LaqJLvfu

1import java.net.*;
2import java.io.*;
3import javax.crypto.*;
4import javax.crypto.spec.IvParameterSpec;
5import javax.crypto.spec.SecretKeySpec;
6import java.security.*;
7
8public class Client {
9    public static void main(String args[]) {
10
11        Socket s = null;
12        int serversocket = 4567;
13        try {
14            s = new Socket("127.0.0.1", serversocket);
15
16            DataInputStream in = new DataInputStream(s.getInputStream());
17            DataOutputStream out = new DataOutputStream(s.getOutputStream());
18
19            while (true){
20                //key
21                byte [] key = {1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4};
22                SecretKey secretKey = new SecretKeySpec(key, 0, key.length, "AES");
23
24                //hash function
25                MessageDigest md = MessageDigest.getInstance("SHA");
26                byte [] aux = {1};
27                byte [] key1= md.digest(aux);
28                //COMO FAZER E=(m, k1)=c ???????????
29
30                //nonce
31                byte[] bytesForIV=new byte[16];
32                SecureRandom sr = new SecureRandom();
33                sr.nextBytes(bytesForIV);
34                IvParameterSpec iv = new IvParameterSpec(bytesForIV);
35
36                //sends the bytes in plaintext so that the server can create the same IV
37                out.write(bytesForIV);
38
39                Cipher c = Cipher.getInstance("AES/CTR/PKCS5Padding");
40                c.init(Cipher.ENCRYPT_MODE, secretKey, iv);
41
42                OutputStream ot = out;
43                CipherOutputStream cos = new CipherOutputStream(ot, c);
44                int text;
45                while((text=System.in.read())!=-1){
46                    cos.write((byte)text);
47                    cos.flush();
48                }
49
50            }
51        } catch (UnknownHostException e) {
52            System.out.println("Sock:" + e.getMessage());
53        } catch (EOFException e) {
54            System.out.println("EOF:" + e.getMessage());
55        } catch (IOException e) {
56            System.out.println("IO:" + e.getMessage());
57        } catch (NoSuchPaddingException e) {
58            e.printStackTrace();
59        } catch (NoSuchAlgorithmException e) {
60            e.printStackTrace();
61        } catch (InvalidAlgorithmParameterException e) {
62            e.printStackTrace();
63        } catch (InvalidKeyException e) {
64            e.printStackTrace();
65        } finally {
66            if (s != null)
67                try {
68                    s.close();
69                } catch (IOException e) {
70                    System.out.println("close:" + e.getMessage());
71                }
72        }
73    }
74}