feat: send invites over federation

src/client_server/membership.rs

@@ -5,6 +5,7 @@ use crate::{
     server_server, utils, ConduitResult, Database, Error, Result, Ruma,
 };
 use log::{error, warn};
+use member::{MemberEventContent, MembershipState};
 use rocket::futures;
 use ruma::{
     api::{
@@ -16,16 +17,21 @@ use ruma::{
                 unban_user, IncomingThirdPartySigned,
             },
         },
-        federation,
+        federation::{self, membership::create_invite},
+    },
+    events::{
+        pdu::Pdu,
+        room::{create::CreateEventContent, member},
+        EventType,
     },
-    events::{pdu::Pdu, room::member, EventType},
     serde::{to_canonical_value, CanonicalJsonObject, Raw},
-    EventId, RoomId, RoomVersionId, ServerName, UserId,
+    uint, EventId, RoomId, RoomVersionId, ServerName, UserId,
 };
+use state_res::EventMap;
 use std::{
     collections::{BTreeMap, HashSet},
-    convert::TryFrom,
-    sync::RwLock,
+    convert::{TryFrom, TryInto},
+    sync::{Arc, RwLock},
 };
 
 #[cfg(feature = "conduit_bin")]
@@ -152,35 +158,8 @@ pub async fn invite_user_route(
     let sender_user = body.sender_user.as_ref().expect("user is authenticated");
 
     if let invite_user::IncomingInvitationRecipient::UserId { user_id } = &body.recipient {
-        if body.room_id.server_name() != db.globals.server_name() {
-            return Err(Error::BadRequest(
-                ErrorKind::Forbidden,
-                "Inviting users from other homeservers is not implemented yet.",
-            ));
-        }
-
-        db.rooms.build_and_append_pdu(
-            PduBuilder {
-                event_type: EventType::RoomMember,
-                content: serde_json::to_value(member::MemberEventContent {
-                    membership: member::MembershipState::Invite,
-                    displayname: db.users.displayname(&user_id)?,
-                    avatar_url: db.users.avatar_url(&user_id)?,
-                    is_direct: None,
-                    third_party_invite: None,
-                })
-                .expect("event is valid, we just created it"),
-                unsigned: None,
-                state_key: Some(user_id.to_string()),
-                redacts: None,
-            },
-            &sender_user,
-            &body.room_id,
-            &db,
-        )?;
-
+        invite_helper(sender_user, user_id, &body.room_id, &db, false).await?;
         db.flush().await?;
-
         Ok(invite_user::Response.into())
     } else {
         Err(Error::BadRequest(ErrorKind::NotFound, "User not found."))
@@ -744,3 +723,241 @@ async fn validate_and_add_event_id(
 
     Ok((event_id, value))
 }
+
+pub async fn invite_helper(
+    sender_user: &UserId,
+    user_id: &UserId,
+    room_id: &RoomId,
+    db: &Database,
+    is_direct: bool,
+) -> Result<()> {
+    if user_id.server_name() != db.globals.server_name() {
+        let prev_events = db
+            .rooms
+            .get_pdu_leaves(room_id)?
+            .into_iter()
+            .take(20)
+            .collect::<Vec<_>>();
+
+        let create_event = db
+            .rooms
+            .room_state_get(room_id, &EventType::RoomCreate, "")?;
+
+        let create_event_content = create_event
+            .as_ref()
+            .map(|create_event| {
+                Ok::<_, Error>(
+                    serde_json::from_value::<Raw<CreateEventContent>>(create_event.content.clone())
+                        .expect("Raw::from_value always works.")
+                        .deserialize()
+                        .map_err(|_| Error::bad_database("Invalid PowerLevels event in db."))?,
+                )
+            })
+            .transpose()?;
+
+        let create_prev_event = if prev_events.len() == 1
+            && Some(&prev_events[0]) == create_event.as_ref().map(|c| &c.event_id)
+        {
+            create_event.map(Arc::new)
+        } else {
+            None
+        };
+
+        // If there was no create event yet, assume we are creating a version 6 room right now
+        let room_version = create_event_content.map_or(RoomVersionId::Version6, |create_event| {
+            create_event.room_version
+        });
+
+        let content = serde_json::to_value(MemberEventContent {
+            avatar_url: None,
+            displayname: None,
+            is_direct: Some(is_direct),
+            membership: MembershipState::Invite,
+            third_party_invite: None,
+        })
+        .expect("member event is valid value");
+
+        let state_key = user_id.to_string();
+        let kind = EventType::RoomMember;
+
+        let auth_events =
+            db.rooms
+                .get_auth_events(room_id, &kind, &sender_user, Some(&state_key), &content)?;
+
+        // Our depth is the maximum depth of prev_events + 1
+        let depth = prev_events
+            .iter()
+            .filter_map(|event_id| Some(db.rooms.get_pdu(event_id).ok()??.depth))
+            .max()
+            .unwrap_or_else(|| uint!(0))
+            + uint!(1);
+
+        let mut unsigned = BTreeMap::new();
+
+        if let Some(prev_pdu) = db.rooms.room_state_get(room_id, &kind, &state_key)? {
+            unsigned.insert("prev_content".to_owned(), prev_pdu.content);
+            unsigned.insert(
+                "prev_sender".to_owned(),
+                serde_json::to_value(prev_pdu.sender).expect("UserId::to_value always works"),
+            );
+        }
+
+        let pdu = PduEvent {
+            event_id: ruma::event_id!("$thiswillbefilledinlater"),
+            room_id: room_id.clone(),
+            sender: sender_user.clone(),
+            origin_server_ts: utils::millis_since_unix_epoch()
+                .try_into()
+                .expect("time is valid"),
+            kind,
+            content,
+            state_key: Some(state_key),
+            prev_events,
+            depth,
+            auth_events: auth_events
+                .iter()
+                .map(|(_, pdu)| pdu.event_id.clone())
+                .collect(),
+            redacts: None,
+            unsigned,
+            hashes: ruma::events::pdu::EventHash {
+                sha256: "aaa".to_owned(),
+            },
+            signatures: BTreeMap::new(),
+        };
+
+        let auth_check = state_res::auth_check(
+            &room_version,
+            &Arc::new(pdu.clone()),
+            create_prev_event,
+            &auth_events,
+            None, // TODO: third_party_invite
+        )
+        .map_err(|e| {
+            error!("{:?}", e);
+            Error::bad_database("Auth check failed.")
+        })?;
+
+        if !auth_check {
+            return Err(Error::BadRequest(
+                ErrorKind::InvalidParam,
+                "Event is not authorized.",
+            ));
+        }
+
+        // Hash and sign
+        let mut pdu_json =
+            utils::to_canonical_object(&pdu).expect("event is valid, we just created it");
+
+        pdu_json.remove("event_id");
+
+        // Add origin because synapse likes that (and it's required in the spec)
+        pdu_json.insert(
+            "origin".to_owned(),
+            to_canonical_value(db.globals.server_name())
+                .expect("server name is a valid CanonicalJsonValue"),
+        );
+
+        ruma::signatures::hash_and_sign_event(
+            db.globals.server_name().as_str(),
+            db.globals.keypair(),
+            &mut pdu_json,
+            &room_version,
+        )
+        .expect("event is valid, we just created it");
+
+        let invite_room_state = db.rooms.calculate_invite_state(&pdu)?;
+        let response = db
+            .sending
+            .send_federation_request(
+                &db.globals,
+                user_id.server_name(),
+                create_invite::v2::Request {
+                    room_id: room_id.clone(),
+                    event_id: ruma::event_id!("$receivingservershouldsetthis"),
+                    room_version: RoomVersionId::Version6,
+                    event: PduEvent::convert_to_outgoing_federation_event(pdu_json),
+                    invite_room_state,
+                },
+            )
+            .await?;
+
+        let pub_key_map = RwLock::new(BTreeMap::new());
+        let mut auth_cache = EventMap::new();
+
+        // We do not add the event_id field to the pdu here because of signature and hashes checks
+        let (event_id, value) = match crate::pdu::gen_event_id_canonical_json(&response.event) {
+            Ok(t) => t,
+            Err(_) => {
+                // Event could not be converted to canonical json
+                return Err(Error::BadRequest(
+                    ErrorKind::InvalidParam,
+                    "Could not convert event to canonical json.",
+                ));
+            }
+        };
+
+        let origin = serde_json::from_value::<Box<ServerName>>(
+            serde_json::to_value(value.get("origin").ok_or(Error::BadRequest(
+                ErrorKind::InvalidParam,
+                "Event needs an origin field.",
+            ))?)
+            .expect("CanonicalJson is valid json value"),
+        )
+        .map_err(|_| Error::BadRequest(ErrorKind::InvalidParam, "Origin field is invalid."))?;
+
+        let pdu_id = server_server::handle_incoming_pdu(
+            &origin,
+            &event_id,
+            value,
+            true,
+            &db,
+            &pub_key_map,
+            &mut auth_cache,
+        )
+        .await
+        .map_err(|_| {
+            Error::BadRequest(
+                ErrorKind::InvalidParam,
+                "Error while handling incoming PDU.",
+            )
+        })?
+        .ok_or(Error::BadRequest(
+            ErrorKind::InvalidParam,
+            "Could not accept incoming PDU as timeline event.",
+        ))?;
+
+        for server in db
+            .rooms
+            .room_servers(room_id)
+            .filter_map(|r| r.ok())
+            .filter(|server| &**server != db.globals.server_name())
+        {
+            db.sending.send_pdu(&server, &pdu_id)?;
+        }
+
+        return Ok(());
+    }
+
+    db.rooms.build_and_append_pdu(
+        PduBuilder {
+            event_type: EventType::RoomMember,
+            content: serde_json::to_value(member::MemberEventContent {
+                membership: member::MembershipState::Invite,
+                displayname: db.users.displayname(&user_id)?,
+                avatar_url: db.users.avatar_url(&user_id)?,
+                is_direct: None,
+                third_party_invite: None,
+            })
+            .expect("event is valid, we just created it"),
+            unsigned: None,
+            state_key: Some(user_id.to_string()),
+            redacts: None,
+        },
+        &sender_user,
+        room_id,
+        &db,
+    )?;
+
+    Ok(())
+}