Ensure the type of URL attributes is always str when matching against preview blacklist (#12333)

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Brendan Abolivier 2022-03-31 11:49:49 +02:00 committed by GitHub
parent c31c1091d4
commit f96b85eca8
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3 changed files with 49 additions and 4 deletions

1
changelog.d/12333.bugfix Normal file
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@ -0,0 +1 @@
Fix a long-standing bug affecting URL previews that would generate a 500 response instead of a 403 if the previewed URL includes a port that isn't allowed by the relevant blacklist.

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@ -200,12 +200,17 @@ class PreviewUrlResource(DirectServeJsonResource):
match = False
continue
# Some attributes might not be parsed as strings by urlsplit (such as the
# port, which is parsed as an int). Because we use match functions that
# expect strings, we want to make sure that's what we give them.
value_str = str(value)
if pattern.startswith("^"):
if not re.match(pattern, getattr(url_tuple, attrib)):
if not re.match(pattern, value_str):
match = False
continue
else:
if not fnmatch.fnmatch(getattr(url_tuple, attrib), pattern):
if not fnmatch.fnmatch(value_str, pattern):
match = False
continue
if match:

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@ -17,7 +17,7 @@ import json
import os
import re
from typing import Any, Dict, Optional, Sequence, Tuple, Type
from urllib.parse import urlencode
from urllib.parse import quote, urlencode
from twisted.internet._resolver import HostResolution
from twisted.internet.address import IPv4Address, IPv6Address
@ -69,7 +69,6 @@ class URLPreviewTests(unittest.HomeserverTestCase):
"2001:800::/21",
)
config["url_preview_ip_range_whitelist"] = ("1.1.1.1",)
config["url_preview_url_blacklist"] = []
config["url_preview_accept_language"] = [
"en-UK",
"en-US;q=0.9",
@ -1123,3 +1122,43 @@ class URLPreviewTests(unittest.HomeserverTestCase):
os.path.exists(path),
f"{os.path.relpath(path, self.media_store_path)} was not deleted",
)
@unittest.override_config({"url_preview_url_blacklist": [{"port": "*"}]})
def test_blacklist_port(self) -> None:
"""Tests that blacklisting URLs with a port makes previewing such URLs
fail with a 403 error and doesn't impact other previews.
"""
self.lookups["matrix.org"] = [(IPv4Address, "10.1.2.3")]
bad_url = quote("http://matrix.org:8888/foo")
good_url = quote("http://matrix.org/foo")
channel = self.make_request(
"GET",
"preview_url?url=" + bad_url,
shorthand=False,
await_result=False,
)
self.pump()
self.assertEqual(channel.code, 403, channel.result)
channel = self.make_request(
"GET",
"preview_url?url=" + good_url,
shorthand=False,
await_result=False,
)
self.pump()
client = self.reactor.tcpClients[0][2].buildProtocol(None)
server = AccumulatingProtocol()
server.makeConnection(FakeTransport(client, self.reactor))
client.makeConnection(FakeTransport(server, self.reactor))
client.dataReceived(
b"HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/html\r\n\r\n"
% (len(self.end_content),)
+ self.end_content
)
self.pump()
self.assertEqual(channel.code, 200)