forked-synapse/synapse/handlers/identity.py
Patrick Cloke d8cc86eff4
Remove redundant types from comments. (#14412)
Remove type hints from comments which have been added
as Python type hints. This helps avoid drift between comments
and reality, as well as removing redundant information.

Also adds some missing type hints which were simple to fill in.
2022-11-16 15:25:24 +00:00

811 lines
30 KiB
Python

# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2017 Vector Creations Ltd
# Copyright 2018 New Vector Ltd
#
# 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.
"""Utilities for interacting with Identity Servers"""
import logging
import urllib.parse
from typing import TYPE_CHECKING, Awaitable, Callable, Dict, List, Optional, Tuple
from synapse.api.errors import (
CodeMessageException,
Codes,
HttpResponseException,
SynapseError,
)
from synapse.api.ratelimiting import Ratelimiter
from synapse.http import RequestTimedOutError
from synapse.http.client import SimpleHttpClient
from synapse.http.site import SynapseRequest
from synapse.types import JsonDict, Requester
from synapse.util import json_decoder
from synapse.util.hash import sha256_and_url_safe_base64
from synapse.util.stringutils import (
assert_valid_client_secret,
random_string,
valid_id_server_location,
)
if TYPE_CHECKING:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
id_server_scheme = "https://"
class IdentityHandler:
def __init__(self, hs: "HomeServer"):
self.store = hs.get_datastores().main
# An HTTP client for contacting trusted URLs.
self.http_client = SimpleHttpClient(hs)
# An HTTP client for contacting identity servers specified by clients.
self.blacklisting_http_client = SimpleHttpClient(
hs,
ip_blacklist=hs.config.server.federation_ip_range_blacklist,
ip_whitelist=hs.config.server.federation_ip_range_whitelist,
)
self.federation_http_client = hs.get_federation_http_client()
self.hs = hs
self._web_client_location = hs.config.email.invite_client_location
# Ratelimiters for `/requestToken` endpoints.
self._3pid_validation_ratelimiter_ip = Ratelimiter(
store=self.store,
clock=hs.get_clock(),
rate_hz=hs.config.ratelimiting.rc_3pid_validation.per_second,
burst_count=hs.config.ratelimiting.rc_3pid_validation.burst_count,
)
self._3pid_validation_ratelimiter_address = Ratelimiter(
store=self.store,
clock=hs.get_clock(),
rate_hz=hs.config.ratelimiting.rc_3pid_validation.per_second,
burst_count=hs.config.ratelimiting.rc_3pid_validation.burst_count,
)
async def ratelimit_request_token_requests(
self,
request: SynapseRequest,
medium: str,
address: str,
) -> None:
"""Used to ratelimit requests to `/requestToken` by IP and address.
Args:
request: The associated request
medium: The type of threepid, e.g. "msisdn" or "email"
address: The actual threepid ID, e.g. the phone number or email address
"""
await self._3pid_validation_ratelimiter_ip.ratelimit(
None, (medium, request.getClientAddress().host)
)
await self._3pid_validation_ratelimiter_address.ratelimit(
None, (medium, address)
)
async def threepid_from_creds(
self, id_server: str, creds: Dict[str, str]
) -> Optional[JsonDict]:
"""
Retrieve and validate a threepid identifier from a "credentials" dictionary against a
given identity server
Args:
id_server: The identity server to validate 3PIDs against. Must be a
complete URL including the protocol (http(s)://)
creds: Dictionary containing the following keys:
* client_secret|clientSecret: A unique secret str provided by the client
* sid: The ID of the validation session
Returns:
A dictionary consisting of response params to the /getValidated3pid
endpoint of the Identity Service API, or None if the threepid was not found
"""
client_secret = creds.get("client_secret") or creds.get("clientSecret")
if not client_secret:
raise SynapseError(
400, "Missing param client_secret in creds", errcode=Codes.MISSING_PARAM
)
assert_valid_client_secret(client_secret)
session_id = creds.get("sid")
if not session_id:
raise SynapseError(
400, "Missing param session_id in creds", errcode=Codes.MISSING_PARAM
)
query_params = {"sid": session_id, "client_secret": client_secret}
url = id_server + "/_matrix/identity/api/v1/3pid/getValidated3pid"
try:
data = await self.http_client.get_json(url, query_params)
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
except HttpResponseException as e:
logger.info(
"%s returned %i for threepid validation for: %s",
id_server,
e.code,
creds,
)
return None
# Old versions of Sydent return a 200 http code even on a failed validation
# check. Thus, in addition to the HttpResponseException check above (which
# checks for non-200 errors), we need to make sure validation_session isn't
# actually an error, identified by the absence of a "medium" key
# See https://github.com/matrix-org/sydent/issues/215 for details
if "medium" in data:
return data
logger.info("%s reported non-validated threepid: %s", id_server, creds)
return None
async def bind_threepid(
self,
client_secret: str,
sid: str,
mxid: str,
id_server: str,
id_access_token: str,
) -> JsonDict:
"""Bind a 3PID to an identity server
Args:
client_secret: A unique secret provided by the client
sid: The ID of the validation session
mxid: The MXID to bind the 3PID to
id_server: The domain of the identity server to query
id_access_token: The access token to authenticate to the identity
server with
Raises:
SynapseError: On any of the following conditions
- the supplied id_server is not a valid identity server name
- we failed to contact the supplied identity server
Returns:
The response from the identity server
"""
logger.debug("Proxying threepid bind request for %s to %s", mxid, id_server)
if not valid_id_server_location(id_server):
raise SynapseError(
400,
"id_server must be a valid hostname with optional port and path components",
)
bind_data = {"sid": sid, "client_secret": client_secret, "mxid": mxid}
bind_url = "https://%s/_matrix/identity/v2/3pid/bind" % (id_server,)
headers = {"Authorization": create_id_access_token_header(id_access_token)}
try:
# Use the blacklisting http client as this call is only to identity servers
# provided by a client
data = await self.blacklisting_http_client.post_json_get_json(
bind_url, bind_data, headers=headers
)
# Remember where we bound the threepid
await self.store.add_user_bound_threepid(
user_id=mxid,
medium=data["medium"],
address=data["address"],
id_server=id_server,
)
return data
except HttpResponseException as e:
logger.error("3PID bind failed with Matrix error: %r", e)
raise e.to_synapse_error()
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
except CodeMessageException as e:
data = json_decoder.decode(e.msg) # XXX WAT?
return data
async def try_unbind_threepid(self, mxid: str, threepid: dict) -> bool:
"""Attempt to remove a 3PID from an identity server, or if one is not provided, all
identity servers we're aware the binding is present on
Args:
mxid: Matrix user ID of binding to be removed
threepid: Dict with medium & address of binding to be
removed, and an optional id_server.
Raises:
SynapseError: If we failed to contact the identity server
Returns:
True on success, otherwise False if the identity
server doesn't support unbinding (or no identity server found to
contact).
"""
if threepid.get("id_server"):
id_servers = [threepid["id_server"]]
else:
id_servers = await self.store.get_id_servers_user_bound(
user_id=mxid, medium=threepid["medium"], address=threepid["address"]
)
# We don't know where to unbind, so we don't have a choice but to return
if not id_servers:
return False
changed = True
for id_server in id_servers:
changed &= await self.try_unbind_threepid_with_id_server(
mxid, threepid, id_server
)
return changed
async def try_unbind_threepid_with_id_server(
self, mxid: str, threepid: dict, id_server: str
) -> bool:
"""Removes a binding from an identity server
Args:
mxid: Matrix user ID of binding to be removed
threepid: Dict with medium & address of binding to be removed
id_server: Identity server to unbind from
Raises:
SynapseError: On any of the following conditions
- the supplied id_server is not a valid identity server name
- we failed to contact the supplied identity server
Returns:
True on success, otherwise False if the identity
server doesn't support unbinding
"""
if not valid_id_server_location(id_server):
raise SynapseError(
400,
"id_server must be a valid hostname with optional port and path components",
)
url = "https://%s/_matrix/identity/v2/3pid/unbind" % (id_server,)
url_bytes = b"/_matrix/identity/v2/3pid/unbind"
content = {
"mxid": mxid,
"threepid": {"medium": threepid["medium"], "address": threepid["address"]},
}
# we abuse the federation http client to sign the request, but we have to send it
# using the normal http client since we don't want the SRV lookup and want normal
# 'browser-like' HTTPS.
auth_headers = self.federation_http_client.build_auth_headers(
destination=None,
method=b"POST",
url_bytes=url_bytes,
content=content,
destination_is=id_server.encode("ascii"),
)
headers = {b"Authorization": auth_headers}
try:
# Use the blacklisting http client as this call is only to identity servers
# provided by a client
await self.blacklisting_http_client.post_json_get_json(
url, content, headers
)
changed = True
except HttpResponseException as e:
changed = False
if e.code in (400, 404, 501):
# The remote server probably doesn't support unbinding (yet)
logger.warning("Received %d response while unbinding threepid", e.code)
else:
logger.error("Failed to unbind threepid on identity server: %s", e)
raise SynapseError(500, "Failed to contact identity server")
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
await self.store.remove_user_bound_threepid(
user_id=mxid,
medium=threepid["medium"],
address=threepid["address"],
id_server=id_server,
)
return changed
async def send_threepid_validation(
self,
email_address: str,
client_secret: str,
send_attempt: int,
send_email_func: Callable[[str, str, str, str], Awaitable],
next_link: Optional[str] = None,
) -> str:
"""Send a threepid validation email for password reset or
registration purposes
Args:
email_address: The user's email address
client_secret: The provided client secret
send_attempt: Which send attempt this is
send_email_func: A function that takes an email address, token,
client_secret and session_id, sends an email
and returns an Awaitable.
next_link: The URL to redirect the user to after validation
Returns:
The new session_id upon success
Raises:
SynapseError is an error occurred when sending the email
"""
# Check that this email/client_secret/send_attempt combo is new or
# greater than what we've seen previously
session = await self.store.get_threepid_validation_session(
"email", client_secret, address=email_address, validated=False
)
# Check to see if a session already exists and that it is not yet
# marked as validated
if session and session.get("validated_at") is None:
session_id = session["session_id"]
last_send_attempt = session["last_send_attempt"]
# Check that the send_attempt is higher than previous attempts
if send_attempt <= last_send_attempt:
# If not, just return a success without sending an email
return session_id
else:
# An non-validated session does not exist yet.
# Generate a session id
session_id = random_string(16)
if next_link:
# Manipulate the next_link to add the sid, because the caller won't get
# it until we send a response, by which time we've sent the mail.
if "?" in next_link:
next_link += "&"
else:
next_link += "?"
next_link += "sid=" + urllib.parse.quote(session_id)
# Generate a new validation token
token = random_string(32)
# Send the mail with the link containing the token, client_secret
# and session_id
try:
await send_email_func(email_address, token, client_secret, session_id)
except Exception:
logger.exception(
"Error sending threepid validation email to %s", email_address
)
raise SynapseError(500, "An error was encountered when sending the email")
token_expires = (
self.hs.get_clock().time_msec()
+ self.hs.config.email.email_validation_token_lifetime
)
await self.store.start_or_continue_validation_session(
"email",
email_address,
session_id,
client_secret,
send_attempt,
next_link,
token,
token_expires,
)
return session_id
async def requestMsisdnToken(
self,
id_server: str,
country: str,
phone_number: str,
client_secret: str,
send_attempt: int,
next_link: Optional[str] = None,
) -> JsonDict:
"""
Request an external server send an SMS message on our behalf for the purposes of
threepid validation.
Args:
id_server: The identity server to proxy to
country: The country code of the phone number
phone_number: The number to send the message to
client_secret: The unique client_secret sends by the user
send_attempt: Which attempt this is
next_link: A link to redirect the user to once they submit the token
Returns:
The json response body from the server
"""
params = {
"country": country,
"phone_number": phone_number,
"client_secret": client_secret,
"send_attempt": send_attempt,
}
if next_link:
params["next_link"] = next_link
try:
data = await self.http_client.post_json_get_json(
id_server + "/_matrix/identity/api/v1/validate/msisdn/requestToken",
params,
)
except HttpResponseException as e:
logger.info("Proxied requestToken failed: %r", e)
raise e.to_synapse_error()
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
# we need to tell the client to send the token back to us, since it doesn't
# otherwise know where to send it, so add submit_url response parameter
# (see also MSC2078)
data["submit_url"] = (
self.hs.config.server.public_baseurl
+ "_matrix/client/unstable/add_threepid/msisdn/submit_token"
)
return data
async def validate_threepid_session(
self, client_secret: str, sid: str
) -> Optional[JsonDict]:
"""Validates a threepid session with only the client secret and session ID
Tries validating against any configured account_threepid_delegates as well as locally.
Args:
client_secret: A secret provided by the client
sid: The ID of the session
Returns:
The json response if validation was successful, otherwise None
"""
# XXX: We shouldn't need to keep wrapping and unwrapping this value
threepid_creds = {"client_secret": client_secret, "sid": sid}
# We don't actually know which medium this 3PID is. Thus we first assume it's email,
# and if validation fails we try msisdn
validation_session = None
# Try to validate as email
if self.hs.config.email.can_verify_email:
# Get a validated session matching these details
validation_session = await self.store.get_threepid_validation_session(
"email", client_secret, sid=sid, validated=True
)
if validation_session:
return validation_session
# Try to validate as msisdn
if self.hs.config.registration.account_threepid_delegate_msisdn:
# Ask our delegated msisdn identity server
validation_session = await self.threepid_from_creds(
self.hs.config.registration.account_threepid_delegate_msisdn,
threepid_creds,
)
return validation_session
async def proxy_msisdn_submit_token(
self, id_server: str, client_secret: str, sid: str, token: str
) -> JsonDict:
"""Proxy a POST submitToken request to an identity server for verification purposes
Args:
id_server: The identity server URL to contact
client_secret: Secret provided by the client
sid: The ID of the session
token: The verification token
Raises:
SynapseError: If we failed to contact the identity server
Returns:
The response dict from the identity server
"""
body = {"client_secret": client_secret, "sid": sid, "token": token}
try:
return await self.http_client.post_json_get_json(
id_server + "/_matrix/identity/api/v1/validate/msisdn/submitToken",
body,
)
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
except HttpResponseException as e:
logger.warning("Error contacting msisdn account_threepid_delegate: %s", e)
raise SynapseError(400, "Error contacting the identity server")
async def lookup_3pid(
self, id_server: str, medium: str, address: str, id_access_token: str
) -> Optional[str]:
"""Looks up a 3pid in the passed identity server.
Args:
id_server: The server name (including port, if required)
of the identity server to use.
medium: The type of the third party identifier (e.g. "email").
address: The third party identifier (e.g. "foo@example.com").
id_access_token: The access token to authenticate to the identity
server with
Returns:
the matrix ID of the 3pid, or None if it is not recognized.
"""
try:
results = await self._lookup_3pid_v2(
id_server, id_access_token, medium, address
)
return results
except Exception as e:
logger.warning("Error when looking up hashing details: %s", e)
return None
async def _lookup_3pid_v2(
self, id_server: str, id_access_token: str, medium: str, address: str
) -> Optional[str]:
"""Looks up a 3pid in the passed identity server using v2 lookup.
Args:
id_server: The server name (including port, if required)
of the identity server to use.
id_access_token: The access token to authenticate to the identity server with
medium: The type of the third party identifier (e.g. "email").
address: The third party identifier (e.g. "foo@example.com").
Returns:
the matrix ID of the 3pid, or None if it is not recognised.
"""
# Check what hashing details are supported by this identity server
try:
hash_details = await self.blacklisting_http_client.get_json(
"%s%s/_matrix/identity/v2/hash_details" % (id_server_scheme, id_server),
{"access_token": id_access_token},
)
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
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 = await self.blacklisting_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 RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
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
async def ask_id_server_for_third_party_invite(
self,
requester: Requester,
id_server: str,
medium: str,
address: str,
room_id: str,
inviter_user_id: str,
room_alias: str,
room_avatar_url: str,
room_join_rules: str,
room_name: str,
room_type: Optional[str],
inviter_display_name: str,
inviter_avatar_url: str,
id_access_token: str,
) -> Tuple[str, List[Dict[str, str]], Dict[str, str], str]:
"""
Asks an identity server for a third party invite.
Args:
requester
id_server: hostname + optional port for the identity server.
medium: The literal string "email".
address: The third party address being invited.
room_id: The ID of the room to which the user is invited.
inviter_user_id: The user ID of the inviter.
room_alias: An alias for the room, for cosmetic notifications.
room_avatar_url: The URL of the room's avatar, for cosmetic
notifications.
room_join_rules: The join rules of the email (e.g. "public").
room_name: The m.room.name of the room.
room_type: The type of the room from its m.room.create event (e.g "m.space").
inviter_display_name: The current display name of the
inviter.
inviter_avatar_url: The URL of the inviter's avatar.
id_access_token: The access token to authenticate to the identity
server with
Returns:
A tuple containing:
token: The token which must be signed to prove authenticity.
public_keys ([{"public_key": str, "key_validity_url": str}]):
public_key is a base64-encoded ed25519 public key.
fallback_public_key: One element from public_keys.
display_name: A user-friendly name to represent the invited user.
"""
invite_config = {
"medium": medium,
"address": address,
"room_id": room_id,
"room_alias": room_alias,
"room_avatar_url": room_avatar_url,
"room_join_rules": room_join_rules,
"room_name": room_name,
"sender": inviter_user_id,
"sender_display_name": inviter_display_name,
"sender_avatar_url": inviter_avatar_url,
}
if room_type is not None:
invite_config["room_type"] = room_type
# If a custom web client location is available, include it in the request.
if self._web_client_location:
invite_config["org.matrix.web_client_location"] = self._web_client_location
# Add the identity service access token to the JSON body and use the v2
# Identity Service endpoints
data = None
key_validity_url = "%s%s/_matrix/identity/v2/pubkey/isvalid" % (
id_server_scheme,
id_server,
)
url = "%s%s/_matrix/identity/v2/store-invite" % (id_server_scheme, id_server)
try:
data = await self.blacklisting_http_client.post_json_get_json(
url,
invite_config,
{"Authorization": create_id_access_token_header(id_access_token)},
)
except RequestTimedOutError:
raise SynapseError(500, "Timed out contacting identity server")
token = data["token"]
public_keys = data.get("public_keys", [])
if "public_key" in data:
fallback_public_key = {
"public_key": data["public_key"],
"key_validity_url": key_validity_url,
}
else:
fallback_public_key = public_keys[0]
if not public_keys:
public_keys.append(fallback_public_key)
display_name = data["display_name"]
return token, public_keys, fallback_public_key, display_name
def create_id_access_token_header(id_access_token: str) -> List[str]:
"""Create an Authorization header for passing to SimpleHttpClient as the header value
of an HTTP request.
Args:
id_access_token: An identity server access token.
Returns:
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"