add Touch ID wallet unlock via Swift biometric helper + Bun spawn

apps/desktop/src/bun/index.ts

@@ -27,6 +27,7 @@ import {
 	getBinaryDir,
 	MoneroWalletManager,
 } from './lib/monero'
+import { canPromptTouchID, promptTouchID } from './lib/biometric'
 
 const env = getENV()
 
@@ -133,6 +134,14 @@ type TxEntry = {
 type RPC = {
 	bun: RPCSchema<{
 		requests: {
+			biometricCanAuth: {
+				params: {}
+				response: boolean
+			}
+			biometricAuth: {
+				params: { reason: string }
+				response: boolean
+			}
 			getSecret: {
 				params: {
 					service: string
@@ -357,6 +366,20 @@ const rpc = BrowserView.defineRPC<RPC>({
 	maxRequestTime: 120000,
 	handlers: {
 		requests: {
+			biometricCanAuth: async () => {
+				try {
+					return canPromptTouchID()
+				} catch {
+					return false
+				}
+			},
+			biometricAuth: async ({ reason }) => {
+				try {
+					return promptTouchID(reason)
+				} catch {
+					return false
+				}
+			},
 			getSecret: async ({ name, service }) => {
 				return await Bun.secrets.get({ name, service })
 			},

apps/desktop/src/bun/lib/biometric.ts

@@ -0,0 +1,31 @@
+import { existsSync } from 'fs'
+import { join } from 'path'
+import { fileURLToPath } from 'url'
+import { PATHS } from 'electrobun/bun'
+
+const __dirname = fileURLToPath(new URL('.', import.meta.url))
+
+function findHelper(): string {
+	const candidates = [
+		join(__dirname, '..', 'native', 'biometric-helper'),
+		join(PATHS.RESOURCES_FOLDER, 'native', 'biometric-helper'),
+	]
+	for (const p of candidates) {
+		if (existsSync(p)) return p
+	}
+	throw new Error(
+		`biometric-helper not found at any of:\n${candidates.join('\n')}`,
+	)
+}
+
+const HELPER_PATH = findHelper()
+
+export function canPromptTouchID(): boolean {
+	const result = Bun.spawnSync([HELPER_PATH, '--check'])
+	return result.exitCode === 0
+}
+
+export function promptTouchID(reason: string): boolean {
+	const result = Bun.spawnSync([HELPER_PATH, reason])
+	return result.exitCode === 0
+}

apps/desktop/src/bun/native/biometric-helper.swift

@@ -0,0 +1,32 @@
+import Foundation
+import LocalAuthentication
+
+let context = LAContext()
+var error: NSError?
+let available = context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
+
+let isCheck = CommandLine.arguments.contains("--check")
+if isCheck {
+    print(available)
+    exit(available ? 0 : 1)
+}
+
+guard available else {
+    print(error!.localizedDescription)
+    exit(1)
+}
+
+let reason = CommandLine.arguments.last ?? "Authenticate"
+let sem = DispatchSemaphore(value: 0)
+
+context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { success, authError in
+    if success {
+        exit(0)
+    }
+    if let err = authError {
+        print(err.localizedDescription)
+    }
+    exit(1)
+}
+
+_ = sem.wait(timeout: .distantFuture)