fingerprint lock

main fest

<uses-permission android:name="android.permission.USE_FINGERPRINT" />













activity main xml 








<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="START AUTHENTICATION"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />


</android.support.constraint.ConstraintLayout>

















The code for the dialog_fingerprint.xml is given below:







 <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="24dp"
    android:paddingTop="24dp"
    android:paddingRight="24dp"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent">

    <TextView
        android:id="@+id/titleTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Fingerprint Dialog"
        android:textAppearance="?android:attr/textAppearanceLarge"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent" />

    <TextView
        android:id="@+id/subtitleTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="Confirm fingerprint to continue."
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/titleTextView" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="28dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@id/subtitleTextView"
        app:srcCompat="@drawable/ic_fingerprint_white_24dp" />

    <TextView
        android:id="@+id/errorTextView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="16dp"
        android:gravity="center_vertical"
        android:text="Touch sensor"
        app:layout_constraintBottom_toBottomOf="@id/fab"
        app:layout_constraintLeft_toRightOf="@id/fab"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="@id/fab" />

    <LinearLayout
        android:id="@+id/buttons"
        style="?android:attr/buttonBarStyle"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:gravity="end"
        android:orientation="horizontal"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/fab">

        <Button
            android:id="@+id/btnCancel"
            style="?android:attr/buttonBarButtonStyle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Cancel" />
    </LinearLayout>


</android.support.constraint.ConstraintLayout>

















FingerprintHelper.java










 package com.journaldev.androidfingerprintapi;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.fingerprint.FingerprintManager;
import android.os.CancellationSignal;
import android.support.v4.app.ActivityCompat;

public class FingerprintHelper extends FingerprintManager.AuthenticationCallback {


    private Context mContext;
    private FingerprintManager mFingerprintManager;
    private CancellationSignal mCancellationSignal;
    private Callback mCallback;


    public FingerprintHelper(FingerprintManager fingerprintManager, Context context, Callback callback) {
        mContext = context;
        mFingerprintManager = fingerprintManager;
        mCallback = callback;

    }


    public boolean isFingerprintAuthAvailable() {

        return mFingerprintManager.isHardwareDetected()
                && mFingerprintManager.hasEnrolledFingerprints();
    }


    public void startAuthentication(FingerprintManager manager, FingerprintManager.CryptoObject cryptoObject) {

        if (!isFingerprintAuthAvailable())
            return;

        mCancellationSignal = new CancellationSignal();
        if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
            return;
        }

        manager.authenticate(cryptoObject, mCancellationSignal, 0, this, null);
    }


    public void stopListening() {
        if (mCancellationSignal != null) {
            mCancellationSignal.cancel();
            mCancellationSignal = null;
        }
    }

    @Override
    public void onAuthenticationError(int errMsgId, CharSequence errString) {
        mCallback.onError(errString.toString());
    }


    @Override
    public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
        mCallback.onHelp(helpString.toString());
    }


    @Override
    public void onAuthenticationFailed() {
        mCallback.onAuthenticated(false);
    }


    @Override
    public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
        mCallback.onAuthenticated(true);
    }


    public interface Callback {

        void onAuthenticated(boolean b);

        void onError(String s);

        void onHelp(String s);
    }
}















manager.authenticate(cryptoObject, mCancellationSignal, 0, this, null);
















MainActivity.java 







 package com.journaldev.androidfingerprintapi;

import android.support.v4.hardware.fingerprint.FingerprintManagerCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    Button button;
    FingerprintManagerCompat managerCompat;

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

        button = findViewById(R.id.button);
        button.setOnClickListener(this);

    }

    private void showFingerPrintDialog() {

        FingerprintDialog fragment = new FingerprintDialog();
        fragment.setContext(this);
        fragment.show(getSupportFragmentManager(), "");


    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button:
                managerCompat = FingerprintManagerCompat.from(MainActivity.this);

                if (managerCompat.isHardwareDetected() && managerCompat.hasEnrolledFingerprints()) {
                    showFingerPrintDialog();
                } else {
                    Toast.makeText(getApplicationContext(), "Fingerprint not supported", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }

}














FingerprintDialog.java







 package com.journaldev.androidfingerprintapi;

import android.app.KeyguardManager;
import android.content.Context;
import android.content.Intent;
import android.hardware.fingerprint.FingerprintManager;
import android.os.Bundle;
import android.security.keystore.KeyGenParameterSpec;
import android.security.keystore.KeyPermanentlyInvalidatedException;
import android.security.keystore.KeyProperties;
import android.support.v4.app.DialogFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;

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 FingerprintDialog extends DialogFragment
        implements FingerprintHelper.Callback {

    Button mCancelButton;
    public static final String DEFAULT_KEY_NAME = "default_key";
    FingerprintManager mFingerprintManager;

    private FingerprintManager.CryptoObject mCryptoObject;
    private FingerprintHelper mFingerprintHelper;

    KeyStore mKeyStore = null;
    KeyGenerator mKeyGenerator = null;
    KeyguardManager mKeyguardManager;

    private Context mContext;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setRetainInstance(true);
        setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Material_Light_Dialog);

        try {
            mKeyStore = KeyStore.getInstance("AndroidKeyStore");

        } catch (KeyStoreException e) {
            e.printStackTrace();
        }

        try {
            mKeyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        }

        Cipher defaultCipher;
        try {
            defaultCipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
                    + KeyProperties.BLOCK_MODE_CBC + "/"
                    + KeyProperties.ENCRYPTION_PADDING_PKCS7);
        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
            throw new RuntimeException("Failed to get an instance of Cipher", e);
        }

        mKeyguardManager = getContext().getSystemService(KeyguardManager.class);
        mFingerprintManager = getContext().getSystemService(FingerprintManager.class);

        mFingerprintHelper = new FingerprintHelper(mFingerprintManager, getContext(), this);

        if (!mKeyguardManager.isKeyguardSecure()) {
            Toast.makeText(getContext(),
                    "Lock screen not set up.\n"
                            + "Go to 'Settings -> Security -> Fingerprint' to set up a fingerprint",
                    Toast.LENGTH_LONG).show();
            return;
        }

        createKey(DEFAULT_KEY_NAME);

        if (initCipher(defaultCipher, DEFAULT_KEY_NAME)) {
            mCryptoObject = new FingerprintManager.CryptoObject(defaultCipher);
        }
    }

    private boolean initCipher(Cipher cipher, String keyName) {
        try {
            mKeyStore.load(null);
            SecretKey key = (SecretKey) mKeyStore.getKey(keyName, null);
            cipher.init(Cipher.ENCRYPT_MODE, key);


            return true;
        } catch (KeyPermanentlyInvalidatedException e) {
            Toast.makeText(mContext, "Keys are invalidated after created. Retry the purchase\n"
                            + e.getMessage(),
                    Toast.LENGTH_LONG).show();

            return false;
        } catch (KeyStoreException | CertificateException | UnrecoverableKeyException | IOException
                | NoSuchAlgorithmException | InvalidKeyException e) {
            Toast.makeText(mContext, "Failed to init cipher", Toast.LENGTH_LONG).show();
            return false;
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.dialog_fingerprint, container, false);
        mCancelButton = v.findViewById(R.id.btnCancel);
        mCancelButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                dismiss();
            }
        });

        return v;
    }

    @Override
    public void onResume() {
        super.onResume();

        if (mCryptoObject != null) {
            mFingerprintHelper.startAuthentication(mFingerprintManager, mCryptoObject);
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        mFingerprintHelper.stopListening();
    }

    public void setContext(Context context) {
        mContext = context;
    }


    public void createKey(String keyName) {
        try {
            mKeyStore.load(null);
           

            KeyGenParameterSpec.Builder builder = new KeyGenParameterSpec.Builder(keyName,
                    KeyProperties.PURPOSE_ENCRYPT |
                            KeyProperties.PURPOSE_DECRYPT)
                    .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                    .setUserAuthenticationRequired(true)
                    .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7);

            mKeyGenerator.init(builder.build());
            mKeyGenerator.generateKey();
        } catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException
                | CertificateException | IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void onAuthenticated(boolean b) {
        if (b) {
            Toast.makeText(mContext.getApplicationContext(), "Auth success", Toast.LENGTH_LONG).show();
            dismiss();
        } else
            Toast.makeText(mContext.getApplicationContext(), "Auth failed", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onError(String s) {
        Toast.makeText(mContext.getApplicationContext(), s, Toast.LENGTH_LONG).show();
    }

    @Override
    public void onHelp(String s) {
        Toast.makeText(mContext.getApplicationContext(), "Auth help message:" + s, Toast.LENGTH_LONG).show();
    }
}