Use the federation blacklist for requests to untrusted Identity Servers (#6000)

Uses a SimpleHttpClient instance equipped with the federation_ip_range_blacklist list for requests to identity servers provided by user input. Does not use a blacklist when contacting identity servers specified by account_threepid_delegates. The homeserver trusts the latter and we don't want to prevent homeserver admins from specifying delegates that are on internal IP addresses.

Fixes #5935
This commit is contained in:
Andrew Morgan 2019-09-23 21:23:20 +02:00 committed by Richard van der Hoff
parent 1ea3ed7620
commit e08ea43463
5 changed files with 28 additions and 4 deletions

1
changelog.d/6000.feature Normal file
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@ -0,0 +1 @@
Apply the federation blacklist to requests to identity servers.

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@ -110,6 +110,9 @@ pid_file: DATADIR/homeserver.pid
# blacklist IP address CIDR ranges. If this option is not specified, or
# specified with an empty list, no ip range blacklist will be enforced.
#
# As of Synapse v1.4.0 this option also affects any outbound requests to identity
# servers provided by user input.
#
# (0.0.0.0 and :: are always blacklisted, whether or not they are explicitly
# listed here, since they correspond to unroutable addresses.)
#

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@ -545,6 +545,9 @@ class ServerConfig(Config):
# blacklist IP address CIDR ranges. If this option is not specified, or
# specified with an empty list, no ip range blacklist will be enforced.
#
# As of Synapse v1.4.0 this option also affects any outbound requests to identity
# servers provided by user input.
#
# (0.0.0.0 and :: are always blacklisted, whether or not they are explicitly
# listed here, since they correspond to unroutable addresses.)
#

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@ -31,6 +31,7 @@ from synapse.api.errors import (
SynapseError,
)
from synapse.config.emailconfig import ThreepidBehaviour
from synapse.http.client import SimpleHttpClient
from synapse.util.stringutils import random_string
from ._base import BaseHandler
@ -42,7 +43,12 @@ class IdentityHandler(BaseHandler):
def __init__(self, hs):
super(IdentityHandler, self).__init__(hs)
self.http_client = hs.get_simple_http_client()
self.http_client = SimpleHttpClient(hs)
# We create a blacklisting instance of SimpleHttpClient for contacting identity
# servers specified by clients
self.blacklisting_http_client = SimpleHttpClient(
hs, ip_blacklist=hs.config.federation_ip_range_blacklist
)
self.federation_http_client = hs.get_http_client()
self.hs = hs
@ -143,7 +149,9 @@ class IdentityHandler(BaseHandler):
bind_url = "https://%s/_matrix/identity/api/v1/3pid/bind" % (id_server,)
try:
data = yield self.http_client.post_json_get_json(
# Use the blacklisting http client as this call is only to identity servers
# provided by a client
data = yield self.blacklisting_http_client.post_json_get_json(
bind_url, bind_data, headers=headers
)
@ -246,7 +254,11 @@ class IdentityHandler(BaseHandler):
headers = {b"Authorization": auth_headers}
try:
yield self.http_client.post_json_get_json(url, content, headers)
# Use the blacklisting http client as this call is only to identity servers
# provided by a client
yield self.blacklisting_http_client.post_json_get_json(
url, content, headers
)
changed = True
except HttpResponseException as e:
changed = False

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@ -31,6 +31,7 @@ from synapse import types
from synapse.api.constants import EventTypes, Membership
from synapse.api.errors import AuthError, Codes, HttpResponseException, SynapseError
from synapse.handlers.identity import LookupAlgorithm, create_id_access_token_header
from synapse.http.client import SimpleHttpClient
from synapse.types import RoomID, UserID
from synapse.util.async_helpers import Linearizer
from synapse.util.distributor import user_joined_room, user_left_room
@ -62,7 +63,11 @@ class RoomMemberHandler(object):
self.auth = hs.get_auth()
self.state_handler = hs.get_state_handler()
self.config = hs.config
self.simple_http_client = hs.get_simple_http_client()
# We create a blacklisting instance of SimpleHttpClient for contacting identity
# servers specified by clients
self.simple_http_client = SimpleHttpClient(
hs, ip_blacklist=hs.config.federation_ip_range_blacklist
)
self.federation_handler = hs.get_handlers().federation_handler
self.directory_handler = hs.get_handlers().directory_handler