Support biometric login

app/src/google/AndroidManifest.xml

@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    package="org.traccar.manager">
+    xmlns:tools="http://schemas.android.com/tools">
 
     <application
         android:name=".GoogleMainApplication"

app/src/main/java/org/traccar/manager/MainFragment.kt

@@ -42,7 +42,19 @@ class MainFragment : WebViewFragment() {
         @JavascriptInterface
         fun postMessage(message: String) {
             if (message.startsWith("login")) {
+                if (message.length > 6) {
+                    SecurityManager.saveToken(activity, message.substring(6))
+                }
                 broadcastManager.sendBroadcast(Intent(EVENT_LOGIN))
+            } else if (message.startsWith("authentication")) {
+                SecurityManager.readToken(activity) { token ->
+                    if (token != null) {
+                        val code = "handleLoginToken && handleLoginToken('$token')"
+                        webView.evaluateJavascript(code, null)
+                    }
+                }
+            } else if (message.startsWith("logout")) {
+                SecurityManager.deleteToken(activity)
             } else if (message.startsWith("server")) {
                 val url = message.substring(7)
                 PreferenceManager.getDefaultSharedPreferences(activity)

app/src/main/java/org/traccar/manager/SecurityManager.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2022 Anton Tananaev (anton@traccar.org)
+ *
+ * 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 org.traccar.manager
+
+import android.app.Activity
+import androidx.biometric.BiometricPrompt
+import androidx.core.content.ContextCompat
+import androidx.fragment.app.FragmentActivity
+import androidx.preference.PreferenceManager
+
+object SecurityManager {
+
+    fun saveToken(activity: Activity, token: String) {
+        PreferenceManager.getDefaultSharedPreferences(activity)
+            .edit().putString(KEY_TOKEN, token).apply()
+    }
+
+    fun readToken(activity: Activity, onResult: (String?) -> Unit) {
+        val token = PreferenceManager.getDefaultSharedPreferences(activity)
+            .getString(KEY_TOKEN, null)
+        if (token != null) {
+            authenticate(activity) {
+                onResult(if (it) token else null)
+            }
+        }
+        onResult(null)
+    }
+
+    fun deleteToken(activity: Activity) {
+        PreferenceManager.getDefaultSharedPreferences(activity)
+            .edit().remove(KEY_TOKEN).apply()
+    }
+
+    private fun authenticate(activity: Activity, onResult: (Boolean) -> Unit) {
+        val executor = ContextCompat.getMainExecutor(activity)
+        val biometricPrompt = BiometricPrompt(
+            activity as FragmentActivity,
+            executor,
+            object : BiometricPrompt.AuthenticationCallback() {
+                override fun onAuthenticationError(errorCode: Int, errString: CharSequence) {
+                    onResult(false)
+                }
+
+                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult) {
+                    onResult(true)
+                }
+
+                override fun onAuthenticationFailed() {
+                    onResult(false)
+                }
+            },
+        )
+        val promptInfo = BiometricPrompt.PromptInfo.Builder()
+            .setTitle(activity.getString(R.string.biometric_title))
+            .setNegativeButtonText(activity.getString(R.string.biometric_cancel))
+            .build()
+        activity.runOnUiThread { biometricPrompt.authenticate(promptInfo) }
+    }
+
+    private const val KEY_TOKEN = "managerToken"
+
+}

app/src/main/res/values/strings.xml

@@ -7,4 +7,6 @@
     <string name="file_browser">File Browser</string>
     <string name="notification_channel">Default</string>
     <string name="permission_location_rationale">App requires location permission to show current location on the map</string>
+    <string name="biometric_title">Biometric login</string>
+    <string name="biometric_cancel">Use account password</string>
 </resources>