fix: Enforce limits when joining rooms

conduwuit-example.toml

@@ -586,13 +586,10 @@
 #allow_unstable_room_versions = true
 
 # Default room version continuwuity will create rooms with.
-# Note that this has to be a string since the room version is a string
-# rather than an integer. Forgetting the quotes will make the server fail
-# to start!
 #
-# Per spec, room version "11" is the default.
+# Per spec, room version 11 is the default.
 #
-#default_room_version = "11"
+#default_room_version = 11
 
 # Enable OpenTelemetry OTLP tracing export. This replaces the deprecated
 # Jaeger exporter. Traces will be sent via OTLP to a collector (such as

nix/tests/default.nix

@@ -6,69 +6,6 @@
       pkgs,
       ...
     }:
-    let
-      baseTestScript =
-        pkgs.writers.writePython3Bin "do_test" { libraries = [ pkgs.python3Packages.matrix-nio ]; }
-          ''
-            import asyncio
-            import nio
-
-
-            async def main() -> None:
-                # Connect to continuwuity
-                client = nio.AsyncClient("http://continuwuity:6167", "alice")
-
-                # Register as user alice
-                response = await client.register("alice", "my-secret-password")
-
-                # Log in as user alice
-                response = await client.login("my-secret-password")
-
-                # Create a new room
-                response = await client.room_create(federate=False)
-                print("Matrix room create response:", response)
-                assert isinstance(response, nio.RoomCreateResponse)
-                room_id = response.room_id
-
-                # Join the room
-                response = await client.join(room_id)
-                print("Matrix join response:", response)
-                assert isinstance(response, nio.JoinResponse)
-
-                # Send a message to the room
-                response = await client.room_send(
-                    room_id=room_id,
-                    message_type="m.room.message",
-                    content={
-                        "msgtype": "m.text",
-                        "body": "Hello continuwuity!"
-                    }
-                )
-                print("Matrix room send response:", response)
-                assert isinstance(response, nio.RoomSendResponse)
-
-                # Sync responses
-                response = await client.sync(timeout=30000)
-                print("Matrix sync response:", response)
-                assert isinstance(response, nio.SyncResponse)
-
-                # Check the message was received by continuwuity
-                last_message = response.rooms.join[room_id].timeline.events[-1].body
-                assert last_message == "Hello continuwuity!"
-
-                # Leave the room
-                response = await client.room_leave(room_id)
-                print("Matrix room leave response:", response)
-                assert isinstance(response, nio.RoomLeaveResponse)
-
-                # Close the client
-                await client.close()
-
-
-            if __name__ == "__main__":
-                asyncio.run(main())
-          '';
-    in
     {
       # run some nixos tests as checks
       checks = lib.pipe self'.packages [
@@ -81,69 +18,106 @@
         # this test was initially yoinked from
         #
         # https://github.com/NixOS/nixpkgs/blob/960ce26339661b1b69c6f12b9063ca51b688615f/nixos/tests/matrix/continuwuity.nix
-        (builtins.concatMap (
-          name:
-          builtins.map
-            (
-              { config, suffix }:
-              {
-                name = "test-${name}-${suffix}";
-                value = pkgs.testers.runNixOSTest {
-                  inherit name;
+        (builtins.map (name: {
+          name = "test-${name}";
+          value = pkgs.testers.runNixOSTest {
+            inherit name;
 
-                  nodes = {
-                    continuwuity = {
-                      services.matrix-continuwuity = {
-                        enable = true;
-                        package = self'.packages.${name};
-                        settings = config;
-                        extraEnvironment.RUST_BACKTRACE = "yes";
-                      };
-                      networking.firewall.allowedTCPPorts = [ 6167 ];
-                    };
-                    client.environment.systemPackages = [ baseTestScript ];
-                  };
-
-                  testScript = ''
-                    start_all()
-
-                    with subtest("start continuwuity"):
-                          continuwuity.wait_for_unit("continuwuity.service")
-                          continuwuity.wait_for_open_port(6167)
-
-                    with subtest("ensure messages can be exchanged"):
-                          client.succeed("${lib.getExe baseTestScript} >&2")
-                  '';
-
-                };
-              }
-            )
-            [
-              {
-                suffix = "base";
-                config = {
-                  global = {
+            nodes = {
+              continuwuity = {
+                services.matrix-continuwuity = {
+                  enable = true;
+                  package = self'.packages.${name};
+                  settings.global = {
                     server_name = name;
                     address = [ "0.0.0.0" ];
                     allow_registration = true;
                     yes_i_am_very_very_sure_i_want_an_open_registration_server_prone_to_abuse = true;
                   };
+                  extraEnvironment.RUST_BACKTRACE = "yes";
                 };
-              }
-              {
-                suffix = "with-room-version";
-                config = {
-                  global = {
-                    server_name = name;
-                    address = [ "0.0.0.0" ];
-                    allow_registration = true;
-                    yes_i_am_very_very_sure_i_want_an_open_registration_server_prone_to_abuse = true;
-                    default_room_version = "12";
-                  };
+                networking.firewall.allowedTCPPorts = [ 6167 ];
+              };
+              client =
+                { pkgs, ... }:
+                {
+                  environment.systemPackages = [
+                    (pkgs.writers.writePython3Bin "do_test" { libraries = [ pkgs.python3Packages.matrix-nio ]; } ''
+                      import asyncio
+                      import nio
+
+
+                      async def main() -> None:
+                          # Connect to continuwuity
+                          client = nio.AsyncClient("http://continuwuity:6167", "alice")
+
+                          # Register as user alice
+                          response = await client.register("alice", "my-secret-password")
+
+                          # Log in as user alice
+                          response = await client.login("my-secret-password")
+
+                          # Create a new room
+                          response = await client.room_create(federate=False)
+                          print("Matrix room create response:", response)
+                          assert isinstance(response, nio.RoomCreateResponse)
+                          room_id = response.room_id
+
+                          # Join the room
+                          response = await client.join(room_id)
+                          print("Matrix join response:", response)
+                          assert isinstance(response, nio.JoinResponse)
+
+                          # Send a message to the room
+                          response = await client.room_send(
+                              room_id=room_id,
+                              message_type="m.room.message",
+                              content={
+                                  "msgtype": "m.text",
+                                  "body": "Hello continuwuity!"
+                              }
+                          )
+                          print("Matrix room send response:", response)
+                          assert isinstance(response, nio.RoomSendResponse)
+
+                          # Sync responses
+                          response = await client.sync(timeout=30000)
+                          print("Matrix sync response:", response)
+                          assert isinstance(response, nio.SyncResponse)
+
+                          # Check the message was received by continuwuity
+                          last_message = response.rooms.join[room_id].timeline.events[-1].body
+                          assert last_message == "Hello continuwuity!"
+
+                          # Leave the room
+                          response = await client.room_leave(room_id)
+                          print("Matrix room leave response:", response)
+                          assert isinstance(response, nio.RoomLeaveResponse)
+
+                          # Close the client
+                          await client.close()
+
+
+                      if __name__ == "__main__":
+                          asyncio.run(main())
+                    '')
+                  ];
                 };
-              }
-            ]
-        ))
+            };
+
+            testScript = ''
+              start_all()
+
+              with subtest("start continuwuity"):
+                    continuwuity.wait_for_unit("continuwuity.service")
+                    continuwuity.wait_for_open_port(6167)
+
+              with subtest("ensure messages can be exchanged"):
+                    client.succeed("do_test >&2")
+            '';
+
+          };
+        }))
         builtins.listToAttrs
       ];
     };

src/api/client/membership/join.rs

@@ -44,6 +44,7 @@
 	rooms::{
 		state::RoomMutexGuard,
 		state_compressor::{CompressedState, HashSetCompressStateEvent},
+		timeline::pdu_fits,
 	},
 };
 
@@ -573,6 +574,13 @@ async fn join_room_by_id_helper_remote(
 					return state;
 				},
 			};
+			if !pdu_fits(&mut value.clone()) {
+				warn!(
+					"dropping incoming PDU {event_id} in room {room_id} from room join because \
+					 it exceeds 65535 bytes or is otherwise too large."
+				);
+				return state;
+			}
 			services.rooms.outlier.add_pdu_outlier(&event_id, &value);
 			if let Some(state_key) = &pdu.state_key {
 				let shortstatekey = services

src/core/config/mod.rs

@@ -703,13 +703,10 @@ pub struct Config {
 	pub allow_unstable_room_versions: bool,
 
 	/// Default room version continuwuity will create rooms with.
-	/// Note that this has to be a string since the room version is a string
-	/// rather than an integer. Forgetting the quotes will make the server fail
-	/// to start!
 	///
-	/// Per spec, room version "11" is the default.
+	/// Per spec, room version 11 is the default.
 	///
-	/// default: "11"
+	/// default: 11
 	#[serde(default = "default_default_room_version")]
 	pub default_room_version: RoomVersionId,
 

src/core/matrix/state_res/event_auth.rs

@@ -177,11 +177,6 @@ pub async fn auth_check<E, F, Fut>(
 
 	// [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)
-
 	let sender = incoming_event.sender();
 
 	// Implementation of https://spec.matrix.org/latest/rooms/v1/#authorization-rules

src/service/globals/mod.rs

@@ -31,12 +31,13 @@ fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
 
 		let turn_secret = config.turn_secret_file.as_ref().map_or_else(
 			|| config.turn_secret.clone(),
-			|path| {
-				std::fs::read_to_string(path).unwrap_or_else(|e| {
+			|path| match std::fs::read_to_string(path) {
+				| Ok(secret) => secret.trim().to_owned(),
+				| Err(e) => {
 					error!("Failed to read the TURN secret file: {e}");
 
 					config.turn_secret.clone()
-				})
+				},
 			},
 		);
 
@@ -49,7 +50,7 @@ fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
 					return config.registration_token.clone();
 				};
 
-				Some(token)
+				Some(token.trim().to_owned())
 			},
 		);
 

src/service/migrations.rs

@@ -590,6 +590,10 @@ async fn fix_readreceiptid_readreceipt_duplicates(services: &Services) -> Result
 
 const FIXED_CORRUPT_MSC4133_FIELDS_MARKER: &[u8] = b"fix_corrupt_msc4133_fields";
 async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
+	// Due to an old bug, some conduwuit databases have `us.cloke.msc4175.tz` user
+	// profile fields with raw strings instead of quoted JSON ones.
+	// This migration fixes that.
+
 	use serde_json::{Value, from_slice};
 	type KeyVal<'a> = ((OwnedUserId, String), &'a [u8]);
 
@@ -606,24 +610,28 @@ async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
 			async |(mut total, mut fixed),
 			       ((user, key), value): KeyVal<'_>|
 			       -> Result<(usize, usize)> {
-				if let Err(error) = from_slice::<Value>(value) {
-					// Due to an old bug, some conduwuit databases have `us.cloke.msc4175.tz` user
-					// profile fields with raw strings instead of quoted JSON ones.
-					// This migration fixes that.
-					let new_value = if key == "us.cloke.msc4175.tz" {
-						Value::String(String::from_utf8(value.to_vec())?)
-					} else {
-						return Err!(
-							"failed to deserialize msc4133 key {} of user {}: {}",
-							key,
-							user,
-							error
+				match from_slice::<Value>(value) {
+					// corrupted timezone field
+					| Err(_) if key == "us.cloke.msc4175.tz" => {
+						let new_value = Value::String(String::from_utf8(value.to_vec())?);
+						useridprofilekey_value.put((user, key), Json(new_value));
+						fixed = fixed.saturating_add(1);
+					},
+					// corrupted value for some other key
+					| Err(error) => {
+						warn!(
+							"deleting MSC4133 key {} for user {} due to deserialization \
+							 failure: {}",
+							key, user, error
 						);
-					};
-
-					useridprofilekey_value.put((user, key), Json(new_value));
-					fixed = fixed.saturating_add(1);
+						useridprofilekey_value.del((user, key));
+					},
+					// other key with no issues
+					| Ok(_) => {
+						// do nothing
+					},
 				}
+
 				total = total.saturating_add(1);
 
 				Ok((total, fixed))

src/service/rooms/event_handler/handle_incoming_pdu.rs

@@ -14,7 +14,7 @@
 use ruma::{CanonicalJsonValue, EventId, RoomId, ServerName, UserId, events::StateEventType};
 use tracing::debug;
 
-use crate::rooms::timeline::RawPduId;
+use crate::rooms::timeline::{RawPduId, pdu_fits};
 
 /// When receiving an event one needs to:
 /// 0. Check the server is in the room
@@ -62,6 +62,13 @@ pub async fn handle_incoming_pdu<'a>(
 	if let Ok(pdu_id) = self.services.timeline.get_pdu_id(event_id).await {
 		return Ok(Some(pdu_id));
 	}
+	if !pdu_fits(&mut value.clone()) {
+		warn!(
+			"dropping incoming PDU {event_id} in room {room_id} from {origin} because it \
+			 exceeds 65535 bytes or is otherwise too large."
+		);
+		return Err!(Request(TooLarge("PDU is too large")));
+	}
 
 	// 1.1 Check the server is in the room
 	let meta_exists = self.services.metadata.exists(room_id).map(Ok);

src/service/rooms/event_handler/handle_outlier_pdu.rs

@@ -1,7 +1,8 @@
 use std::collections::{BTreeMap, HashMap, hash_map};
 
 use conduwuit::{
-	Err, Event, PduEvent, Result, debug, debug_info, debug_warn, err, implement, state_res, trace,
+	Err, Event, PduEvent, Result, debug, debug_info, debug_warn, err, implement, state_res,
+	trace, warn,
 };
 use futures::future::ready;
 use ruma::{
@@ -10,6 +11,7 @@
 };
 
 use super::{check_room_id, get_room_version_id, to_room_version};
+use crate::rooms::timeline::pdu_fits;
 
 #[implement(super::Service)]
 #[allow(clippy::too_many_arguments)]
@@ -25,6 +27,13 @@ pub(super) async fn handle_outlier_pdu<'a, Pdu>(
 where
 	Pdu: Event + Send + Sync,
 {
+	if !pdu_fits(&mut value.clone()) {
+		warn!(
+			"dropping incoming PDU {event_id} in room {room_id} from {origin} because it \
+			 exceeds 65535 bytes or is otherwise too large."
+		);
+		return Err!(Request(TooLarge("PDU is too large")));
+	}
 	// 1. Remove unsigned field
 	value.remove("unsigned");
 

src/service/rooms/timeline/create.rs

@@ -23,6 +23,40 @@
 
 use super::RoomMutexGuard;
 
+pub fn pdu_fits(owned_obj: &mut CanonicalJsonObject) -> bool {
+	// room IDs, event IDs, senders, types, and state keys must all be <= 255 bytes
+	if let Some(CanonicalJsonValue::String(room_id)) = owned_obj.get("room_id") {
+		if room_id.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(event_id)) = owned_obj.get("event_id") {
+		if event_id.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(sender)) = owned_obj.get("sender") {
+		if sender.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(kind)) = owned_obj.get("type") {
+		if kind.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(state_key)) = owned_obj.get("state_key") {
+		if state_key.len() > 255 {
+			return false;
+		}
+	}
+	// Now check the full PDU size
+	match serde_json::to_string(owned_obj) {
+		| Ok(s) => s.len() <= 65535,
+		| Err(_) => false,
+	}
+}
+
 #[implement(super::Service)]
 pub async fn create_hash_and_sign_event(
 	&self,
@@ -148,19 +182,6 @@ fn from_evt(
 		}
 	}
 
-	// if event_type != TimelineEventType::RoomCreate && prev_events.is_empty() {
-	// 	return Err!(Request(Unknown("Event incorrectly had zero prev_events.")));
-	// }
-	// if state_key.is_none() && depth.lt(&uint!(2)) {
-	// 	// The first two events in a room are always m.room.create and
-	// m.room.member, 	// so any other events with that same depth are illegal.
-	// 	warn!(
-	// 		"Had unsafe depth {depth} when creating non-state event in {}. Cowardly
-	// aborting", 		room_id.expect("room_id is Some here").as_str()
-	// 	);
-	// 	return Err!(Request(Unknown("Unsafe depth for non-state event.")));
-	// }
-
 	let mut pdu = PduEvent {
 		event_id: ruma::event_id!("$thiswillbefilledinlater").into(),
 		room_id: room_id.map(ToOwned::to_owned),
@@ -269,8 +290,16 @@ fn from_evt(
 	}
 	// Generate event id
 	pdu.event_id = gen_event_id(&pdu_json, &room_version_id)?;
-	// Check with the policy server
 	pdu_json.insert("event_id".into(), CanonicalJsonValue::String(pdu.event_id.clone().into()));
+	// Verify that the *full* PDU isn't over 64KiB.
+	// Ruma only validates that it's under 64KiB before signing and hashing.
+	// Has to be cloned to prevent mutating pdu_json itself :(
+	if !pdu_fits(&mut pdu_json.clone()) {
+		// feckin huge PDU mate
+		return Err!(Request(TooLarge("Message/PDU is too long (exceeds 65535 bytes)")));
+	}
+
+	// Check with the policy server
 	if room_id.is_some() {
 		trace!(
 			"Checking event in room {} with policy server",

src/service/rooms/timeline/mod.rs

@@ -26,7 +26,7 @@
 use serde::Deserialize;
 
 use self::data::Data;
-pub use self::data::PdusIterItem;
+pub use self::{create::pdu_fits, data::PdusIterItem};
 use crate::{
 	Dep, account_data, admin, appservice, globals, pusher, rooms, sending, server_keys, users,
 };