Added Password Protection and biometric authentication by Encrypted Shared Preferences and biometrics in android

android/app/build.gradle.kts

@@ -66,7 +66,7 @@ android {
 }
 
 dependencies {
-
+    implementation("androidx.appcompat:appcompat:1.7.0")
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.lifecycle.runtime.ktx)
     implementation(libs.androidx.activity.compose)
@@ -108,7 +108,8 @@ dependencies {
     implementation ("androidx.glance:glance-appwidget:1.0.0")
     implementation ("androidx.glance:glance-material3:1.0.0")
     implementation ("androidx.lifecycle:lifecycle-livedata-ktx:2.8.6")
-
+    implementation("androidx.security:security-crypto:1.1.0-alpha04")
+    implementation("androidx.biometric:biometric:1.4.0-alpha02")
 }
 
 kapt{

android/app/src/main/java/rocks/poopjournal/fucksgiven/MainActivity.kt

@@ -1,29 +1,31 @@
 package rocks.poopjournal.fucksgiven
 
-import android.app.LocaleConfig
-import android.app.LocaleManager
 import android.os.Build
-import android.os.Build.VERSION.SDK_INT
 import android.os.Bundle
-import android.os.LocaleList
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.annotation.RequiresApi
-import androidx.appcompat.app.AppCompatDelegate
+import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.runtime.collectAsState
-import androidx.core.os.LocaleListCompat
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.navigation.compose.rememberNavController
 import dagger.hilt.android.AndroidEntryPoint
+import rocks.poopjournal.fucksgiven.data.getPasswordProtectionEnabled
+import rocks.poopjournal.fucksgiven.presentation.component.BiometricPromptManager
 import rocks.poopjournal.fucksgiven.presentation.navigation.NavGraph
+import rocks.poopjournal.fucksgiven.presentation.screens.PasswordPromptScreen
 import rocks.poopjournal.fucksgiven.presentation.ui.theme.FucksGivenTheme
 import rocks.poopjournal.fucksgiven.presentation.ui.utils.AppTheme
 import rocks.poopjournal.fucksgiven.presentation.ui.utils.ThemeSetting
 import javax.inject.Inject
 
 @AndroidEntryPoint
-class MainActivity : ComponentActivity() {
+class MainActivity : AppCompatActivity() {
     @Inject
     lateinit var themeSetting: ThemeSetting
 
@@ -39,7 +41,15 @@ class MainActivity : ComponentActivity() {
                 AppTheme.DARK -> true
             }
             FucksGivenTheme(darkTheme = useDarkColors) {
-                NavGraph(navController = rememberNavController(), themeSetting = themeSetting, context = this)
+                var isAuthenticated by remember { mutableStateOf(false) }
+                val isPasswordProtectionEnabled = getPasswordProtectionEnabled(context = this)
+                if (isAuthenticated || !isPasswordProtectionEnabled) {
+                    NavGraph(navController = rememberNavController(), themeSetting = themeSetting, context = this)
+                } else {
+                    PasswordPromptScreen(context = this) {
+                        isAuthenticated = true
+                    }
+                }
             }
         }
     }

android/app/src/main/java/rocks/poopjournal/fucksgiven/data/SecureStorage.kt

@@ -0,0 +1,49 @@
+package rocks.poopjournal.fucksgiven.data
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKeys
+
+fun getEncryptedSharedPreferences(context: Context): SharedPreferences {
+    val masterKeyAlias = MasterKeys.getOrCreate(MasterKeys.AES256_GCM_SPEC)
+
+    return EncryptedSharedPreferences.create(
+        "secure_prefs",
+        masterKeyAlias,
+        context,
+        EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+        EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+    )
+}
+
+fun savePassword(context: Context, password: String) {
+    val sharedPreferences = getEncryptedSharedPreferences(context)
+    val editor = sharedPreferences.edit()
+    editor.putString("user_password", password)
+    editor.apply()
+}
+
+fun getPassword(context: Context): String? {
+    val sharedPreferences = getEncryptedSharedPreferences(context)
+    return sharedPreferences.getString("user_password", null)
+}
+
+fun clearStoredPassword(context: Context) {
+    val sharedPreferences = getEncryptedSharedPreferences(context)
+    val editor = sharedPreferences.edit()
+    editor.remove("user_password")
+    editor.apply()
+}
+
+fun setPasswordProtectionEnabled(context: Context, enabled: Boolean) {
+    val sharedPreferences = getEncryptedSharedPreferences(context)
+    val editor = sharedPreferences.edit()
+    editor.putBoolean("password_protection_enabled", enabled)
+    editor.apply()
+}
+
+fun getPasswordProtectionEnabled(context: Context): Boolean {
+    val sharedPreferences = getEncryptedSharedPreferences(context)
+    return sharedPreferences.getBoolean("password_protection_enabled", false)
+}

android/app/src/main/java/rocks/poopjournal/fucksgiven/presentation/component/BiometricPromptManager.kt

@@ -0,0 +1,83 @@
+package rocks.poopjournal.fucksgiven.presentation.component
+
+import android.os.Build
+import androidx.appcompat.app.AppCompatActivity
+import androidx.biometric.BiometricManager
+import androidx.biometric.BiometricManager.Authenticators.BIOMETRIC_STRONG
+import androidx.biometric.BiometricManager.Authenticators.DEVICE_CREDENTIAL
+import androidx.biometric.BiometricPrompt
+import androidx.biometric.BiometricPrompt.PromptInfo
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.receiveAsFlow
+
+class BiometricPromptManager(
+    private val activity: AppCompatActivity
+) {
+    private val resultChannel = Channel<BiometricResult>()
+    val promptResults = resultChannel.receiveAsFlow()
+
+    fun showBiometricPrompt(
+        title: String,
+        description: String
+    ) {
+        val manager = BiometricManager.from(activity)
+        val authenticators = if(Build.VERSION.SDK_INT >= 30) {
+            BIOMETRIC_STRONG or DEVICE_CREDENTIAL
+        } else BIOMETRIC_STRONG
+
+        val promptInfo = PromptInfo.Builder()
+            .setTitle(title)
+            .setDescription(description)
+            .setAllowedAuthenticators(authenticators)
+
+        if(Build.VERSION.SDK_INT < 30) {
+            promptInfo.setNegativeButtonText("Cancel")
+        }
+
+        when(manager.canAuthenticate(authenticators)) {
+            BiometricManager.BIOMETRIC_ERROR_HW_UNAVAILABLE -> {
+                resultChannel.trySend(BiometricResult.HardwareUnavailable)
+                return
+            }
+            BiometricManager.BIOMETRIC_ERROR_NO_HARDWARE -> {
+                resultChannel.trySend(BiometricResult.FeatureUnavailable)
+                return
+            }
+            BiometricManager.BIOMETRIC_ERROR_NONE_ENROLLED -> {
+                resultChannel.trySend(BiometricResult.AuthenticationNotSet)
+                return
+            }
+            else -> Unit
+        }
+
+        val prompt = BiometricPrompt(
+            activity,
+            object : BiometricPrompt.AuthenticationCallback() {
+                override fun onAuthenticationError(errorCode: Int, errString: CharSequence) {
+                    super.onAuthenticationError(errorCode, errString)
+                    resultChannel.trySend(BiometricResult.AuthenticationError(errString.toString()))
+                }
+
+                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult) {
+                    super.onAuthenticationSucceeded(result)
+                    resultChannel.trySend(BiometricResult.AuthenticationSuccess)
+                }
+
+                override fun onAuthenticationFailed() {
+                    super.onAuthenticationFailed()
+                    resultChannel.trySend(BiometricResult.AuthenticationFailed)
+                }
+            }
+        )
+        prompt.authenticate(promptInfo.build())
+    }
+
+    sealed interface BiometricResult {
+        data object HardwareUnavailable: BiometricResult
+        data object FeatureUnavailable: BiometricResult
+        data class AuthenticationError(val error: String): BiometricResult
+        data object AuthenticationFailed: BiometricResult
+        data object AuthenticationSuccess: BiometricResult
+        data object AuthenticationNotSet: BiometricResult
+    }
+}

android/app/src/main/java/rocks/poopjournal/fucksgiven/presentation/navigation/AppRoutes.kt

@@ -3,4 +3,5 @@ package rocks.poopjournal.fucksgiven.presentation.navigation
 const val HOME_SCREEN = "HomeScreen"
 const val SETTINGS_SCREEN = "SettingsScreen"
 const val STATS_SCREEN = "StatsScreen"
-const val ABOUT_SCREEN = "AboutScreen"
+const val ABOUT_SCREEN = "AboutScreen"
+const val PASSWORD_PROMPT_SCREEN = "PasswordPromptScreen"

android/app/src/main/java/rocks/poopjournal/fucksgiven/presentation/navigation/NavGraph.kt

@@ -11,6 +11,7 @@ import androidx.navigation.compose.composable
 import rocks.poopjournal.fucksgiven.presentation.screens.AboutScreen
 import rocks.poopjournal.fucksgiven.presentation.viewmodel.HomeViewModel
 import rocks.poopjournal.fucksgiven.presentation.screens.HomeScreen
+import rocks.poopjournal.fucksgiven.presentation.screens.PasswordPromptScreen
 import rocks.poopjournal.fucksgiven.presentation.screens.SettingScreen
 import rocks.poopjournal.fucksgiven.presentation.screens.StatsScreen
 import rocks.poopjournal.fucksgiven.presentation.ui.utils.ThemeSetting
@@ -19,7 +20,7 @@ import rocks.poopjournal.fucksgiven.presentation.viewmodel.StatsViewModel
 
 @RequiresApi(Build.VERSION_CODES.P)
 @Composable
-fun NavGraph(navController: NavHostController,themeSetting: ThemeSetting,context: Context){
+fun NavGraph(navController: NavHostController,themeSetting: ThemeSetting, context: Context){
     val viewModel : HomeViewModel = hiltViewModel()
     val statsViewModel : StatsViewModel = hiltViewModel()
     val settingsViewModel : SettingsViewModel = hiltViewModel()
@@ -37,8 +38,12 @@ fun NavGraph(navController: NavHostController,themeSetting: ThemeSetting,context
         }
 
         composable(route = SETTINGS_SCREEN){
-            SettingScreen(navController = navController, viewModel = settingsViewModel)
+            SettingScreen(navController = navController, viewModel = settingsViewModel, context = context)
+        }
+        composable(route = PASSWORD_PROMPT_SCREEN){
+            PasswordPromptScreen(context, onAuthenticated = {
+                navController.navigate(HOME_SCREEN)
+            })
         }
-
     }
 }