exzj1TZQ

1private static void cifra (String file, SecretKey key) {
2    try {
3        Cipher c = Cipher.getInstance("AES");
4        c.init(Cipher.ENCRYPT_MODE, key);
5        FileInputStream fis;
6        FileOutputStream fos;
7        CipherOutputStream cos;
8        fis = new FileInputStream(file);
9        fos = new FileOutputStream(file);
10        cos = new CipherOutputStream(fos, c);
11        byte[] b = new byte[16];
12        int i;
13        while ((i=fis.read(b) )!= -1) {
14            cos.write(b, 0, i);
15        }
16        cos.close();
17        fos.close();
18        fis.close();
19    }catch (Exception e) {
20        e.printStackTrace();
21    }
22}
23
24public static void decifra (String file, SecretKey key) {
25    try {
26        byte[] keyEncoded = key.getEncoded();
27        SecretKeySpec keySpec2 = new SecretKeySpec(keyEncoded, "AES");
28        Cipher c = Cipher.getInstance("AES");
29        c.init(Cipher.DECRYPT_MODE, keySpec2);  
30        FileInputStream fis;
31        FileOutputStream fos;
32        CipherInputStream cos;
33        fis = new FileInputStream(file + ".cif");
34        cos = new CipherInputStream(fis, c);
35        byte[] b = new byte[16];
36        int i;
37        while ((i=fis.read(b) )!= -1) {
38            cos.read(b, 0, i);
39        }
40        cos.close();
41        fis.close();
42    }catch (Exception e) {
43        // TODO: handle exception
44    }
45}
46
47private static SecretKey chaveSimetrica () {
48
49    try {
50        KeyGenerator kg = KeyGenerator.getInstance("AES");
51        kg.init(128);
52        SecretKey key = kg.generateKey();
53        return key;
54    } catch (NoSuchAlgorithmException e) {
55        e.printStackTrace();
56    }
57    return null;
58}