Create dsa android fingerprint alg.java

Java/dsa android fingerprint alg.java

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+package com.paulsofts.gfgfingerprintauthentication;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+
+import android.Manifest;
+import android.annotation.TargetApi;
+import android.app.KeyguardManager;
+import android.content.pm.PackageManager;
+import android.hardware.fingerprint.FingerprintManager;
+import android.os.Build;
+import android.os.Bundle;
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyPermanentlyInvalidatedException;
+import android.security.keystore.KeyProperties;
+import android.widget.TextView;
+
+import java.io.IOException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.UnrecoverableKeyException;
+import java.security.cert.CertificateException;
+
+import javax.crypto.Cipher;
+import javax.crypto.KeyGenerator;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+
+public class MainActivity extends AppCompatActivity {
+
+	private KeyStore keyStore;
+	// Defining variable for storing
+	// key in android keystore container
+	private static final String KEY_NAME = "GEEKSFORGEEKS";
+	private Cipher cipher;
+	private TextView errorText;
+
+	@Override
+	protected void onCreate(Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		setContentView(R.layout.activity_main);
+
+		// Initializing KeyguardManager and FingerprintManager
+		KeyguardManager keyguardManager = (KeyguardManager) getSystemService(KEYGUARD_SERVICE);
+		FingerprintManager fingerprintManager = (FingerprintManager) getSystemService(FINGERPRINT_SERVICE);
+
+		// Initializing our error text
+		errorText = (TextView) findViewById(R.id.errorText);
+
+		// Here, we are using various security checks
+		// Checking device is inbuilt with fingerprint sensor or not
+		if(!fingerprintManager.isHardwareDetected()){
+
+			// Setting error message if device
+			// doesn't have fingerprint sensor
+			errorText.setText("Device does not support fingerprint sensor");
+		}else {
+			// Checking fingerprint permission
+			if (ActivityCompat.checkSelfPermission(this, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
+				errorText.setText("Fingerprint authentication is not enabled");
+			}else{
+				// Check for at least one registered finger
+				if (!fingerprintManager.hasEnrolledFingerprints()) {
+					errorText.setText("Register at least one finger");
+				}else{
+					// Checking for screen lock security
+					if (!keyguardManager.isKeyguardSecure()) {
+						errorText.setText("Screen lock security not enabled");
+					}else{
+
+						// if everything is enabled and correct then we will generate
+						// the encryption key which will be stored on the device
+						generateKey();
+						if (cipherInit()) {
+							FingerprintManager.CryptoObject cryptoObject = new FingerprintManager.CryptoObject(cipher);
+							FingerprintHandler helper = new FingerprintHandler(this);
+							helper.startAuth(fingerprintManager, cryptoObject);
+						}
+					}
+				}
+			}
+		}
+	}
+
+
+	@TargetApi(Build.VERSION_CODES.M)
+	protected void generateKey() {
+		try {
+			keyStore = KeyStore.getInstance("AndroidKeyStore");
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+
+
+		KeyGenerator keyGenerator;
+		try {
+			keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
+		} catch (NoSuchAlgorithmException | NoSuchProviderException e) {
+			throw new RuntimeException("KeyGenerator instance failed", e);
+		}
+
+		try {
+			keyStore.load(null);
+			keyGenerator.init(new
+					KeyGenParameterSpec.Builder(KEY_NAME,
+					KeyProperties.PURPOSE_ENCRYPT |
+							KeyProperties.PURPOSE_DECRYPT)
+					.setBlockModes(KeyProperties.BLOCK_MODE_CBC)
+					.setUserAuthenticationRequired(true)
+					.setEncryptionPaddings(
+							KeyProperties.ENCRYPTION_PADDING_PKCS7)
+					.build());
+			keyGenerator.generateKey();
+		} catch (NoSuchAlgorithmException |
+				InvalidAlgorithmParameterException
+				| CertificateException | IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+
+	@TargetApi(Build.VERSION_CODES.M)
+	public boolean cipherInit() {
+		try {
+			cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/" + KeyProperties.BLOCK_MODE_CBC + "/" + KeyProperties.ENCRYPTION_PADDING_PKCS7);
+		} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
+			throw new RuntimeException("Cipher failed", e);
+		}
+
+		try {
+			keyStore.load(null);
+			SecretKey key = (SecretKey) keyStore.getKey(KEY_NAME,
+					null);
+			cipher.init(Cipher.ENCRYPT_MODE, key);
+			return true;
+		} catch (KeyPermanentlyInvalidatedException e) {
+			return false;
+		} catch (KeyStoreException | CertificateException | UnrecoverableKeyException | IOException | NoSuchAlgorithmException | InvalidKeyException e) {
+			throw new RuntimeException("Cipher initialization failed", e);
+		}
+	}
+}