id(handle_or_id) is False:
if cls.owns_handle(handle_or_id) is False:
error(f"{handle_or_id} doesn't look like a {cls.LABEL} id or handle",
status=404)
id = cls.handle_to_id(handle_or_id)
if not id:
error(f"Couldn't resolve {handle_or_id} as a {cls.LABEL} handle",
status=404)
else:
id = handle_or_id
assert id
user = cls.get_or_create(id)
if not user:
error(f'{cls.LABEL} user {id} not found', status=404)
id = user.id_as(ActivityPub)
# check that we're serving from the right subdomain
if request.host != urlparse(id).netloc:
return redirect(id)
if not user.obj or not user.obj.as1:
user.obj = cls.load(user.profile_id(), gateway=True)
if user.obj:
user.obj.put()
actor = ActivityPub.convert(user.obj, from_user=user) or {
'@context': [as2.CONTEXT],
'type': 'Person',
}
actor = postprocess_as2_actor(actor, user=user)
actor.update({
'id': id,
'inbox': id + '/inbox',
'outbox': id + '/outbox',
'following': id + '/following',
'followers': id + '/followers',
'endpoints': {
'sharedInbox': subdomain_wrap(cls, '/ap/sharedInbox'),
},
# add this if we ever change the Web actor ids to be /web/[id]
# 'alsoKnownAs': [host_url(id)],
})
logger.info(f'Returning: {json_dumps(actor, indent=2)}')
return actor, {
'Content-Type': as2.CONTENT_TYPE_LD_PROFILE,
'Access-Control-Allow-Origin': '*',
}
# note that this shared inbox path overlaps with the /ap/<handle_or_id> actor
# route above, but doesn't collide because this is POST and that one is GET.
@app.post('/ap/sharedInbox')
# source protocol in subdomain
@app.post(f'/ap/<id>/inbox')
# source protocol in path; primarily for backcompat
@app.post(f'/ap/<protocol>/<id>/inbox')
# special case Web users without /ap/web/ prefix, for backward compatibility
@app.post('/inbox')
@app.post(f'/<regex("{DOMAIN_RE}"):id>/inbox')
def inbox(protocol=None, id=None):
"""Handles ActivityPub inbox delivery."""
# parse and validate AS2 activity
try:
activity = request.json
assert activity and isinstance(activity, dict)
except (TypeError, ValueError, AssertionError):
body = request.get_data(as_text=True)
error(f"Couldn't parse body as non-empty JSON mapping: {body}", exc_info=True)
type = activity.get('type')
actor = as1.get_object(activity, 'actor')
actor_id = actor.get('id')
logger.info(f'Got {type} from {actor_id}: {json_dumps(activity, indent=2)}')
if ActivityPub.is_blocklisted(actor_id):
error(f'Actor {actor_id} is blocklisted')
authed_as = ActivityPub.verify_signature(activity)
# check that this activity is public. only do this for creates, not likes,
# follows, or other activity types, since Mastodon doesn't currently mark
# those as explicitly public. Use as2's is_public instead of as1's because
# as1's interprets unlisted as true.
if type == 'Create' and not as2.is_public(activity, unlisted=False):
logger.info('Dropping non-public activity')
return 'OK'
if type == 'Follow':
# rendered mf2 HTML proxy pages (in render.py) fall back to redirecting
# to the follow's AS2 id field, but Mastodon's Accept ids are URLs that
# don't load in browsers, eg:
# https://jawns.club/ac33c547-ca6b-4351-80d5-d11a6879a7b0
#
# so, set a synthetic URL based on the follower's profile.
# https://github.com/snarfed/bridgy-fed/issues/336
follower_url = unwrap(util.get_url(activity, 'actor'))
followee_url = unwrap(util.get_url(activity, 'object'))
activity.setdefault('url', f'{follower_url}#followed-{followee_url}')
obj = Object(id=activity.get('id'), as2=unwrap(activity))
return ActivityPub.receive(obj, authed_as=authed_as)
# protocol in subdomain
@app.get(f'/ap/<id>/<any(followers,following):collection>')
# source protocol in path; primarily for backcompat
@app.get(f'/ap/web/<regex("{DOMAIN_RE}"):id>/<any(followers,following):collection>')
# special case Web users without /ap/web/ prefix, for backward compatibility
@app.route(f'/<regex("{DOMAIN_RE}"):id>/<any(followers,following):collection>',
methods=['GET', 'HEAD'])
@flask_util.cached(cache, CACHE_TIME)
def follower_collection(id, collection):
"""ActivityPub Followers and Following collections.
* https://www.w3.org/TR/activitypub/#followers
* https://www.w3.org/TR/activitypub/#collections
* https://www.w3.org/TR/activitystreams-core/#paging
TODO: unify page generation with outbox()
"""
if (request.path.startswith('/ap/')
and request.host in (PRIMARY_DOMAIN,) + LOCAL_DOMAINS):
# UI request. unfortunate that the URL paths overlap like this!
import pages
return pages.followers_or_following('ap', id, collection)
protocol = Protocol.for_request(fed='web')
assert protocol
user = protocol.get_by_id(id)
if not user:
return f'{protocol} user {id} not found', 404
if request.method == 'HEAD':
return '', {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
# page
followers, new_before, new_after = Follower.fetch_page(collection, user=user)
page = {
'type': 'CollectionPage',
'partOf': request.base_url,
'items': util.trim_nulls([ActivityPub.convert(f.user.obj, from_user=f.user)
for f in followers]),
}
if new_before:
page['next'] = f'{request.base_url}?before={new_before}'
if new_after:
page['prev'] = f'{request.base_url}?after={new_after}'
if 'before' in request.args or 'after' in request.args:
page.update({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.url,
})
logger.info(f'Returning {json_dumps(page, indent=2)}')
return page, {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
# collection
num_followers, num_following = user.count_followers()
collection = {
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.base_url,
'type': 'Collection',
'summary': f"{id}'s {collection}",
'totalItems': num_followers if collection == 'followers' else num_following,
'first': page,
}
logger.info(f'Returning {json_dumps(collection, indent=2)}')
return collection, {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
# protocol in subdomain
@app.get(f'/ap/<id>/outbox')
# source protocol in path; primarily for backcompat
@app.get(f'/ap/web/<regex("{DOMAIN_RE}"):id>/outbox')
# special case Web users without /ap/web/ prefix, for backward compatibility
@app.route(f'/<regex("{DOMAIN_RE}"):id>/outbox', methods=['GET', 'HEAD'])
@flask_util.cached(cache, CACHE_TIME)
def outbox(id):
"""Serves a user's AP outbox.
TODO: unify page generation with follower_collection()
"""
protocol = Protocol.for_request(fed='web')
if not protocol:
error(f"Couldn't determine protocol", status=404)
user = protocol.get_by_id(id)
if not user:
error(f'User {id} not found', status=404)
if request.method == 'HEAD':
return '', {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
query = Object.query(Object.users == user.key)
objects, new_before, new_after = fetch_objects(query, by=Object.updated,
user=user)
# page
page = {
'type': 'CollectionPage',
'partOf': request.base_url,
'items': util.trim_nulls([ActivityPub.convert(obj, from_user=user)
for obj in objects]),
}
if new_before:
page['next'] = f'{request.base_url}?before={new_before}'
if new_after:
page['prev'] = f'{request.base_url}?after={new_after}'
if 'before' in request.args or 'after' in request.args:
page.update({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.url,
})
logger.info(f'Returning {json_dumps(page, indent=2)}')
return page, {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
# collection
return {
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.url,
'type': 'OrderedCollection',
'summary': f"{id}'s outbox",
'totalItems': query.count(),
'first': page,
}, {'Content-Type': as2.CONTENT_TYPE_LD_PROFILE}
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