Move /send_leave to GMSL

handleleave.go

@@ -15,9 +15,11 @@
 package gomatrixserverlib
 
 import (
+	"context"
 	"fmt"
 
 	"github.com/matrix-org/gomatrixserverlib/spec"
+	"github.com/matrix-org/util"
 )
 
 type HandleMakeLeaveResponse struct {
@@ -39,6 +41,7 @@
 	BuildEventTemplate func(*ProtoEvent) (PDU, []PDU, error)
 }
 
+// HandleMakeLeave handles requests to `/make_leave`
 func HandleMakeLeave(input HandleMakeLeaveInput) (*HandleMakeLeaveResponse, error) {
 
 	if input.UserID.Domain() != input.RequestOrigin {
@@ -100,3 +103,124 @@
 	}
 	return &makeLeaveResponse, nil
 }
+
+type CurrentStateQuerier interface {
+	CurrentStateEvent(ctx context.Context, roomID spec.RoomID, eventType string, stateKey string) (PDU, error)
+}
+
+// HandleSendLeave handles requests to `/send_leave
+// Returns the parsed event or an error.
+func HandleSendLeave(ctx context.Context,
+	content []byte,
+	origin spec.ServerName,
+	roomVersion RoomVersion,
+	eventID, roomID string,
+	querier CurrentStateQuerier,
+	verifier JSONVerifier,
+) (PDU, error) {
+
+	rID, err := spec.NewRoomID(roomID)
+	if err != nil {
+		return nil, err
+	}
+
+	verImpl, err := GetRoomVersion(roomVersion)
+	if err != nil {
+		return nil, spec.UnsupportedRoomVersion(fmt.Sprintf("Room version %s is not supported by this server", roomVersion))
+	}
+
+	event, err := verImpl.NewEventFromUntrustedJSON(content)
+	switch err.(type) {
+	case BadJSONError:
+		return nil, spec.BadJSON(err.Error())
+	case nil:
+	default:
+		return nil, spec.NotJSON("The request body could not be decoded into valid JSON. " + err.Error())
+	}
+
+	// Check that the room ID is correct.
+	if event.RoomID().String() != roomID {
+		return nil, spec.BadJSON("The room ID in the request path must match the room ID in the leave event JSON")
+	}
+
+	// Check that the event ID is correct.
+	if event.EventID() != eventID {
+		return nil, spec.BadJSON("The event ID in the request path must match the event ID in the leave event JSON")
+	}
+
+	// Sanity check that we really received a state event
+	if event.StateKey() == nil || event.StateKeyEquals("") {
+		return nil, spec.BadJSON("No state key was provided in the leave event.")
+	}
+	if !event.StateKeyEquals(event.SenderID().ToUserID().String()) {
+		return nil, spec.BadJSON("Event state key must match the event sender.")
+	}
+
+	// check membership is set to leave
+	mem, err := event.Membership()
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Error("event.Membership failed")
+		return nil, spec.BadJSON("missing content.membership key")
+	}
+	if mem != spec.Leave {
+		return nil, spec.BadJSON("The membership in the event content must be set to leave")
+	}
+
+	leavingUser, err := spec.NewUserID(*event.StateKey(), true)
+	if err != nil {
+		return nil, spec.Forbidden("The leaving user ID is invalid")
+	}
+
+	// Check that the sender belongs to the server that is sending us
+	// the request. By this point we've already asserted that the sender
+	// and the state key are equal so we don't need to check both.
+	sender, err := spec.NewUserID(event.SenderID().ToUserID().String(), true)
+	if err != nil {
+		return nil, spec.Forbidden("The sender of the join is invalid")
+	}
+	if sender.Domain() != origin {
+		return nil, spec.Forbidden("The sender does not match the server that originated the request")
+	}
+
+	// Check the current membership of this user and
+	// if we maybe can just no-op this request.
+	stateEvent, err := querier.CurrentStateEvent(ctx, *rID, spec.MRoomMember, leavingUser.String())
+	if err != nil {
+		return nil, err
+	}
+	// The user isn't joined at all
+	if stateEvent == nil {
+		return nil, nil
+	}
+	// The user has already left.
+	if mem, merr := stateEvent.Membership(); merr == nil && mem == spec.Leave {
+		return nil, nil
+	}
+	// we already processed this event
+	if event.EventID() == stateEvent.EventID() {
+		return nil, nil
+	}
+
+	// Check that the event is signed by the server sending the request.
+	redacted, err := verImpl.RedactEventJSON(event.JSON())
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Errorf("unable to redact event")
+		return nil, spec.BadJSON("The event JSON could not be redacted")
+	}
+	verifyRequests := []VerifyJSONRequest{{
+		ServerName:           sender.Domain(),
+		Message:              redacted,
+		AtTS:                 event.OriginServerTS(),
+		ValidityCheckingFunc: StrictValiditySignatureCheck,
+	}}
+	verifyResults, err := verifier.VerifyJSONs(ctx, verifyRequests)
+	if err != nil {
+		util.GetLogger(ctx).WithError(err).Error("keys.VerifyJSONs failed")
+		return nil, spec.InternalServerError{}
+	}
+	if verifyResults[0].Error != nil {
+		return nil, spec.Forbidden("The leave must be signed by the server it originated on")
+	}
+
+	return event, nil
+}

handleleave_test.go

@@ -1,6 +1,7 @@
 package gomatrixserverlib
 
 import (
+	"context"
 	"crypto/rand"
 	"fmt"
 	"testing"
@@ -228,3 +229,177 @@ func TestHandleMakeLeave(t *testing.T) {
 		})
 	}
 }
+
+type dummyQuerier struct {
+	pdu PDU
+}
+
+func (d dummyQuerier) CurrentStateEvent(ctx context.Context, roomID spec.RoomID, eventType string, stateKey string) (PDU, error) {
+	return d.pdu, nil
+}
+
+type noopJSONVerifier struct {
+	err     error
+	results []VerifyJSONResult
+}
+
+func (v *noopJSONVerifier) VerifyJSONs(ctx context.Context, requests []VerifyJSONRequest) ([]VerifyJSONResult, error) {
+	return v.results, v.err
+}
+
+func TestHandleSendLeave(t *testing.T) {
+	type args struct {
+		ctx            context.Context
+		requestContent []byte
+		origin         spec.ServerName
+		roomVersion    RoomVersion
+		eventID        string
+		roomID         string
+		querier        CurrentStateQuerier
+		verifier       JSONVerifier
+	}
+
+	_, sk, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("Failed generating key: %v", err)
+	}
+	keyID := KeyID("ed25519:1234")
+
+	validUser, _ := spec.NewUserID("@valid:localhost", true)
+
+	stateKey := ""
+	eb := MustGetRoomVersion(RoomVersionV10).NewEventBuilderFromProtoEvent(&ProtoEvent{
+		SenderID:   validUser.String(),
+		RoomID:     "!valid:localhost",
+		Type:       spec.MRoomCreate,
+		StateKey:   &stateKey,
+		PrevEvents: []interface{}{},
+		AuthEvents: []interface{}{},
+		Depth:      0,
+		Content:    spec.RawJSON(`{"creator":"@user:local","m.federate":true,"room_version":"10"}`),
+		Unsigned:   spec.RawJSON(""),
+	})
+	createEvent, err := eb.Build(time.Now(), "localhost", keyID, sk)
+	if err != nil {
+		t.Fatalf("Failed building create event: %v", err)
+	}
+
+	stateKey = validUser.String()
+	eb = MustGetRoomVersion(RoomVersionV10).NewEventBuilderFromProtoEvent(&ProtoEvent{
+		SenderID:   validUser.String(),
+		RoomID:     "!valid:localhost",
+		Type:       spec.MRoomMember,
+		StateKey:   &stateKey,
+		PrevEvents: []interface{}{},
+		AuthEvents: []interface{}{},
+		Depth:      0,
+		Content:    spec.RawJSON(`{"membership":"leave"}`),
+		Unsigned:   spec.RawJSON(""),
+	})
+	leaveEvent, err := eb.Build(time.Now(), "localhost", keyID, sk)
+	if err != nil {
+		t.Fatalf("Failed building create event: %v", err)
+	}
+
+	eb = MustGetRoomVersion(RoomVersionV10).NewEventBuilderFromProtoEvent(&ProtoEvent{
+		SenderID:   validUser.String(),
+		RoomID:     "!valid:localhost",
+		Type:       spec.MRoomMember,
+		StateKey:   &stateKey,
+		PrevEvents: []interface{}{},
+		AuthEvents: []interface{}{},
+		Depth:      0,
+		Content:    spec.RawJSON(`{"membership":"join"}`),
+		Unsigned:   spec.RawJSON(""),
+	})
+	joinEvent, err := eb.Build(time.Now(), "localhost", keyID, sk)
+	if err != nil {
+		t.Fatalf("Failed building create event: %v", err)
+	}
+
+	tests := []struct {
+		name    string
+		args    args
+		want    PDU
+		wantErr assert.ErrorAssertionFunc
+	}{
+		{
+			name:    "invalid roomID",
+			args:    args{roomID: "@notvalid:localhost"},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "invalid room version",
+			args:    args{roomID: "!notvalid:localhost", roomVersion: "-1"},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "invalid content body",
+			args:    args{roomID: "!notvalid:localhost", roomVersion: RoomVersionV1, requestContent: []byte("{")},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "not canonical JSON",
+			args:    args{roomID: "!notvalid:localhost", roomVersion: RoomVersionV10, requestContent: []byte(`{"int":9007199254740992}`)}, // number to large, not canonical json
+			wantErr: assert.Error,
+		},
+		{
+			name:    "wrong roomID in request",
+			args:    args{roomID: "!notvalid:localhost", roomVersion: RoomVersionV10, requestContent: createEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "wrong eventID in request",
+			args:    args{roomID: "!valid:localhost", roomVersion: RoomVersionV10, requestContent: createEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "empty statekey",
+			args:    args{roomID: "!valid:localhost", roomVersion: RoomVersionV10, eventID: createEvent.EventID(), requestContent: createEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "wrong request origin",
+			args:    args{roomID: "!valid:localhost", roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "never joined the room no-ops",
+			args:    args{roomID: "!valid:localhost", querier: dummyQuerier{}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.NoError,
+		},
+		{
+			name:    "already left the room no-ops",
+			args:    args{roomID: "!valid:localhost", querier: dummyQuerier{pdu: leaveEvent}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.NoError,
+		},
+		{
+			name:    "JSON validation fails",
+			args:    args{ctx: context.Background(), roomID: "!valid:localhost", querier: dummyQuerier{pdu: createEvent}, verifier: &noopJSONVerifier{err: fmt.Errorf("err")}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "JSON validation fails 2",
+			args:    args{ctx: context.Background(), roomID: "!valid:localhost", querier: dummyQuerier{pdu: createEvent}, verifier: &noopJSONVerifier{results: []VerifyJSONResult{{Error: fmt.Errorf("err")}}}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "membership not set to leave",
+			args:    args{ctx: context.Background(), roomID: "!valid:localhost", querier: dummyQuerier{pdu: createEvent}, verifier: &noopJSONVerifier{results: []VerifyJSONResult{{}}}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: joinEvent.EventID(), requestContent: joinEvent.JSON()},
+			wantErr: assert.Error,
+		},
+		{
+			name:    "membership set to leave",
+			args:    args{ctx: context.Background(), roomID: "!valid:localhost", querier: dummyQuerier{pdu: createEvent}, verifier: &noopJSONVerifier{results: []VerifyJSONResult{{}}}, origin: validUser.Domain(), roomVersion: RoomVersionV10, eventID: leaveEvent.EventID(), requestContent: leaveEvent.JSON()},
+			wantErr: assert.NoError,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := HandleSendLeave(tt.args.ctx, tt.args.requestContent, tt.args.origin, tt.args.roomVersion, tt.args.eventID, tt.args.roomID, tt.args.querier, tt.args.verifier)
+			if !tt.wantErr(t, err, fmt.Sprintf("HandleSendLeave(%v, %v, %v, %v, %v, %v, %v, %v)", tt.args.ctx, tt.args.requestContent, tt.args.origin, tt.args.roomVersion, tt.args.eventID, tt.args.roomID, tt.args.querier, tt.args.verifier)) {
+				return
+			}
+		})
+	}
+}