Add password manager with Android autofill, master key encryption, and tooltip accessibility

.github/workflows/ci.yml

@@ -0,0 +1,18 @@
+name: CI
+on:
+  push:
+    branches: [versionF]
+  pull_request:
+    branches: [versionF]
+
+jobs:
+  analyze-and-test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+      - run: flutter pub get
+      - run: flutter analyze
+      - run: flutter test

analysis_options.yaml

@@ -9,20 +9,10 @@
 # packages, and plugins designed to encourage good coding practices.
 include: package:flutter_lints/flutter.yaml
 
+analyzer:
+  exclude:
+    - "lib/examples/**"
+
 linter:
-  # The lint rules applied to this project can be customized in the
-  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
-  # included above or to enable additional rules. A list of all available lints
-  # and their documentation is published at https://dart.dev/lints.
-  #
-  # Instead of disabling a lint rule for the entire project in the
-  # section below, it can also be suppressed for a single line of code
-  # or a specific dart file by using the `// ignore: name_of_lint` and
-  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
-  # producing the lint.
   rules:
-    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
-    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
-
-# Additional information about this file can be found at
-# https://dart.dev/guides/language/analysis-options
+    avoid_print: true

android/app/build.gradle

@@ -47,7 +47,6 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId = "com.mossapps.locker"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
@@ -69,6 +68,9 @@ android {
     buildTypes {
         release {
             signingConfig = signingConfigs.release
+            minifyEnabled true
+            shrinkResources true
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
 }

android/app/proguard-rules.pro

@@ -0,0 +1,12 @@
+# Flutter
+-keep class io.flutter.** { *; }
+-keep class io.flutter.plugins.** { *; }
+-dontwarn io.flutter.embedding.**
+
+# pointycastle (crypto)
+-keep class org.bouncycastle.** { *; }
+-dontwarn org.bouncycastle.**
+
+# Autofill service
+-keep class com.mossapps.locker.AutofillService { *; }
+-keep class com.mossapps.locker.AutofillSelectionActivity { *; }

android/app/src/main/AndroidManifest.xml

@@ -29,7 +29,10 @@
         android:label="Latch"
         android:name="${applicationName}"
         android:icon="@mipmap/launcher_icon"
-        android:requestLegacyExternalStorage="true">
+        android:requestLegacyExternalStorage="true"
+        android:allowBackup="false"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:networkSecurityConfig="@xml/network_security_config">
 
         <activity
             android:name=".MainActivity"
@@ -78,6 +81,27 @@
             android:name="flutterEmbedding"
             android:value="2" />
 
+        <service
+            android:name=".AutofillService"
+            android:label="Latch"
+            android:exported="true"
+            android:permission="android.permission.BIND_AUTOFILL_SERVICE">
+            <intent-filter>
+                <action android:name="android.service.autofill.AutofillService" />
+            </intent-filter>
+            <meta-data
+                android:name="android.autofill"
+                android:resource="@xml/autofill_service" />
+        </service>
+
+        <activity
+            android:name=".AutofillSelectionActivity"
+            android:exported="false"
+            android:excludeFromRecents="true"
+            android:theme="@style/NormalTheme"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:windowSoftInputMode="adjustResize" />
+
     </application>
 
     <!-- Required to query activities that can process text, see:

android/app/src/main/kotlin/com/mossapps/locker/AutofillCallbackHolder.kt

@@ -0,0 +1,31 @@
+package com.mossapps.locker
+
+import android.app.assist.AssistStructure
+import android.service.autofill.FillCallback
+import android.view.autofill.AutofillId
+
+enum class FieldType { USERNAME, PASSWORD }
+
+data class AutofillField(val autofillId: AutofillId, val type: FieldType)
+
+object AutofillCallbackHolder {
+    var callback: FillCallback? = null
+        private set
+    var fields: List<AutofillField>? = null
+        private set
+
+    fun set(callback: FillCallback, fields: List<AutofillField>) {
+        this.callback = callback
+        this.fields = fields
+    }
+
+    fun cancel() {
+        try { callback?.onSuccess(null) } catch (_: Exception) {}
+        clear()
+    }
+
+    fun clear() {
+        callback = null
+        fields = null
+    }
+}

android/app/src/main/kotlin/com/mossapps/locker/AutofillSelectionActivity.kt

@@ -0,0 +1,108 @@
+package com.mossapps.locker
+
+import android.app.assist.AssistStructure
+import android.os.Build
+import android.os.Bundle
+import android.service.autofill.Dataset
+import android.service.autofill.FillResponse
+import android.util.Log
+import android.view.View
+import android.view.WindowManager
+import android.view.autofill.AutofillValue
+import android.widget.RemoteViews
+import androidx.annotation.RequiresApi
+import io.flutter.embedding.android.FlutterFragmentActivity
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.MethodChannel
+
+@RequiresApi(Build.VERSION_CODES.O)
+class AutofillSelectionActivity : FlutterFragmentActivity() {
+
+    private val CHANNEL = "com.mossapps.locker/autofill"
+
+    override fun getDartEntrypointFunctionName(): String = "autofillMain"
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        window.setFlags(WindowManager.LayoutParams.FLAG_SECURE, WindowManager.LayoutParams.FLAG_SECURE)
+    }
+
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "fillCredentials" -> {
+                    val username = call.argument<String>("username") ?: ""
+                    val password = call.argument<String>("password") ?: ""
+                    val title = call.argument<String>("title") ?: "Latch"
+                    fillCredentials(username, password, title, result)
+                }
+                "cancel" -> {
+                    AutofillCallbackHolder.cancel()
+                    result.success(null)
+                    finish()
+                }
+                else -> result.notImplemented()
+            }
+        }
+    }
+
+    private fun fillCredentials(username: String, password: String, title: String, result: MethodChannel.Result) {
+        val callback = AutofillCallbackHolder.callback
+        val fields = AutofillCallbackHolder.fields
+
+        if (callback == null || fields == null) {
+            result.error("no_callback", "No fill request pending", null)
+            finish()
+            return
+        }
+
+        try {
+            val presentation = RemoteViews(packageName, R.layout.autofill_suggestion)
+            presentation.setTextViewText(R.id.autofill_title, title)
+
+            val builder = Dataset.Builder()
+            var matched = false
+
+            for (field in fields) {
+                when (field.type) {
+                    FieldType.USERNAME -> {
+                        if (username.isNotEmpty()) {
+                            builder.setValue(field.autofillId, AutofillValue.forText(username), presentation)
+                            matched = true
+                        }
+                    }
+                    FieldType.PASSWORD -> {
+                        if (password.isNotEmpty()) {
+                            builder.setValue(field.autofillId, AutofillValue.forText(password), presentation)
+                            matched = true
+                        }
+                    }
+                }
+            }
+
+            if (!matched) {
+                AutofillCallbackHolder.cancel()
+                result.success(null)
+                finish()
+                return
+            }
+
+            val response = FillResponse.Builder().addDataset(builder.build()).build()
+            callback.onSuccess(response)
+            AutofillCallbackHolder.clear()
+            result.success(null)
+            finish()
+        } catch (e: Exception) {
+            Log.e("AutofillSelection", "fill failed", e)
+            AutofillCallbackHolder.cancel()
+            result.error("fill_error", e.message, null)
+            finish()
+        }
+    }
+
+    override fun onDestroy() {
+        AutofillCallbackHolder.cancel()
+        super.onDestroy()
+    }
+}

android/app/src/main/kotlin/com/mossapps/locker/AutofillService.kt

@@ -0,0 +1,92 @@
+package com.mossapps.locker
+
+import android.app.assist.AssistStructure
+import android.content.Intent
+import android.os.Build
+import android.os.CancellationSignal
+import android.service.autofill.AutofillService
+import android.service.autofill.FillCallback
+import android.service.autofill.FillRequest
+import android.service.autofill.FillResponse
+import android.service.autofill.SaveRequest
+import android.text.InputType
+import android.view.View
+import android.view.autofill.AutofillId
+import androidx.annotation.RequiresApi
+
+@RequiresApi(Build.VERSION_CODES.O)
+class AutofillService : AutofillService() {
+
+    override fun onFillRequest(request: FillRequest, cancellationSignal: CancellationSignal, callback: FillCallback) {
+        val structure = request.fillContexts.lastOrNull()?.structure
+        if (structure == null) {
+            callback.onSuccess(null)
+            return
+        }
+
+        val fields = parseFields(structure)
+        if (fields.isEmpty()) {
+            callback.onSuccess(null)
+            return
+        }
+
+        AutofillCallbackHolder.set(callback, fields)
+
+        val intent = Intent(this, AutofillSelectionActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK
+        }
+        startActivity(intent)
+    }
+
+    override fun onSaveRequest(request: SaveRequest, callback: android.service.autofill.SaveCallback) {
+        callback.onSuccess()
+    }
+
+    private fun parseFields(structure: AssistStructure): List<AutofillField> {
+        val fields = mutableListOf<AutofillField>()
+        val seenIds = mutableSetOf<AutofillId>()
+
+        for (i in 0 until structure.windowNodeCount) {
+            traverseNode(structure.getWindowNodeAt(i).rootViewNode, fields, seenIds)
+        }
+        return fields
+    }
+
+    private fun traverseNode(node: AssistStructure.ViewNode, fields: MutableList<AutofillField>, seenIds: MutableSet<AutofillId>) {
+        val id = node.autofillId
+        if (id != null && id !in seenIds) {
+            val type = classifyField(node)
+            if (type != null) {
+                fields.add(AutofillField(id, type))
+                seenIds.add(id)
+            }
+        }
+
+        for (i in 0 until node.childCount) {
+            traverseNode(node.getChildAt(i), fields, seenIds)
+        }
+    }
+
+    private fun classifyField(node: AssistStructure.ViewNode): FieldType? {
+        val hints = node.autofillHints
+        if (hints != null) {
+            for (hint in hints) {
+                when (hint) {
+                    View.AUTOFILL_HINT_USERNAME, View.AUTOFILL_HINT_EMAIL_ADDRESS -> return FieldType.USERNAME
+                    View.AUTOFILL_HINT_PASSWORD -> return FieldType.PASSWORD
+                }
+            }
+        }
+
+        val inputType = node.inputType
+        val variation = inputType and InputType.TYPE_MASK_VARIATION
+        when (variation) {
+            InputType.TYPE_TEXT_VARIATION_PASSWORD,
+            InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD,
+            InputType.TYPE_NUMBER_VARIATION_PASSWORD -> return FieldType.PASSWORD
+            InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS -> return FieldType.USERNAME
+        }
+
+        return null
+    }
+}

android/app/src/main/res/layout/autofill_suggestion.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="horizontal"
+    android:padding="12dp"
+    android:gravity="center_vertical">
+
+    <ImageView
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:src="@mipmap/launcher_icon"
+        android:layout_marginEnd="12dp" />
+
+    <TextView
+        android:id="@+id/autofill_title"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:textSize="16sp"
+        android:textColor="#FFFFFF"
+        android:singleLine="true"
+        android:ellipsize="end" />
+</LinearLayout>

android/app/src/main/res/xml/autofill_service.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<autofill-service xmlns:android="http://schemas.android.com/apk/res/android"
+    android:settingsActivity="com.mossapps.locker.MainActivity" />

android/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude domain="sharedpref" />
+        <exclude domain="file" />
+        <exclude domain="database" />
+        <exclude domain="root" />
+    </cloud-backup>
+    <device-transfer>
+        <exclude domain="sharedpref" />
+        <exclude domain="file" />
+        <exclude domain="database" />
+        <exclude domain="root" />
+    </device-transfer>
+</data-extraction-rules>