From c61ea16c022b0955e347b3952db3e555ba9df60a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Torma=20Krist=C3=B3f?= Date: Sat, 24 Apr 2021 23:35:25 +0200 Subject: [PATCH] netwrapper client done --- client/netwrapper.py | 172 ++++++++++++++++++++++++------------------- requirements.txt | 3 +- 2 files changed, 98 insertions(+), 77 deletions(-) diff --git a/client/netwrapper.py b/client/netwrapper.py index 056fa26..4ac8d85 100644 --- a/client/netwrapper.py +++ b/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") diff --git a/requirements.txt b/requirements.txt index c21b6ec..5da17aa 100644 --- a/requirements.txt +++ b/requirements.txt @@ -1 +1,2 @@ -pycryptodome \ No newline at end of file +pycryptodome +pydh \ No newline at end of file