WagnVCEu

1public class PrefCryptor {
2    private Cipher _cx;
3    private byte[]  _iv;
4    private static PrefCryptor instance;
5    private static Object mutext = new Object();
6    private static final String TAG = PrefCryptor.class.getName();
7    private SecretKey secretKey;
8
9    public static PrefCryptor getInstance() {
10        if (instance == null) {
11            synchronized (mutext) {
12                instance = new PrefCryptor();
13            }
14        }
15        return instance;
16    }
17
18    
19
20    private PrefCryptor() {
21        init();
22    }
23
24    private void init() {
25        try {
26            _cx = Cipher.getInstance("AES/CBC/PKCS5Padding");
27            secretKey =KeyChainUtils.getInstance().getKey();
28            _iv = getIV16().getBytes("UTF-8");
29        } catch (  NoSuchAlgorithmException | NoSuchPaddingException | UnsupportedEncodingException e) {
30            e.printStackTrace();
31        }
32    }
33
34    private byte[] encryptDecrypt(String inputText, int mode) throws UnsupportedEncodingException,
35            InvalidKeyException, InvalidAlgorithmParameterException,
36            IllegalBlockSizeException, BadPaddingException {
37       // SecretKeySpec keySpec = new SecretKeySpec(secretKey, "AES");
38        IvParameterSpec ivSpec = new IvParameterSpec(_iv);
39        // encryption
40        if (mode == Cipher.ENCRYPT_MODE) {
41            _cx.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);// Initialize this cipher instance
42            return _cx.doFinal(inputText.getBytes("UTF-8")); // Finish multi-part transformation (encryption)
43        } else {
44            _cx.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);// Initialize this cipher instance
45            byte[] decodedValue = Base64.decode(inputText.getBytes(), Base64.DEFAULT);
46            return _cx.doFinal(decodedValue);// Finish multi-part transformation (decryption)
47        }
48    }
49
50    public String encryptData(String plainText) {
51        if(_cx==null)
52            init();
53        if (_cx != null) {
54            try {
55                byte[] bytes = encryptDecrypt(plainText, Cipher.ENCRYPT_MODE);
56                return Base64.encodeToString(bytes, Base64.DEFAULT);
57            } catch (Exception e) {
58                e.printStackTrace();
59            }
60        } else {
61            Log.e(TAG, "Crypto not initialized yet");
62        }
63        return null;
64    }
65
66    public String decryptData(String cipherText) {
67        if(_cx==null)
68            init();
69        if (_cx != null) {
70            if (!TextUtils.isEmpty(cipherText)) {
71                try {
72                    byte[] bytes = encryptDecrypt(cipherText, Cipher.DECRYPT_MODE);
73                    return new String(bytes);
74                } catch (Exception e) {
75                    e.printStackTrace();
76                }
77            }
78        }else {
79            Log.e(TAG, "Crypto not initialized yet");
80        }
81        return cipherText;
82    }
83
84    public String getIV16() {
85        SharedPreferences keyPreference = PreferenceManager.getDefaultSharedPreferences(MyApplication.getApplication());
86        String keyIV=keyPreference.getString("keyIV_EC","");
87        if(TextUtils.isEmpty(keyIV)){
88            SecureRandom ranGen = new SecureRandom();
89            byte[] aesKey = new byte[16];
90            ranGen.nextBytes(aesKey);
91            StringBuilder result = new StringBuilder();
92            for (byte b : aesKey) {
93                result.append(String.format("%02x", b)); //convert to hex
94            }
95            if (16 > result.toString().length()) {
96                keyIV= result.toString();
97            } else {
98                keyIV= result.toString().substring(0, 16);
99            }
100            keyPreference.edit().putString("keyIV_EC",keyIV).apply();
101        }
102        return keyIV;
103    }
104}