samples/BiometricDemos/src/main/java/com/example/android/biometric/BiometricPromptDemoBiometricBoundKeyActivity.java - platform/frameworks/support - Git at Google

 /*
  * Copyright 2019 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.example.android.biometric;

 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
 import android.util.Log;
 import android.view.View;
 import android.widget.TextView;

 import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
 import androidx.biometric.BiometricPrompt;
 import androidx.fragment.app.FragmentActivity;

 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
 import java.security.NoSuchProviderException;
 import java.security.UnrecoverableKeyException;
 import java.security.cert.CertificateException;
 import java.util.Arrays;
 import java.util.concurrent.Executor;

 import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
 import javax.crypto.IllegalBlockSizeException;
 import javax.crypto.NoSuchPaddingException;
 import javax.crypto.SecretKey;
 import javax.crypto.spec.IvParameterSpec;

 /**
  * Demo activity that shows how BiometricPrompt can be used with biometric bound secret keys.
  */
 @RequiresApi(api = Build.VERSION_CODES.M)
 public class BiometricPromptDemoBiometricBoundKeyActivity extends FragmentActivity {

     private static final String TAG = "bio_prompt_demo_control";
     private static final String LOG_BUNDLE = "log";
     private static final String KEY_NAME = "demo_key";
     private static final String PAYLOAD = "hello";

     private final Handler mHandler = new Handler(Looper.getMainLooper());
     private final Executor mExecutor = mHandler::post;
     private BiometricPrompt mBiometricPrompt;
     private TextView mLogTextView;
     private Cipher mEncryptingCipher;
     private View mEncryptButton;
     private byte[] mEncryptedBytes;
     // If true decrypt, if false encrypt.
     private boolean mShouldDecrypt;

     private void log(String s) {
         Log.d(TAG, s);
         mLogTextView.append(s + '\n');
     }

     private void log(String s, Throwable tr) {
         Log.e(TAG, "", tr);
         mLogTextView.append(s + '\n' + tr.toString() + '\n');
     }

     private final BiometricPrompt.PromptInfo mPromptInfo = new BiometricPrompt.PromptInfo.Builder()
             .setTitle("Title")
             .setSubtitle("Subtitle")
             .setDescription("Description")
             .setNegativeButtonText("Negative Button")
             .build();

     private final BiometricPrompt.AuthenticationCallback mAuthenticationCallback =
             new BiometricPrompt.AuthenticationCallback() {

                 @Override
                 public void onAuthenticationError(int err, @NonNull CharSequence message) {
                     log("onAuthenticationError " + err + ": " + message);
                 }

                 @Override
                 public void onAuthenticationSucceeded(
                         @NonNull BiometricPrompt.AuthenticationResult result) {
                     final BiometricPrompt.CryptoObject cryptoObject = result.getCryptoObject();
                     log("onAuthenticationSucceeded, cryptoObject: " + cryptoObject);
                     if (cryptoObject != null) {
                         try {
                             if (mShouldDecrypt) {
                                 log("Decrypted payload: " + new String(
                                         cryptoObject.getCipher().doFinal(mEncryptedBytes)));
                             } else {
                                 // Save the cipher to use for decryption.
                                 mEncryptingCipher = cryptoObject.getCipher();
                                 mEncryptedBytes = mEncryptingCipher.doFinal(
                                         PAYLOAD.getBytes(Charset.defaultCharset()));
                                 log("Test payload: " + PAYLOAD);
                                 log("Encrypted payload: " + Arrays.toString(mEncryptedBytes));
                             }
                         } catch (BadPaddingException | IllegalBlockSizeException e) {
                             log("Failed to encrypt", e);
                         }
                     }
                 }

                 @Override
                 public void onAuthenticationFailed() {
                     log("onAuthenticationFailed");
                     mBiometricPrompt.cancelAuthentication();
                 }
             };

     private View.OnClickListener mGenerateKeyListener = view -> {
         try {
             BiometricPromptDemoSecretKeyHelper.generateBiometricBoundKey(KEY_NAME,
                     true /* invalidatedByBiometricEnrollment */);
             log("Generated a key");
         } catch (InvalidAlgorithmParameterException | NoSuchAlgorithmException
                 | NoSuchProviderException e) {
             log("Failed to generate key", e);
         }
     };

     private Cipher getCryptoCipher() {
         Cipher cipher = null;
         try {
             cipher = BiometricPromptDemoSecretKeyHelper.getCipher();
         } catch (NoSuchPaddingException | NoSuchAlgorithmException e) {
             log("Failed to get cipher", e);
         }
         return cipher;
     }

     private SecretKey getSecretKey() {
         SecretKey secretKey = null;
         try {
             secretKey = BiometricPromptDemoSecretKeyHelper.getSecretKey(KEY_NAME);
         } catch (KeyStoreException | CertificateException | NoSuchAlgorithmException | IOException
                 | UnrecoverableKeyException e) {
             log("Failed to get secret key", e);
         }
         return secretKey;
     }

     private void authenticateWithCrypto(Cipher cipher) {
         mBiometricPrompt.authenticate(mPromptInfo, new BiometricPrompt.CryptoObject(cipher));
     }

     private void authenticateWithEncryption() {
         Cipher cipher = getCryptoCipher();
         SecretKey secretKey = getSecretKey();
         if (cipher == null || secretKey == null) {
             return;
         }
         try {
             cipher.init(Cipher.ENCRYPT_MODE, secretKey);
             mBiometricPrompt.authenticate(mPromptInfo,
                     new BiometricPrompt.CryptoObject(cipher));
             log("Started authentication with a crypto object");
             authenticateWithCrypto(cipher);
             mShouldDecrypt = false;
         } catch (InvalidKeyException e) {
             log("Failed to init cipher", e);
         }
     }

     private void authenticateWithDecryption() {
         Cipher cipher = getCryptoCipher();
         SecretKey secretKey = getSecretKey();
         if (cipher == null || secretKey == null) {
             return;
         }
         if (mEncryptingCipher == null) {
             log("User must first encrypt a message");
             flashEncryptButton();
             return;
         }

         try {
             cipher.init(Cipher.DECRYPT_MODE, secretKey,
                     new IvParameterSpec(mEncryptingCipher.getIV()));
             mBiometricPrompt.authenticate(mPromptInfo,
                     new BiometricPrompt.CryptoObject(cipher));
             log("Started authentication with a crypto object");
             authenticateWithCrypto(cipher);
             mShouldDecrypt = true;
         } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
             log("Failed to init cipher", e);
         }
     }

     private void flashEncryptButton() {
         mEncryptButton.animate().alpha(0).setDuration(1000).withEndAction(new Runnable() {
             @Override
             public void run() {
                 mEncryptButton.animate().alpha(1).setDuration(1000);
             }
         });
     }

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

         mLogTextView = findViewById(R.id.text_view_log);
         mBiometricPrompt = new BiometricPrompt(this, mExecutor, mAuthenticationCallback);

         ((TextView) findViewById(R.id.text_view_activity_description)).setText(
                 R.string.label_biometric_bound_key_activity_description);

         if (savedInstanceState != null) {
             mLogTextView.setText(savedInstanceState.getCharSequence(LOG_BUNDLE));
         }

         findViewById(R.id.button_generate_key).setOnClickListener(mGenerateKeyListener);
         mEncryptButton = findViewById(R.id.button_unlock_and_use_key);
         mEncryptButton.setOnClickListener(v -> authenticateWithEncryption());
         findViewById(R.id.button_clear_log).setOnClickListener(v -> mLogTextView.setText(""));
         findViewById(R.id.button_decrypt).setOnClickListener(v -> authenticateWithDecryption());
     }

     @Override
     protected void onPause() {
         mEncryptingCipher = null;
         mShouldDecrypt = false;
         mBiometricPrompt.cancelAuthentication();
         super.onPause();
     }

     @Override
     protected void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
         outState.putCharSequence(LOG_BUNDLE, mLogTextView.getText());
     }
 }
	/*
	* Copyright 2019 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.example.android.biometric;

	import android.os.Build;
	import android.os.Bundle;
	import android.os.Handler;
	import android.os.Looper;
	import android.util.Log;
	import android.view.View;
	import android.widget.TextView;

	import androidx.annotation.NonNull;
	import androidx.annotation.RequiresApi;
	import androidx.biometric.BiometricPrompt;
	import androidx.fragment.app.FragmentActivity;

	import java.io.IOException;
	import java.nio.charset.Charset;
	import java.security.InvalidAlgorithmParameterException;
	import java.security.InvalidKeyException;
	import java.security.KeyStoreException;
	import java.security.NoSuchAlgorithmException;
	import java.security.NoSuchProviderException;
	import java.security.UnrecoverableKeyException;
	import java.security.cert.CertificateException;
	import java.util.Arrays;
	import java.util.concurrent.Executor;

	import javax.crypto.BadPaddingException;
	import javax.crypto.Cipher;
	import javax.crypto.IllegalBlockSizeException;
	import javax.crypto.NoSuchPaddingException;
	import javax.crypto.SecretKey;
	import javax.crypto.spec.IvParameterSpec;

	/**
	* Demo activity that shows how BiometricPrompt can be used with biometric bound secret keys.
	*/
	@RequiresApi(api = Build.VERSION_CODES.M)
	public class BiometricPromptDemoBiometricBoundKeyActivity extends FragmentActivity {

	private static final String TAG = "bio_prompt_demo_control";
	private static final String LOG_BUNDLE = "log";
	private static final String KEY_NAME = "demo_key";
	private static final String PAYLOAD = "hello";

	private final Handler mHandler = new Handler(Looper.getMainLooper());
	private final Executor mExecutor = mHandler::post;
	private BiometricPrompt mBiometricPrompt;
	private TextView mLogTextView;
	private Cipher mEncryptingCipher;
	private View mEncryptButton;
	private byte[] mEncryptedBytes;
	// If true decrypt, if false encrypt.
	private boolean mShouldDecrypt;

	private void log(String s) {
	Log.d(TAG, s);
	mLogTextView.append(s + '\n');
	}

	private void log(String s, Throwable tr) {
	Log.e(TAG, "", tr);
	mLogTextView.append(s + '\n' + tr.toString() + '\n');
	}

	private final BiometricPrompt.PromptInfo mPromptInfo = new BiometricPrompt.PromptInfo.Builder()
	.setTitle("Title")
	.setSubtitle("Subtitle")
	.setDescription("Description")
	.setNegativeButtonText("Negative Button")
	.build();

	private final BiometricPrompt.AuthenticationCallback mAuthenticationCallback =
	new BiometricPrompt.AuthenticationCallback() {

	@Override
	public void onAuthenticationError(int err, @NonNull CharSequence message) {
	log("onAuthenticationError " + err + ": " + message);
	}

	@Override
	public void onAuthenticationSucceeded(
	@NonNull BiometricPrompt.AuthenticationResult result) {
	final BiometricPrompt.CryptoObject cryptoObject = result.getCryptoObject();
	log("onAuthenticationSucceeded, cryptoObject: " + cryptoObject);
	if (cryptoObject != null) {
	try {
	if (mShouldDecrypt) {
	log("Decrypted payload: " + new String(
	cryptoObject.getCipher().doFinal(mEncryptedBytes)));
	} else {
	// Save the cipher to use for decryption.
	mEncryptingCipher = cryptoObject.getCipher();
	mEncryptedBytes = mEncryptingCipher.doFinal(
	PAYLOAD.getBytes(Charset.defaultCharset()));
	log("Test payload: " + PAYLOAD);
	log("Encrypted payload: " + Arrays.toString(mEncryptedBytes));
	}
	} catch (BadPaddingException \| IllegalBlockSizeException e) {
	log("Failed to encrypt", e);
	}
	}
	}

	@Override
	public void onAuthenticationFailed() {
	log("onAuthenticationFailed");
	mBiometricPrompt.cancelAuthentication();
	}
	};

	private View.OnClickListener mGenerateKeyListener = view -> {
	try {
	BiometricPromptDemoSecretKeyHelper.generateBiometricBoundKey(KEY_NAME,
	true /* invalidatedByBiometricEnrollment */);
	log("Generated a key");
	} catch (InvalidAlgorithmParameterException \| NoSuchAlgorithmException
	\| NoSuchProviderException e) {
	log("Failed to generate key", e);
	}
	};

	private Cipher getCryptoCipher() {
	Cipher cipher = null;
	try {
	cipher = BiometricPromptDemoSecretKeyHelper.getCipher();
	} catch (NoSuchPaddingException \| NoSuchAlgorithmException e) {
	log("Failed to get cipher", e);
	}
	return cipher;
	}

	private SecretKey getSecretKey() {
	SecretKey secretKey = null;
	try {
	secretKey = BiometricPromptDemoSecretKeyHelper.getSecretKey(KEY_NAME);
	} catch (KeyStoreException \| CertificateException \| NoSuchAlgorithmException \| IOException
	\| UnrecoverableKeyException e) {
	log("Failed to get secret key", e);
	}
	return secretKey;
	}

	private void authenticateWithCrypto(Cipher cipher) {
	mBiometricPrompt.authenticate(mPromptInfo, new BiometricPrompt.CryptoObject(cipher));
	}

	private void authenticateWithEncryption() {
	Cipher cipher = getCryptoCipher();
	SecretKey secretKey = getSecretKey();
	if (cipher == null \|\| secretKey == null) {
	return;
	}
	try {
	cipher.init(Cipher.ENCRYPT_MODE, secretKey);
	mBiometricPrompt.authenticate(mPromptInfo,
	new BiometricPrompt.CryptoObject(cipher));
	log("Started authentication with a crypto object");
	authenticateWithCrypto(cipher);
	mShouldDecrypt = false;
	} catch (InvalidKeyException e) {
	log("Failed to init cipher", e);
	}
	}

	private void authenticateWithDecryption() {
	Cipher cipher = getCryptoCipher();
	SecretKey secretKey = getSecretKey();
	if (cipher == null \|\| secretKey == null) {
	return;
	}
	if (mEncryptingCipher == null) {
	log("User must first encrypt a message");
	flashEncryptButton();
	return;
	}

	try {
	cipher.init(Cipher.DECRYPT_MODE, secretKey,
	new IvParameterSpec(mEncryptingCipher.getIV()));
	mBiometricPrompt.authenticate(mPromptInfo,
	new BiometricPrompt.CryptoObject(cipher));
	log("Started authentication with a crypto object");
	authenticateWithCrypto(cipher);
	mShouldDecrypt = true;
	} catch (InvalidKeyException \| InvalidAlgorithmParameterException e) {
	log("Failed to init cipher", e);
	}
	}

	private void flashEncryptButton() {
	mEncryptButton.animate().alpha(0).setDuration(1000).withEndAction(new Runnable() {
	@Override
	public void run() {
	mEncryptButton.animate().alpha(1).setDuration(1000);
	}
	});
	}

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

	mLogTextView = findViewById(R.id.text_view_log);
	mBiometricPrompt = new BiometricPrompt(this, mExecutor, mAuthenticationCallback);

	((TextView) findViewById(R.id.text_view_activity_description)).setText(
	R.string.label_biometric_bound_key_activity_description);

	if (savedInstanceState != null) {
	mLogTextView.setText(savedInstanceState.getCharSequence(LOG_BUNDLE));
	}

	findViewById(R.id.button_generate_key).setOnClickListener(mGenerateKeyListener);
	mEncryptButton = findViewById(R.id.button_unlock_and_use_key);
	mEncryptButton.setOnClickListener(v -> authenticateWithEncryption());
	findViewById(R.id.button_clear_log).setOnClickListener(v -> mLogTextView.setText(""));
	findViewById(R.id.button_decrypt).setOnClickListener(v -> authenticateWithDecryption());
	}

	@Override
	protected void onPause() {
	mEncryptingCipher = null;
	mShouldDecrypt = false;
	mBiometricPrompt.cancelAuthentication();
	super.onPause();
	}

	@Override
	protected void onSaveInstanceState(@NonNull Bundle outState) {
	super.onSaveInstanceState(outState);
	outState.putCharSequence(LOG_BUNDLE, mLogTextView.getText());
	}
	}