336 lines
12 KiB
Python
336 lines
12 KiB
Python
# Copyright 2019 The Matrix.org Foundation C.I.C.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
import logging
|
|
import re
|
|
from typing import Any, Dict, Optional, Tuple
|
|
from urllib.parse import urlparse
|
|
from urllib.request import ( # type: ignore[attr-defined]
|
|
getproxies_environment,
|
|
proxy_bypass_environment,
|
|
)
|
|
|
|
from zope.interface import implementer
|
|
|
|
from twisted.internet import defer
|
|
from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
|
|
from twisted.internet.interfaces import IReactorCore, IStreamClientEndpoint
|
|
from twisted.python.failure import Failure
|
|
from twisted.web.client import (
|
|
URI,
|
|
BrowserLikePolicyForHTTPS,
|
|
HTTPConnectionPool,
|
|
_AgentBase,
|
|
)
|
|
from twisted.web.error import SchemeNotSupported
|
|
from twisted.web.http_headers import Headers
|
|
from twisted.web.iweb import IAgent, IBodyProducer, IPolicyForHTTPS
|
|
|
|
from synapse.http.connectproxyclient import HTTPConnectProxyEndpoint, ProxyCredentials
|
|
from synapse.types import ISynapseReactor
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
_VALID_URI = re.compile(br"\A[\x21-\x7e]+\Z")
|
|
|
|
|
|
@implementer(IAgent)
|
|
class ProxyAgent(_AgentBase):
|
|
"""An Agent implementation which will use an HTTP proxy if one was requested
|
|
|
|
Args:
|
|
reactor: twisted reactor to place outgoing
|
|
connections.
|
|
|
|
proxy_reactor: twisted reactor to use for connections to the proxy server
|
|
reactor might have some blacklisting applied (i.e. for DNS queries),
|
|
but we need unblocked access to the proxy.
|
|
|
|
contextFactory: A factory for TLS contexts, to control the
|
|
verification parameters of OpenSSL. The default is to use a
|
|
`BrowserLikePolicyForHTTPS`, so unless you have special
|
|
requirements you can leave this as-is.
|
|
|
|
connectTimeout: The amount of time that this Agent will wait
|
|
for the peer to accept a connection, in seconds. If 'None',
|
|
HostnameEndpoint's default (30s) will be used.
|
|
This is used for connections to both proxies and destination servers.
|
|
|
|
bindAddress: The local address for client sockets to bind to.
|
|
|
|
pool: connection pool to be used. If None, a
|
|
non-persistent pool instance will be created.
|
|
|
|
use_proxy: Whether proxy settings should be discovered and used
|
|
from conventional environment variables.
|
|
|
|
Raises:
|
|
ValueError if use_proxy is set and the environment variables
|
|
contain an invalid proxy specification.
|
|
RuntimeError if no tls_options_factory is given for a https connection
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
reactor: IReactorCore,
|
|
proxy_reactor: Optional[ISynapseReactor] = None,
|
|
contextFactory: Optional[IPolicyForHTTPS] = None,
|
|
connectTimeout: Optional[float] = None,
|
|
bindAddress: Optional[bytes] = None,
|
|
pool: Optional[HTTPConnectionPool] = None,
|
|
use_proxy: bool = False,
|
|
):
|
|
contextFactory = contextFactory or BrowserLikePolicyForHTTPS()
|
|
|
|
_AgentBase.__init__(self, reactor, pool)
|
|
|
|
if proxy_reactor is None:
|
|
self.proxy_reactor = reactor
|
|
else:
|
|
self.proxy_reactor = proxy_reactor
|
|
|
|
self._endpoint_kwargs: Dict[str, Any] = {}
|
|
if connectTimeout is not None:
|
|
self._endpoint_kwargs["timeout"] = connectTimeout
|
|
if bindAddress is not None:
|
|
self._endpoint_kwargs["bindAddress"] = bindAddress
|
|
|
|
http_proxy = None
|
|
https_proxy = None
|
|
no_proxy = None
|
|
if use_proxy:
|
|
proxies = getproxies_environment()
|
|
http_proxy = proxies["http"].encode() if "http" in proxies else None
|
|
https_proxy = proxies["https"].encode() if "https" in proxies else None
|
|
no_proxy = proxies["no"] if "no" in proxies else None
|
|
|
|
self.http_proxy_endpoint, self.http_proxy_creds = http_proxy_endpoint(
|
|
http_proxy, self.proxy_reactor, contextFactory, **self._endpoint_kwargs
|
|
)
|
|
|
|
self.https_proxy_endpoint, self.https_proxy_creds = http_proxy_endpoint(
|
|
https_proxy, self.proxy_reactor, contextFactory, **self._endpoint_kwargs
|
|
)
|
|
|
|
self.no_proxy = no_proxy
|
|
|
|
self._policy_for_https = contextFactory
|
|
self._reactor = reactor
|
|
|
|
def request(
|
|
self,
|
|
method: bytes,
|
|
uri: bytes,
|
|
headers: Optional[Headers] = None,
|
|
bodyProducer: Optional[IBodyProducer] = None,
|
|
) -> defer.Deferred:
|
|
"""
|
|
Issue a request to the server indicated by the given uri.
|
|
|
|
Supports `http` and `https` schemes.
|
|
|
|
An existing connection from the connection pool may be used or a new one may be
|
|
created.
|
|
|
|
See also: twisted.web.iweb.IAgent.request
|
|
|
|
Args:
|
|
method: The request method to use, such as `GET`, `POST`, etc
|
|
|
|
uri: The location of the resource to request.
|
|
|
|
headers: Extra headers to send with the request
|
|
|
|
bodyProducer: An object which can generate bytes to make up the body of
|
|
this request (for example, the properly encoded contents of a file for
|
|
a file upload). Or, None if the request is to have no body.
|
|
|
|
Returns:
|
|
Deferred[IResponse]: completes when the header of the response has
|
|
been received (regardless of the response status code).
|
|
|
|
Can fail with:
|
|
SchemeNotSupported: if the uri is not http or https
|
|
|
|
twisted.internet.error.TimeoutError if the server we are connecting
|
|
to (proxy or destination) does not accept a connection before
|
|
connectTimeout.
|
|
|
|
... other things too.
|
|
"""
|
|
uri = uri.strip()
|
|
if not _VALID_URI.match(uri):
|
|
raise ValueError(f"Invalid URI {uri!r}")
|
|
|
|
parsed_uri = URI.fromBytes(uri)
|
|
pool_key = (parsed_uri.scheme, parsed_uri.host, parsed_uri.port)
|
|
request_path = parsed_uri.originForm
|
|
|
|
should_skip_proxy = False
|
|
if self.no_proxy is not None:
|
|
should_skip_proxy = proxy_bypass_environment(
|
|
parsed_uri.host.decode(),
|
|
proxies={"no": self.no_proxy},
|
|
)
|
|
|
|
if (
|
|
parsed_uri.scheme == b"http"
|
|
and self.http_proxy_endpoint
|
|
and not should_skip_proxy
|
|
):
|
|
# Determine whether we need to set Proxy-Authorization headers
|
|
if self.http_proxy_creds:
|
|
# Set a Proxy-Authorization header
|
|
if headers is None:
|
|
headers = Headers()
|
|
headers.addRawHeader(
|
|
b"Proxy-Authorization",
|
|
self.http_proxy_creds.as_proxy_authorization_value(),
|
|
)
|
|
# Cache *all* connections under the same key, since we are only
|
|
# connecting to a single destination, the proxy:
|
|
pool_key = ("http-proxy", self.http_proxy_endpoint)
|
|
endpoint = self.http_proxy_endpoint
|
|
request_path = uri
|
|
elif (
|
|
parsed_uri.scheme == b"https"
|
|
and self.https_proxy_endpoint
|
|
and not should_skip_proxy
|
|
):
|
|
endpoint = HTTPConnectProxyEndpoint(
|
|
self.proxy_reactor,
|
|
self.https_proxy_endpoint,
|
|
parsed_uri.host,
|
|
parsed_uri.port,
|
|
self.https_proxy_creds,
|
|
)
|
|
else:
|
|
# not using a proxy
|
|
endpoint = HostnameEndpoint(
|
|
self._reactor, parsed_uri.host, parsed_uri.port, **self._endpoint_kwargs
|
|
)
|
|
|
|
logger.debug("Requesting %s via %s", uri, endpoint)
|
|
|
|
if parsed_uri.scheme == b"https":
|
|
tls_connection_creator = self._policy_for_https.creatorForNetloc(
|
|
parsed_uri.host, parsed_uri.port
|
|
)
|
|
endpoint = wrapClientTLS(tls_connection_creator, endpoint)
|
|
elif parsed_uri.scheme == b"http":
|
|
pass
|
|
else:
|
|
return defer.fail(
|
|
Failure(
|
|
SchemeNotSupported("Unsupported scheme: %r" % (parsed_uri.scheme,))
|
|
)
|
|
)
|
|
|
|
return self._requestWithEndpoint(
|
|
pool_key, endpoint, method, parsed_uri, headers, bodyProducer, request_path
|
|
)
|
|
|
|
|
|
def http_proxy_endpoint(
|
|
proxy: Optional[bytes],
|
|
reactor: IReactorCore,
|
|
tls_options_factory: Optional[IPolicyForHTTPS],
|
|
**kwargs,
|
|
) -> Tuple[Optional[IStreamClientEndpoint], Optional[ProxyCredentials]]:
|
|
"""Parses an http proxy setting and returns an endpoint for the proxy
|
|
|
|
Args:
|
|
proxy: the proxy setting in the form: [scheme://][<username>:<password>@]<host>[:<port>]
|
|
This currently supports http:// and https:// proxies.
|
|
A hostname without scheme is assumed to be http.
|
|
|
|
reactor: reactor to be used to connect to the proxy
|
|
|
|
tls_options_factory: the TLS options to use when connecting through a https proxy
|
|
|
|
kwargs: other args to be passed to HostnameEndpoint
|
|
|
|
Returns:
|
|
a tuple of
|
|
endpoint to use to connect to the proxy, or None
|
|
ProxyCredentials or if no credentials were found, or None
|
|
|
|
Raise:
|
|
ValueError if proxy has no hostname or unsupported scheme.
|
|
RuntimeError if no tls_options_factory is given for a https connection
|
|
"""
|
|
if proxy is None:
|
|
return None, None
|
|
|
|
# Note: urlsplit/urlparse cannot be used here as that does not work (for Python
|
|
# 3.9+) on scheme-less proxies, e.g. host:port.
|
|
scheme, host, port, credentials = parse_proxy(proxy)
|
|
|
|
proxy_endpoint = HostnameEndpoint(reactor, host, port, **kwargs)
|
|
|
|
if scheme == b"https":
|
|
if tls_options_factory:
|
|
tls_options = tls_options_factory.creatorForNetloc(host, port)
|
|
proxy_endpoint = wrapClientTLS(tls_options, proxy_endpoint)
|
|
else:
|
|
raise RuntimeError(
|
|
f"No TLS options for a https connection via proxy {proxy!s}"
|
|
)
|
|
|
|
return proxy_endpoint, credentials
|
|
|
|
|
|
def parse_proxy(
|
|
proxy: bytes, default_scheme: bytes = b"http", default_port: int = 1080
|
|
) -> Tuple[bytes, bytes, int, Optional[ProxyCredentials]]:
|
|
"""
|
|
Parse a proxy connection string.
|
|
|
|
Given a HTTP proxy URL, breaks it down into components and checks that it
|
|
has a hostname (otherwise it is not useful to us when trying to find a
|
|
proxy) and asserts that the URL has a scheme we support.
|
|
|
|
|
|
Args:
|
|
proxy: The proxy connection string. Must be in the form '[scheme://][<username>:<password>@]host[:port]'.
|
|
default_scheme: The default scheme to return if one is not found in `proxy`. Defaults to http
|
|
default_port: The default port to return if one is not found in `proxy`. Defaults to 1080
|
|
|
|
Returns:
|
|
A tuple containing the scheme, hostname, port and ProxyCredentials.
|
|
If no credentials were found, the ProxyCredentials instance is replaced with None.
|
|
|
|
Raise:
|
|
ValueError if proxy has no hostname or unsupported scheme.
|
|
"""
|
|
# First check if we have a scheme present
|
|
# Note: urlsplit/urlparse cannot be used (for Python # 3.9+) on scheme-less proxies, e.g. host:port.
|
|
if b"://" not in proxy:
|
|
proxy = b"".join([default_scheme, b"://", proxy])
|
|
|
|
url = urlparse(proxy)
|
|
|
|
if not url.hostname:
|
|
raise ValueError("Proxy URL did not contain a hostname! Please specify one.")
|
|
|
|
if url.scheme not in (b"http", b"https"):
|
|
raise ValueError(
|
|
f"Unknown proxy scheme {url.scheme!s}; only 'http' and 'https' is supported."
|
|
)
|
|
|
|
credentials = None
|
|
if url.username and url.password:
|
|
credentials = ProxyCredentials(b"".join([url.username, b":", url.password]))
|
|
|
|
return url.scheme, url.hostname, url.port or default_port, credentials
|