synapse-old/synapse/handlers/identity.py

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# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2017 Vector Creations Ltd
# Copyright 2018 New Vector Ltd
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#
# 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
import attr
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from synapse.api.errors import (
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CodeMessageException,
Codes,
HttpResponseException,
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SynapseError,
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)
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,
)
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if TYPE_CHECKING:
from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
id_server_scheme = "https://"
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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._http_client = SimpleHttpClient(
hs,
ip_blocklist=hs.config.server.federation_ip_range_blocklist,
ip_allowlist=hs.config.server.federation_ip_range_allowlist,
)
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(),
cfg=hs.config.ratelimiting.rc_3pid_validation,
)
self._3pid_validation_ratelimiter_address = Ratelimiter(
store=self.store,
clock=hs.get_clock(),
cfg=hs.config.ratelimiting.rc_3pid_validation,
)
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._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, medium: str, address: str, id_server: Optional[str]
) -> bool:
"""Attempt to remove a 3PID from one or more identity servers.
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Args:
mxid: Matrix user ID of binding to be removed
medium: The medium of the third-party ID.
address: The address of the third-party ID.
id_server: An identity server to attempt to unbind from. If None,
attempt to remove the association from all identity servers
known to potentially have it.
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Raises:
SynapseError: If we failed to contact one or more identity servers.
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Returns:
True on success, otherwise False if the identity server doesn't
support unbinding (or no identity server to contact was found).
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"""
if id_server:
id_servers = [id_server]
else:
id_servers = await self.store.get_id_servers_user_bound(
mxid, medium, address
)
# We don't know where to unbind, so we don't have a choice but to return
if not id_servers:
return False
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changed = True
for id_server in id_servers:
changed &= await self._try_unbind_threepid_with_id_server(
mxid, medium, address, id_server
)
return changed
async def _try_unbind_threepid_with_id_server(
self, mxid: str, medium: str, address: str, id_server: str
) -> bool:
"""Removes a binding from an identity server
Args:
mxid: Matrix user ID of binding to be removed
medium: The medium of the third-party ID
address: The address of the third-party ID
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": medium, "address": 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._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:
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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(mxid, medium, address, 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.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
# 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 attr.asdict(validation_session)
# Try to validate as msisdn
if self.hs.config.registration.account_threepid_delegate_msisdn:
# Ask our delegated msisdn identity server
return await self.threepid_from_creds(
self.hs.config.registration.account_threepid_delegate_msisdn,
threepid_creds,
)
return None
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._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._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._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"