diff options
Diffstat (limited to 'synapse/handlers/identity.py')
| -rw-r--r-- | synapse/handlers/identity.py | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py index 6d42a1aed8..ba99ddf76d 100644 --- a/synapse/handlers/identity.py +++ b/synapse/handlers/identity.py @@ -21,11 +21,15 @@ import logging import urllib from canonicaljson import json +from signedjson.key import decode_verify_key_bytes +from signedjson.sign import verify_signed_json +from unpaddedbase64 import decode_base64 from twisted.internet import defer from twisted.internet.error import TimeoutError from synapse.api.errors import ( + AuthError, CodeMessageException, Codes, HttpResponseException, @@ -33,12 +37,15 @@ from synapse.api.errors import ( ) from synapse.config.emailconfig import ThreepidBehaviour from synapse.http.client import SimpleHttpClient +from synapse.util.hash import sha256_and_url_safe_base64 from synapse.util.stringutils import random_string from ._base import BaseHandler logger = logging.getLogger(__name__) +id_server_scheme = "https://" + class IdentityHandler(BaseHandler): def __init__(self, hs): @@ -557,6 +564,352 @@ class IdentityHandler(BaseHandler): logger.warning("Error contacting msisdn account_threepid_delegate: %s", e) raise SynapseError(400, "Error contacting the identity server") + @defer.inlineCallbacks + 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. + medium (str): The type of the third party identifier (e.g. "email"). + address (str): The third party identifier (e.g. "foo@example.com"). + + Returns: + str: the matrix ID of the 3pid, or None if it is not recognized. + """ + try: + data = yield self.blacklisting_http_client.get_json( + "%s%s/_matrix/identity/api/v1/lookup" % (id_server_scheme, id_server), + {"medium": medium, "address": address}, + ) + + if "mxid" in data: + if "signatures" not in data: + raise AuthError(401, "No signatures on 3pid binding") + yield self._verify_any_signature(data, id_server) + return data["mxid"] + except TimeoutError: + raise SynapseError(500, "Timed out contacting identity server") + except IOError as 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 + try: + hash_details = yield self.blacklisting_http_client.get_json( + "%s%s/_matrix/identity/v2/hash_details" % (id_server_scheme, id_server), + {"access_token": id_access_token}, + ) + except TimeoutError: + 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 = yield 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 TimeoutError: + 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 + + @defer.inlineCallbacks + def _verify_any_signature(self, data, server_hostname): + if server_hostname not in data["signatures"]: + raise AuthError(401, "No signature from server %s" % (server_hostname,)) + for key_name, signature in data["signatures"][server_hostname].items(): + try: + key_data = yield self.blacklisting_http_client.get_json( + "%s%s/_matrix/identity/api/v1/pubkey/%s" + % (id_server_scheme, server_hostname, key_name) + ) + except TimeoutError: + raise SynapseError(500, "Timed out contacting identity server") + if "public_key" not in key_data: + raise AuthError( + 401, "No public key named %s from %s" % (key_name, server_hostname) + ) + verify_signed_json( + data, + server_hostname, + decode_verify_key_bytes( + key_name, decode_base64(key_data["public_key"]) + ), + ) + return + + @defer.inlineCallbacks + def ask_id_server_for_third_party_invite( + self, + requester, + id_server, + medium, + address, + room_id, + inviter_user_id, + room_alias, + room_avatar_url, + room_join_rules, + room_name, + inviter_display_name, + inviter_avatar_url, + id_access_token=None, + ): + """ + Asks an identity server for a third party invite. + + Args: + requester (Requester) + id_server (str): hostname + optional port for the identity server. + medium (str): The literal string "email". + address (str): The third party address being invited. + room_id (str): The ID of the room to which the user is invited. + inviter_user_id (str): The user ID of the inviter. + room_alias (str): An alias for the room, for cosmetic notifications. + room_avatar_url (str): The URL of the room's avatar, for cosmetic + notifications. + room_join_rules (str): The join rules of the email (e.g. "public"). + room_name (str): The m.room.name of the room. + inviter_display_name (str): The current display name of the + inviter. + inviter_avatar_url (str): The URL of the inviter's avatar. + id_access_token (str|None): The access token to authenticate to the identity + server with + + Returns: + A deferred tuple containing: + token (str): 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 (str): 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, + } + + # Add the identity service access token to the JSON body and use the v2 + # Identity Service endpoints if id_access_token is present + data = None + base_url = "%s%s/_matrix/identity" % (id_server_scheme, id_server) + + if id_access_token: + key_validity_url = "%s%s/_matrix/identity/v2/pubkey/isvalid" % ( + id_server_scheme, + id_server, + ) + + # Attempt a v2 lookup + url = base_url + "/v2/store-invite" + try: + data = yield self.blacklisting_http_client.post_json_get_json( + url, + invite_config, + {"Authorization": create_id_access_token_header(id_access_token)}, + ) + except TimeoutError: + raise SynapseError(500, "Timed out contacting identity server") + except HttpResponseException as e: + if e.code != 404: + logger.info("Failed to POST %s with JSON: %s", url, e) + raise e + + if data is None: + key_validity_url = "%s%s/_matrix/identity/api/v1/pubkey/isvalid" % ( + id_server_scheme, + id_server, + ) + url = base_url + "/api/v1/store-invite" + + try: + data = yield self.blacklisting_http_client.post_json_get_json( + url, invite_config + ) + except TimeoutError: + raise SynapseError(500, "Timed out contacting identity server") + except HttpResponseException as e: + logger.warning( + "Error trying to call /store-invite on %s%s: %s", + id_server_scheme, + id_server, + e, + ) + + if data is None: + # Some identity servers may only support application/x-www-form-urlencoded + # types. This is especially true with old instances of Sydent, see + # https://github.com/matrix-org/sydent/pull/170 + try: + data = yield self.blacklisting_http_client.post_urlencoded_get_json( + url, invite_config + ) + except HttpResponseException as e: + logger.warning( + "Error calling /store-invite on %s%s with fallback " + "encoding: %s", + id_server_scheme, + id_server, + e, + ) + raise e + + # TODO: Check for success + 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): """Create an Authorization header for passing to SimpleHttpClient as the header value |