Cryptage RSA

src/client/Client.java

@@ -5,10 +5,13 @@ import java.net.Socket;
 import java.nio.charset.StandardCharsets;
 import java.rmi.UnknownHostException;
 import java.security.Key;
+import java.security.KeyPair;
+import java.security.PublicKey;
 import java.util.Arrays;
 import java.util.Scanner;
 
 import reseau.AES;
+import reseau.RSA;
 
 public class Client {
 
@@ -20,8 +23,10 @@ public class Client {
         ObjectInputStream in = null;
 
         // Clé de chiffrage
-        Key key = AES.genererCle();
-        AES.sauvegarderCle(key);
+        KeyPair clientKeyPair = RSA.genererCle();
+        PublicKey serverKey = null;
+
+//        AES.sauvegarderCle(key);
 
         // Création des Sockets
         try {
@@ -31,10 +36,9 @@ public class Client {
             in = new ObjectInputStream(serverSocket.getInputStream());
 
             // On envoie la clé de chiffrage
-            out.writeObject(key);
+            out.writeObject(clientKeyPair.getPublic());
 
-            System.out.println("Clé envoyé");
-            System.out.println(Arrays.toString(key.getEncoded()));
+            serverKey = (PublicKey) in.readObject();
 
         } catch (UnknownHostException e) {
             System.out.println("Destination unknown");
@@ -42,6 +46,8 @@ public class Client {
         } catch (IOException e) {
             System.out.println("now to investigate this IO issue");
             System.exit(-1);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException(e);
         }
 
         // Communication
@@ -52,13 +58,13 @@ public class Client {
                 // Envoi du message
                 System.out.print("client > ");
                 message = scan.nextLine();
-                messageCrypte = AES.encrypter(message, key);
+                messageCrypte = RSA.encrypter(message, serverKey);
                 out.writeObject(messageCrypte);
 
                 // Reception du message
                 messageCrypte = (byte[]) in.readObject();
-                message = AES.decrypter(messageCrypte, key);
-                System.out.printf("serveur > %s -> %s\n", new String(messageCrypte, StandardCharsets.UTF_8), message);
+                message = RSA.decrypter(messageCrypte, clientKeyPair.getPrivate());
+                System.out.printf("serveur > %s\n", message);
             } while (!message.equals("bye"));
 
             out.close();

src/reseau/AES.java

@@ -4,7 +4,6 @@ import javax.crypto.*;
 import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.security.*;
-import java.util.Arrays;
 
 public class AES {
 

src/reseau/RSA.java

@@ -0,0 +1,44 @@
+package reseau;
+
+import javax.crypto.Cipher;
+import java.nio.charset.StandardCharsets;
+import java.security.*;
+
+public class RSA {
+
+    public static KeyPair genererCle() {
+        KeyPair keyPair = null;
+
+        try {
+            KeyPairGenerator keyGenerator = KeyPairGenerator.getInstance("RSA");
+            keyGenerator.initialize(2048);
+
+            keyPair = keyGenerator.generateKeyPair();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return keyPair;
+    }
+
+    public static byte[] encrypter(String msg, PublicKey key){
+        try {
+            Cipher cipher = Cipher.getInstance("RSA") ;
+            cipher.init(Cipher.ENCRYPT_MODE, key) ;
+            return cipher.doFinal(msg.getBytes());
+        } catch(Exception e){
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    public static String decrypter(byte[] msg, PrivateKey key) {
+        try {
+            Cipher cipher = Cipher.getInstance("RSA") ;
+            cipher.init(Cipher.DECRYPT_MODE, key);
+            return new String(cipher.doFinal(msg), StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+}

src/serveur/Serveur.java

@@ -1,13 +1,13 @@
 package serveur;
 
-import reseau.AES;
+import reseau.RSA;
 
 import java.io.*;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.nio.charset.StandardCharsets;
-import java.security.Key;
-import java.util.Arrays;
+import java.security.KeyPair;
+import java.security.PublicKey;
 import java.util.Scanner;
 
 public class Serveur {
@@ -18,7 +18,9 @@ public class Serveur {
     public static void main(String[] args) {
         ServerSocket serverSocket = null;
         Socket clientSocket = null;
-        Key clientKey;
+
+        KeyPair serverKeyPairs = RSA.genererCle();
+        PublicKey clientKey;
 
         // Connexion
         try {
@@ -40,10 +42,8 @@ public class Serveur {
             out = new ObjectOutputStream(clientSocket.getOutputStream());
 
             // On récupère la clé du client
-            clientKey = (Key) in.readObject();
-
-            System.out.println("Clé reçue");
-            System.out.println(Arrays.toString(clientKey.getEncoded()));
+            clientKey = (PublicKey) in.readObject();
+            out.writeObject(serverKeyPairs.getPublic());
 
             // Communication
             String message;
@@ -51,14 +51,14 @@ public class Serveur {
             do {
                 // Envoi du message
                 messageCrypte = (byte[]) in.readObject();
-                message = AES.decrypter(messageCrypte, clientKey);
-                System.out.printf("client > %s -> %s\n", new String(messageCrypte, StandardCharsets.UTF_8), message);
+                message = RSA.decrypter(messageCrypte, serverKeyPairs.getPrivate());
+                System.out.printf("client > %s\n", message);
 
 
                 // Reception du message
                 System.out.print("serveur > ");
                 message = scan.nextLine();
-                messageCrypte = AES.encrypter(message, clientKey);
+                messageCrypte = RSA.encrypter(message, clientKey);
                 out.writeObject(messageCrypte);
             } while (!message.equals("bye"));