Add support for MSC4190

appservice/registration.go

@@ -29,6 +29,7 @@ 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"`
+	MSC4190             bool `yaml:"io.element.msc4190,omitempty" json:"io.element.msc4190,omitempty"`
 }
 
 // CreateRegistration creates a Registration with random appservice and homeserver tokens.

bridge/crypto.go

@@ -232,6 +232,16 @@ func (helper *CryptoHelper) loginBot(ctx context.Context) (*mautrix.Client, bool
 	} else if !flows.HasFlow(mautrix.AuthTypeAppservice) {
 		return nil, deviceID != "", fmt.Errorf("homeserver does not support appservice login")
 	}
+	initialDeviceDisplayName := fmt.Sprintf("%s bridge", helper.bridge.ProtocolName)
+	if helper.bridge.AS.Registration.MSC4190 {
+		err = client.CreateDeviceMSC4190(ctx, deviceID, initialDeviceDisplayName)
+		if err != nil {
+			return nil, deviceID != "", fmt.Errorf("failed to log in as bridge bot: %w", err)
+		}
+		helper.store.DeviceID = client.DeviceID
+		return client, deviceID != "", nil
+	}
+
 	resp, err := client.Login(ctx, &mautrix.ReqLogin{
 		Type: mautrix.AuthTypeAppservice,
 		Identifier: mautrix.UserIdentifier{
@@ -241,7 +251,7 @@ func (helper *CryptoHelper) loginBot(ctx context.Context) (*mautrix.Client, bool
 		DeviceID:         deviceID,
 		StoreCredentials: true,
 
-		InitialDeviceDisplayName: fmt.Sprintf("%s bridge", helper.bridge.ProtocolName),
+		InitialDeviceDisplayName: initialDeviceDisplayName,
 	})
 	if err != nil {
 		return nil, deviceID != "", fmt.Errorf("failed to log in as bridge bot: %w", err)

bridgev2/matrix/crypto.go

@@ -247,17 +247,25 @@ func (helper *CryptoHelper) loginBot(ctx context.Context) (*mautrix.Client, bool
 	} else if !flows.HasFlow(mautrix.AuthTypeAppservice) {
 		return nil, deviceID != "", fmt.Errorf("homeserver does not support appservice login")
 	}
+	initialDeviceDisplayName := fmt.Sprintf("%s bridge", helper.bridge.Bridge.Network.GetName().DisplayName)
+	if helper.bridge.AS.Registration.MSC4190 {
+		err = client.CreateDeviceMSC4190(ctx, deviceID, initialDeviceDisplayName)
+		if err != nil {
+			return nil, deviceID != "", fmt.Errorf("failed to log in as bridge bot: %w", err)
+		}
+		helper.store.DeviceID = client.DeviceID
+		return client, deviceID != "", nil
+	}
+
 	resp, err := client.Login(ctx, &mautrix.ReqLogin{
 		Type: mautrix.AuthTypeAppservice,
 		Identifier: mautrix.UserIdentifier{
 			Type: mautrix.IdentifierTypeUser,
 			User: string(helper.bridge.AS.BotMXID()),
 		},
-		DeviceID:         deviceID,
-		StoreCredentials: true,
-
-		// TODO find proper bridge name
-		InitialDeviceDisplayName: "Megabridge", // fmt.Sprintf("%s bridge", helper.bridge.ProtocolName),
+		DeviceID:                 deviceID,
+		StoreCredentials:         true,
+		InitialDeviceDisplayName: initialDeviceDisplayName,
 	})
 	if err != nil {
 		return nil, deviceID != "", fmt.Errorf("failed to log in as bridge bot: %w", err)

client.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/rs/zerolog"
 	"go.mau.fi/util/ptr"
+	"go.mau.fi/util/random"
 	"go.mau.fi/util/retryafter"
 	"golang.org/x/exp/maps"
 
@@ -897,6 +898,27 @@ func (cli *Client) Login(ctx context.Context, req *ReqLogin) (resp *RespLogin, e
 	return
 }
 
+// Create a Device for a user of the homeserver using appservice interface defined in MSC4190
+func (cli *Client) CreateDeviceMSC4190(ctx context.Context, deviceID id.DeviceID, initialDispalyName string) (err error) {
+	if len(deviceID) == 0 {
+		deviceID = id.DeviceID(random.String(10))
+	}
+	if !cli.SetAppServiceUserID {
+		return fmt.Errorf("CreateDeviceMSC4190 requires SetAppServiceUserID to be enabled")
+	}
+	if cli.AccessToken == "" {
+		return fmt.Errorf("CreateDeviceMSC4190 requires The AS AccessToken token to be set as the client AccessToken")
+	}
+	_, err = cli.MakeRequest(ctx, http.MethodPost, cli.BuildClientURL("v3", "devices", deviceID), ReqPutDevice{
+		DisplayName: initialDispalyName,
+	}, nil)
+	if err != nil {
+		return err
+	}
+	cli.DeviceID = deviceID
+	return nil
+}
+
 // Logout the current user. See https://spec.matrix.org/v1.2/client-server-api/#post_matrixclientv3logout
 // This does not clear the credentials from the client instance. See ClearCredentials() instead.
 func (cli *Client) Logout(ctx context.Context) (resp *RespLogout, err error) {

crypto/cryptohelper/cryptohelper.go

@@ -37,6 +37,7 @@ type CryptoHelper struct {
 	DecryptErrorCallback func(*event.Event, error)
 
 	LoginAs *mautrix.ReqLogin
+	MSC4190 bool
 
 	ASEventProcessor  crypto.ASEventProcessor
 	CustomPostDecrypt func(context.Context, *event.Event)
@@ -152,7 +153,20 @@ func (helper *CryptoHelper) Init(ctx context.Context) error {
 			return fmt.Errorf("failed to find existing device ID: %w", err)
 		}
 		if helper.LoginAs != nil && helper.LoginAs.Type == mautrix.AuthTypeAppservice && helper.client.SetAppServiceDeviceID {
-			if storedDeviceID == "" {
+			if storedDeviceID != "" {
+				helper.log.Debug().
+					Str("username", helper.LoginAs.Identifier.User).
+					Stringer("device_id", storedDeviceID).
+					Msg("Using existing device")
+				rawCryptoStore.DeviceID = storedDeviceID
+				helper.client.DeviceID = storedDeviceID
+			} else if helper.MSC4190 {
+				helper.log.Debug().
+					Str("username", helper.LoginAs.Identifier.User).
+					Msg("Creating device with MSC4190")
+				helper.client.CreateDeviceMSC4190(ctx, storedDeviceID, "")
+				rawCryptoStore.DeviceID = helper.client.DeviceID
+			} else {
 				helper.log.Debug().
 					Str("username", helper.LoginAs.Identifier.User).
 					Msg("Logging in with appservice")
@@ -163,13 +177,6 @@ func (helper *CryptoHelper) Init(ctx context.Context) error {
 				}
 				rawCryptoStore.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")
-				rawCryptoStore.DeviceID = storedDeviceID
-				helper.client.DeviceID = storedDeviceID
 			}
 		} else if helper.LoginAs != nil {
 			if storedDeviceID != "" {

requests.go

@@ -90,6 +90,9 @@ type ReqLogin struct {
 	// Whether or not the returned .well-known data should update the homeserver URL in the Client
 	StoreHomeserverURL bool `json:"-"`
 }
+type ReqPutDevice struct {
+	DisplayName string `json:"display_name,omitempty"`
+}
 
 type ReqUIAuthFallback struct {
 	Session string `json:"session"`