UqAPuT9C

1import java.net.*;
2import java.io.*;
3import java.security.*;
4import javax.crypto.*;
5import java.util.*;
6import javax.crypto.spec.IvParameterSpec;
7
8
9
10public class Server{
11    public static void main(String args[]){
12
13        int number=0;
14        try{
15            int serverPort = 4567;
16            ServerSocket listenSocket = new ServerSocket(serverPort);
17            while(true) {
18                Socket clientSocket = listenSocket.accept();
19                new Connection(clientSocket,number);
20                number++;
21            }
22        }catch(IOException e)
23        {System.out.println("Listen:" + e.getMessage());}
24    }
25}
26
27class Connection extends Thread {
28    DataInputStream in;
29    DataOutputStream out;
30    Socket clientSocket;
31    int number;
32
33    public Connection (Socket aClientSocket,int clientNumber) {
34
35        try{
36            number=clientNumber;
37            clientSocket = aClientSocket;
38            in = new DataInputStream(clientSocket.getInputStream());
39            out = new DataOutputStream(clientSocket.getOutputStream());
40            this.start();
41        }catch(IOException e){System.out.println("Connection:" + e.getMessage());}
42    }
43
44    public void run(){
45        try{
46            while(true){
47
48                String data = in.readUTF();
49
50                try {
51
52                    // Key
53                    KeyGenerator keyGen = KeyGenerator.getInstance("AES");
54                    keyGen.init(128);
55                    SecretKey secretKey = keyGen.generateKey();
56
57
58
59                    // NONCE
60                    // tem de ser gerado
61                    byte[] nonce={1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};
62                    IvParameterSpec iv = new IvParameterSpec(nonce);
63
64
65                    Cipher c = Cipher.getInstance("AES/CTR/NoPadding"); // tem de conter /PKCS5Padding se nao da erro
66                    byte[] m ={'a','a','a','a','a','a','a','a','a','a','a','a','a','a','a','a'};
67                    System.out.println("bytes originais : "+Arrays.toString(m));
68
69                    // cifra
70                    c.init(Cipher.ENCRYPT_MODE,secretKey,iv);
71                    byte[] cifrados=c.update(m);
72                    c.doFinal();
73                    System.out.println("bytes cifrados : "+Arrays.toString(cifrados));
74
75
76                    //decifra
77                    c.init(Cipher.DECRYPT_MODE,secretKey,iv);
78                    byte[] decifrados=c.update(cifrados);
79                    c.doFinal();
80                    System.out.println("bytes decifrados : "+ Arrays.toString(decifrados));
81
82
83
84                } catch (NoSuchAlgorithmException e) {
85                    e.printStackTrace();
86                } catch (NoSuchPaddingException e) {
87                    e.printStackTrace();
88                } catch (InvalidKeyException e) {
89                    System.out.println("Failed init");
90                } catch (BadPaddingException e) {
91                    System.out.println("Failed doFinal");
92                } catch (IllegalBlockSizeException e) {
93                    e.printStackTrace();
94                } catch (InvalidAlgorithmParameterException e) {
95                    e.printStackTrace();
96                }
97
98                System.out.println("["+number+"]"+" "+data);
99            }
100        }catch(EOFException e){System.out.println("=["+number+"]=");
101        }catch(IOException e){System.out.println("IO:" + e);}
102    }
103}