client,crypto,appservice: add MSC3202 features

appservice/registration.go

@@ -28,6 +28,7 @@ type Registration struct {
 
 	SoruEphemeralEvents bool `yaml:"de.sorunome.msc2409.push_ephemeral,omitempty" json:"de.sorunome.msc2409.push_ephemeral,omitempty"`
 	EphemeralEvents     bool `yaml:"push_ephemeral,omitempty" json:"push_ephemeral,omitempty"`
+	MSC3202             bool `yaml:"org.matrix.msc3202,omitempty" json:"org.matrix.msc3202,omitempty"`
 }
 
 // CreateRegistration creates a Registration with random appservice and homeserver tokens.

client.go

@@ -110,6 +110,9 @@ type Client struct {
 	// Should the ?user_id= query parameter be set in requests?
 	// See https://spec.matrix.org/v1.6/application-service-api/#identity-assertion
 	SetAppServiceUserID bool
+	// Should the org.matrix.msc3202.device_id query parameter be set in requests?
+	// See https://github.com/matrix-org/matrix-spec-proposals/pull/3202
+	SetAppServiceDeviceID bool
 
 	syncingID uint32 // Identifies the current Sync. Only one Sync can be active at any given time.
 }

crypto/cryptohelper/cryptohelper.go

@@ -38,6 +38,8 @@ type CryptoHelper struct {
 
 	LoginAs *mautrix.ReqLogin
 
+	ASEventProcessor crypto.ASEventProcessor
+
 	DBAccountID string
 }
 
@@ -58,7 +60,7 @@ func NewCryptoHelper(cli *mautrix.Client, pickleKey []byte, store any) (*CryptoH
 		return nil, fmt.Errorf("pickle key must be provided")
 	}
 	_, isExtensible := cli.Syncer.(mautrix.ExtensibleSyncer)
-	if !isExtensible {
+	if !cli.SetAppServiceDeviceID && !isExtensible {
 		return nil, fmt.Errorf("the client syncer must implement ExtensibleSyncer")
 	}
 
@@ -111,7 +113,11 @@ func (helper *CryptoHelper) Init(ctx context.Context) error {
 	}
 	syncer, ok := helper.client.Syncer.(mautrix.ExtensibleSyncer)
 	if !ok {
-		return fmt.Errorf("the client syncer must implement ExtensibleSyncer")
+		if !helper.client.SetAppServiceDeviceID {
+			return fmt.Errorf("the client syncer must implement ExtensibleSyncer")
+		} else if helper.ASEventProcessor == nil {
+			return fmt.Errorf("an appservice must be provided when using appservice mode encryption")
+		}
 	}
 
 	var stateStore crypto.StateStore
@@ -140,7 +146,27 @@ func (helper *CryptoHelper) Init(ctx context.Context) error {
 		if err != nil {
 			return fmt.Errorf("failed to find existing device ID: %w", err)
 		}
-		if helper.LoginAs != nil {
+		if helper.LoginAs != nil && helper.LoginAs.Type == mautrix.AuthTypeAppservice && helper.client.SetAppServiceDeviceID {
+			if storedDeviceID == "" {
+				helper.log.Debug().
+					Str("username", helper.LoginAs.Identifier.User).
+					Msg("Logging in with appservice")
+				var resp *mautrix.RespLogin
+				resp, err = helper.client.Login(ctx, helper.LoginAs)
+				if err != nil {
+					return err
+				}
+				managedCryptoStore.DeviceID = resp.DeviceID
+				helper.client.DeviceID = resp.DeviceID
+			} else {
+				helper.log.Debug().
+					Str("username", helper.LoginAs.Identifier.User).
+					Stringer("device_id", storedDeviceID).
+					Msg("Using existing device")
+				managedCryptoStore.DeviceID = storedDeviceID
+				helper.client.DeviceID = storedDeviceID
+			}
+		} else if helper.LoginAs != nil {
 			if storedDeviceID != "" {
 				helper.LoginAs.DeviceID = storedDeviceID
 			}
@@ -177,16 +203,29 @@ func (helper *CryptoHelper) Init(ctx context.Context) error {
 		return err
 	}
 
-	syncer.OnSync(helper.mach.ProcessSyncResponse)
-	syncer.OnEventType(event.StateMember, helper.mach.HandleMemberEvent)
-	if _, ok = helper.client.Syncer.(mautrix.DispatchableSyncer); ok {
-		syncer.OnEventType(event.EventEncrypted, helper.HandleEncrypted)
+	if syncer != nil {
+		syncer.OnSync(helper.mach.ProcessSyncResponse)
+		syncer.OnEventType(event.StateMember, helper.mach.HandleMemberEvent)
+		if _, ok = helper.client.Syncer.(mautrix.DispatchableSyncer); ok {
+			syncer.OnEventType(event.EventEncrypted, helper.HandleEncrypted)
+		} else {
+			helper.log.Warn().Msg("Client syncer does not implement DispatchableSyncer. Events will not be decrypted automatically.")
+		}
+		if helper.managedStateStore != nil {
+			syncer.OnEvent(helper.client.StateStoreSyncHandler)
+		}
 	} else {
-		helper.log.Warn().Msg("Client syncer does not implement DispatchableSyncer. Events will not be decrypted automatically.")
+		helper.mach.AddAppserviceListener(helper.ASEventProcessor)
+		helper.ASEventProcessor.On(event.EventEncrypted, helper.HandleEncrypted)
 	}
-	if helper.managedStateStore != nil {
-		syncer.OnEvent(helper.client.StateStoreSyncHandler)
+
+	if helper.client.SetAppServiceDeviceID {
+		err = helper.mach.ShareKeys(ctx, -1)
+		if err != nil {
+			return fmt.Errorf("failed to share keys: %w", err)
+		}
 	}
+
 	return nil
 }
 
@@ -281,7 +320,11 @@ func (helper *CryptoHelper) HandleEncrypted(ctx context.Context, evt *event.Even
 
 func (helper *CryptoHelper) postDecrypt(ctx context.Context, decrypted *event.Event) {
 	decrypted.Mautrix.EventSource |= event.SourceDecrypted
-	helper.client.Syncer.(mautrix.DispatchableSyncer).Dispatch(ctx, decrypted)
+	if helper.ASEventProcessor != nil {
+		helper.ASEventProcessor.Dispatch(ctx, decrypted)
+	} else {
+		helper.client.Syncer.(mautrix.DispatchableSyncer).Dispatch(ctx, decrypted)
+	}
 }
 
 func (helper *CryptoHelper) RequestSession(ctx context.Context, roomID id.RoomID, senderKey id.SenderKey, sessionID id.SessionID, userID id.UserID, deviceID id.DeviceID) {

crypto/machine.go

@@ -208,13 +208,14 @@ func (mach *OlmMachine) OwnIdentity() *id.Device {
 	}
 }
 
-type asEventProcessor interface {
+type ASEventProcessor interface {
 	On(evtType event.Type, handler func(ctx context.Context, evt *event.Event))
 	OnOTK(func(ctx context.Context, otk *mautrix.OTKCount))
 	OnDeviceList(func(ctx context.Context, lists *mautrix.DeviceLists, since string))
+	Dispatch(ctx context.Context, evt *event.Event)
 }
 
-func (mach *OlmMachine) AddAppserviceListener(ep asEventProcessor) {
+func (mach *OlmMachine) AddAppserviceListener(ep ASEventProcessor) {
 	// ToDeviceForwardedRoomKey and ToDeviceRoomKey should only be present inside encrypted to-device events
 	ep.On(event.ToDeviceEncrypted, mach.HandleToDeviceEvent)
 	ep.On(event.ToDeviceRoomKeyRequest, mach.HandleToDeviceEvent)

requests.go

@@ -225,7 +225,7 @@ func (otk *OneTimeKey) MarshalJSON() ([]byte, error) {
 
 type ReqUploadKeys struct {
 	DeviceKeys  *DeviceKeys             `json:"device_keys,omitempty"`
-	OneTimeKeys map[id.KeyID]OneTimeKey `json:"one_time_keys"`
+	OneTimeKeys map[id.KeyID]OneTimeKey `json:"one_time_keys,omitempty"`
 }
 
 type ReqKeysSignatures struct {

url.go

@@ -102,6 +102,10 @@ func (cli *Client) BuildURLWithQuery(urlPath PrefixableURLPath, urlQuery map[str
 	if cli.SetAppServiceUserID {
 		query.Set("user_id", string(cli.UserID))
 	}
+	if cli.SetAppServiceDeviceID && cli.DeviceID != "" {
+		query.Set("device_id", string(cli.DeviceID))
+		query.Set("org.matrix.msc3202.device_id", string(cli.DeviceID))
+	}
 	if urlQuery != nil {
 		for k, v := range urlQuery {
 			query.Set(k, v)