Implement /federation/v1/invite/{roomID}/{eventID} (#197)

* Implement /federation/v1/invite/{roomID}/{eventID}

* Use NotJSON instead of BadJSON when the JSON couldn't be decoded

src/github.com/matrix-org/dendrite/clientapi/producers/roomserver.go

@@ -78,10 +78,18 @@ func (c *RoomserverProducer) SendEventWithState(state gomatrixserverlib.RespStat
 	return c.SendInputRoomEvents(ires)
 }
 
-// SendInputRoomEvents writes the given input room events to the roomserver input log. The length of both
-// arrays must match, and each element must correspond to the same event.
+// SendInputRoomEvents writes the given input room events to the roomserver input API.
 func (c *RoomserverProducer) SendInputRoomEvents(ires []api.InputRoomEvent) error {
 	request := api.InputRoomEventsRequest{InputRoomEvents: ires}
 	var response api.InputRoomEventsResponse
 	return c.InputAPI.InputRoomEvents(&request, &response)
 }
+
+// SendInvite writes the invite event to the roomserver input API.
+func (c *RoomserverProducer) SendInvite(inviteEvent gomatrixserverlib.Event) error {
+	request := api.InputRoomEventsRequest{
+		InputInviteEvents: []api.InputInviteEvent{{Event: inviteEvent}},
+	}
+	var response api.InputRoomEventsResponse
+	return c.InputAPI.InputRoomEvents(&request, &response)
+}

src/github.com/matrix-org/dendrite/federationapi/routing/routing.go

@@ -57,7 +57,7 @@ func Setup(
 	v2keysmux.Handle("/server/{keyID}", localKeys)
 	v2keysmux.Handle("/server/", localKeys)
 
-	v1fedmux.Handle("/send/{txnID}/", makeAPI("send",
+	v1fedmux.Handle("/send/{txnID}/", makeAPI("federation_send",
 		func(req *http.Request) util.JSONResponse {
 			vars := mux.Vars(req)
 			return writers.Send(
@@ -67,6 +67,17 @@ func Setup(
 			)
 		},
 	))
+
+	v1fedmux.Handle("/invite/{roomID}/{eventID}", makeAPI("federation_invite",
+		func(req *http.Request) util.JSONResponse {
+			vars := mux.Vars(req)
+			return writers.Invite(
+				req, vars["roomID"], vars["eventID"],
+				time.Now(),
+				cfg, producer, keys,
+			)
+		},
+	))
 }
 
 func makeAPI(metricsName string, f func(*http.Request) util.JSONResponse) http.Handler {

src/github.com/matrix-org/dendrite/federationapi/writers/invite.go

@@ -0,0 +1,98 @@
+package writers
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"github.com/matrix-org/util"
+
+	"github.com/matrix-org/dendrite/clientapi/httputil"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/clientapi/producers"
+	"github.com/matrix-org/dendrite/common/config"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// Invite implements /_matrix/federation/v1/invite/{roomID}/{eventID}
+func Invite(
+	req *http.Request,
+	roomID string,
+	eventID string,
+	now time.Time,
+	cfg config.Dendrite,
+	producer *producers.RoomserverProducer,
+	keys gomatrixserverlib.KeyRing,
+) util.JSONResponse {
+	request, errResp := gomatrixserverlib.VerifyHTTPRequest(req, now, cfg.Matrix.ServerName, keys)
+	if request == nil {
+		return errResp
+	}
+
+	// Decode the event JSON from the request.
+	var event gomatrixserverlib.Event
+	if err := json.Unmarshal(request.Content(), &event); err != nil {
+		return util.JSONResponse{
+			Code: 400,
+			JSON: jsonerror.NotJSON("The request body could not be decoded into valid JSON. " + err.Error()),
+		}
+	}
+
+	// Check that the room ID is correct.
+	if event.RoomID() != roomID {
+		return util.JSONResponse{
+			Code: 400,
+			JSON: jsonerror.BadJSON("The room ID in the request path must match the room ID in the invite event JSON"),
+		}
+	}
+
+	// Check that the event ID is correct.
+	if event.EventID() != eventID {
+		return util.JSONResponse{
+			Code: 400,
+			JSON: jsonerror.BadJSON("The event ID in the request path must match the event ID in the invite event JSON"),
+		}
+	}
+
+	// Check that the event is from the server sending the request.
+	if event.Origin() != request.Origin() {
+		return util.JSONResponse{
+			Code: 403,
+			JSON: jsonerror.Forbidden("The invite must be sent by the server it originated on"),
+		}
+	}
+
+	// Check that the event is signed by the server sending the request.
+	verifyRequests := []gomatrixserverlib.VerifyJSONRequest{{
+		ServerName: event.Origin(),
+		Message:    event.JSON(),
+		AtTS:       event.OriginServerTS(),
+	}}
+	verifyResults, err := keys.VerifyJSONs(verifyRequests)
+	if err != nil {
+		return httputil.LogThenError(req, err)
+	}
+	if verifyResults[0].Error != nil {
+		return util.JSONResponse{
+			Code: 403,
+			JSON: jsonerror.Forbidden("The invite must be signed by the server it originated on"),
+		}
+	}
+
+	// Sign the event so that other servers will know that we have received the invite.
+	signedEvent := event.Sign(
+		string(cfg.Matrix.ServerName), cfg.Matrix.KeyID, cfg.Matrix.PrivateKey,
+	)
+
+	// Add the invite event to the roomserver.
+	if err = producer.SendInvite(signedEvent); err != nil {
+		return httputil.LogThenError(req, err)
+	}
+
+	// Return the signed event to the originating server, it should then tell
+	// the other servers in the room that we have been invited.
+	return util.JSONResponse{
+		Code: 200,
+		JSON: &signedEvent,
+	}
+}

src/github.com/matrix-org/dendrite/federationapi/writers/send.go

@@ -3,6 +3,9 @@ package writers
 import (
 	"encoding/json"
 	"fmt"
+	"net/http"
+	"time"
+
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
@@ -10,8 +13,6 @@ import (
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
-	"net/http"
-	"time"
 )
 
 // Send implements /_matrix/federation/v1/send/{txnID}
@@ -39,7 +40,7 @@ func Send(
 	if err := json.Unmarshal(request.Content(), &t); err != nil {
 		return util.JSONResponse{
 			Code: 400,
-			JSON: jsonerror.BadJSON("The request body could not be decoded into valid JSON. " + err.Error()),
+			JSON: jsonerror.NotJSON("The request body could not be decoded into valid JSON. " + err.Error()),
 		}
 	}