gT0apT1N

1package knjigazis;
2import java.io.File;
3import java.io.FileInputStream;
4import java.io.FileNotFoundException;
5import java.io.FileOutputStream;
6import java.io.IOException;
7import java.nio.file.Files;
8import java.nio.file.Path;
9import java.nio.file.Paths;
10import java.nio.file.StandardOpenOption;
11import java.security.InvalidKeyException;
12import java.security.NoSuchAlgorithmException;
13import javax.crypto.Cipher;
14import javax.crypto.CipherInputStream;
15import javax.crypto.KeyGenerator;
16import javax.crypto.NoSuchPaddingException;
17import javax.crypto.SecretKey;
18import javax.crypto.spec.SecretKeySpec;
19public class AESsifraCFB16 {
20    public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, FileNotFoundException, IOException {
21        //Generisanje tajnog ključa
22        KeyGenerator kg = KeyGenerator.getInstance("AES");
23        SecretKey kljuc = kg.generateKey();
24        byte[] AESkljuc = kljuc.getEncoded();
25        SecretKeySpec specifikacijaKljuca = new SecretKeySpec(AESkljuc, "AES");
26        
27        //CFB šifruje po 16 bitova u jednom taktu
28        Cipher sifra = Cipher.getInstance("AES/CFB16/PKCS5Padding"); 
29        sifra.init(Cipher.ENCRYPT_MODE, specifikacijaKljuca);        
30        FileInputStream fis = new FileInputStream("moji_podaci.txt");
31        CipherInputStream cis = new CipherInputStream(fis, sifra); 
32        
33        //Upis šifrata u datoteku
34        File datoteka = new File("moji_podaci_sifrat.AES");
35        FileOutputStream fos = new FileOutputStream(datoteka);
36        
37        //Broj bitova koji će biti prosesuiran u toku po jednom taktu 
38        byte cipherText[]= new byte[16];
39        int i=0;        
40        while((i=cis.read(cipherText))!= -1){
41            fos.write(cipherText,0,i);
42        }
43        System.out.println("Svi podaci iz toka su šifrovani!");
44                
45        //Memorisanje ključa i IV-a 
46        AESsifraCFB16.sacuvajIV(sifra.getIV(), "IV.txt");
47        AESsifraCFB16.sacuvajKljuc(specifikacijaKljuca.getEncoded(),"kljuc.txt");
48    }
49    //Metode za upis ključa i IV u datoteku
50    public static void sacuvajKljuc(byte kljuc[], String nazivDatoteke) throws IOException{
51        Path lokacija = Paths.get(nazivDatoteke);
52        Files.write(lokacija, kljuc, StandardOpenOption.CREATE_NEW);
53    }
54    public static void sacuvajIV(byte IV[], String nazivDatoteke) throws IOException{
55        Path lokacija = Paths.get(nazivDatoteke);
56        Files.write(lokacija, IV, StandardOpenOption.CREATE_NEW);
57    }    
58}