Implemented encrypting Room database, but storing password just in plain text yet

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/activities/LandingActivity.kt

@@ -24,9 +24,7 @@ open class LandingActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        val authenticationType = authenticationService.getAuthenticationType()
+        if (authenticationService.authenticationType == AuthenticationType.None) {
-
-        if (authenticationType == AuthenticationType.None) {
             launchActivity(MainActivity::class.java)
         }
         else {

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/activities/LoginActivity.kt

@@ -2,6 +2,7 @@ package net.dankito.banking.ui.android.activities
 
 import android.os.Bundle
 import android.view.View
+import android.widget.Toast
 import kotlinx.android.synthetic.main.activity_login.*
 import net.dankito.banking.ui.android.MainActivity
 import net.dankito.banking.ui.android.R
@@ -48,8 +49,11 @@ open class LoginActivity : BaseActivity() {
 
 
     protected open fun checkEnteredPasswordAndLogIn() {
-        if (authenticationService.isCorrectUserPassword(edtxtLoginPassword.text)) {
+        val enteredPassword = edtxtLoginPassword.text
-            logIn()
+
+        if (authenticationService.isCorrectUserPassword(enteredPassword)) {
+            authenticationService.userLoggedInWithPassword(enteredPassword)
+            navigateToMainActivity()
         }
         else {
             Toast.makeText(this, R.string.activity_login_incorrect_password_entered, Toast.LENGTH_SHORT).show()
@@ -57,10 +61,11 @@ open class LoginActivity : BaseActivity() {
     }
 
     protected open fun biometricAuthenticationSuccessful() {
-        logIn()
+        authenticationService.userLoggedInWithBiometricAuthentication()
+        navigateToMainActivity()
     }
 
-    protected open fun logIn() {
+    protected open fun navigateToMainActivity() {
         navigateToActivity(MainActivity::class.java)
     }
 

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/authentication/AuthenticationService.kt

@@ -1,14 +1,16 @@
 package net.dankito.banking.ui.android.authentication
 
+import net.dankito.banking.persistence.IBankingPersistence
 import net.dankito.banking.util.ISerializer
 import net.dankito.utils.multiplatform.File
 import org.slf4j.LoggerFactory
 
 
 open class AuthenticationService(
-    protected val biometricAuthenticationService: IBiometricAuthenticationService,
+    protected open val biometricAuthenticationService: IBiometricAuthenticationService,
-    protected val dataFolder: File,
+    protected open val persistence: IBankingPersistence,
-    protected val serializer: ISerializer
+    protected open val dataFolder: File,
+    protected open val serializer: ISerializer
 ) {
 
     companion object {
@@ -29,11 +31,40 @@ open class AuthenticationService(
 
     init {
         authenticationType = loadAuthenticationType()
+
+        if (authenticationType == AuthenticationType.None) {
+            val authenticationSettings = loadAuthenticationSettings()
+
+            if (authenticationSettings == null) { // first app run -> create a default password
+                removeAppProtection()
+            }
+            else {
+                openDatabase(authenticationSettings)
+            }
+        }
     }
 
 
+    open fun userLoggedInWithBiometricAuthentication() {
+        loadAuthenticationSettings()?.let {
+            openDatabase(it)
+        }
+    }
+
+    open fun userLoggedInWithPassword(enteredPassword: String) {
+        openDatabase(enteredPassword)
+    }
+
+    protected open fun openDatabase(authenticationSettings: AuthenticationSettings) {
+        openDatabase(authenticationSettings.userPassword)
+    }
+
+    protected open fun openDatabase(password: String?) {
+        persistence.decryptData(password)
+    }
+
     open fun setAuthenticationMethodToBiometric() {
-        if (saveUserPasswordIfChanged(null)) {
+        if (saveNewUserPassword(generateRandomPassword())) {
             if (saveAuthenticationType(AuthenticationType.Biometric)) {
                 authenticationType = AuthenticationType.Biometric
             }
@@ -41,7 +72,7 @@ open class AuthenticationService(
     }
 
     open fun setAuthenticationMethodToPassword(newPassword: String) {
-        if (saveUserPasswordIfChanged(newPassword)) {
+        if (saveNewUserPassword(newPassword)) {
             if (saveAuthenticationType(AuthenticationType.Password)) {
                 authenticationType = AuthenticationType.Password
             }
@@ -49,7 +80,7 @@ open class AuthenticationService(
     }
 
     open fun removeAppProtection() {
-        if (saveUserPasswordIfChanged(null)) {
+        if (saveNewUserPassword(generateRandomPassword())) {
             if (saveAuthenticationType(AuthenticationType.None)) {
                 authenticationType = AuthenticationType.None
             }
@@ -103,16 +134,22 @@ open class AuthenticationService(
     }
 
 
-    protected open fun saveUserPasswordIfChanged(userPassword: String?): Boolean {
+    protected open fun saveNewUserPassword(newPassword: String?): Boolean {
         val settings = loadOrCreateDefaultAuthenticationSettings()
+        val currentPassword = settings.userPassword
 
-        if (settings.userPassword != userPassword) {
+        if (currentPassword != newPassword) {
-            settings.userPassword = userPassword
+            settings.userPassword = newPassword
 
-            return saveAuthenticationSettings(settings)
+            if (saveAuthenticationSettings(settings)) {
+                persistence.changePassword(currentPassword, newPassword) // TODO: actually this is bad. If changing password fails then password is saved in AuthenticationSettings but DB has a different password
+                return true
+            }
+
+            return false
         }
 
-        return false
+        return true
     }
 
     protected open fun loadOrCreateDefaultAuthenticationSettings(): AuthenticationSettings {
@@ -151,4 +188,20 @@ open class AuthenticationService(
         return false
     }
 
+
+    open fun generateRandomPassword(): String {
+        return generateRandomPassword(30)
+    }
+
+    open fun generateRandomPassword(passwordLength: Int): String {
+        val dictionary = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789§±!@#$%^&*-_=+;:|/?.>,<"
+
+        val passwordBuilder = StringBuilder()
+        IntRange(0, passwordLength).forEach {
+            passwordBuilder.append(dictionary.random())
+        }
+
+        return passwordBuilder.toString()
+    }
+
 }

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/authentication/AuthenticationSettings.kt

@@ -0,0 +1,6 @@
+package net.dankito.banking.ui.android.authentication
+
+
+open class AuthenticationSettings(
+    var userPassword: String? = null
+)

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/authentication/AuthenticationType.kt

@@ -1,12 +1,12 @@
 package net.dankito.banking.ui.android.authentication
 
 
-enum class AuthenticationType {
+enum class AuthenticationType(internal val rawValue: Int) {
 
-    None,
+    None(3),
 
-    Password,
+    Password(7),
 
-    Biometric
+    Biometric(9)
 
 }

ui/BankingAndroidApp/src/main/java/net/dankito/banking/ui/android/di/BankingModule.kt

@@ -89,8 +89,9 @@ class BankingModule(private val applicationContext: Context) {
 
     @Provides
     @Singleton
-    fun provideAuthenticationService(biometricAuthenticationService: IBiometricAuthenticationService, @Named(DataFolderKey) dataFolder: File, serializer: ISerializer) : AuthenticationService {
+    fun provideAuthenticationService(biometricAuthenticationService: IBiometricAuthenticationService, persistence: IBankingPersistence,
-        return AuthenticationService(biometricAuthenticationService, dataFolder, serializer)
+                                     @Named(DataFolderKey) dataFolder: File, serializer: ISerializer) : AuthenticationService {
+        return AuthenticationService(biometricAuthenticationService, persistence, dataFolder, serializer)
     }
 
     @Provides