mirror of
https://mau.dev/maunium/synapse.git
synced 2024-12-14 23:53:51 +01:00
Add url_preview_enabled config option to turn on/off preview_url endpoint. defaults to off.
Add url_preview_ip_range_blacklist to let admins specify internal IP ranges that must not be spidered. Add url_preview_url_blacklist to let admins specify URL patterns that must not be spidered. Implement a custom SpiderEndpoint and associated support classes to implement url_preview_ip_range_blacklist Add commentary and generally address PR feedback
This commit is contained in:
Matthew Hodgson
parent
d6e7333ae4
commit
dafef5a688
6 changed files with 214 additions and 31 deletions
|
|
@ -16,6 +16,8 @@
|
|||
from ._base import Config
|
||||
from collections import namedtuple
|
||||
|
||||
import sys
|
||||
|
||||
ThumbnailRequirement = namedtuple(
|
||||
"ThumbnailRequirement", ["width", "height", "method", "media_type"]
|
||||
)
|
||||
|
|
@ -23,7 +25,7 @@ ThumbnailRequirement = namedtuple(
|
|||
|
||||
def parse_thumbnail_requirements(thumbnail_sizes):
|
||||
""" Takes a list of dictionaries with "width", "height", and "method" keys
|
||||
and creates a map from image media types to the thumbnail size, thumnailing
|
||||
and creates a map from image media types to the thumbnail size, thumbnailing
|
||||
method, and thumbnail media type to precalculate
|
||||
|
||||
Args:
|
||||
|
|
@ -60,6 +62,18 @@ class ContentRepositoryConfig(Config):
|
|||
self.thumbnail_requirements = parse_thumbnail_requirements(
|
||||
config["thumbnail_sizes"]
|
||||
)
|
||||
self.url_preview_enabled = config["url_preview_enabled"]
|
||||
if self.url_preview_enabled:
|
||||
try:
|
||||
from netaddr import IPSet
|
||||
if "url_preview_ip_range_blacklist" in config:
|
||||
self.url_preview_ip_range_blacklist = IPSet(
|
||||
config["url_preview_ip_range_blacklist"]
|
||||
)
|
||||
if "url_preview_url_blacklist" in config:
|
||||
self.url_preview_url_blacklist = config["url_preview_url_blacklist"]
|
||||
except ImportError:
|
||||
sys.stderr.write("\nmissing netaddr dep - disabling preview_url API\n")
|
||||
|
||||
def default_config(self, **kwargs):
|
||||
media_store = self.default_path("media_store")
|
||||
|
|
@ -74,9 +88,6 @@ class ContentRepositoryConfig(Config):
|
|||
# The largest allowed upload size in bytes
|
||||
max_upload_size: "10M"
|
||||
|
||||
# The largest allowed URL preview spidering size in bytes
|
||||
max_spider_size: "10M"
|
||||
|
||||
# Maximum number of pixels that will be thumbnailed
|
||||
max_image_pixels: "32M"
|
||||
|
||||
|
|
@ -104,4 +115,62 @@ class ContentRepositoryConfig(Config):
|
|||
- width: 800
|
||||
height: 600
|
||||
method: scale
|
||||
|
||||
# Is the preview URL API enabled? If enabled, you *must* specify
|
||||
# an explicit url_preview_ip_range_blacklist of IPs that the spider is
|
||||
# denied from accessing.
|
||||
url_preview_enabled: False
|
||||
|
||||
# List of IP address CIDR ranges that the URL preview spider is denied
|
||||
# from accessing. There are no defaults: you must explicitly
|
||||
# specify a list for URL previewing to work. You should specify any
|
||||
# internal services in your network that you do not want synapse to try
|
||||
# to connect to, otherwise anyone in any Matrix room could cause your
|
||||
# synapse to issue arbitrary GET requests to your internal services,
|
||||
# causing serious security issues.
|
||||
#
|
||||
# url_preview_ip_range_blacklist:
|
||||
# - '127.0.0.0/8'
|
||||
# - '10.0.0.0/8'
|
||||
# - '172.16.0.0/12'
|
||||
# - '192.168.0.0/16'
|
||||
|
||||
# Optional list of URL matches that the URL preview spider is
|
||||
# denied from accessing. You should use url_preview_ip_range_blacklist
|
||||
# in preference to this, otherwise someone could define a public DNS
|
||||
# entry that points to a private IP address and circumvent the blacklist.
|
||||
# This is more useful if you know there is an entire shape of URL that
|
||||
# you know that will never want synapse to try to spider.
|
||||
#
|
||||
# Each list entry is a dictionary of url component attributes as returned
|
||||
# by urlparse.urlsplit as applied to the absolute form of the URL. See
|
||||
# https://docs.python.org/2/library/urlparse.html#urlparse.urlsplit
|
||||
# The values of the dictionary are treated as an filename match pattern
|
||||
# applied to that component of URLs, unless they start with a ^ in which
|
||||
# case they are treated as a regular expression match. If all the
|
||||
# specified component matches for a given list item succeed, the URL is
|
||||
# blacklisted.
|
||||
#
|
||||
# url_preview_url_blacklist:
|
||||
# # blacklist any URL with a username in its URI
|
||||
# - username: '*''
|
||||
#
|
||||
# # blacklist all *.google.com URLs
|
||||
# - netloc: 'google.com'
|
||||
# - netloc: '*.google.com'
|
||||
#
|
||||
# # blacklist all plain HTTP URLs
|
||||
# - scheme: 'http'
|
||||
#
|
||||
# # blacklist http(s)://www.acme.com/foo
|
||||
# - netloc: 'www.acme.com'
|
||||
# path: '/foo'
|
||||
#
|
||||
# # blacklist any URL with a literal IPv4 address
|
||||
# - netloc: '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'
|
||||
|
||||
# The largest allowed URL preview spidering size in bytes
|
||||
max_spider_size: "10M"
|
||||
|
||||
|
||||
""" % locals()
|
||||
|
|
|
|||
|
|
@ -20,10 +20,12 @@ from synapse.api.errors import (
|
|||
)
|
||||
from synapse.util.logcontext import preserve_context_over_fn
|
||||
import synapse.metrics
|
||||
from synapse.http.endpoint import SpiderEndpoint
|
||||
|
||||
from canonicaljson import encode_canonical_json
|
||||
|
||||
from twisted.internet import defer, reactor, ssl, protocol
|
||||
from twisted.internet.endpoints import SSL4ClientEndpoint, TCP4ClientEndpoint
|
||||
from twisted.web.client import (
|
||||
BrowserLikeRedirectAgent, ContentDecoderAgent, GzipDecoder, Agent,
|
||||
readBody, FileBodyProducer, PartialDownloadError,
|
||||
|
|
@ -364,6 +366,35 @@ class CaptchaServerHttpClient(SimpleHttpClient):
|
|||
defer.returnValue(e.response)
|
||||
|
||||
|
||||
class SpiderEndpointFactory(object):
|
||||
def __init__(self, hs):
|
||||
self.blacklist = hs.config.url_preview_ip_range_blacklist
|
||||
self.policyForHTTPS = hs.get_http_client_context_factory()
|
||||
|
||||
def endpointForURI(self, uri):
|
||||
logger.info("Getting endpoint for %s", uri.toBytes())
|
||||
if uri.scheme == "http":
|
||||
return SpiderEndpoint(
|
||||
reactor, uri.host, uri.port, self.blacklist,
|
||||
endpoint=TCP4ClientEndpoint,
|
||||
endpoint_kw_args={
|
||||
'timeout': 15
|
||||
},
|
||||
)
|
||||
elif uri.scheme == "https":
|
||||
tlsPolicy = self.policyForHTTPS.creatorForNetloc(uri.host, uri.port)
|
||||
return SpiderEndpoint(
|
||||
reactor, uri.host, uri.port, self.blacklist,
|
||||
endpoint=SSL4ClientEndpoint,
|
||||
endpoint_kw_args={
|
||||
'sslContextFactory': tlsPolicy,
|
||||
'timeout': 15
|
||||
},
|
||||
)
|
||||
else:
|
||||
logger.warn("Can't get endpoint for unrecognised scheme %s", uri.scheme)
|
||||
|
||||
|
||||
class SpiderHttpClient(SimpleHttpClient):
|
||||
"""
|
||||
Separate HTTP client for spidering arbitrary URLs.
|
||||
|
|
@ -375,11 +406,14 @@ class SpiderHttpClient(SimpleHttpClient):
|
|||
def __init__(self, hs):
|
||||
SimpleHttpClient.__init__(self, hs)
|
||||
# clobber the base class's agent and UA:
|
||||
self.agent = ContentDecoderAgent(BrowserLikeRedirectAgent(Agent(
|
||||
reactor,
|
||||
connectTimeout=15,
|
||||
contextFactory=hs.get_http_client_context_factory()
|
||||
)), [('gzip', GzipDecoder)])
|
||||
self.agent = ContentDecoderAgent(
|
||||
BrowserLikeRedirectAgent(
|
||||
Agent.usingEndpointFactory(
|
||||
reactor,
|
||||
SpiderEndpointFactory(hs)
|
||||
)
|
||||
), [('gzip', GzipDecoder)]
|
||||
)
|
||||
# We could look like Chrome:
|
||||
# self.user_agent = ("Mozilla/5.0 (%s) (KHTML, like Gecko)
|
||||
# Chrome Safari" % hs.version_string)
|
||||
|
|
|
|||
|
|
@ -74,6 +74,37 @@ def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None,
|
|||
return transport_endpoint(reactor, domain, port, **endpoint_kw_args)
|
||||
|
||||
|
||||
class SpiderEndpoint(object):
|
||||
"""An endpoint which refuses to connect to blacklisted IP addresses
|
||||
Implements twisted.internet.interfaces.IStreamClientEndpoint.
|
||||
"""
|
||||
def __init__(self, reactor, host, port, blacklist,
|
||||
endpoint=TCP4ClientEndpoint, endpoint_kw_args={}):
|
||||
self.reactor = reactor
|
||||
self.host = host
|
||||
self.port = port
|
||||
self.blacklist = blacklist
|
||||
self.endpoint = endpoint
|
||||
self.endpoint_kw_args = endpoint_kw_args
|
||||
|
||||
@defer.inlineCallbacks
|
||||
def connect(self, protocolFactory):
|
||||
address = yield self.reactor.resolve(self.host)
|
||||
|
||||
from netaddr import IPAddress
|
||||
if IPAddress(address) in self.blacklist:
|
||||
raise ConnectError(
|
||||
"Refusing to spider blacklisted IP address %s" % address
|
||||
)
|
||||
|
||||
logger.info("Connecting to %s:%s", address, self.port)
|
||||
endpoint = self.endpoint(
|
||||
self.reactor, address, self.port, **self.endpoint_kw_args
|
||||
)
|
||||
connection = yield endpoint.connect(protocolFactory)
|
||||
defer.returnValue(connection)
|
||||
|
||||
|
||||
class SRVClientEndpoint(object):
|
||||
"""An endpoint which looks up SRV records for a service.
|
||||
Cycles through the list of servers starting with each call to connect
|
||||
|
|
@ -118,7 +149,7 @@ class SRVClientEndpoint(object):
|
|||
return self.default_server
|
||||
else:
|
||||
raise ConnectError(
|
||||
"Not server available for %s", self.service_name
|
||||
"Not server available for %s" % self.service_name
|
||||
)
|
||||
|
||||
min_priority = self.servers[0].priority
|
||||
|
|
@ -166,7 +197,7 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE):
|
|||
and answers[0].type == dns.SRV
|
||||
and answers[0].payload
|
||||
and answers[0].payload.target == dns.Name('.')):
|
||||
raise ConnectError("Service %s unavailable", service_name)
|
||||
raise ConnectError("Service %s unavailable" % service_name)
|
||||
|
||||
for answer in answers:
|
||||
if answer.type != dns.SRV or not answer.payload:
|
||||
|
|
|
|||
|
|
@ -36,13 +36,16 @@ REQUIREMENTS = {
|
|||
"blist": ["blist"],
|
||||
"pysaml2>=3.0.0,<4.0.0": ["saml2>=3.0.0,<4.0.0"],
|
||||
"pymacaroons-pynacl": ["pymacaroons"],
|
||||
"lxml>=3.6.0": ["lxml"],
|
||||
"pyjwt": ["jwt"],
|
||||
}
|
||||
CONDITIONAL_REQUIREMENTS = {
|
||||
"web_client": {
|
||||
"matrix_angular_sdk>=0.6.8": ["syweb>=0.6.8"],
|
||||
}
|
||||
},
|
||||
"preview_url": {
|
||||
"lxml>=3.6.0": ["lxml"],
|
||||
"netaddr>=0.7.18": ["netaddr"],
|
||||
},
|
||||
}
|
||||
|
||||
|
||||
|
|
|
|||
|
|
@ -79,4 +79,9 @@ class MediaRepositoryResource(Resource):
|
|||
self.putChild("download", DownloadResource(hs, filepaths))
|
||||
self.putChild("thumbnail", ThumbnailResource(hs, filepaths))
|
||||
self.putChild("identicon", IdenticonResource())
|
||||
self.putChild("preview_url", PreviewUrlResource(hs, filepaths))
|
||||
if hs.config.url_preview_enabled:
|
||||
try:
|
||||
self.putChild("preview_url", PreviewUrlResource(hs, filepaths))
|
||||
except Exception as e:
|
||||
logger.warn("Failed to mount preview_url")
|
||||
logger.exception(e)
|
||||
|
|
|
|||
|
|
@ -17,34 +17,52 @@ from .base_resource import BaseMediaResource
|
|||
|
||||
from twisted.web.server import NOT_DONE_YET
|
||||
from twisted.internet import defer
|
||||
from lxml import html
|
||||
from urlparse import urlparse, urlunparse
|
||||
from urlparse import urlparse, urlsplit, urlunparse
|
||||
|
||||
from synapse.api.errors import Codes
|
||||
from synapse.util.stringutils import random_string
|
||||
from synapse.util.caches.expiringcache import ExpiringCache
|
||||
from synapse.http.client import SpiderHttpClient
|
||||
from synapse.http.server import (
|
||||
request_handler, respond_with_json, respond_with_json_bytes
|
||||
request_handler, respond_with_json_bytes
|
||||
)
|
||||
from synapse.util.async import ObservableDeferred
|
||||
from synapse.util.stringutils import is_ascii
|
||||
|
||||
import os
|
||||
import re
|
||||
import fnmatch
|
||||
import cgi
|
||||
import ujson as json
|
||||
|
||||
import logging
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
try:
|
||||
from lxml import html
|
||||
except ImportError:
|
||||
pass
|
||||
|
||||
|
||||
class PreviewUrlResource(BaseMediaResource):
|
||||
isLeaf = True
|
||||
|
||||
def __init__(self, hs, filepaths):
|
||||
if not html:
|
||||
logger.warn("Disabling PreviewUrlResource as lxml not available")
|
||||
raise
|
||||
|
||||
if not hasattr(hs.config, "url_preview_ip_range_blacklist"):
|
||||
logger.warn(
|
||||
"For security, you must specify an explicit target IP address "
|
||||
"blacklist in url_preview_ip_range_blacklist for url previewing "
|
||||
"to work"
|
||||
)
|
||||
raise
|
||||
|
||||
BaseMediaResource.__init__(self, hs, filepaths)
|
||||
self.client = SpiderHttpClient(hs)
|
||||
if hasattr(hs.config, "url_preview_url_blacklist"):
|
||||
self.url_preview_url_blacklist = hs.config.url_preview_url_blacklist
|
||||
|
||||
# simple memory cache mapping urls to OG metadata
|
||||
self.cache = ExpiringCache(
|
||||
|
|
@ -74,6 +92,36 @@ class PreviewUrlResource(BaseMediaResource):
|
|||
else:
|
||||
ts = self.clock.time_msec()
|
||||
|
||||
# impose the URL pattern blacklist
|
||||
if hasattr(self, "url_preview_url_blacklist"):
|
||||
url_tuple = urlsplit(url)
|
||||
for entry in self.url_preview_url_blacklist:
|
||||
match = True
|
||||
for attrib in entry:
|
||||
pattern = entry[attrib]
|
||||
value = getattr(url_tuple, attrib)
|
||||
logger.debug("Matching attrib '%s' with value '%s' against pattern '%s'" % (
|
||||
attrib, value, pattern
|
||||
))
|
||||
|
||||
if value is None:
|
||||
match = False
|
||||
continue
|
||||
|
||||
if pattern.startswith('^'):
|
||||
if not re.match(pattern, getattr(url_tuple, attrib)):
|
||||
match = False
|
||||
continue
|
||||
else:
|
||||
if not fnmatch.fnmatch(getattr(url_tuple, attrib), pattern):
|
||||
match = False
|
||||
continue
|
||||
if match:
|
||||
logger.warn(
|
||||
"URL %s blocked by url_blacklist entry %s", url, entry
|
||||
)
|
||||
raise
|
||||
|
||||
# first check the memory cache - good to handle all the clients on this
|
||||
# HS thundering away to preview the same URL at the same time.
|
||||
try:
|
||||
|
|
@ -177,17 +225,6 @@ class PreviewUrlResource(BaseMediaResource):
|
|||
|
||||
respond_with_json_bytes(request, 200, json.dumps(og), send_cors=True)
|
||||
except:
|
||||
# XXX: if we don't explicitly respond here, the request never returns.
|
||||
# isn't this what server.py's wrapper is meant to be doing for us?
|
||||
respond_with_json(
|
||||
request,
|
||||
500,
|
||||
{
|
||||
"error": "Internal server error",
|
||||
"errcode": Codes.UNKNOWN,
|
||||
},
|
||||
send_cors=True
|
||||
)
|
||||
raise
|
||||
|
||||
@defer.inlineCallbacks
|
||||
|
|
@ -282,8 +319,12 @@ class PreviewUrlResource(BaseMediaResource):
|
|||
if meta_description:
|
||||
og['og:description'] = meta_description[0]
|
||||
else:
|
||||
# text_nodes = tree.xpath("//h1/text() | //h2/text() | //h3/text() | "
|
||||
# "//p/text() | //div/text() | //span/text() | //a/text()")
|
||||
# grab any text nodes which are inside the <body/> tag...
|
||||
# unless they are within an HTML5 semantic markup tag...
|
||||
# <header/>, <nav/>, <aside/>, <footer/>
|
||||
# ...or if they are within a <script/> or <style/> tag.
|
||||
# This is a very very very coarse approximation to a plain text
|
||||
# render of the page.
|
||||
text_nodes = tree.xpath("//text()[not(ancestor::header | ancestor::nav | "
|
||||
"ancestor::aside | ancestor::footer | "
|
||||
"ancestor::script | ancestor::style)]" +
|
||||
|
|
|
|||
Loading…
Reference in a new issue