fix: Filter out invalid replacements from bundled aggregations

This commit is contained in:
Jade Ellis 2025-06-04 22:50:17 +01:00 committed by Jacob Taylor
parent 69c66af0ea
commit 908efef692

View file

@ -43,7 +43,10 @@ impl super::Service {
return Ok(None);
}
let mut replace_events = Vec::with_capacity(relations.len().min(10)); // Most events have few replacements
// Get the original event for validation of replacement events
let original_event = self.services.timeline.get_pdu(event_id).await?;
let mut replace_events = Vec::with_capacity(relations.len());
let mut reference_events = Vec::with_capacity(relations.len());
for relation in &relations {
@ -56,7 +59,10 @@ impl super::Service {
if let Some(rel_type) = relates_to.get("rel_type") {
match rel_type.as_str() {
| Some("m.replace") => {
replace_events.push(relation);
// Only consider valid replacements
if Self::is_valid_replacement_event(&original_event, pdu).await? {
replace_events.push(relation);
}
},
| Some("m.reference") => {
reference_events.push(relation);
@ -228,6 +234,56 @@ impl super::Service {
Ok(())
}
/// Validates that an event is acceptable as a replacement for another event
/// See C/S spec "Validity of replacement events"
#[tracing::instrument(level = "debug")]
async fn is_valid_replacement_event(
original_event: &PduEvent,
replacement_event: &PduEvent,
) -> Result<bool> {
// 1. Same room_id
if original_event.room_id() != replacement_event.room_id() {
return Ok(false);
}
// 2. Same sender
if original_event.sender() != replacement_event.sender() {
return Ok(false);
}
// 3. Same type
if original_event.event_type() != replacement_event.event_type() {
return Ok(false);
}
// 4. Neither event should have a state_key property
if original_event.state_key().is_some() || replacement_event.state_key().is_some() {
return Ok(false);
}
// 5. Original event must not have rel_type of m.replace
let original_content = original_event.get_content_as_value();
if let Some(relates_to) = original_content.get("m.relates_to") {
if let Some(rel_type) = relates_to.get("rel_type") {
if rel_type.as_str() == Some("m.replace") {
return Ok(false);
}
}
}
// 6. Replacement event must have m.new_content property
// Skip this check for encrypted events, as m.new_content would be inside the
// encrypted payload
if replacement_event.event_type() != &ruma::events::TimelineEventType::RoomEncrypted {
let replacement_content = replacement_event.get_content_as_value();
if replacement_content.get("m.new_content").is_none() {
return Ok(false);
}
}
Ok(true)
}
}
#[cfg(test)]
@ -391,4 +447,319 @@ mod tests {
assert!(result.is_err(), "fails when existing unsigned is invalid");
// Should we ignore the error and overwrite anyway?
}
// Test helper function to create test PDU events
fn create_test_event(
event_id: &str,
room_id: &str,
sender: &str,
event_type: TimelineEventType,
content: &JsonValue,
state_key: Option<&str>,
) -> PduEvent {
PduEvent {
event_id: event_id.try_into().unwrap(),
room_id: room_id.try_into().unwrap(),
sender: sender.try_into().unwrap(),
origin_server_ts: UInt::try_from(1_234_567_890_u64).unwrap(),
kind: event_type,
content: to_raw_value(&content).unwrap(),
state_key: state_key.map(Into::into),
prev_events: vec![],
depth: UInt::from(1_u32),
auth_events: vec![],
redacts: None,
unsigned: None,
hashes: EventHash { sha256: "test_hash".to_owned() },
signatures: None,
origin: None,
}
}
/// Test that a valid replacement event passes validation
#[tokio::test]
async fn test_valid_replacement_event() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({"msgtype": "m.text", "body": "original message"}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited message",
"m.new_content": {
"msgtype": "m.text",
"body": "edited message"
},
"m.relates_to": {
"rel_type": "m.replace",
"event_id": "$original:example.com"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(result.unwrap(), "Valid replacement event should be accepted");
}
/// Test replacement event with different room ID is rejected
#[tokio::test]
async fn test_replacement_event_different_room() {
let original = create_test_event(
"$original:example.com",
"!room1:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({"msgtype": "m.text", "body": "original message"}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room2:example.com", // Different room
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited message",
"m.new_content": {
"msgtype": "m.text",
"body": "edited message"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Different room ID should be rejected");
}
/// Test replacement event with different sender is rejected
#[tokio::test]
async fn test_replacement_event_different_sender() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user1:example.com",
TimelineEventType::RoomMessage,
&json!({"msgtype": "m.text", "body": "original message"}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user2:example.com", // Different sender
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited message",
"m.new_content": {
"msgtype": "m.text",
"body": "edited message"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Different sender should be rejected");
}
/// Test replacement event with different type is rejected
#[tokio::test]
async fn test_replacement_event_different_type() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({"msgtype": "m.text", "body": "original message"}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomTopic, // Different event type
&json!({
"topic": "new topic",
"m.new_content": {
"topic": "new topic"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Different event type should be rejected");
}
/// Test replacement event with state key is rejected
#[tokio::test]
async fn test_replacement_event_with_state_key() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomName,
&json!({"name": "room name"}),
Some(""), // Has state key
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomName,
&json!({
"name": "new room name",
"m.new_content": {
"name": "new room name"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Event with state key should be rejected");
}
/// Test replacement of an event that is already a replacement is rejected
#[tokio::test]
async fn test_replacement_event_original_is_replacement() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited message",
"m.relates_to": {
"rel_type": "m.replace", // Original is already a replacement
"event_id": "$some_other:example.com"
}
}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited again",
"m.new_content": {
"msgtype": "m.text",
"body": "edited again"
}
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Replacement of replacement should be rejected");
}
/// Test replacement event missing m.new_content is rejected
#[tokio::test]
async fn test_replacement_event_missing_new_content() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({"msgtype": "m.text", "body": "original message"}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomMessage,
&json!({
"msgtype": "m.text",
"body": "* edited message"
// Missing m.new_content
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(!result.unwrap(), "Missing m.new_content should be rejected");
}
/// Test encrypted replacement event without m.new_content is accepted
#[tokio::test]
async fn test_replacement_event_encrypted_missing_new_content_is_valid() {
let original = create_test_event(
"$original:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomEncrypted,
&json!({
"algorithm": "m.megolm.v1.aes-sha2",
"ciphertext": "encrypted_payload_base64",
"sender_key": "sender_key",
"session_id": "session_id"
}),
None,
);
let replacement = create_test_event(
"$replacement:example.com",
"!room:example.com",
"@user:example.com",
TimelineEventType::RoomEncrypted,
&json!({
"algorithm": "m.megolm.v1.aes-sha2",
"ciphertext": "encrypted_replacement_payload_base64",
"sender_key": "sender_key",
"session_id": "session_id",
"m.relates_to": {
"rel_type": "m.replace",
"event_id": "$original:example.com"
}
// No m.new_content in cleartext - this is valid for encrypted events
}),
None,
);
let result =
super::super::Service::is_valid_replacement_event(&original, &replacement).await;
assert!(result.is_ok(), "Validation should succeed");
assert!(
result.unwrap(),
"Encrypted replacement without cleartext m.new_content should be accepted"
);
}
}