From 79a1c0574b33955d28bfb12697ccd5a7be779b36 Mon Sep 17 00:00:00 2001 From: Daniel Wagner-Hall Date: Fri, 5 Feb 2016 11:22:30 +0000 Subject: [PATCH] Allocate guest user IDs numericcally The current random IDs are ugly and confusing when presented in UIs. This makes them prettier and easier to read. Also, disable non-automated registration of numeric IDs so that we don't need to worry so much about people carving out our automated address space and us needing to keep retrying ID registration. --- synapse/handlers/register.py | 55 +++++++++++++++++++++------------ synapse/storage/registration.py | 36 +++++++++++++++++++++ 2 files changed, 72 insertions(+), 19 deletions(-) diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py index b8fbcf923..2660fd21a 100644 --- a/synapse/handlers/register.py +++ b/synapse/handlers/register.py @@ -21,7 +21,6 @@ from synapse.api.errors import ( AuthError, Codes, SynapseError, RegistrationError, InvalidCaptchaError ) from ._base import BaseHandler -import synapse.util.stringutils as stringutils from synapse.util.async import run_on_reactor from synapse.http.client import CaptchaServerHttpClient @@ -45,6 +44,8 @@ class RegistrationHandler(BaseHandler): self.distributor.declare("registered_user") self.captcha_client = CaptchaServerHttpClient(hs) + self._next_generated_user_id = None + @defer.inlineCallbacks def check_username(self, localpart, guest_access_token=None): yield run_on_reactor() @@ -91,7 +92,7 @@ class RegistrationHandler(BaseHandler): Args: localpart : The local part of the user ID to register. If None, - one will be randomly generated. + one will be generated. password (str) : The password to assign to this user so they can login again. This can be None which means they cannot login again via a password (e.g. the user is an application service user). @@ -108,6 +109,18 @@ class RegistrationHandler(BaseHandler): if localpart: yield self.check_username(localpart, guest_access_token=guest_access_token) + was_guest = guest_access_token is not None + + if not was_guest: + try: + int(localpart) + raise RegistrationError( + 400, + "Numeric user IDs are reserved for guest users." + ) + except ValueError: + pass + user = UserID(localpart, self.hs.hostname) user_id = user.to_string() @@ -118,40 +131,36 @@ class RegistrationHandler(BaseHandler): user_id=user_id, token=token, password_hash=password_hash, - was_guest=guest_access_token is not None, + was_guest=was_guest, make_guest=make_guest, ) yield registered_user(self.distributor, user) else: - # autogen a random user ID + # autogen a sequential user ID attempts = 0 - user_id = None token = None - while not user_id: + user = None + while not user: + localpart = yield self._generate_user_id(attempts > 0) + user = UserID(localpart, self.hs.hostname) + user_id = user.to_string() + yield self.check_user_id_is_valid(user_id) + if generate_token: + token = self.auth_handler().generate_access_token(user_id) try: - localpart = self._generate_user_id() - user = UserID(localpart, self.hs.hostname) - user_id = user.to_string() - yield self.check_user_id_is_valid(user_id) - if generate_token: - token = self.auth_handler().generate_access_token(user_id) yield self.store.register( user_id=user_id, token=token, password_hash=password_hash, make_guest=make_guest ) - - yield registered_user(self.distributor, user) except SynapseError: # if user id is taken, just generate another user_id = None token = None attempts += 1 - if attempts > 5: - raise RegistrationError( - 500, "Cannot generate user ID.") + yield registered_user(self.distributor, user) # We used to generate default identicons here, but nowadays # we want clients to generate their own as part of their branding @@ -283,8 +292,16 @@ class RegistrationHandler(BaseHandler): errcode=Codes.EXCLUSIVE ) - def _generate_user_id(self): - return "-" + stringutils.random_string(18) + @defer.inlineCallbacks + def _generate_user_id(self, reseed=False): + if reseed or self._next_generated_user_id is None: + self._next_generated_user_id = ( + yield self.store.find_next_generated_user_id_localpart() + ) + + id = self._next_generated_user_id + self._next_generated_user_id += 1 + defer.returnValue(str(id)) @defer.inlineCallbacks def _validate_captcha(self, ip_addr, private_key, challenge, response): diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py index bd35e19be..967c732bd 100644 --- a/synapse/storage/registration.py +++ b/synapse/storage/registration.py @@ -13,6 +13,8 @@ # See the License for the specific language governing permissions and # limitations under the License. +import re + from twisted.internet import defer from synapse.api.errors import StoreError, Codes @@ -351,3 +353,37 @@ class RegistrationStore(SQLBaseStore): ret = yield self.runInteraction("count_users", _count_users) defer.returnValue(ret) + + @defer.inlineCallbacks + def find_next_generated_user_id_localpart(self): + """ + Gets the localpart of the next generated user ID. + + Generated user IDs are integers, and we aim for them to be as small as + we can. Unfortunately, it's possible some of them are already taken by + existing users, and there may be gaps in the already taken range. This + function returns the start of the first allocatable gap. This is to + avoid the case of ID 10000000 being pre-allocated, so us wasting the + first (and shortest) many generated user IDs. + """ + def _find_next_generated_user_id(txn): + txn.execute("SELECT name FROM users") + rows = self.cursor_to_dict(txn) + + regex = re.compile("^@(\d+):") + + found = set() + + for r in rows: + user_id = r["name"] + match = regex.search(user_id) + if match: + found.add(int(match.group(1))) + for i in xrange(len(found) + 1): + if i not in found: + return i + + defer.returnValue((yield self.runInteraction( + "find_next_generated_user_id", + _find_next_generated_user_id + )))