relay/relay/misc.py
2022-11-10 12:40:48 -05:00

554 lines
12 KiB
Python

import asyncio
import base64
import json
import logging
import socket
import traceback
import uuid
from Crypto.Hash import SHA, SHA256, SHA512
from Crypto.PublicKey import RSA
from Crypto.Signature import PKCS1_v1_5
from aiohttp import ClientSession
from aiohttp.hdrs import METH_ALL as METHODS
from aiohttp.web import Response as AiohttpResponse, View as AiohttpView
from datetime import datetime
from json.decoder import JSONDecodeError
from urllib.parse import urlparse
from uuid import uuid4
from .http_debug import http_debug
app = None
HASHES = {
'sha1': SHA,
'sha256': SHA256,
'sha512': SHA512
}
MIMETYPES = {
'activity': 'application/activity+json',
'html': 'text/html',
'json': 'application/json',
'text': 'text/plain'
}
NODEINFO_NS = {
'20': 'http://nodeinfo.diaspora.software/ns/schema/2.0',
'21': 'http://nodeinfo.diaspora.software/ns/schema/2.1'
}
def set_app(new_app):
global app
app = new_app
def build_signing_string(headers, used_headers):
return '\n'.join(map(lambda x: ': '.join([x.lower(), headers[x]]), used_headers))
def check_open_port(host, port):
if host == '0.0.0.0':
host = '127.0.0.1'
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
try:
return s.connect_ex((host , port)) != 0
except socket.error as e:
return False
def create_signature_header(headers):
headers = {k.lower(): v for k, v in headers.items()}
used_headers = headers.keys()
sigstring = build_signing_string(headers, used_headers)
sig = {
'keyId': app.config.keyid,
'algorithm': 'rsa-sha256',
'headers': ' '.join(used_headers),
'signature': sign_signing_string(sigstring, app.database.PRIVKEY)
}
chunks = ['{}="{}"'.format(k, v) for k, v in sig.items()]
return ','.join(chunks)
def distill_inboxes(actor, object_id):
for inbox in app.database.inboxes:
if inbox != actor.shared_inbox and urlparse(inbox).hostname != urlparse(object_id).hostname:
yield inbox
def generate_body_digest(body):
bodyhash = app.cache.digests.get(body)
if bodyhash:
return bodyhash
h = SHA256.new(body.encode('utf-8'))
bodyhash = base64.b64encode(h.digest()).decode('utf-8')
app.cache.digests[body] = bodyhash
return bodyhash
def sign_signing_string(sigstring, key):
pkcs = PKCS1_v1_5.new(key)
h = SHA256.new()
h.update(sigstring.encode('ascii'))
sigdata = pkcs.sign(h)
return base64.b64encode(sigdata).decode('utf-8')
def split_signature(sig):
default = {"headers": "date"}
sig = sig.strip().split(',')
for chunk in sig:
k, _, v = chunk.partition('=')
v = v.strip('\"')
default[k] = v
default['headers'] = default['headers'].split()
return default
async def fetch_actor_key(actor):
actor_data = await request(actor)
if not actor_data:
return None
try:
return RSA.importKey(actor_data['publicKey']['publicKeyPem'])
except Exception as e:
logging.debug(f'Exception occured while fetching actor key: {e}')
async def fetch_nodeinfo(domain):
nodeinfo_url = None
wk_nodeinfo = await request(f'https://{domain}/.well-known/nodeinfo', sign_headers=False, activity=False)
if not wk_nodeinfo:
return
wk_nodeinfo = WKNodeinfo(wk_nodeinfo)
for version in ['20', '21']:
try:
nodeinfo_url = wk_nodeinfo.get_url(version)
except KeyError:
pass
if not nodeinfo_url:
logging.verbose(f'Failed to fetch nodeinfo url for domain: {domain}')
return False
nodeinfo = await request(nodeinfo_url, sign_headers=False, activity=False)
try:
return nodeinfo['software']['name']
except KeyError:
return False
async def request(uri, data=None, force=False, sign_headers=True, activity=True):
## If a get request and not force, try to use the cache first
if not data and not force:
try:
return app.cache.json[uri]
except KeyError:
pass
url = urlparse(uri)
method = 'POST' if data else 'GET'
action = data.get('type') if data else None
headers = {
'Accept': f'{MIMETYPES["activity"]}, {MIMETYPES["json"]};q=0.9',
'User-Agent': 'ActivityRelay',
}
if data:
headers['Content-Type'] = MIMETYPES['activity' if activity else 'json']
if sign_headers:
signing_headers = {
'(request-target)': f'{method.lower()} {url.path}',
'Date': datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT'),
'Host': url.netloc
}
if data:
assert isinstance(data, dict)
data = json.dumps(data)
signing_headers.update({
'Digest': f'SHA-256={generate_body_digest(data)}',
'Content-Length': str(len(data.encode('utf-8')))
})
signing_headers['Signature'] = create_signature_header(signing_headers)
del signing_headers['(request-target)']
del signing_headers['Host']
headers.update(signing_headers)
try:
if data:
logging.verbose(f'Sending "{action}" to inbox: {uri}')
else:
logging.verbose(f'Sending GET request to url: {uri}')
async with ClientSession(trace_configs=http_debug()) as session, app.semaphore:
async with session.request(method, uri, headers=headers, data=data) as resp:
## aiohttp has been known to leak if the response hasn't been read,
## so we're just gonna read the request no matter what
resp_data = await resp.read()
## Not expecting a response, so just return
if resp.status == 202:
return
elif resp.status != 200:
if not resp_data:
return logging.verbose(f'Received error when requesting {uri}: {resp.status} {resp_data}')
return logging.verbose(f'Received error when sending {action} to {uri}: {resp.status} {resp_data}')
if resp.content_type == MIMETYPES['activity']:
resp_data = await resp.json(loads=Message.new_from_json)
elif resp.content_type == MIMETYPES['json']:
resp_data = await resp.json(loads=DotDict.new_from_json)
else:
logging.verbose(f'Invalid Content-Type for "{url}": {resp.content_type}')
return logging.debug(f'Response: {resp_data}')
logging.debug(f'{uri} >> resp {resp_data}')
app.cache.json[uri] = resp_data
return resp_data
except JSONDecodeError:
return
except Exception:
traceback.print_exc()
async def validate_signature(actor, http_request):
pubkey = await fetch_actor_key(actor)
if not pubkey:
return False
logging.debug(f'actor key: {pubkey}')
headers = {key.lower(): value for key, value in http_request.headers.items()}
headers['(request-target)'] = ' '.join([http_request.method.lower(), http_request.path])
sig = split_signature(headers['signature'])
logging.debug(f'sigdata: {sig}')
sigstring = build_signing_string(headers, sig['headers'])
logging.debug(f'sigstring: {sigstring}')
sign_alg, _, hash_alg = sig['algorithm'].partition('-')
logging.debug(f'sign alg: {sign_alg}, hash alg: {hash_alg}')
sigdata = base64.b64decode(sig['signature'])
pkcs = PKCS1_v1_5.new(pubkey)
h = HASHES[hash_alg].new()
h.update(sigstring.encode('ascii'))
result = pkcs.verify(h, sigdata)
http_request['validated'] = result
logging.debug(f'validates? {result}')
return result
class DotDict(dict):
def __init__(self, _data, **kwargs):
dict.__init__(self)
self.update(_data, **kwargs)
def __getattr__(self, k):
try:
return self[k]
except KeyError:
raise AttributeError(f'{self.__class__.__name__} object has no attribute {k}') from None
def __setattr__(self, k, v):
if k.startswith('_'):
super().__setattr__(k, v)
else:
self[k] = v
def __setitem__(self, k, v):
if type(v) == dict:
v = DotDict(v)
super().__setitem__(k, v)
def __delattr__(self, k):
try:
dict.__delitem__(self, k)
except KeyError:
raise AttributeError(f'{self.__class__.__name__} object has no attribute {k}') from None
@classmethod
def new_from_json(cls, data):
if not data:
raise JSONDecodeError('Empty body', data, 1)
try:
return cls(json.loads(data))
except ValueError:
raise JSONDecodeError('Invalid body', data, 1)
def to_json(self, indent=None):
return json.dumps(self, indent=indent)
def update(self, _data, **kwargs):
if isinstance(_data, dict):
for key, value in _data.items():
self[key] = value
elif isinstance(_data, (list, tuple, set)):
for key, value in _data:
self[key] = value
for key, value in kwargs.items():
self[key] = value
class Message(DotDict):
@classmethod
def new_actor(cls, host, pubkey, description=None):
return cls({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': f'https://{host}/actor',
'type': 'Application',
'preferredUsername': 'relay',
'name': 'ActivityRelay',
'summary': description or 'ActivityRelay bot',
'followers': f'https://{host}/followers',
'following': f'https://{host}/following',
'inbox': f'https://{host}/inbox',
'url': f'https://{host}/inbox',
'endpoints': {
'sharedInbox': f'https://{host}/inbox'
},
'publicKey': {
'id': f'https://{host}/actor#main-key',
'owner': f'https://{host}/actor',
'publicKeyPem': pubkey
}
})
@classmethod
def new_announce(cls, host, object):
return cls({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': f'https://{host}/activities/{uuid.uuid4()}',
'type': 'Announce',
'to': [f'https://{host}/followers'],
'actor': f'https://{host}/actor',
'object': object
})
@classmethod
def new_follow(cls, host, actor):
return cls({
'@context': 'https://www.w3.org/ns/activitystreams',
'type': 'Follow',
'to': [actor],
'object': actor,
'id': f'https://{host}/activities/{uuid.uuid4()}',
'actor': f'https://{host}/actor'
})
@classmethod
def new_unfollow(cls, host, actor, follow):
return cls({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': f'https://{host}/activities/{uuid.uuid4()}',
'type': 'Undo',
'to': [actor],
'actor': f'https://{host}/actor',
'object': follow
})
@classmethod
def new_response(cls, host, actor, followid, accept):
return cls({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': f'https://{host}/activities/{uuid.uuid4()}',
'type': 'Accept' if accept else 'Reject',
'to': [actor],
'actor': f'https://{host}/actor',
'object': {
'id': followid,
'type': 'Follow',
'object': f'https://{host}/actor',
'actor': actor
}
})
# misc properties
@property
def domain(self):
return urlparse(self.id).hostname
# actor properties
@property
def pubkey(self):
return self.publicKey.publicKeyPem
@property
def shared_inbox(self):
return self.get('endpoints', {}).get('sharedInbox', self.inbox)
# activity properties
@property
def actorid(self):
if isinstance(self.actor, dict):
return self.actor.id
return self.actor
@property
def objectid(self):
if isinstance(self.object, dict):
return self.object.id
return self.object
class Response(AiohttpResponse):
@classmethod
def new(cls, body='', status=200, headers=None, ctype='text'):
kwargs = {
'status': status,
'headers': headers,
'content_type': MIMETYPES[ctype]
}
if isinstance(body, bytes):
kwargs['body'] = body
elif isinstance(body, dict) and ctype in {'json', 'activity'}:
kwargs['text'] = json.dumps(body)
else:
kwargs['text'] = body
return cls(**kwargs)
@classmethod
def new_error(cls, status, body, ctype='text'):
if ctype == 'json':
body = json.dumps({'status': status, 'error': body})
return cls(body=body, status=status, ctype=ctype)
@property
def location(self):
return self.headers.get('Location')
@location.setter
def location(self, value):
self.headers['Location'] = value
class View(AiohttpView):
async def _iter(self):
if self.request.method not in METHODS:
self._raise_allowed_methods()
method = getattr(self, self.request.method.lower(), None)
if method is None:
self._raise_allowed_methods()
return await method(**self.request.match_info)
@property
def app(self):
return self._request.app
@property
def cache(self):
return self.app.cache
@property
def config(self):
return self.app.config
@property
def database(self):
return self.app.database
class WKNodeinfo(DotDict):
@classmethod
def new(cls, v20, v21):
return cls({
'links': [
{'rel': NODEINFO_NS['20'], 'href': v20},
{'rel': NODEINFO_NS['21'], 'href': v21}
]
})
def get_url(self, version='20'):
for item in self.links:
if item['rel'] == NODEINFO_NS[version]:
return item['href']
raise KeyError(version)