Merge pull request #563 from synonymdev/ovi/trezor-bridge-transport

feat: add Trezor emulator bridge

Author: ovitrif

Bitkit/Constants/Env.swift

@@ -30,6 +30,19 @@ enum Env {
         return trimmed?.isEmpty == false ? trimmed : nil
     }
 
+    private static func configValue(_ key: String) -> String? {
+        let envValue = ProcessInfo.processInfo.environment[key]?.trimmingCharacters(in: .whitespacesAndNewlines)
+        if envValue?.isEmpty == false {
+            return envValue
+        }
+        return infoPlistValue(key)
+    }
+
+    private static func boolConfigValue(_ key: String) -> Bool {
+        guard let value = configValue(key)?.lowercased() else { return false }
+        return ["1", "true", "yes", "y"].contains(value)
+    }
+
     private static var e2eBackend: String {
         (infoPlistValue("E2E_BACKEND") ?? "local").lowercased()
     }
@@ -140,6 +153,19 @@ enum Env {
         }
     }
 
+    static var trezorBridgeEnabled: Bool {
+        (isDebug || isE2E) && boolConfigValue("TREZOR_BRIDGE")
+    }
+
+    static var trezorBridgeUrl: String {
+        configValue("TREZOR_BRIDGE_URL") ?? "http://127.0.0.1:21325"
+    }
+
+    static var trezorElectrumUrl: String? {
+        guard isDebug || isE2E else { return nil }
+        return configValue("TREZOR_ELECTRUM_URL")
+    }
+
     static var appStorageUrl: URL {
         // App group so files can be shared with extensions
         guard let documentsDirectory = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.bitkit") else {

Bitkit/Services/Trezor/TrezorBridgeTransport.swift

@@ -0,0 +1,278 @@
+import BitkitCore
+import Foundation
+
+/// Dev/E2E-only transport for talking to the Trezor Bridge exposed by bitkit-docker.
+final class TrezorBridgeTransport {
+    static let shared = TrezorBridgeTransport()
+
+    private static let pathPrefix = "bridge:"
+    private static let deviceName = "Trezor Bridge Emulator"
+    private static let vendorId = UInt16(0x1209)
+    private static let productId = UInt16(0x53C1)
+    private static let headerSize = 6
+    private static let connectTimeout: TimeInterval = 5
+    private static let readTimeout: TimeInterval = 30
+
+    private let decoder = JSONDecoder()
+    private let sessionLock = NSLock()
+    private var openSessions: [String: String] = [:]
+    private var enumeratedSessions: [String: String] = [:]
+
+    private init() {}
+
+    var isEnabled: Bool {
+        Env.trezorBridgeEnabled
+    }
+
+    func isBridgeDevice(path: String) -> Bool {
+        isEnabled && path.hasPrefix(Self.pathPrefix)
+    }
+
+    func enumerateDevices() -> [NativeDeviceInfo] {
+        guard isEnabled else { return [] }
+
+        do {
+            let response = try post(path: "/enumerate")
+            let bridgeDevices = try decoder.decode([BridgeDevice].self, from: Data(response.utf8))
+
+            let devices = bridgeDevices.map { device in
+                let bridgePath = Self.toBridgePath(device.path)
+                sessionLock.lock()
+                if let session = device.session {
+                    enumeratedSessions[bridgePath] = session
+                } else {
+                    enumeratedSessions.removeValue(forKey: bridgePath)
+                }
+                sessionLock.unlock()
+
+                return NativeDeviceInfo(
+                    path: bridgePath,
+                    transportType: "usb",
+                    name: Self.deviceName,
+                    vendorId: Self.vendorId,
+                    productId: Self.productId
+                )
+            }
+
+            debugLog("enumerateDevices: \(devices.count) Bridge device(s)")
+            return devices
+        } catch {
+            debugLog("enumerateDevices FAILED: \(error.localizedDescription)")
+            return []
+        }
+    }
+
+    func openDevice(path: String) -> TrezorTransportWriteResult {
+        let rawPath = Self.rawBridgePath(path)
+
+        sessionLock.lock()
+        let previousSession = openSessions.removeValue(forKey: path) ?? enumeratedSessions[path] ?? "null"
+        sessionLock.unlock()
+
+        do {
+            let response = try post(path: "/acquire/\(Self.encode(rawPath))/\(Self.encode(previousSession))")
+            let bridgeSession = try decoder.decode(BridgeSession.self, from: Data(response.utf8))
+
+            sessionLock.lock()
+            openSessions[path] = bridgeSession.session
+            sessionLock.unlock()
+
+            debugLog("openDevice: \(path)")
+            return TrezorTransportWriteResult(success: true, error: "")
+        } catch {
+            debugLog("openDevice FAILED: \(error.localizedDescription)")
+            return TrezorTransportWriteResult(success: false, error: error.localizedDescription)
+        }
+    }
+
+    func closeDevice(path: String) -> TrezorTransportWriteResult {
+        sessionLock.lock()
+        let session = openSessions.removeValue(forKey: path)
+        sessionLock.unlock()
+
+        guard let session else {
+            return TrezorTransportWriteResult(success: true, error: "")
+        }
+
+        do {
+            _ = try post(path: "/release/\(Self.encode(session))")
+            debugLog("closeDevice: \(path)")
+            return TrezorTransportWriteResult(success: true, error: "")
+        } catch {
+            debugLog("closeDevice FAILED: \(error.localizedDescription)")
+            return TrezorTransportWriteResult(success: false, error: error.localizedDescription)
+        }
+    }
+
+    func readChunk(path: String) -> TrezorTransportReadResult {
+        TrezorTransportReadResult(success: false, data: Data(), error: "Trezor Bridge uses callMessage for \(path)")
+    }
+
+    func writeChunk(path: String, data: Data) -> TrezorTransportWriteResult {
+        TrezorTransportWriteResult(success: false, error: "Trezor Bridge uses callMessage for \(path) and ignored \(data.count) bytes")
+    }
+
+    func callMessage(path: String, messageType: UInt16, data: Data) -> TrezorCallMessageResult {
+        sessionLock.lock()
+        let session = openSessions[path]
+        sessionLock.unlock()
+
+        guard let session else {
+            return TrezorCallMessageResult(success: false, messageType: 0, data: Data(), error: "Trezor Bridge device not open: \(path)")
+        }
+
+        do {
+            let request = Self.encodeFrame(messageType: messageType, data: data)
+            let response = try post(path: "/call/\(Self.encode(session))", body: request)
+            return try Self.decodeFrame(response)
+        } catch {
+            debugLog("callMessage FAILED: \(error.localizedDescription)")
+            return TrezorCallMessageResult(success: false, messageType: 0, data: Data(), error: error.localizedDescription)
+        }
+    }
+
+    private func post(path: String, body: String? = nil) throws -> String {
+        guard let url = URL(string: "\(Env.trezorBridgeUrl.trimmingCharacters(in: CharacterSet(charactersIn: "/")))\(path)") else {
+            throw TrezorBridgeTransportError.invalidUrl
+        }
+
+        var request = URLRequest(url: url)
+        request.httpMethod = "POST"
+        request.timeoutInterval = body == nil ? Self.connectTimeout : Self.readTimeout
+        request.cachePolicy = .reloadIgnoringLocalCacheData
+        if let body {
+            request.httpBody = Data(body.utf8)
+            request.setValue("text/plain", forHTTPHeaderField: "Content-Type")
+        }
+
+        let semaphore = DispatchSemaphore(value: 0)
+        var result: Result<(Data, HTTPURLResponse), Error>?
+
+        URLSession.shared.dataTask(with: request) { data, response, error in
+            defer { semaphore.signal() }
+            if let error {
+                result = .failure(error)
+                return
+            }
+            guard let httpResponse = response as? HTTPURLResponse else {
+                result = .failure(TrezorBridgeTransportError.invalidResponse)
+                return
+            }
+            result = .success((data ?? Data(), httpResponse))
+        }.resume()
+
+        semaphore.wait()
+
+        let (data, response) = try result?.get() ?? (Data(), HTTPURLResponse())
+        let responseText = String(data: data, encoding: .utf8) ?? ""
+        guard 200 ..< 300 ~= response.statusCode else {
+            throw TrezorBridgeTransportError.httpError(statusCode: response.statusCode, body: responseText)
+        }
+        return responseText
+    }
+
+    private static func encodeFrame(messageType: UInt16, data: Data) -> String {
+        var frame = Data()
+        frame.append(UInt8((messageType >> 8) & 0xFF))
+        frame.append(UInt8(messageType & 0xFF))
+
+        let length = UInt32(data.count)
+        frame.append(UInt8((length >> 24) & 0xFF))
+        frame.append(UInt8((length >> 16) & 0xFF))
+        frame.append(UInt8((length >> 8) & 0xFF))
+        frame.append(UInt8(length & 0xFF))
+        frame.append(data)
+
+        return frame.map { String(format: "%02x", $0) }.joined()
+    }
+
+    private static func decodeFrame(_ hex: String) throws -> TrezorCallMessageResult {
+        let bytes = try Data(hexEncoded: hex.trimmingCharacters(in: .whitespacesAndNewlines))
+        guard bytes.count >= headerSize else {
+            throw TrezorBridgeTransportError.shortResponse
+        }
+
+        let messageType = (UInt16(bytes[0]) << 8) | UInt16(bytes[1])
+        let length = (UInt32(bytes[2]) << 24) | (UInt32(bytes[3]) << 16) | (UInt32(bytes[4]) << 8) | UInt32(bytes[5])
+        guard bytes.count >= headerSize + Int(length) else {
+            throw TrezorBridgeTransportError.invalidPayloadLength
+        }
+
+        let payload = bytes.subdata(in: headerSize ..< headerSize + Int(length))
+        return TrezorCallMessageResult(success: true, messageType: messageType, data: payload, error: "")
+    }
+
+    private static func toBridgePath(_ path: String) -> String {
+        "\(pathPrefix)\(path)"
+    }
+
+    private static func rawBridgePath(_ path: String) -> String {
+        String(path.dropFirst(pathPrefix.count))
+    }
+
+    private static func encode(_ value: String) -> String {
+        var allowed = CharacterSet.urlPathAllowed
+        allowed.remove(charactersIn: "/")
+        return value.addingPercentEncoding(withAllowedCharacters: allowed) ?? value
+    }
+
+    private func debugLog(_ message: String) {
+        Logger.debug(message, context: "TrezorBridgeTransport")
+        TrezorDebugLog.shared.log("[Bridge] \(message)")
+    }
+}
+
+private struct BridgeDevice: Decodable {
+    let path: String
+    let session: String?
+}
+
+private struct BridgeSession: Decodable {
+    let session: String
+}
+
+private enum TrezorBridgeTransportError: LocalizedError {
+    case invalidUrl
+    case invalidResponse
+    case httpError(statusCode: Int, body: String)
+    case invalidHex
+    case shortResponse
+    case invalidPayloadLength
+
+    var errorDescription: String? {
+        switch self {
+        case .invalidUrl:
+            return "Invalid Trezor Bridge URL"
+        case .invalidResponse:
+            return "Invalid Trezor Bridge response"
+        case let .httpError(statusCode, body):
+            return "Bridge request failed with HTTP \(statusCode): \(body)"
+        case .invalidHex:
+            return "Bridge returned invalid hex"
+        case .shortResponse:
+            return "Bridge response is shorter than the message header"
+        case .invalidPayloadLength:
+            return "Bridge response payload length exceeds available data"
+        }
+    }
+}
+
+private extension Data {
+    init(hexEncoded hex: String) throws {
+        guard hex.count.isMultiple(of: 2) else {
+            throw TrezorBridgeTransportError.invalidHex
+        }
+
+        var data = Data(capacity: hex.count / 2)
+        var index = hex.startIndex
+        while index < hex.endIndex {
+            let nextIndex = hex.index(index, offsetBy: 2)
+            guard let byte = UInt8(hex[index ..< nextIndex], radix: 16) else {
+                throw TrezorBridgeTransportError.invalidHex
+            }
+            data.append(byte)
+            index = nextIndex
+        }
+        self = data
+    }
+}