Simple Chat with Encryption

client_encrypted.py

@@ -0,0 +1,95 @@
+# client.py
+# Chat Client terenkripsi dua arah menggunakan Fernet (AES-GCM)
+# Jalankan: python client.py --host 127.0.0.1 --port 12345
+# Pastikan: pip install cryptography
+
+import socket
+import threading
+import sys
+import argparse
+from cryptography.fernet import Fernet
+
+KEY_FILE = "secret.key"
+
+# Load key (harus sama dengan server)
+try:
+    with open(KEY_FILE, "rb") as f:
+        KEY = f.read()
+except FileNotFoundError:
+    print(f"[!] File '{KEY_FILE}' tidak ditemukan. Copy dari server terlebih dahulu.")
+    sys.exit(1)
+
+CIPHER = Fernet(KEY)
+
+
+def receive(sock):
+    """Thread untuk menerima pesan terenkripsi dari server."""
+    while True:
+        try:
+            data = sock.recv(4096)
+            if not data:
+                print("[!] Koneksi ke server terputus.")
+                break
+
+            # Dekripsi pesan dari server
+            try:
+                plain = CIPHER.decrypt(data).decode()
+                print(plain)
+            except Exception:
+                try:
+                    print(data.decode())
+                except:
+                    print("[!] Pesan tidak dapat didekripsi.")
+        except Exception:
+            print("[!] Terputus dari server.")
+            break
+
+
+def start_client(host, port):
+    """Mulai koneksi ke server dan kirim pesan terenkripsi."""
+    client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    try:
+        client.connect((host, port))
+    except Exception as e:
+        print(f"[x] Gagal terhubung ke server {host}:{port} — {e}")
+        sys.exit(1)
+
+    threading.Thread(target=receive, args=(client,), daemon=True).start()
+
+    print(f"Connected to chat {host}:{port}")
+    print("Ketik pesanmu (atau 'exit' untuk keluar):")
+
+    while True:
+        try:
+            msg = input("")
+            if msg.strip() == "":
+                continue
+
+            if msg.lower() == "exit":
+                encrypted_exit = CIPHER.encrypt("exit".encode())
+                client.sendall(encrypted_exit)
+                client.close()
+                print("Bye 👋")
+                sys.exit(0)
+
+            # Enkripsi pesan sebelum dikirim
+            encrypted_msg = CIPHER.encrypt(msg.encode())
+            client.sendall(encrypted_msg)
+
+        except KeyboardInterrupt:
+            print("\n[!] Keluar dengan Ctrl+C")
+            client.close()
+            sys.exit(0)
+        except Exception as e:
+            print(f"[!] Error: {e}")
+            client.close()
+            break
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--host", type=str, required=True, help="Alamat IP server")
+    parser.add_argument("--port", type=int, required=True, help="Port server")
+    args = parser.parse_args()
+
+    start_client(args.host, args.port)

server_encrypted.py

@@ -0,0 +1,126 @@
+# server.py
+# Chat Server terenkripsi dua arah menggunakan Fernet (AES-GCM)
+# Jalankan: python server.py
+# Pastikan: pip install cryptography
+
+import socket
+import threading
+import sys
+import os
+from cryptography.fernet import Fernet
+
+HOST = "0.0.0.0"
+PORT = 12345
+KEY_FILE = "secret.key"
+
+clients = []
+
+
+# -----------------------------
+# Fungsi untuk memuat atau membuat key
+# -----------------------------
+def load_or_create_key(path=KEY_FILE):
+    if os.path.exists(path):
+        with open(path, "rb") as f:
+            key = f.read()
+        print(f"[*] Loaded existing key from {path}")
+    else:
+        key = Fernet.generate_key()
+        with open(path, "wb") as f:
+            f.write(key)
+        print(f"[*] Generated new key and saved to {path}")
+    return key
+
+
+KEY = load_or_create_key()
+CIPHER = Fernet(KEY)
+
+
+# -----------------------------
+# Fungsi untuk menangani client
+# -----------------------------
+def handle_client(conn, addr):
+    print(f"[+] Connected with {addr}")
+    clients.append(conn)
+
+    while True:
+        try:
+            data = conn.recv(4096)
+            if not data:
+                break
+
+            # Dekripsi pesan dari client
+            try:
+                msg = CIPHER.decrypt(data).decode()
+            except Exception:
+                msg = data.decode(errors="ignore")
+
+            if msg.lower().strip() == "exit":
+                print(f"[-] {addr} keluar dari chat")
+                break
+
+            print(f"{addr}: {msg}")
+
+            # Enkripsi ulang pesan untuk dikirim ke client lain
+            broadcast_text = f"{addr}: {msg}"
+            encrypted_broadcast = CIPHER.encrypt(broadcast_text.encode())
+
+            for client in clients:
+                if client != conn:
+                    try:
+                        client.sendall(encrypted_broadcast)
+                    except:
+                        pass
+
+        except Exception:
+            break
+
+    conn.close()
+    if conn in clients:
+        clients.remove(conn)
+    print(f"[-] Disconnected {addr}")
+
+
+# -----------------------------
+# Fungsi untuk console server
+# -----------------------------
+def server_console():
+    if sys.stdin.isatty():
+        while True:
+            cmd = input("> ")
+            if cmd.lower() == "exit":
+                print("[!] Server dimatikan...")
+                for c in list(clients):
+                    try:
+                        c.sendall(CIPHER.encrypt("[Server dimatikan]".encode()))
+                        c.close()
+                    except:
+                        pass
+                os._exit(0)
+
+
+# -----------------------------
+# Fungsi utama server
+# -----------------------------
+def start_server():
+    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    server.bind((HOST, PORT))
+    server.listen()
+    print(f"[*] Server running on {HOST}:{PORT}")
+    print(f"[*] Key file: {KEY_FILE}")
+
+    threading.Thread(target=server_console, daemon=True).start()
+
+    try:
+        while True:
+            conn, addr = server.accept()
+            threading.Thread(target=handle_client, args=(conn, addr), daemon=True).start()
+    except KeyboardInterrupt:
+        print("\n[!] Server dihentikan manual.")
+        server.close()
+        sys.exit(0)
+
+
+if __name__ == "__main__":
+    start_server()