JS8HhXyJ

1/*
2 * To change this template, choose Tools | Templates
3 * and open the template in the editor.
4 */
5package cryptonita;
6
7import com.sun.org.apache.xml.internal.security.utils.Base64;
8import java.io.BufferedReader;
9import java.io.FileNotFoundException;
10import java.io.FileReader;
11import java.security.MessageDigest;
12import java.util.Arrays;
13import java.util.Random;
14import javax.crypto.Cipher;
15import javax.crypto.IllegalBlockSizeException;
16import javax.crypto.SecretKey;
17import javax.crypto.spec.IvParameterSpec;
18import javax.crypto.spec.SecretKeySpec;
19
20/**
21 *
22 * @author albert
23 */
24public class Cryptonita {
25
26    /**
27     * @param args the command line arguments
28     * 
29     */
30    
31    private final static String TDES_CIPHER = "DESede/CBC/PKCS5Padding";
32    
33    public static void main(String[] args) throws Exception {
34        
35        String filepath = "symmetric.key";
36        
37        // Llegim el fitxer amb la clau
38        BufferedReader br = new BufferedReader(new FileReader(filepath));
39        String base64 = br.readLine();
40        br.close();
41        
42        System.out.println("Clau llegida en Base64: " + base64);
43        
44        // Passem la clau a bytes
45        byte [] keyBytes = Base64.decode(base64);
46        
47        System.out.print("Clau llegida en bytes: ");
48        for (int i = 0; i < keyBytes.length; i++) {
49            System.out.print(keyBytes[i] + " ");
50        }
51        System.out.println(" ");
52        
53        String text = "41.13226,1.24486,75.0";
54   
55        byte [] codedText = encrypt(text, keyBytes);
56        
57        String textB64 = Base64.encode(codedText);
58        System.out.println(textB64);
59        
60        String decodedText = decrypt(codedText, keyBytes);
61        
62        System.out.println(decodedText);      
63        
64                
65    }
66    
67    public static byte [] encrypt (String message, byte [] key) throws Exception {
68       
69        final SecretKey secret = new SecretKeySpec(key, "DESede");
70        
71        // Generem el vector IV
72        Random r = new Random(secret.hashCode());
73        byte [] b = new byte [8];
74        r.nextBytes(b);
75        final IvParameterSpec iv = new IvParameterSpec(b);
76        
77        
78        //final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
79        final Cipher cipher = Cipher.getInstance(TDES_CIPHER);
80        cipher.init(Cipher.ENCRYPT_MODE, secret, iv);
81        
82        final byte [] plainBytes = message.getBytes("UTF-8");
83        final byte [] cipherText = cipher.doFinal(plainBytes);
84        
85        return cipherText;
86    }
87    
88    public static String decrypt (byte [] message, byte [] key) throws Exception {
89        
90        final SecretKey secret = new SecretKeySpec(key, "DESede");
91        
92        // Generem el vector IV
93        Random r = new Random(secret.hashCode());
94        byte [] b = new byte [8];
95        r.nextBytes(b);
96        final IvParameterSpec iv = new IvParameterSpec(b);
97        
98        //final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
99        final Cipher cipher = Cipher.getInstance(TDES_CIPHER);
100        cipher.init(Cipher.DECRYPT_MODE, secret, iv);
101        
102        final byte [] plainText = cipher.doFinal(message);
103        
104        return new String (plainText, "UTF-8");
105    }
106    
107}