Add Security Features for kiwix Android App

[787IYO]

import android.os.Bundle;
import android.widget.EditText;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

public class LoginActivity extends AppCompatActivity {

private EditText emailEditText, passwordEditText;
private FirebaseAuth mAuth;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);

    mAuth = FirebaseAuth.getInstance();

    emailEditText = findViewById(R.id.emailEditText);
    passwordEditText = findViewById(R.id.passwordEditText);

    findViewById(R.id.loginButton).setOnClickListener(view -> loginUser());
}

private void loginUser() {
    String email = emailEditText.getText().toString().trim();
    String password = passwordEditText.getText().toString().trim();

    mAuth.signInWithEmailAndPassword(email, password)
            .addOnCompleteListener(this, task -> {
                if (task.isSuccessful()) {
                    // Sign in success, update UI with the signed-in user's information
                    FirebaseUser user = mAuth.getCurrentUser();
                    Toast.makeText(LoginActivity.this, "Login successful.",
                            Toast.LENGTH_SHORT).show();
                    // Proceed to the main activity or any other activity
                } else {
                    // If sign in fails, display a message to the user.
                    Toast.makeText(LoginActivity.this, "Authentication failed.",
                            Toast.LENGTH_SHORT).show();
                }
            });
}

}
import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.hardware.fingerprint.FingerprintManager
import android.os.Bundle
import android.security.keystore.KeyGenParameterSpec
import android.security.keystore.KeyProperties
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import java.security.KeyStore
import javax.crypto.Cipher
import javax.crypto.KeyGenerator
import javax.crypto.SecretKey

class LoginActivity : AppCompatActivity() {

private lateinit var fingerprintManager: FingerprintManager
private lateinit var keyStore: KeyStore
private lateinit var keyGenerator: KeyGenerator
private lateinit var cipher: Cipher

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_login)

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT)
        != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this,
            arrayOf(Manifest.permission.USE_FINGERPRINT), REQUEST_PERMISSIONS_CODE)
    }

    // Check if the device supports fingerprint authentication
    val fingerprintManager = getSystemService(Context.FINGERPRINT_SERVICE) as FingerprintManager
    if (!fingerprintManager.isHardwareDetected) {
        // Device doesn't support fingerprint authentication
        Toast.makeText(this, "Fingerprint authentication not supported", Toast.LENGTH_SHORT).show()
        return
    }

    // Check if fingerprint permission is granted
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
        Toast.makeText(this, "Fingerprint permission not granted", Toast.LENGTH_SHORT).show()
        return
    }

    // Generate the key used for encryption
    try {
        keyStore = KeyStore.getInstance("AndroidKeyStore")
        keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")

        keyStore.load(null)
        val keySpec = KeyGenParameterSpec.Builder(
            KEY_NAME,
            KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
        )
            .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
            .setUserAuthenticationRequired(true)
            .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7)
            .build()

        keyGenerator.init(keySpec)
        keyGenerator.generateKey()

    } catch (e: Exception) {
        e.printStackTrace()
    }

    // Initialize the cipher
    try {
        cipher = Cipher.getInstance(
            KeyProperties.KEY_ALGORITHM_AES + "/" +
                    KeyProperties.BLOCK_MODE_CBC + "/" +
                    KeyProperties.ENCRYPTION_PADDING_PKCS7
        )
        val key = keyStore.getKey(KEY_NAME, null) as SecretKey
        cipher.init(Cipher.ENCRYPT_MODE, key)

        // Authenticate user using fingerprint
        val cryptoObject = FingerprintManager.CryptoObject(cipher)
        val helper = FingerprintHandler(this)
        helper.startAuth(fingerprintManager, cryptoObject)

    } catch (e: Exception) {
        e.printStackTrace()
    }
}

companion object {
    private const val REQUEST_PERMISSIONS_CODE = 123
    private const val KEY_NAME = "YourKeyName"
}

}
import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.hardware.fingerprint.FingerprintManager
import android.os.CancellationSignal
import android.widget.Toast
import androidx.core.app.ActivityCompat

class FingerprintHandler(private val context: Context) : FingerprintManager.AuthenticationCallback() {

fun startAuth(manager: FingerprintManager, cryptoObject: FingerprintManager.CryptoObject) {
    val cancellationSignal = CancellationSignal()
    if (ActivityCompat.checkSelfPermission(
            context,
            Manifest.permission.USE_FINGERPRINT
        ) != PackageManager.PERMISSION_GRANTED
    ) {
        return
    }
    manager.authenticate(cryptoObject, cancellationSignal, 0, this, null)
}

override fun onAuthenticationError(errMsgId: Int, errString: CharSequence?) {
    super.onAuthenticationError(errMsgId, errString)
    Toast.makeText(context, "Authentication error: $errString", Toast.LENGTH_SHORT).show()
}

override fun onAuthenticationHelp(helpMsgId: Int, helpString: CharSequence?) {
    super.onAuthenticationHelp(helpMsgId, helpString)
    Toast.makeText(context, "Authentication help: $helpString", Toast.LENGTH_SHORT

[kelson42]

I have no clue what this messages means. @MohitMaliDeveloper Do you?