Add v1/v2 support to gen_event_id() scheme. (#12)

Add v1/v2 and improve reference and content hashing suite. (#12)

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/matrix/event/id.rs

@@ -1,4 +1,4 @@
-use ruma::{CanonicalJsonObject, OwnedEventId, RoomVersionId};
+use ruma::{CanonicalJsonObject, CanonicalJsonValue, OwnedEventId, RoomVersionId};
 use serde_json::value::RawValue as RawJsonValue;
 
 use crate::{Result, debug_error, err, matrix::room_version};
@@ -20,13 +20,36 @@ pub fn gen_event_id_canonical_json(
 	Ok((event_id, value))
 }
 
-/// Generates a correct eventId for the incoming pdu.
+/// Generates a correct eventId for the PDU. For v1/v2 incoming PDU's the
+/// value's event_id is passed through. For all outgoing PDU's and for v3+
+/// incoming PDU's it is generated.
 pub fn gen_event_id(
 	value: &CanonicalJsonObject,
 	room_version_id: &RoomVersionId,
 ) -> Result<OwnedEventId> {
 	let room_version_rules = room_version::rules(room_version_id)?;
+	let require_event_id = room_version_rules.event_format.require_event_id;
+
+	// We don't actually generate any event_id for incoming events in v1/v2 rooms,
+	// just pass them through.
+	if let Some(event_id) = require_event_id
+		.then(|| value.get("event_id"))
+		.flatten()
+		.and_then(CanonicalJsonValue::as_str)
+		.map(OwnedEventId::try_from)
+		.transpose()?
+	{
+		return Ok(event_id);
+	}
+
+	// For outgoing v1/v2 add the server part. This has to be our origin but we
+	// can't assert that here.
+	let server_name = require_event_id
+		.then(|| value.get("origin"))
+		.flatten()
+		.and_then(CanonicalJsonValue::as_str);
+
 	let reference_hash = ruma::signatures::reference_hash(value, &room_version_rules)?;
 
-	OwnedEventId::from_parts('$', &reference_hash, None).map_err(Into::into)
+	OwnedEventId::from_parts('$', &reference_hash, server_name).map_err(Into::into)
 }

src/service/server_keys/sign.rs

@@ -1,28 +1,71 @@
-use ruma::{CanonicalJsonObject, RoomVersionId};
+use ruma::{CanonicalJsonObject, CanonicalJsonValue, OwnedEventId, RoomVersionId};
-use tuwunel_core::{Result, err, implement};
+use tuwunel_core::{
+	Result, implement,
+	matrix::{event::gen_event_id, room_version},
+};
 
 #[implement(super::Service)]
-pub fn sign_json(&self, object: &mut CanonicalJsonObject) -> Result {
+pub fn gen_id_hash_and_sign_event(
-	use ruma::signatures::sign_json;
+	&self,
+	object: &mut CanonicalJsonObject,
+	room_version_id: &RoomVersionId,
+) -> Result<OwnedEventId> {
+	object.remove("event_id");
 
-	let server_name = self.services.globals.server_name().as_str();
+	if room_version::rules(room_version_id)?
-	sign_json(server_name, self.keypair(), object).map_err(Into::into)
+		.event_format
+		.require_event_id
+	{
+		self.gen_id_hash_and_sign_event_v1(object, room_version_id)
+	} else {
+		self.gen_id_hash_and_sign_event_v3(object, room_version_id)
+	}
+}
+
+#[implement(super::Service)]
+fn gen_id_hash_and_sign_event_v1(
+	&self,
+	object: &mut CanonicalJsonObject,
+	room_version_id: &RoomVersionId,
+) -> Result<OwnedEventId> {
+	let event_id = gen_event_id(object, room_version_id)?;
+
+	object.insert("event_id".into(), CanonicalJsonValue::String(event_id.clone().into()));
+
+	self.services
+		.server_keys
+		.hash_and_sign_event(object, room_version_id)?;
+
+	Ok(event_id)
+}
+
+#[implement(super::Service)]
+fn gen_id_hash_and_sign_event_v3(
+	&self,
+	object: &mut CanonicalJsonObject,
+	room_version_id: &RoomVersionId,
+) -> Result<OwnedEventId> {
+	self.services
+		.server_keys
+		.hash_and_sign_event(object, room_version_id)?;
+
+	let event_id = gen_event_id(object, room_version_id)?;
+
+	object.insert("event_id".into(), CanonicalJsonValue::String(event_id.clone().into()));
+
+	Ok(event_id)
 }
 
 #[implement(super::Service)]
 pub fn hash_and_sign_event(
 	&self,
 	object: &mut CanonicalJsonObject,
-	room_version: &RoomVersionId,
+	room_version_id: &RoomVersionId,
 ) -> Result {
 	use ruma::signatures::hash_and_sign_event;
 
 	let server_name = &self.services.server.name;
-	let room_version_rules = room_version.rules().ok_or_else(|| {
+	let room_version_rules = room_version::rules(room_version_id)?;
-		err!(Request(UnsupportedRoomVersion(
-			"Cannot hash and sign event for unknown room version {room_version:?}."
-		)))
-	})?;
 
 	hash_and_sign_event(
 		server_name.as_str(),
@@ -32,3 +75,12 @@ pub fn hash_and_sign_event(
 	)
 	.map_err(Into::into)
 }
+
+#[implement(super::Service)]
+pub fn sign_json(&self, object: &mut CanonicalJsonObject) -> Result {
+	use ruma::signatures::sign_json;
+
+	let server_name = self.services.globals.server_name().as_str();
+
+	sign_json(server_name, self.keypair(), object).map_err(Into::into)
+}