26PBEj4Z

1package com.ebookfrenzy.fingerprintdemo;
2
3import com.ebookfrenzy.fingerprintdemo.FingerprintHandler;
4import android.support.v7.app.AppCompatActivity;
5import android.os.Bundle;
6import android.app.KeyguardManager;
7import android.hardware.fingerprint.FingerprintManager;
8import android.widget.Toast;
9import android.Manifest;
10import android.content.pm.PackageManager;
11import android.support.v4.app.ActivityCompat;
12
13import java.security.KeyStore;
14import android.security.keystore.KeyProperties;
15
16import java.security.NoSuchAlgorithmException;
17import java.security.NoSuchProviderException;
18
19import javax.crypto.KeyGenerator;
20import android.security.keystore.KeyGenParameterSpec;
21import java.security.cert.CertificateException;
22import java.security.InvalidAlgorithmParameterException;
23import java.io.IOException;
24import android.security.keystore.KeyPermanentlyInvalidatedException;
25import java.security.InvalidKeyException;
26import java.security.KeyStoreException;
27import java.security.UnrecoverableKeyException;
28import javax.crypto.NoSuchPaddingException;
29import javax.crypto.SecretKey;
30import javax.crypto.Cipher;
31
32public class FingerprintDemoActivity extends AppCompatActivity {
33
34    private static final String KEY_NAME = "example_key";
35    private FingerprintManager fingerprintManager;
36    private KeyguardManager keyguardManager;
37    private KeyStore keyStore;
38    private KeyGenerator keyGenerator;
39    private Cipher cipher;
40    private FingerprintManager.CryptoObject cryptoObject;
41
42    @Override
43    protected void onCreate(Bundle savedInstanceState) {
44        super.onCreate(savedInstanceState);
45        setContentView(R.layout.activity_fingerprint_demo);
46
47        keyguardManager =
48                (KeyguardManager) getSystemService(KEYGUARD_SERVICE);
49        fingerprintManager =
50                (FingerprintManager) getSystemService(FINGERPRINT_SERVICE);
51
52        if (!keyguardManager.isKeyguardSecure()) {
53
54            Toast.makeText(this,
55                    "Lock screen security not enabled in Settings",
56                    Toast.LENGTH_LONG).show();
57            return;
58        }
59
60        if (ActivityCompat.checkSelfPermission(this,
61                Manifest.permission.USE_FINGERPRINT) !=
62                PackageManager.PERMISSION_GRANTED) {
63            Toast.makeText(this,
64                    "Fingerprint authentication permission not enabled",
65                    Toast.LENGTH_LONG).show();
66
67            return;
68        }
69
70        if (!fingerprintManager.hasEnrolledFingerprints()) {
71
72            // This happens when no fingerprints are registered.
73            Toast.makeText(this,
74                    "Register at least one fingerprint in Settings",
75                    Toast.LENGTH_LONG).show();
76            return;
77        }
78
79        generateKey();
80
81        if (cipherInit()) {
82            cryptoObject =
83                    new FingerprintManager.CryptoObject(cipher);
84            FingerprintHandler helper = new FingerprintHandler(this);
85            helper.startAuth(fingerprintManager, cryptoObject);
86        }
87
88    }
89
90
91        protected void generateKey() {
92            try {
93                keyStore = KeyStore.getInstance("AndroidKeyStore");
94            } catch (Exception e) {
95                e.printStackTrace();
96            }
97
98            try {
99                keyGenerator = KeyGenerator.getInstance(
100                        KeyProperties.KEY_ALGORITHM_AES,
101                        "AndroidKeyStore");
102            } catch (NoSuchAlgorithmException |
103                    NoSuchProviderException e) {
104                throw new RuntimeException(
105                        "Failed to get KeyGenerator instance", e);
106            }
107
108            try {
109                keyStore.load(null);
110                keyGenerator.init(new
111                        KeyGenParameterSpec.Builder(KEY_NAME,
112                        KeyProperties.PURPOSE_ENCRYPT |
113                                KeyProperties.PURPOSE_DECRYPT)
114                        .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
115                        .setUserAuthenticationRequired(true)
116                        .setEncryptionPaddings(
117                                KeyProperties.ENCRYPTION_PADDING_PKCS7)
118                        .build());
119                keyGenerator.generateKey();
120            } catch (NoSuchAlgorithmException |
121                    InvalidAlgorithmParameterException
122                    | CertificateException | IOException e) {
123                throw new RuntimeException(e);
124            }
125
126        }
127
128    public boolean cipherInit() {
129        try {
130            cipher = Cipher.getInstance(
131                    KeyProperties.KEY_ALGORITHM_AES + "/"
132                            + KeyProperties.BLOCK_MODE_CBC + "/"
133                            + KeyProperties.ENCRYPTION_PADDING_PKCS7);
134        } catch (NoSuchAlgorithmException |
135                NoSuchPaddingException e) {
136            throw new RuntimeException("Failed to get Cipher", e);
137        }
138
139        try {
140            keyStore.load(null);
141            SecretKey key = (SecretKey) keyStore.getKey(KEY_NAME,
142                    null);
143            cipher.init(Cipher.ENCRYPT_MODE, key);
144            return true;
145        } catch (KeyPermanentlyInvalidatedException e) {
146            return false;
147        } catch (KeyStoreException | CertificateException
148                | UnrecoverableKeyException | IOException
149                | NoSuchAlgorithmException | InvalidKeyException e) {
150            throw new RuntimeException("Failed to init Cipher", e);
151        }
152    }
153
154}