Update gomatrixserverlib

vendor/manifest

@@ -98,7 +98,7 @@
 		{
 			"importpath": "github.com/matrix-org/gomatrixserverlib",
 			"repository": "https://github.com/matrix-org/gomatrixserverlib",
-			"revision": "785a53c41170526aa7a91a1fc534afac6ce01a9b",
+			"revision": "9cefcd6c3a00bff51e719a33e19a16edf52cdd6f",
 			"branch": "master"
 		},
 		{

vendor/src/github.com/matrix-org/gomatrixserverlib/clientevent.go

@@ -30,7 +30,7 @@ const (
 type ClientEvent struct {
 	Content        rawJSON   `json:"content"`
 	EventID        string    `json:"event_id"`
-	OriginServerTS int64   `json:"origin_server_ts"`
+	OriginServerTS Timestamp `json:"origin_server_ts"`
 	// RoomID is omitted on /sync responses
 	RoomID   string  `json:"room_id,omitempty"`
 	Sender   string  `json:"sender"`

vendor/src/github.com/matrix-org/gomatrixserverlib/event.go

@@ -103,7 +103,8 @@ type eventFields struct {
 	Redacts        string           `json:"redacts"`
 	Depth          int64            `json:"depth"`
 	Unsigned       rawJSON          `json:"unsigned"`
-	OriginServerTS int64            `json:"origin_server_ts"`
+	OriginServerTS Timestamp        `json:"origin_server_ts"`
+	Origin         ServerName       `json:"origin"`
 }
 
 var emptyEventReferenceList = []EventReference{}
@@ -145,8 +146,6 @@ func (eb *EventBuilder) Build(eventID string, now time.Time, origin ServerName,
 		event.PrevState = &emptyEventReferenceList
 	}
 
-	// TODO: Check size limits.
-
 	var eventJSON []byte
 
 	if eventJSON, err = json.Marshal(&event); err != nil {
@@ -166,7 +165,14 @@ func (eb *EventBuilder) Build(eventID string, now time.Time, origin ServerName,
 	}
 
 	result.eventJSON = eventJSON
-	err = json.Unmarshal(eventJSON, &result.fields)
+	if err = json.Unmarshal(eventJSON, &result.fields); err != nil {
+		return
+	}
+
+	if err = result.CheckFields(); err != nil {
+		return
+	}
+
 	return
 }
 
@@ -185,9 +191,6 @@ func NewEventFromUntrustedJSON(eventJSON []byte) (result Event, err error) {
 	delete(event, "destinations")
 	delete(event, "age_ts")
 
-	// TODO: Check that the event fields are correctly defined.
-	// TODO: Check size limits.
-
 	if eventJSON, err = json.Marshal(event); err != nil {
 		return
 	}
@@ -206,7 +209,14 @@ func NewEventFromUntrustedJSON(eventJSON []byte) (result Event, err error) {
 	}
 
 	result.eventJSON = eventJSON
-	err = json.Unmarshal(eventJSON, &result.fields)
+	if err = json.Unmarshal(eventJSON, &result.fields); err != nil {
+		return
+	}
+
+	if err = result.CheckFields(); err != nil {
+		return
+	}
+
 	return
 }
 
@@ -303,6 +313,125 @@ func (e Event) StateKeyEquals(stateKey string) bool {
 	return *e.fields.StateKey == stateKey
 }
 
+const (
+	// The event ID, room ID, sender, event type and state key fields cannot be
+	// bigger than this.
+	// https://github.com/matrix-org/synapse/blob/v0.21.0/synapse/event_auth.py#L173-L182
+	maxIDLength = 255
+	// The entire event JSON, including signatures cannot be bigger than this.
+	// https://github.com/matrix-org/synapse/blob/v0.21.0/synapse/event_auth.py#L183-184
+	maxEventLength = 65536
+)
+
+// CheckFields checks that the event fields are valid.
+// Returns an error if the IDs have the wrong format or too long.
+// Returns an error if the total length of the event JSON is too long.
+// Returns an error if the event ID doesn't match the origin of the event.
+// https://matrix.org/docs/spec/client_server/r0.2.0.html#size-limits
+func (e Event) CheckFields() error {
+	if len(e.eventJSON) > maxEventLength {
+		return fmt.Errorf(
+			"gomatrixserverlib: event is too long, length %d > maximum %d",
+			len(e.eventJSON), maxEventLength,
+		)
+	}
+
+	if len(e.fields.Type) > maxIDLength {
+		return fmt.Errorf(
+			"gomatrixserverlib: event type is too long, length %d > maximum %d",
+			len(e.fields.Type), maxIDLength,
+		)
+	}
+
+	if e.fields.StateKey != nil && len(*e.fields.StateKey) > maxIDLength {
+		return fmt.Errorf(
+			"gomatrixserverlib: state key is too long, length %d > maximum %d",
+			len(*e.fields.StateKey), maxIDLength,
+		)
+	}
+
+	_, err := checkID(e.fields.RoomID, "room", '!')
+	if err != nil {
+		return err
+	}
+
+	senderDomain, err := checkID(e.fields.Sender, "user", '@')
+	if err != nil {
+		return err
+	}
+
+	eventDomain, err := checkID(e.fields.EventID, "event", '$')
+	if err != nil {
+		return err
+	}
+
+	// Synapse requires that the event ID domain has a valid signature.
+	// https://github.com/matrix-org/synapse/blob/v0.21.0/synapse/event_auth.py#L66-L68
+	// Synapse requires that the event origin has a valid signature.
+	// https://github.com/matrix-org/synapse/blob/v0.21.0/synapse/federation/federation_base.py#L133-L136
+	// Since both domains must be valid domains, and there is no good reason for them
+	// to be different we might as well ensure that they are the same since it
+	// makes the signature checks simpler.
+	if e.fields.Origin != ServerName(eventDomain) {
+		return fmt.Errorf(
+			"gomatrixserverlib: event ID domain doesn't match origin: %q != %q",
+			eventDomain, e.fields.Origin,
+		)
+	}
+
+	if eventDomain != senderDomain {
+		// For the most part all events should be sent by a user on the
+		// originating server
+		// However "m.room.member" events created from third-party invites
+		// are allowed to have a different sender because they have the same
+		// sender as the "m.room.third_party_invite" event they derived from.
+		// https://github.com/matrix-org/synapse/blob/v0.21.0/synapse/event_auth.py#L58-L64
+		if e.fields.Type != "m.room.member" {
+			return fmt.Errorf(
+				"gomatrixserverlib: sender domain doesn't match origin: %q != %q",
+				eventDomain, e.fields.Origin,
+			)
+		}
+		c, err := newMemberContentFromEvent(e)
+		if err != nil {
+			return err
+		}
+		if c.Membership != invite || c.ThirdPartyInvite == nil {
+			return fmt.Errorf(
+				"gomatrixserverlib: sender domain doesn't match origin: %q != %q",
+				eventDomain, e.fields.Origin,
+			)
+		}
+	}
+
+	return nil
+}
+
+func checkID(id, kind string, sigil byte) (domain string, err error) {
+	domain, err = domainFromID(id)
+	if err != nil {
+		return
+	}
+	if id[0] != sigil {
+		err = fmt.Errorf(
+			"gomatrixserverlib: invalid %s ID, wanted first byte to be '%c' got '%c'",
+			kind, sigil, id[0],
+		)
+		return
+	}
+	if len(id) > maxIDLength {
+		err = fmt.Errorf(
+			"gomatrixserverlib: %s ID is too long, length %d > maximum %d",
+			kind, len(id), maxIDLength,
+		)
+		return
+	}
+	return
+}
+
+// Origin returns the name of the server that sent the event
+func (e Event) Origin() ServerName { return e.fields.Origin }
+
 // EventID returns the event ID of the event.
 func (e Event) EventID() string {
 	return e.fields.EventID
@@ -319,7 +448,7 @@ func (e Event) Type() string {
 }
 
 // OriginServerTS returns the unix timestamp when this event was created on the origin server, with millisecond resolution.
-func (e Event) OriginServerTS() int64 {
+func (e Event) OriginServerTS() Timestamp {
 	return e.fields.OriginServerTS
 }
 

vendor/src/github.com/matrix-org/gomatrixserverlib/eventauth.go

@@ -247,7 +247,7 @@ type AuthEvents struct {
 // the event is replaced with the new event. Only returns an error if the event is not a state event.
 func (a *AuthEvents) AddEvent(event *Event) error {
 	if event.StateKey() == nil {
-		return fmt.Errorf("AddEvent: event %s does not have a state key", event.Type())
+		return fmt.Errorf("AddEvent: event %q does not have a state key", event.Type())
 	}
 	a.events[StateKeyTuple{event.Type(), *event.StateKey()}] = event
 	return nil

vendor/src/github.com/matrix-org/gomatrixserverlib/eventcrypto.go

@@ -184,3 +184,55 @@ func verifyEventSignature(signingName string, keyID KeyID, publicKey ed25519.Pub
 
 	return VerifyJSON(signingName, keyID, publicKey, redactedJSON)
 }
+
+// VerifyEventSignatures checks that each event in a list of events has valid
+// signatures from the server that sent it.
+func VerifyEventSignatures(events []Event, keyRing KeyRing) error {
+	var toVerify []VerifyJSONRequest
+	for _, event := range events {
+		redactedJSON, err := redactEvent(event.eventJSON)
+		if err != nil {
+			return err
+		}
+		v := VerifyJSONRequest{
+			Message:    redactedJSON,
+			AtTS:       event.OriginServerTS(),
+			ServerName: event.Origin(),
+		}
+		toVerify = append(toVerify, v)
+
+		// "m.room.member" invite events are signed by both the server sending
+		// the invite and the server the invite is for.
+		if event.Type() == "m.room.member" && event.StateKey() != nil {
+			targetDomain, err := domainFromID(*event.StateKey())
+			if err != nil {
+				return err
+			}
+			if ServerName(targetDomain) != event.Origin() {
+				c, err := newMemberContentFromEvent(event)
+				if err != nil {
+					return err
+				}
+				if c.Membership == invite {
+					v.ServerName = ServerName(targetDomain)
+					toVerify = append(toVerify, v)
+				}
+			}
+		}
+	}
+
+	results, err := keyRing.VerifyJSONs(toVerify)
+	if err != nil {
+		return err
+	}
+
+	// Check that all the event JSON was correctly signed.
+	for _, result := range results {
+		if result.Error != nil {
+			return result.Error
+		}
+	}
+
+	// Everything was okay.
+	return nil
+}

vendor/src/github.com/matrix-org/gomatrixserverlib/federationtypes.go

@@ -34,6 +34,53 @@ type RespState struct {
 	AuthEvents []Event `json:"auth_chain"`
 }
 
+// Check that a response to /state is valid.
+func (r RespState) Check(keyRing KeyRing) error {
+	var allEvents []Event
+	for _, event := range r.AuthEvents {
+		if event.StateKey() == nil {
+			return fmt.Errorf("gomatrixserverlib: event %q does not have a state key", event.EventID())
+		}
+		allEvents = append(allEvents, event)
+	}
+
+	stateTuples := map[StateKeyTuple]bool{}
+	for _, event := range r.StateEvents {
+		if event.StateKey() == nil {
+			return fmt.Errorf("gomatrixserverlib: event %q does not have a state key", event.EventID())
+		}
+		stateTuple := StateKeyTuple{event.Type(), *event.StateKey()}
+		if stateTuples[stateTuple] {
+			return fmt.Errorf(
+				"gomatrixserverlib: duplicate state key tuple (%q, %q)",
+				event.Type(), *event.StateKey(),
+			)
+		}
+		stateTuples[stateTuple] = true
+		allEvents = append(allEvents, event)
+	}
+
+	// Check if the events pass signature checks.
+	if err := VerifyEventSignatures(allEvents, keyRing); err != nil {
+		return nil
+	}
+
+	eventsByID := map[string]*Event{}
+	// Collect a map of event reference to event
+	for i := range allEvents {
+		eventsByID[allEvents[i].EventID()] = &allEvents[i]
+	}
+
+	// Check whether the events are allowed by the auth rules.
+	for _, event := range allEvents {
+		if err := checkAllowedByAuthEvents(event, eventsByID); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // A RespMakeJoin is the content of a response to GET /_matrix/federation/v1/make_join/{roomID}/{userID}
 type RespMakeJoin struct {
 	// An incomplete m.room.member event for a user on the requesting server
@@ -43,6 +90,7 @@ type RespMakeJoin struct {
 }
 
 // A RespSendJoin is the content of a response to PUT /_matrix/federation/v1/send_join/{roomID}/{eventID}
+// It has the same data as a response to /state, but in a slightly different wire format.
 type RespSendJoin RespState
 
 // MarshalJSON implements json.Marshaller
@@ -93,6 +141,43 @@ type respSendJoinFields struct {
 	AuthEvents  []Event `json:"auth_chain"`
 }
 
+// Check that a reponse to /send_join is valid.
+// This checks that it would be valid as a response to /state
+// This also checks that the join event is allowed by the state.
+func (r RespSendJoin) Check(keyRing KeyRing, joinEvent Event) error {
+	// First check that the state is valid.
+	// The response to /send_join has the same data as a response to /state
+	// and the checks for a response to /state also apply.
+	if err := RespState(r).Check(keyRing); err != nil {
+		return err
+	}
+
+	stateEventsByID := map[string]*Event{}
+	authEvents := NewAuthEvents(nil)
+	for i, event := range r.StateEvents {
+		stateEventsByID[event.EventID()] = &r.StateEvents[i]
+		if err := authEvents.AddEvent(&r.StateEvents[i]); err != nil {
+			return err
+		}
+	}
+
+	// Now check that the join event is valid against its auth events.
+	if err := checkAllowedByAuthEvents(joinEvent, stateEventsByID); err != nil {
+		return err
+	}
+
+	// Now check that the join event is valid against the supplied state.
+	if err := Allowed(joinEvent, &authEvents); err != nil {
+		return fmt.Errorf(
+			"gomatrixserverlib: event with ID %q is not allowed by the supplied state: %s",
+			joinEvent.EventID(), err.Error(),
+		)
+
+	}
+
+	return nil
+}
+
 // A RespDirectory is the content of a response to GET  /_matrix/federation/v1/query/directory
 // This is returned when looking up a room alias from a remote server.
 // See https://matrix.org/docs/spec/server_server/unstable.html#directory
@@ -104,3 +189,26 @@ type RespDirectory struct {
 	// before it finds one that it can use to join the room.
 	Servers []ServerName `json:"servers"`
 }
+
+func checkAllowedByAuthEvents(event Event, eventsByID map[string]*Event) error {
+	authEvents := NewAuthEvents(nil)
+	for _, authRef := range event.AuthEvents() {
+		authEvent := eventsByID[authRef.EventID]
+		if authEvent == nil {
+			return fmt.Errorf(
+				"gomatrixserverlib: missing auth event with ID %q for event %q",
+				authRef.EventID, event.EventID(),
+			)
+		}
+		if err := authEvents.AddEvent(authEvent); err != nil {
+			return err
+		}
+	}
+	if err := Allowed(event, &authEvents); err != nil {
+		return fmt.Errorf(
+			"gomatrixserverlib: event with ID %q is not allowed by its auth_events: %s",
+			event.EventID(), err.Error(),
+		)
+	}
+	return nil
+}

vendor/src/github.com/matrix-org/gomatrixserverlib/keyring.go

@@ -58,7 +58,7 @@ type VerifyJSONResult struct {
 	// Whether the message passed the signature checks.
 	// This will be nil if the message passed the checks.
 	// This will have an error if the message did not pass the checks.
-	Result error
+	Error error
 }
 
 // VerifyJSONs performs bulk JSON signature verification for a list of VerifyJSONRequests.
@@ -73,7 +73,7 @@ func (k *KeyRing) VerifyJSONs(requests []VerifyJSONRequest) ([]VerifyJSONResult,
 	for i := range requests {
 		ids, err := ListKeyIDs(string(requests[i].ServerName), requests[i].Message)
 		if err != nil {
-			results[i].Result = fmt.Errorf("gomatrixserverlib: error extracting key IDs")
+			results[i].Error = fmt.Errorf("gomatrixserverlib: error extracting key IDs")
 			continue
 		}
 		for _, keyID := range ids {
@@ -82,7 +82,7 @@ func (k *KeyRing) VerifyJSONs(requests []VerifyJSONRequest) ([]VerifyJSONResult,
 			}
 		}
 		if len(keyIDs[i]) == 0 {
-			results[i].Result = fmt.Errorf(
+			results[i].Error = fmt.Errorf(
 				"gomatrixserverlib: not signed by %q with a supported algorithm", requests[i].ServerName,
 			)
 			continue
@@ -91,7 +91,7 @@ func (k *KeyRing) VerifyJSONs(requests []VerifyJSONRequest) ([]VerifyJSONResult,
 		// This will be unset if one of the signature checks passes.
 		// This will be overwritten if one of the signature checks fails.
 		// Therefore this will only remain in place if the keys couldn't be downloaded.
-		results[i].Result = fmt.Errorf(
+		results[i].Error = fmt.Errorf(
 			"gomatrixserverlib: could not download key for %q", requests[i].ServerName,
 		)
 	}
@@ -139,7 +139,7 @@ func (k *KeyRing) isAlgorithmSupported(keyID KeyID) bool {
 func (k *KeyRing) publicKeyRequests(requests []VerifyJSONRequest, results []VerifyJSONResult, keyIDs [][]KeyID) map[PublicKeyRequest]Timestamp {
 	keyRequests := map[PublicKeyRequest]Timestamp{}
 	for i := range requests {
-		if results[i].Result == nil {
+		if results[i].Error == nil {
 			// We've already verified this message, we don't need to refetch the keys for it.
 			continue
 		}
@@ -165,7 +165,7 @@ func (k *KeyRing) checkUsingKeys(
 	keys map[PublicKeyRequest]ServerKeys,
 ) {
 	for i := range requests {
-		if results[i].Result == nil {
+		if results[i].Error == nil {
 			// We've already checked this message and it passed the signature checks.
 			// So we can skip to the next message.
 			continue
@@ -180,7 +180,7 @@ func (k *KeyRing) checkUsingKeys(
 			if publicKey == nil {
 				// The key wasn't valid at the timestamp we needed it to be valid at.
 				// So skip onto the next key.
-				results[i].Result = fmt.Errorf(
+				results[i].Error = fmt.Errorf(
 					"gomatrixserverlib: key with ID %q for %q not valid at %d",
 					keyID, requests[i].ServerName, requests[i].AtTS,
 				)
@@ -190,11 +190,11 @@ func (k *KeyRing) checkUsingKeys(
 				string(requests[i].ServerName), keyID, ed25519.PublicKey(publicKey), requests[i].Message,
 			); err != nil {
 				// The signature wasn't valid, record the error and try the next key ID.
-				results[i].Result = err
+				results[i].Error = err
 				continue
 			}
 			// The signature is valid, set the result to nil.
-			results[i].Result = nil
+			results[i].Error = nil
 			break
 		}
 	}

vendor/src/github.com/matrix-org/gomatrixserverlib/keyring_test.go

@@ -70,8 +70,8 @@ func TestVerifyJSONsSuccess(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(results) != 1 || results[0].Result != nil {
+	if len(results) != 1 || results[0].Error != nil {
-		t.Fatalf("VerifyJSON(): Wanted [{Result: nil}] got %#v", results)
+		t.Fatalf("VerifyJSON(): Wanted [{Error: nil}] got %#v", results)
 	}
 }
 
@@ -86,8 +86,8 @@ func TestVerifyJSONsUnknownServerFails(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(results) != 1 || results[0].Result == nil {
+	if len(results) != 1 || results[0].Error == nil {
-		t.Fatalf("VerifyJSON(): Wanted [{Result: <some error>}] got %#v", results)
+		t.Fatalf("VerifyJSON(): Wanted [{Error: <some error>}] got %#v", results)
 	}
 }
 
@@ -103,8 +103,8 @@ func TestVerifyJSONsDistantFutureFails(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(results) != 1 || results[0].Result == nil {
+	if len(results) != 1 || results[0].Error == nil {
-		t.Fatalf("VerifyJSON(): Wanted [{Result: <some error>}] got %#v", results)
+		t.Fatalf("VerifyJSON(): Wanted [{Error: <some error>}] got %#v", results)
 	}
 }
 

vendor/src/github.com/matrix-org/gomatrixserverlib/request.go

@@ -224,9 +224,9 @@ func VerifyHTTPRequest(
 		util.GetLogger(req.Context()).WithError(err).Print(message)
 		return nil, util.MessageResponse(500, message)
 	}
-	if results[0].Result != nil {
+	if results[0].Error != nil {
 		message := "Invalid request signature"
-		util.GetLogger(req.Context()).WithError(results[0].Result).Print(message)
+		util.GetLogger(req.Context()).WithError(results[0].Error).Print(message)
 		return nil, util.MessageResponse(401, message)
 	}