firmware: add bluetooth upgrade

Protobuf msgs taken from:
BitBoxSwiss/bitbox02-firmware#1405

We can add simulator tests later once a BB02+ simulator is ready.

Author: benma

api/firmware/bluetooth.go

@@ -0,0 +1,84 @@
+// Copyright 2025 Shift Crypto AG
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package firmware
+
+import (
+	"github.com/BitBoxSwiss/bitbox02-api-go/api/firmware/messages"
+	"github.com/BitBoxSwiss/bitbox02-api-go/util/errp"
+)
+
+// queryBluetooth is like query, but nested one level deeper for Bluetooth.
+func (device *Device) queryBluetooth(request *messages.BluetoothRequest) (*messages.BluetoothResponse, error) {
+	if !device.SupportsBluetooth() {
+		return nil, errp.New("this device does not support Bluetooth")
+	}
+	response, err := device.query(&messages.Request{
+		Request: &messages.Request_Bluetooth{
+			Bluetooth: request,
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	bluetoothResponse, ok := response.Response.(*messages.Response_Bluetooth)
+	if !ok {
+		return nil, errp.New("unexpected reply")
+	}
+	return bluetoothResponse.Bluetooth, nil
+}
+
+// BluetoothUpgrade attempts an upgrade of the Bluetooth firmware.
+func (device *Device) BluetoothUpgrade(firmware []byte) error {
+	// Send initial upgrade request
+	initReq := &messages.BluetoothUpgradeInitRequest{
+		FirmwareLength: uint32(len(firmware)),
+	}
+	req := &messages.BluetoothRequest{
+		Request: &messages.BluetoothRequest_UpgradeInit{
+			UpgradeInit: initReq,
+		},
+	}
+
+	currentResponse, err := device.queryBluetooth(req)
+	if err != nil {
+		return err
+	}
+
+	for {
+		switch resp := currentResponse.Response.(type) {
+		case *messages.BluetoothResponse_RequestChunk:
+			chunkReq := resp.RequestChunk
+			chunkData := firmware[chunkReq.Offset : chunkReq.Offset+chunkReq.Length]
+
+			currentResponse, err = device.queryBluetooth(&messages.BluetoothRequest{
+				Request: &messages.BluetoothRequest_Chunk{
+					Chunk: &messages.BluetoothChunkRequest{
+						Data: chunkData,
+					},
+				},
+			})
+			if err != nil {
+				return err
+			}
+
+		case *messages.BluetoothResponse_Success:
+			// Upgrade complete
+			return nil
+
+		default:
+			return errp.New("unexpected response type during bluetooth upgrade")
+		}
+	}
+}

api/firmware/device.go

@@ -352,6 +352,11 @@ func (device *Device) SupportsETH(chainID uint64) bool {
 	return false
 }
 
+// SupportsBluetooth returns true if this device supports Bluetooth.
+func (device *Device) SupportsBluetooth() bool {
+	return *device.product == common.ProductBitBox02PlusMulti || *device.product == common.ProductBitBox02PlusBTCOnly
+}
+
 // SupportsERC20 returns true if an ERC20 token is supported by the device api.
 //
 // For now, this list only contains tokens relevant to the BitBoxApp, otherwise the bitbox02-api-js