2021-05-08 00:39:51 +02:00

859 lines
31 KiB
Rust

use std::{convert::TryFrom, sync::Arc};
use log::warn;
use maplit::btreeset;
use ruma::{
events::{
room::{
create::CreateEventContent,
join_rules::{JoinRule, JoinRulesEventContent},
member::{MembershipState, ThirdPartyInvite},
power_levels::PowerLevelsEventContent,
},
EventType,
},
RoomVersionId, UserId,
};
use crate::{room_version::RoomVersion, Error, Event, Result, StateMap};
/// For the given event `kind` what are the relevant auth events
/// that are needed to authenticate this `content`.
pub fn auth_types_for_event(
kind: &EventType,
sender: &UserId,
state_key: Option<String>,
content: serde_json::Value,
) -> Vec<(EventType, String)> {
if kind == &EventType::RoomCreate {
return vec![];
}
let mut auth_types = vec![
(EventType::RoomPowerLevels, "".to_string()),
(EventType::RoomMember, sender.to_string()),
(EventType::RoomCreate, "".to_string()),
];
if kind == &EventType::RoomMember {
if let Some(state_key) = state_key {
if let Some(Ok(membership)) = content
.get("membership")
.map(|m| serde_json::from_value::<MembershipState>(m.clone()))
{
if [MembershipState::Join, MembershipState::Invite].contains(&membership) {
let key = (EventType::RoomJoinRules, "".to_string());
if !auth_types.contains(&key) {
auth_types.push(key)
}
}
let key = (EventType::RoomMember, state_key);
if !auth_types.contains(&key) {
auth_types.push(key)
}
if membership == MembershipState::Invite {
if let Some(Ok(t_id)) = content
.get("third_party_invite")
.map(|t| serde_json::from_value::<ThirdPartyInvite>(t.clone()))
{
let key = (EventType::RoomThirdPartyInvite, t_id.signed.token);
if !auth_types.contains(&key) {
auth_types.push(key)
}
}
}
}
}
}
auth_types
}
/// Authenticate the incoming `event`. The steps of authentication are:
/// * check that the event is being authenticated for the correct room
/// * check that the events signatures are valid
/// * then there are checks for specific event types
///
/// The `auth_events` that are passed to this function should be a state snapshot.
/// We need to know if the event passes auth against some state not a recursive collection
/// of auth_events fields.
///
/// ## Returns
/// This returns an `Error` only when serialization fails or some other fatal outcome.
pub fn auth_check<E: Event>(
room_version: &RoomVersion,
incoming_event: &Arc<E>,
prev_event: Option<Arc<E>>,
auth_events: &StateMap<Arc<E>>,
current_third_party_invite: Option<Arc<E>>,
) -> Result<bool> {
log::info!(
"auth_check beginning for {} ({})",
incoming_event.event_id(),
incoming_event.kind()
);
// [synapse] check that all the events are in the same room as `incoming_event`
// [synapse] do_sig_check check the event has valid signatures for member events
// TODO do_size_check is false when called by `iterative_auth_check`
// do_size_check is also mostly accomplished by ruma with the exception of checking event_type,
// state_key, and json are below a certain size (255 and 65_536 respectively)
// Implementation of https://matrix.org/docs/spec/rooms/v1#authorization-rules
//
// 1. If type is m.room.create:
if incoming_event.kind() == EventType::RoomCreate {
log::info!("start m.room.create check");
// If it has any previous events, reject
if !incoming_event.prev_events().is_empty() {
log::warn!("the room creation event had previous events");
return Ok(false);
}
// If the domain of the room_id does not match the domain of the sender, reject
if incoming_event.room_id().server_name() != incoming_event.sender().server_name() {
log::warn!("creation events server does not match sender");
return Ok(false); // creation events room id does not match senders
}
// If content.room_version is present and is not a recognized version, reject
if serde_json::from_value::<RoomVersionId>(
incoming_event
.content()
.get("room_version")
.cloned()
// TODO synapse defaults to version 1
.unwrap_or_else(|| serde_json::json!("1")),
)
.is_err()
{
log::warn!("invalid room version found in m.room.create event");
return Ok(false);
}
// If content has no creator field, reject
if incoming_event.content().get("creator").is_none() {
log::warn!("no creator field found in room create content");
return Ok(false);
}
log::info!("m.room.create event was allowed");
return Ok(true);
}
/*
// 2. Reject if auth_events
// a. auth_events cannot have duplicate keys since it's a BTree
// b. All entries are valid auth events according to spec
let expected_auth = auth_types_for_event(
incoming_event.kind,
incoming_event.sender(),
incoming_event.state_key,
incoming_event.content().clone(),
);
dbg!(&expected_auth);
for ev_key in auth_events.keys() {
// (b)
if !expected_auth.contains(ev_key) {
log::warn!("auth_events contained invalid auth event");
return Ok(false);
}
}
*/
// 3. If event does not have m.room.create in auth_events reject
if auth_events.get(&(EventType::RoomCreate, "".to_string())).is_none() {
log::warn!("no m.room.create event in auth chain");
return Ok(false);
}
// [synapse] checks for federation here
// 4. if type is m.room.aliases
if incoming_event.kind() == EventType::RoomAliases && room_version.special_case_aliases_auth {
log::info!("starting m.room.aliases check");
// If sender's domain doesn't matches state_key, reject
if incoming_event.state_key() != Some(incoming_event.sender().server_name().to_string()) {
log::warn!("state_key does not match sender");
return Ok(false);
}
log::info!("m.room.aliases event was allowed");
return Ok(true);
}
if incoming_event.kind() == EventType::RoomMember {
log::info!("starting m.room.member check");
let state_key = match incoming_event.state_key() {
None => {
log::warn!("no statekey in member event");
return Ok(false);
}
Some(s) => s,
};
let membership = incoming_event
.content()
.get("membership")
.map(|m| serde_json::from_value::<MembershipState>(m.clone()));
if !matches!(membership, Some(Ok(_))) {
log::warn!("no valid membership field found for m.room.member event content");
return Ok(false);
}
if !valid_membership_change(
&state_key,
incoming_event.sender(),
incoming_event.content(),
prev_event,
current_third_party_invite,
auth_events,
)? {
return Ok(false);
}
log::info!("m.room.member event was allowed");
return Ok(true);
}
// If the sender's current membership state is not join, reject
match check_event_sender_in_room(incoming_event.sender(), auth_events) {
Some(true) => {} // sender in room
Some(false) => {
log::warn!("sender's membership is not join");
return Ok(false);
}
None => {
log::warn!("sender not found in room");
return Ok(false);
}
}
// Allow if and only if sender's current power level is greater than
// or equal to the invite level
if incoming_event.kind() == EventType::RoomThirdPartyInvite
&& !can_send_invite(incoming_event, auth_events)?
{
log::warn!("sender's cannot send invites in this room");
return Ok(false);
}
// If the event type's required power level is greater than the sender's power level, reject
// If the event has a state_key that starts with an @ and does not match the sender, reject.
if !can_send_event(incoming_event, auth_events) {
log::warn!("user cannot send event");
return Ok(false);
}
if incoming_event.kind() == EventType::RoomPowerLevels {
log::info!("starting m.room.power_levels check");
if let Some(required_pwr_lvl) =
check_power_levels(room_version, incoming_event, auth_events)
{
if !required_pwr_lvl {
log::warn!("power level was not allowed");
return Ok(false);
}
} else {
log::warn!("power level was not allowed");
return Ok(false);
}
log::info!("power levels event allowed");
}
// Room version 3: Redaction events are always accepted (provided the event is allowed by
// `events` and `events_default` in the power levels). However, servers should not apply or
// send redaction's to clients until both the redaction event and original event have been
// seen, and are valid. Servers should only apply redaction's to events where the sender's
// domains match, or the sender of the redaction has the appropriate permissions per the
// power levels.
if room_version.extra_redaction_checks
&& incoming_event.kind() == EventType::RoomRedaction
&& !check_redaction(room_version, incoming_event, auth_events)?
{
return Ok(false);
}
log::info!("allowing event passed all checks");
Ok(true)
}
// TODO deserializing the member, power, join_rules event contents is done in conduit
// just before this is called. Could they be passed in?
/// Does the user who sent this member event have required power levels to do so.
///
/// * `user` - Information about the membership event and user making the request.
/// * `prev_event` - The event that occurred immediately before the `user` event or None.
/// * `auth_events` - The set of auth events that relate to a membership event.
/// this is generated by calling `auth_types_for_event` with the membership event and
/// the current State.
pub fn valid_membership_change<E: Event>(
state_key: &str,
user_sender: &UserId,
content: serde_json::Value,
prev_event: Option<Arc<E>>,
current_third_party_invite: Option<Arc<E>>,
auth_events: &StateMap<Arc<E>>,
) -> Result<bool> {
let target_membership = serde_json::from_value::<MembershipState>(
content.get("membership").expect("we should test before that this field exists").clone(),
)?;
let third_party_invite = content
.get("third_party_invite")
.map(|t| serde_json::from_value::<ThirdPartyInvite>(t.clone()));
let target_user_id =
UserId::try_from(state_key).map_err(|e| Error::InvalidPdu(format!("{}", e)))?;
let key = (EventType::RoomMember, user_sender.to_string());
let sender = auth_events.get(&key);
let sender_membership = sender.map_or(Ok::<_, Error>(MembershipState::Leave), |pdu| {
Ok(serde_json::from_value::<MembershipState>(
pdu.content().get("membership").expect("we assume existing events are valid").clone(),
)?)
})?;
let key = (EventType::RoomMember, target_user_id.to_string());
let current = auth_events.get(&key);
let current_membership = current.map_or(Ok::<_, Error>(MembershipState::Leave), |pdu| {
Ok(serde_json::from_value::<MembershipState>(
pdu.content().get("membership").expect("we assume existing events are valid").clone(),
)?)
})?;
let key = (EventType::RoomPowerLevels, "".into());
let power_levels = auth_events.get(&key).map_or_else(
|| Ok::<_, Error>(PowerLevelsEventContent::default()),
|power_levels| {
serde_json::from_value::<PowerLevelsEventContent>(power_levels.content())
.map_err(Into::into)
},
)?;
let sender_power = power_levels.users.get(user_sender).map_or_else(
|| {
if sender_membership != MembershipState::Join {
None
} else {
Some(&power_levels.users_default)
}
},
// If it's okay, wrap with Some(_)
Some,
);
let target_power = power_levels.users.get(&target_user_id).map_or_else(
|| {
if target_membership != MembershipState::Join {
None
} else {
Some(&power_levels.users_default)
}
},
// If it's okay, wrap with Some(_)
Some,
);
let key = (EventType::RoomJoinRules, "".into());
let join_rules_event = auth_events.get(&key);
let mut join_rules = JoinRule::Invite;
if let Some(jr) = join_rules_event {
join_rules = serde_json::from_value::<JoinRulesEventContent>(jr.content())?.join_rule;
}
if let Some(prev) = prev_event {
if prev.kind() == EventType::RoomCreate && prev.prev_events().is_empty() {
return Ok(true);
}
}
Ok(if target_membership == MembershipState::Join {
if user_sender != &target_user_id {
warn!("Can't make other user join");
false
} else if let MembershipState::Ban = current_membership {
warn!("Banned user can't join");
false
} else {
let allow = join_rules == JoinRule::Invite
&& (current_membership == MembershipState::Join
|| current_membership == MembershipState::Invite)
|| join_rules == JoinRule::Public;
if !allow {
warn!("Can't join if join rules is not public and user is not invited/joined");
}
allow
}
} else if target_membership == MembershipState::Invite {
// If content has third_party_invite key
if let Some(Ok(tp_id)) = third_party_invite {
if current_membership == MembershipState::Ban {
warn!("Can't invite banned user");
false
} else {
let allow = verify_third_party_invite(
Some(state_key),
user_sender,
&tp_id,
current_third_party_invite,
);
if !allow {
warn!("Third party invite invalid");
}
allow
}
} else if sender_membership != MembershipState::Join
|| current_membership == MembershipState::Join
|| current_membership == MembershipState::Ban
{
warn!(
"Can't invite user if sender not joined or the user is currently joined or banned"
);
false
} else {
let allow = sender_power.filter(|&p| p >= &power_levels.invite).is_some();
if !allow {
warn!("User does not have enough power to invite");
}
allow
}
} else if target_membership == MembershipState::Leave {
if user_sender == &target_user_id {
let allow = current_membership == MembershipState::Join
|| current_membership == MembershipState::Invite;
if !allow {
warn!("Can't leave if not invited or joined");
}
allow
} else if sender_membership != MembershipState::Join
|| current_membership == MembershipState::Ban
&& sender_power.filter(|&p| p < &power_levels.ban).is_some()
{
warn!("Can't kick if sender not joined or user is already banned");
false
} else {
let allow = sender_power.filter(|&p| p >= &power_levels.kick).is_some()
&& target_power < sender_power;
if !allow {
warn!("User does not have enough power to kick");
}
allow
}
} else if target_membership == MembershipState::Ban {
if sender_membership != MembershipState::Join {
warn!("Can't ban user if sender is not joined");
false
} else {
let allow = sender_power.filter(|&p| p >= &power_levels.ban).is_some()
&& target_power < sender_power;
if !allow {
warn!("User does not have enough power to ban");
}
allow
}
} else {
warn!("Unknown membership transition");
false
})
}
/// Is the event's sender in the room that they sent the event to.
pub fn check_event_sender_in_room<E: Event>(
sender: &UserId,
auth_events: &StateMap<Arc<E>>,
) -> Option<bool> {
let mem = auth_events.get(&(EventType::RoomMember, sender.to_string()))?;
let membership = serde_json::from_value::<MembershipState>(
mem.content()
.get("membership")
.expect("we should test before that this field exists")
.clone(),
)
.ok()?;
Some(membership == MembershipState::Join)
}
/// Is the user allowed to send a specific event based on the rooms power levels. Does the event
/// have the correct userId as it's state_key if it's not the "" state_key.
pub fn can_send_event<E: Event>(event: &Arc<E>, auth_events: &StateMap<Arc<E>>) -> bool {
let ple = auth_events.get(&(EventType::RoomPowerLevels, "".into()));
let event_type_power_level = get_send_level(&event.kind(), event.state_key(), ple);
let user_level = get_user_power_level(event.sender(), auth_events);
log::debug!(
"{} ev_type {} usr {}",
event.event_id().as_str(),
event_type_power_level,
user_level
);
if user_level < event_type_power_level {
return false;
}
if event.state_key().as_ref().map_or(false, |k| k.starts_with('@'))
&& event.state_key().as_deref() != Some(event.sender().as_str())
{
return false; // permission required to post in this room
}
true
}
/// Confirm that the event sender has the required power levels.
pub fn check_power_levels<E: Event>(
room_version: &RoomVersion,
power_event: &Arc<E>,
auth_events: &StateMap<Arc<E>>,
) -> Option<bool> {
let power_event_state_key = power_event.state_key().expect("power events have state keys");
let key = (power_event.kind(), power_event_state_key);
let current_state = if let Some(current_state) = auth_events.get(&key) {
current_state
} else {
// If there is no previous m.room.power_levels event in the room, allow
return Some(true);
};
// If users key in content is not a dictionary with keys that are valid user IDs
// with values that are integers (or a string that is an integer), reject.
let user_content =
serde_json::from_value::<PowerLevelsEventContent>(power_event.content()).unwrap();
let current_content =
serde_json::from_value::<PowerLevelsEventContent>(current_state.content()).unwrap();
// validation of users is done in Ruma, synapse for loops validating user_ids and integers here
log::info!("validation of power event finished");
let user_level = get_user_power_level(power_event.sender(), auth_events);
let mut user_levels_to_check = btreeset![];
let old_list = &current_content.users;
let user_list = &user_content.users;
for user in old_list.keys().chain(user_list.keys()) {
let user: &UserId = user;
user_levels_to_check.insert(user);
}
log::debug!("users to check {:?}", user_levels_to_check);
let mut event_levels_to_check = btreeset![];
let old_list = &current_content.events;
let new_list = &user_content.events;
for ev_id in old_list.keys().chain(new_list.keys()) {
let ev_id: &EventType = ev_id;
event_levels_to_check.insert(ev_id);
}
log::debug!("events to check {:?}", event_levels_to_check);
let old_state = &current_content;
let new_state = &user_content;
// synapse does not have to split up these checks since we can't combine UserIds and
// EventTypes we do 2 loops
// UserId loop
for user in user_levels_to_check {
let old_level = old_state.users.get(user);
let new_level = new_state.users.get(user);
if old_level.is_some() && new_level.is_some() && old_level == new_level {
continue;
}
// If the current value is equal to the sender's current power level, reject
if user != power_event.sender() && old_level.map(|int| (*int).into()) == Some(user_level) {
log::warn!("m.room.power_level cannot remove ops == to own");
return Some(false); // cannot remove ops level == to own
}
// If the current value is higher than the sender's current power level, reject
// If the new value is higher than the sender's current power level, reject
let old_level_too_big = old_level.map(|int| (*int).into()) > Some(user_level);
let new_level_too_big = new_level.map(|int| (*int).into()) > Some(user_level);
if old_level_too_big || new_level_too_big {
log::warn!("m.room.power_level failed to add ops > than own");
return Some(false); // cannot add ops greater than own
}
}
// EventType loop
for ev_type in event_levels_to_check {
let old_level = old_state.events.get(ev_type);
let new_level = new_state.events.get(ev_type);
if old_level.is_some() && new_level.is_some() && old_level == new_level {
continue;
}
// If the current value is higher than the sender's current power level, reject
// If the new value is higher than the sender's current power level, reject
let old_level_too_big = old_level.map(|int| (*int).into()) > Some(user_level);
let new_level_too_big = new_level.map(|int| (*int).into()) > Some(user_level);
if old_level_too_big || new_level_too_big {
log::warn!("m.room.power_level failed to add ops > than own");
return Some(false); // cannot add ops greater than own
}
}
// Notifications, currently there is only @room
if room_version.limit_notifications_power_levels {
let old_level = old_state.notifications.room;
let new_level = new_state.notifications.room;
if old_level != new_level {
// If the current value is higher than the sender's current power level, reject
// If the new value is higher than the sender's current power level, reject
let old_level_too_big = i64::from(old_level) > user_level;
let new_level_too_big = i64::from(new_level) > user_level;
if old_level_too_big || new_level_too_big {
log::warn!("m.room.power_level failed to add ops > than own");
return Some(false); // cannot add ops greater than own
}
}
}
let levels =
["users_default", "events_default", "state_default", "ban", "redact", "kick", "invite"];
let old_state = serde_json::to_value(old_state).unwrap();
let new_state = serde_json::to_value(new_state).unwrap();
for lvl_name in &levels {
if let Some((old_lvl, new_lvl)) = get_deserialize_levels(&old_state, &new_state, lvl_name) {
let old_level_too_big = old_lvl > user_level;
let new_level_too_big = new_lvl > user_level;
if old_level_too_big || new_level_too_big {
log::warn!("cannot add ops > than own");
return Some(false);
}
}
}
Some(true)
}
fn get_deserialize_levels(
old: &serde_json::Value,
new: &serde_json::Value,
name: &str,
) -> Option<(i64, i64)> {
Some((
serde_json::from_value(old.get(name)?.clone()).ok()?,
serde_json::from_value(new.get(name)?.clone()).ok()?,
))
}
/// Does the event redacting come from a user with enough power to redact the given event.
pub fn check_redaction<E: Event>(
_room_version: &RoomVersion,
redaction_event: &Arc<E>,
auth_events: &StateMap<Arc<E>>,
) -> Result<bool> {
let user_level = get_user_power_level(redaction_event.sender(), auth_events);
let redact_level = get_named_level(auth_events, "redact", 50);
if user_level >= redact_level {
log::info!("redaction allowed via power levels");
return Ok(true);
}
// If the domain of the event_id of the event being redacted is the same as the
// domain of the event_id of the m.room.redaction, allow
if redaction_event.event_id().server_name()
== redaction_event.redacts().as_ref().and_then(|id| id.server_name())
{
log::info!("redaction event allowed via room version 1 rules");
return Ok(true);
}
Ok(false)
}
/// Check that the member event matches `state`.
///
/// This function returns false instead of failing when deserialization fails.
pub fn check_membership<E: Event>(member_event: Option<Arc<E>>, state: MembershipState) -> bool {
if let Some(event) = member_event {
if let Some(Ok(membership)) = event
.content()
.get("membership")
.map(|m| serde_json::from_value::<MembershipState>(m.clone()))
{
membership == state
} else {
false
}
} else {
false
}
}
/// Can this room federate based on its m.room.create event.
pub fn can_federate<E: Event>(auth_events: &StateMap<Arc<E>>) -> bool {
let creation_event = auth_events.get(&(EventType::RoomCreate, "".into()));
if let Some(ev) = creation_event {
if let Some(fed) = ev.content().get("m.federate") {
fed == "true"
} else {
false
}
} else {
false
}
}
/// Helper function to fetch a field, `name`, from a "m.room.power_level" event's content.
/// or return `default` if no power level event is found or zero if no field matches `name`.
pub fn get_named_level<E: Event>(auth_events: &StateMap<Arc<E>>, name: &str, default: i64) -> i64 {
let power_level_event = auth_events.get(&(EventType::RoomPowerLevels, "".into()));
if let Some(pl) = power_level_event {
// TODO do this the right way and deserialize
if let Some(level) = pl.content().get(name) {
level.to_string().parse().unwrap_or(default)
} else {
0
}
} else {
default
}
}
/// Helper function to fetch a users default power level from a "m.room.power_level" event's `users`
/// object.
pub fn get_user_power_level<E: Event>(user_id: &UserId, auth_events: &StateMap<Arc<E>>) -> i64 {
if let Some(pl) = auth_events.get(&(EventType::RoomPowerLevels, "".into())) {
if let Ok(content) = serde_json::from_value::<PowerLevelsEventContent>(pl.content()) {
if let Some(level) = content.users.get(user_id) {
(*level).into()
} else {
content.users_default.into()
}
} else {
0 // TODO if this fails DB error?
}
} else {
// if no power level event found the creator gets 100 everyone else gets 0
let key = (EventType::RoomCreate, "".into());
if let Some(create) = auth_events.get(&key) {
if let Ok(c) = serde_json::from_value::<CreateEventContent>(create.content()) {
if &c.creator == user_id {
100
} else {
0
}
} else {
0
}
} else {
0
}
}
}
/// Helper function to fetch the power level needed to send an event of type
/// `e_type` based on the rooms "m.room.power_level" event.
pub fn get_send_level<E: Event>(
e_type: &EventType,
state_key: Option<String>,
power_lvl: Option<&Arc<E>>,
) -> i64 {
log::debug!("{:?} {:?}", e_type, state_key);
power_lvl
.and_then(|ple| {
serde_json::from_value::<PowerLevelsEventContent>(ple.content())
.map(|content| {
content.events.get(e_type).copied().unwrap_or_else(|| {
if state_key.is_some() {
content.state_default
} else {
content.events_default
}
})
})
.ok()
})
.map(i64::from)
.unwrap_or_else(|| if state_key.is_some() { 50 } else { 0 })
}
/// Check user can send invite.
pub fn can_send_invite<E: Event>(event: &Arc<E>, auth_events: &StateMap<Arc<E>>) -> Result<bool> {
let user_level = get_user_power_level(event.sender(), auth_events);
let key = (EventType::RoomPowerLevels, "".into());
let invite_level = auth_events
.get(&key)
.map_or_else(
|| Ok::<_, Error>(ruma::int!(50)),
|power_levels| {
serde_json::from_value::<PowerLevelsEventContent>(power_levels.content())
.map(|pl| pl.invite)
.map_err(Into::into)
},
)?
.into();
Ok(user_level >= invite_level)
}
pub fn verify_third_party_invite<E: Event>(
user_state_key: Option<&str>,
sender: &UserId,
tp_id: &ThirdPartyInvite,
current_third_party_invite: Option<Arc<E>>,
) -> bool {
// 1. check for user being banned happens before this is called
// checking for mxid and token keys is done by ruma when deserializing
if user_state_key != Some(tp_id.signed.mxid.as_str()) {
return false;
}
// If there is no m.room.third_party_invite event in the current room state
// with state_key matching token, reject
if let Some(current_tpid) = current_third_party_invite {
if current_tpid.state_key().as_ref() != Some(&tp_id.signed.token) {
return false;
}
if sender != current_tpid.sender() {
return false;
}
// If any signature in signed matches any public key in the m.room.third_party_invite event,
// allow
if let Ok(tpid_ev) = serde_json::from_value::<
ruma::events::room::third_party_invite::ThirdPartyInviteEventContent,
>(current_tpid.content())
{
// A list of public keys in the public_keys field
for key in tpid_ev.public_keys.unwrap_or_default() {
if key.public_key == tp_id.signed.token {
return true;
}
}
// A single public key in the public_key field
tpid_ev.public_key == tp_id.signed.token
} else {
false
}
} else {
false
}
}