netwrapper client done

client/netwrapper.py

@@ -1,97 +1,117 @@
 #!/usr/bin/env python3
+import random
+import string
+import json
+from base64 import b64encode, b64decode
+import pyDH
+from Crypto.Cipher import PKCS1_OAEP
+from Crypto.PublicKey import RSA
+from Crypto.Cipher import ChaCha20
+from Crypto.Random import get_random_bytes
+
 from netsim import network_interface
 
 
 class NetWrapper:
     SERVER_ADDRESS = 'A'
 
-    def __init__(self, publicKey: str, privateKey: str, clientAddress: str, username: str, cipherKey: str = ""):
+    def __init__(self, privateKey: str, clientAddress: str, username: str, serverPubKey: str = "",
+                 serverAddr: str = 'A'):
         # Create network_interface:  network_interface(path, addr) path root is shared with network / addr is own address
-        self.network = network_interface('./network/', clientAddress)
+        self.network = network_interface('./', clientAddress)
+        self.serverAddr = serverAddr
         self.username = username
-        self.publicKey = publicKey
         self.privateKey = privateKey
-        self.cipherKey = cipherKey
+        self.serverPubKey = serverPubKey
+        self.cipherkey="".encode('UTF-8')
 
-    def identifyServer(self) -> bytes:
-        # Message is coded with Server RSA public key in string byte format
-        # Creat json with format:
-        # fos = {
-        #    'type':'IDY',
-        #    'source':self.network.own_addr,
-        #    'username': self.username,
-        #    'message': message <- random generalt, hogy biztos ne legyen elore ismert a challange
-        # }
-        # jsonmsg = json.dump(fos)
-        # asd = jsonmsg.encode('UTF-8')
-        # network_interface.send_msg(self.SERVER_ADDRESS,asd)
-        # Listen for response
-        # status, msg = network_interface.receive_msg(blocking=True)  -> status is boolean flag, msg is message
-        # truemsg = msg.decode('UTF-8') nezd meg, h ez tenyleg bajttomb-e, testverem
-        # jsonmsg = json.loads(truemsg)
-        # plaintextrcvmsg = jsonmsg['message'] dekodolod rsa-val
-        # if (plaintextrcvmsg == message): akkor goodness else: fail
-        # return status, msg
-        pass
+    def randomStringGenerator(self, str_size: int = 512,
+                              allowed_chars: str = string.ascii_letters + string.punctuation) -> str:
+        return ''.join(random.choice(allowed_chars) for x in range(str_size))
 
+    def identifyServer(self) -> bool:
+        randommsg = self.randomStringGenerator()
+        rsakey = RSA.import_key(self.serverPubKey)
+        cipher = PKCS1_OAEP.new(rsakey)
+        identMsg = json.dumps(
+            {'type': 'IDY', 'source': self.network.own_addr, 'username': self.username,
+             'message': b64encode(cipher.encrypt(randommsg.encode('UTF-8')))}).encode(
+            'UTF-8')
+        self.network.send_msg(self.serverAddr, identMsg)
+        status, msg = self.network.receive_msg(blocking=True)
+        if not status:
+            raise Exception('Network error during connection.')
+        myrsakey = RSA.import_key(self.privateKey)
+        mycipher = PKCS1_OAEP.new(myrsakey)
+        returnJson = json.loads(msg.decode('UTF-8'))
+        retmsg = mycipher.decrypt(b64decode(returnJson['message'])).decode('UTF-8')
+        return retmsg == randommsg
 
     def createEncryptedChannel(self):
-        # pyDH-t hasznalsz
-
-        # pydh = pyDH() #alapertelmezett cuccok jok
-        # mypubkey = pydh.gen_public_key()
-        #    'type':'DH',
-        #    'source':self.network.own_addr
-        # fos = {,
-        #    'message': mypubkey <- pls titkosisd a szerver publikus rsa kulcsaval, hogy authentikalt legyen a dh procedura
-        # }
-        # jsonmsg = json.dump(fos)
-        # asd = jsonmsg.encode('UTF-8')
-        # self.network.send_msg(asd)
-        # status, msg = network_interface.receive_msg(blocking=True)  -> status is boolean flag, msg is message
-        # truemsg = msg.decode('UTF-8') nezd meg, h ez tenyleg bajttomb-e, testverem
-        # jsonmsg = json.loads(truemsg)
-        # self.sharedkey = pydh.gen_shared_key(jsonmsg['message']<-dekoldold a sajat publikus rsa kulccsal)
-        # self.chachageci = ChaChaGeci(self.sharedkey) <- a lenyeg, h a kapott osztott kulccsal legyen egy chacha stream ciphered
-        pass
+        dh = pyDH.DiffieHellman()
+        rsakey = RSA.import_key(self.serverPubKey)
+        cipher = PKCS1_OAEP.new(rsakey)
+        mypubkey = b64encode(cipher.encrypt(str(dh.gen_public_key()).encode('UTF-8')))
+        jsonmsg = json.dumps({'type': 'DH', 'source': self.network.own_addr, 'message': mypubkey}).encode('UTF-8')
+        self.network.send_msg(self.serverAddr,jsonmsg)
+        status, msg = self.network.receive_msg(blocking=True)
+        if not status:
+            raise Exception('Network error during connection.')
+        decodedmsg = json.loads(msg.decode('UTF-8'))
+        myrsakey = RSA.import_key(self.privateKey)
+        mycipher = PKCS1_OAEP.new(myrsakey)
+        serverpubkey = int(mycipher.decrypt(b64decode(decodedmsg['message'])).decode('UTF-8'))
+        self.cipherkey = dh.gen_shared_key(serverpubkey).encode('UTF-8')
 
     def authenticate(self, password: str):
-        # message = self.chachageci.titkosisd_jol_testverem(f'LIN %self.username% %password%')
-        # fos = {
-        #    'type':'AUT',
-        #    'source':self.network.own_addr,
-        #    'nonce': str
-        #    'message': message
-        # }
-        # jsonmsg = json.dump(fos)
-        # asd = jsonmsg.encode('UTF-8')
-        # network_interface.send_msg(self.SERVER_ADDRESS,asd)
-        # status, msg = network_interface.receive_msg(blocking=True)  -> status is boolean flag, msg is message
-        # truemsg = msg.decode('UTF-8') nezd meg, h ez tenyleg bajttomb-e, testverem
-        # jsonmsg = json.loads(truemsg)
-        #
-        pass
+        message = f"LIN {self.username} {password}".encode('UTF-8')
+        cipher = ChaCha20.new(self.cipherkey, get_random_bytes(12))
+        ciphertext = cipher.encrypt(message)
+        nonce = b64encode(cipher.nonce).decode('UTF-8')
+        ct = b64encode(ciphertext).decode('UTF-8')
+        sendjson = json.dumps({'type': 'AUT', 'source': self.network.own_addr, 'nonce': nonce, 'message': ct}).encode('UTF-8')
+        self.network.send_msg(self.serverAddr, sendjson)
+        status, msg = self.network.receive_msg(blocking=True)
+        if not status:
+            raise Exception('Network error during connection.')
+        try:
+            b64 = json.loads(msg)
+            retnonce = b64decode(b64['nonce'])
+            retciphertext = b64decode(b64['message'])
+            retcipher = ChaCha20.new(self.cipherkey, nonce=retnonce)
+            plaintext = retcipher.decrypt(retciphertext).decode('UTF-8')
+            if plaintext != "OK":
+                raise Exception('Authentication error')
+        except Exception:
+            print("Incorrect decryption")
 
     def connectToServer(self):
-        #self.identifyServer()
-        #self.createEncryptedChannel()
-        #self.authenticate()
-        pass
+        identStatus = self.identifyServer()
+        if not identStatus:
+            raise Exception('Server identification faliure')
+        self.createEncryptedChannel()
+        print('Please enter your password:')
+        pw = input()
+        self.authenticate(pw)
 
     def sendMessage(self, message: bytes):
-        # message: encoding message with chacha20
-        # json = {
-        #    'type':'CMD',
-        #    'source':self.network.own_addr,
-        #    'nonce': str
-        #    'message': message
-        # }
-        # message = json.dump()
-        # message.encode('utf-8')
-        # network_interface.send_msg(self.SERVER_ADDRESS,message)
-        pass
+        cipher = ChaCha20.new(self.cipherkey, get_random_bytes(12))
+        ciphertext = cipher.encrypt(message)
+        nonce = b64encode(cipher.nonce).decode('UTF-8')
+        ct = b64encode(ciphertext).decode('UTF-8')
+        sendjson = json.dumps({'type': 'CMD', 'source': self.network.own_addr, 'nonce': nonce, 'message': ct}).encode('UTF-8')
+        self.network.send_msg(self.serverAddr,sendjson)
 
-    def recieveMessage(self, message: bytes):
-        # status, msg = network_interface.receive_msg(blocking=True)  -> status is boolean flag, msg is message
-        # Decode the message with chacha20
-        pass
+    def recieveMessage(self, message: bytes) -> bytes:
+        status, msg = self.network.receive_msg(blocking=True)
+        if not status:
+            raise Exception('Network error during connection.')
+        try:
+            b64 = json.loads(msg)
+            retnonce = b64decode(b64['nonce'])
+            retciphertext = b64decode(b64['message'])
+            retcipher = ChaCha20.new(self.cipherkey, nonce=retnonce)
+            plaintext = retcipher.decrypt(retciphertext)
+            return plaintext
+        except Exception:
+            print("Incorrect decryption")

requirements.txt

@@ -1 +1,2 @@
-pycryptodome
+pycryptodome
+pydh