Use the v2 Identity Service API for lookups (MSC2134 + MSC2140) (#5976)

This is a redo of https://github.com/matrix-org/synapse/pull/5897 but with `id_access_token` accepted.

Implements [MSC2134](https://github.com/matrix-org/matrix-doc/pull/2134) plus Identity Service v2 authentication ala [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140).

Identity lookup-related functions were also moved from `RoomMemberHandler` to `IdentityHandler`.
pull/6020/head
Andrew Morgan 2019-09-11 16:02:42 +01:00 committed by GitHub
parent cbcbfe64a2
commit 9fc71dc5ee
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6 changed files with 238 additions and 35 deletions

1
changelog.d/5897.feature Normal file
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@ -0,0 +1 @@
Switch to using the v2 Identity Service `/lookup` API where available, with fallback to v1. (Implements [MSC2134](https://github.com/matrix-org/matrix-doc/pull/2134) plus id_access_token authentication for v2 Identity Service APIs from [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140)).

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@ -74,25 +74,6 @@ class IdentityHandler(BaseHandler):
id_access_token = creds.get("id_access_token")
return client_secret, id_server, id_access_token
def create_id_access_token_header(self, id_access_token):
"""Create an Authorization header for passing to SimpleHttpClient as the header value
of an HTTP request.
Args:
id_access_token (str): An identity server access token.
Returns:
list[str]: The ascii-encoded bearer token encased in a list.
"""
# Prefix with Bearer
bearer_token = "Bearer %s" % id_access_token
# Encode headers to standard ascii
bearer_token.encode("ascii")
# Return as a list as that's how SimpleHttpClient takes header values
return [bearer_token]
@defer.inlineCallbacks
def threepid_from_creds(self, id_server, creds):
"""
@ -178,9 +159,7 @@ class IdentityHandler(BaseHandler):
bind_data = {"sid": sid, "client_secret": client_secret, "mxid": mxid}
if use_v2:
bind_url = "https://%s/_matrix/identity/v2/3pid/bind" % (id_server,)
headers["Authorization"] = self.create_id_access_token_header(
id_access_token
)
headers["Authorization"] = create_id_access_token_header(id_access_token)
else:
bind_url = "https://%s/_matrix/identity/api/v1/3pid/bind" % (id_server,)
@ -478,3 +457,36 @@ class IdentityHandler(BaseHandler):
except HttpResponseException as e:
logger.info("Proxied requestToken failed: %r", e)
raise e.to_synapse_error()
def create_id_access_token_header(id_access_token):
"""Create an Authorization header for passing to SimpleHttpClient as the header value
of an HTTP request.
Args:
id_access_token (str): An identity server access token.
Returns:
list[str]: The ascii-encoded bearer token encased in a list.
"""
# Prefix with Bearer
bearer_token = "Bearer %s" % id_access_token
# Encode headers to standard ascii
bearer_token.encode("ascii")
# Return as a list as that's how SimpleHttpClient takes header values
return [bearer_token]
class LookupAlgorithm:
"""
Supported hashing algorithms when performing a 3PID lookup.
SHA256 - Hashing an (address, medium, pepper) combo with sha256, then url-safe base64
encoding
NONE - Not performing any hashing. Simply sending an (address, medium) combo in plaintext
"""
SHA256 = "sha256"
NONE = "none"

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@ -579,8 +579,8 @@ class RoomCreationHandler(BaseHandler):
room_id = yield self._generate_room_id(creator_id=user_id, is_public=is_public)
if room_alias:
directory_handler = self.hs.get_handlers().directory_handler
if room_alias:
yield directory_handler.create_association(
requester=requester,
room_id=room_id,
@ -665,6 +665,7 @@ class RoomCreationHandler(BaseHandler):
for invite_3pid in invite_3pid_list:
id_server = invite_3pid["id_server"]
id_access_token = invite_3pid.get("id_access_token") # optional
address = invite_3pid["address"]
medium = invite_3pid["medium"]
yield self.hs.get_room_member_handler().do_3pid_invite(
@ -675,6 +676,7 @@ class RoomCreationHandler(BaseHandler):
id_server,
requester,
txn_id=None,
id_access_token=id_access_token,
)
result = {"room_id": room_id}

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@ -29,9 +29,11 @@ from twisted.internet import defer
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.types import RoomID, UserID
from synapse.util.async_helpers import Linearizer
from synapse.util.distributor import user_joined_room, user_left_room
from synapse.util.hash import sha256_and_url_safe_base64
from ._base import BaseHandler
@ -626,7 +628,7 @@ class RoomMemberHandler(object):
servers.remove(room_alias.domain)
servers.insert(0, room_alias.domain)
return (RoomID.from_string(room_id), servers)
return RoomID.from_string(room_id), servers
@defer.inlineCallbacks
def _get_inviter(self, user_id, room_id):
@ -638,7 +640,15 @@ class RoomMemberHandler(object):
@defer.inlineCallbacks
def do_3pid_invite(
self, room_id, inviter, medium, address, id_server, requester, txn_id
self,
room_id,
inviter,
medium,
address,
id_server,
requester,
txn_id,
id_access_token=None,
):
if self.config.block_non_admin_invites:
is_requester_admin = yield self.auth.is_server_admin(requester.user)
@ -661,7 +671,12 @@ class RoomMemberHandler(object):
Codes.FORBIDDEN,
)
invitee = yield self._lookup_3pid(id_server, medium, address)
if not self._enable_lookup:
raise SynapseError(
403, "Looking up third-party identifiers is denied from this server"
)
invitee = yield self._lookup_3pid(id_server, medium, address, id_access_token)
if invitee:
yield self.update_membership(
@ -673,9 +688,47 @@ class RoomMemberHandler(object):
)
@defer.inlineCallbacks
def _lookup_3pid(self, id_server, medium, address):
def _lookup_3pid(self, id_server, medium, address, id_access_token=None):
"""Looks up a 3pid in the passed identity server.
Args:
id_server (str): The server name (including port, if required)
of the identity server to use.
medium (str): The type of the third party identifier (e.g. "email").
address (str): The third party identifier (e.g. "foo@example.com").
id_access_token (str|None): The access token to authenticate to the identity
server with
Returns:
str|None: the matrix ID of the 3pid, or None if it is not recognized.
"""
if id_access_token is not None:
try:
results = yield self._lookup_3pid_v2(
id_server, id_access_token, medium, address
)
return results
except Exception as e:
# Catch HttpResponseExcept for a non-200 response code
# Check if this identity server does not know about v2 lookups
if isinstance(e, HttpResponseException) and e.code == 404:
# This is an old identity server that does not yet support v2 lookups
logger.warning(
"Attempted v2 lookup on v1 identity server %s. Falling "
"back to v1",
id_server,
)
else:
logger.warning("Error when looking up hashing details: %s", e)
return None
return (yield self._lookup_3pid_v1(id_server, medium, address))
@defer.inlineCallbacks
def _lookup_3pid_v1(self, id_server, medium, address):
"""Looks up a 3pid in the passed identity server using v1 lookup.
Args:
id_server (str): The server name (including port, if required)
of the identity server to use.
@ -685,10 +738,6 @@ class RoomMemberHandler(object):
Returns:
str: the matrix ID of the 3pid, or None if it is not recognized.
"""
if not self._enable_lookup:
raise SynapseError(
403, "Looking up third-party identifiers is denied from this server"
)
try:
data = yield self.simple_http_client.get_json(
"%s%s/_matrix/identity/api/v1/lookup" % (id_server_scheme, id_server),
@ -702,9 +751,116 @@ class RoomMemberHandler(object):
return data["mxid"]
except IOError as e:
logger.warn("Error from identity server lookup: %s" % (e,))
logger.warning("Error from v1 identity server lookup: %s" % (e,))
return None
@defer.inlineCallbacks
def _lookup_3pid_v2(self, id_server, id_access_token, medium, address):
"""Looks up a 3pid in the passed identity server using v2 lookup.
Args:
id_server (str): The server name (including port, if required)
of the identity server to use.
id_access_token (str): The access token to authenticate to the identity server with
medium (str): The type of the third party identifier (e.g. "email").
address (str): The third party identifier (e.g. "foo@example.com").
Returns:
Deferred[str|None]: the matrix ID of the 3pid, or None if it is not recognised.
"""
# Check what hashing details are supported by this identity server
hash_details = yield self.simple_http_client.get_json(
"%s%s/_matrix/identity/v2/hash_details" % (id_server_scheme, id_server),
{"access_token": id_access_token},
)
if not isinstance(hash_details, dict):
logger.warning(
"Got non-dict object when checking hash details of %s%s: %s",
id_server_scheme,
id_server,
hash_details,
)
raise SynapseError(
400,
"Non-dict object from %s%s during v2 hash_details request: %s"
% (id_server_scheme, id_server, hash_details),
)
# Extract information from hash_details
supported_lookup_algorithms = hash_details.get("algorithms")
lookup_pepper = hash_details.get("lookup_pepper")
if (
not supported_lookup_algorithms
or not isinstance(supported_lookup_algorithms, list)
or not lookup_pepper
or not isinstance(lookup_pepper, str)
):
raise SynapseError(
400,
"Invalid hash details received from identity server %s%s: %s"
% (id_server_scheme, id_server, hash_details),
)
# Check if any of the supported lookup algorithms are present
if LookupAlgorithm.SHA256 in supported_lookup_algorithms:
# Perform a hashed lookup
lookup_algorithm = LookupAlgorithm.SHA256
# Hash address, medium and the pepper with sha256
to_hash = "%s %s %s" % (address, medium, lookup_pepper)
lookup_value = sha256_and_url_safe_base64(to_hash)
elif LookupAlgorithm.NONE in supported_lookup_algorithms:
# Perform a non-hashed lookup
lookup_algorithm = LookupAlgorithm.NONE
# Combine together plaintext address and medium
lookup_value = "%s %s" % (address, medium)
else:
logger.warning(
"None of the provided lookup algorithms of %s are supported: %s",
id_server,
supported_lookup_algorithms,
)
raise SynapseError(
400,
"Provided identity server does not support any v2 lookup "
"algorithms that this homeserver supports.",
)
# Authenticate with identity server given the access token from the client
headers = {"Authorization": create_id_access_token_header(id_access_token)}
try:
lookup_results = yield self.simple_http_client.post_json_get_json(
"%s%s/_matrix/identity/v2/lookup" % (id_server_scheme, id_server),
{
"addresses": [lookup_value],
"algorithm": lookup_algorithm,
"pepper": lookup_pepper,
},
headers=headers,
)
except Exception as e:
logger.warning("Error when performing a v2 3pid lookup: %s", e)
raise SynapseError(
500, "Unknown error occurred during identity server lookup"
)
# Check for a mapping from what we looked up to an MXID
if "mappings" not in lookup_results or not isinstance(
lookup_results["mappings"], dict
):
logger.warning("No results from 3pid lookup")
return None
# Return the MXID if it's available, or None otherwise
mxid = lookup_results["mappings"].get(lookup_value)
return mxid
@defer.inlineCallbacks
def _verify_any_signature(self, data, server_hostname):
if server_hostname not in data["signatures"]:
@ -844,7 +1000,6 @@ class RoomMemberHandler(object):
display_name (str): A user-friendly name to represent the invited
user.
"""
is_url = "%s%s/_matrix/identity/api/v1/store-invite" % (
id_server_scheme,
id_server,
@ -862,7 +1017,6 @@ class RoomMemberHandler(object):
"sender_display_name": inviter_display_name,
"sender_avatar_url": inviter_avatar_url,
}
try:
data = yield self.simple_http_client.post_json_get_json(
is_url, invite_config
@ -1049,7 +1203,7 @@ class RoomMemberMasterHandler(RoomMemberHandler):
# The 'except' clause is very broad, but we need to
# capture everything from DNS failures upwards
#
logger.warn("Failed to reject invite: %s", e)
logger.warning("Failed to reject invite: %s", e)
yield self.store.locally_reject_invite(target.to_string(), room_id)
return {}

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@ -701,6 +701,7 @@ class RoomMembershipRestServlet(TransactionRestServlet):
content["id_server"],
requester,
txn_id,
content.get("id_access_token"),
)
return 200, {}

33
synapse/util/hash.py Normal file
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@ -0,0 +1,33 @@
# -*- coding: utf-8 -*-
# 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 hashlib
import unpaddedbase64
def sha256_and_url_safe_base64(input_text):
"""SHA256 hash an input string, encode the digest as url-safe base64, and
return
:param input_text: string to hash
:type input_text: str
:returns a sha256 hashed and url-safe base64 encoded digest
:rtype: str
"""
digest = hashlib.sha256(input_text.encode()).digest()
return unpaddedbase64.encode_base64(digest, urlsafe=True)