bridgy-fed/webfinger.py

218 wiersze
7.7 KiB
Python

"""Handles requests for WebFinger endpoints.
https://webfinger.net/
https://tools.ietf.org/html/rfc7033
"""
import datetime
import logging
import re
import urllib.parse
from flask import render_template, request
from granary import as2, atom, microformats2
import mf2util
from oauth_dropins.webutil import flask_util, util
from oauth_dropins.webutil.flask_util import error
from oauth_dropins.webutil.util import json_dumps
from app import app, cache
import common
from models import User
NON_TLDS = frozenset(('html', 'json', 'php', 'xml'))
logger = logging.getLogger(__name__)
class Actor(flask_util.XrdOrJrd):
"""Fetches a site's home page, converts its mf2 to WebFinger, and serves.
TODO: unify with common.actor()
"""
@flask_util.cached(cache, common.CACHE_TIME, headers=['Accept'])
def dispatch_request(self, *args, **kwargs):
return super().dispatch_request(*args, **kwargs)
def template_prefix(self):
return 'webfinger_user'
def template_vars(self, domain=None, url=None):
logger.debug(f'Headers: {list(request.headers.items())}')
if domain.split('.')[-1] in NON_TLDS:
error(f"{domain} doesn't look like a domain", status=404)
# find representative h-card. try url, then url's home page, then domain
urls = [f'https://{domain}/']
if url:
urls = [url, urllib.parse.urljoin(url, '/')] + urls
for candidate in urls:
try:
resp = util.requests_get(candidate)
except ValueError:
logger.warning('', exc_info=True)
continue
parsed = util.parse_html(resp)
mf2 = util.parse_mf2(parsed, url=resp.url)
# logger.debug(f'Parsed mf2 for {resp.url}: {json_dumps(mf2, indent=2)}')
hcard = mf2util.representative_hcard(mf2, resp.url)
if hcard:
logger.info(f'Representative h-card: {json_dumps(hcard, indent=2)}')
break
else:
error(f"didn't find a representative h-card (http://microformats.org/wiki/representative-hcard-parsing) in any of {urls}")
logger.info(f'Generating WebFinger data for {domain}')
user = User.get_or_create(domain)
props = hcard.get('properties', {})
urls = util.dedupe_urls(props.get('url', []) + [resp.url])
canonical_url = urls[0]
user.actor_as2 = json_dumps(common.postprocess_as2(
as2.from_as1(microformats2.json_to_object(hcard)), user=user))
user.put()
# discover atom feed, if any
feed = parsed.find('link', rel='alternate', type=atom.CONTENT_TYPE)
if feed and feed['href']:
feed = urllib.parse.urljoin(resp.url, feed['href'])
else:
feed = 'https://granary.io/url?' + urllib.parse.urlencode({
'input': 'html',
'output': 'atom',
'url': resp.url,
'hub': resp.url,
})
# discover PuSH, if any
for link in resp.headers.get('Link', '').split(','):
match = common.LINK_HEADER_RE.match(link)
if match and match.group(2) == 'hub':
hub = match.group(1)
else:
hub = 'https://bridgy-fed.superfeedr.com/'
# generate webfinger content
data = util.trim_nulls({
'subject': 'acct:' + user.address().lstrip('@'),
'aliases': urls,
'magic_keys': [{'value': user.href()}],
'links': sum(([{
'rel': 'http://webfinger.net/rel/profile-page',
'type': 'text/html',
'href': url,
}] for url in urls if url.startswith("http")), []) + [{
'rel': 'http://webfinger.net/rel/avatar',
'href': microformats2.get_text(url),
} for url in props.get('photo', [])] + [{
'rel': 'canonical_uri',
'type': 'text/html',
'href': canonical_url,
},
# ActivityPub
{
'rel': 'self',
'type': as2.CONTENT_TYPE,
# WARNING: in python 2 sometimes request.host_url lost port,
# http://localhost:8080 would become just http://localhost. no
# clue how or why. pay attention here if that happens again.
'href': common.host_url(domain),
}, {
# AP reads this and sharedInbox from the AS2 actor, not
# webfinger, so strictly speaking, it's probably not needed here.
'rel': 'inbox',
'type': as2.CONTENT_TYPE,
'href': common.host_url(f'{domain}/inbox'),
}, {
# https://www.w3.org/TR/activitypub/#sharedInbox
'rel': 'sharedInbox',
'type': as2.CONTENT_TYPE,
'href': common.host_url('inbox'),
},
# OStatus
{
'rel': 'http://schemas.google.com/g/2010#updates-from',
'type': atom.CONTENT_TYPE,
'href': feed,
}, {
'rel': 'hub',
'href': hub,
}, {
'rel': 'magic-public-key',
'href': user.href(),
},
# remote follow
# https://socialhub.activitypub.rocks/t/what-is-the-current-spec-for-remote-follow/2020/11?u=snarfed
# https://github.com/snarfed/bridgy-fed/issues/60#issuecomment-1325589750
{
'rel': 'http://ostatus.org/schema/1.0/subscribe',
'template': common.host_url(f'user/{domain}?url={{uri}}'),
}]
})
logger.info(f'Returning WebFinger data: {json_dumps(data, indent=2)}')
return data
class Webfinger(Actor):
"""Handles Webfinger requests.
https://webfinger.net/
Supports both JRD and XRD; defaults to JRD.
https://tools.ietf.org/html/rfc7033#section-4
"""
def template_vars(self):
resource = flask_util.get_required_param('resource').strip()
resource = resource.removeprefix(common.host_url())
# handle Bridgy Fed actor URLs, eg https://fed.brid.gy/snarfed.org
host = util.domain_from_link(common.host_url())
if resource in ('', '/', f'acct:{host}', f'acct:@{host}'):
error('Expected other domain, not fed.brid.gy')
try:
user, domain = util.parse_acct_uri(resource)
if domain in common.DOMAINS:
domain = user
except ValueError:
domain = urllib.parse.urlparse(resource).netloc or resource
url = None
if util.is_web(resource):
url = resource
return super().template_vars(domain=domain, url=url)
class HostMeta(flask_util.XrdOrJrd):
"""Renders and serves the /.well-known/host-meta file.
Supports both JRD and XRD; defaults to XRD.
https://tools.ietf.org/html/rfc6415#section-3
"""
DEFAULT_TYPE = flask_util.XrdOrJrd.XRD
def template_prefix(self):
return 'host-meta'
def template_vars(self):
return {'host_uri': common.host_url()}
@app.get('/.well-known/host-meta.xrds')
def host_meta_xrds():
"""Renders and serves the /.well-known/host-meta.xrds XRDS-Simple file."""
return (render_template('host-meta.xrds', host_uri=common.host_url()),
{'Content-Type': 'application/xrds+xml'})
app.add_url_rule(f'/acct:<regex("{common.DOMAIN_RE}"):domain>',
view_func=Actor.as_view('actor_acct'))
app.add_url_rule('/.well-known/webfinger', view_func=Webfinger.as_view('webfinger'))
app.add_url_rule('/.well-known/host-meta', view_func=HostMeta.as_view('hostmeta'))
app.add_url_rule('/.well-known/host-meta.json', view_func=HostMeta.as_view('hostmeta-json'))