refactor chacha
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This commit is contained in:
Torma Kristóf 2021-04-26 18:13:38 +02:00
parent a8730ceac3
commit 56d77f0476
Signed by: tormakris
GPG Key ID: DC83C4F2C41B1047

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@ -42,8 +42,13 @@ class NetWrapper:
self.network.send_msg(self.clientAddr, identMsg)
def sendMessage(self, message: bytes) -> None:
self.sendTypedMessage(message, "CMD")
def sendTypedMessage(self, message: bytes, type: str) -> None:
if not (type == "IDY" or type == "DH" or type == "CMD"):
raise Exception('Unknown message type')
cipher = ChaCha20_Poly1305.new(key=self.cipherkey)
header = json.dumps({'source': self.network.own_addr, 'type': 'CMD'}).encode('UTF-8')
header = json.dumps({'source': self.network.own_addr, 'type': type}).encode('UTF-8')
cipher.update(header)
ciphertext, tag = cipher.encrypt_and_digest(message)
nonce = b64encode(cipher.nonce).decode('UTF-8')
@ -78,16 +83,11 @@ class NetWrapper:
status, msg = self.network.receive_msg(blocking=True)
if not status:
raise Exception('Network error during connection.')
b64 = json.loads(msg.decode('UTF-8'))
retheader = json.loads(b64decode(b64['header']).decode('UTF-8'))
retnonce = b64decode(b64['nonce'])
retciphertext = b64decode(b64['message'])
rettag = b64decode(b64['tag'])
retcipher = ChaCha20_Poly1305.new(key=self.cipherkey, nonce=retnonce)
retcipher.update(b64decode(b64['header']))
plaintext = retcipher.decrypt_and_verify(retciphertext, rettag).decode('UTF-8').split(' ')
if not (retheader['source'] == self.clientAddr and retheader['type'] == 'AUT'):
cleartext = self.recieveEncryptedMessage(msg, "AUT").decode('UTF-8')
if cleartext=="ERROR":
return False
else:
plaintext = cleartext.split(' ')
self.homeDirectory = self.authenticationInstance.login(plaintext[1], plaintext[2])
linsuccess = (not (len(plaintext) != 3 or plaintext[0] != "LIN" or plaintext[
1] != self.currentUser)) and self.homeDirectory
@ -95,20 +95,10 @@ class NetWrapper:
message = "OK".encode('UTF-8')
else:
message = "ERROR".encode('UTF-8')
header = json.dumps({'source': self.network.own_addr, 'type': 'AUT'}).encode('UTF-8')
cipher = ChaCha20_Poly1305.new(key=self.cipherkey)
cipher.update(header)
ciphertext, tag = cipher.encrypt_and_digest(message)
b64tag = b64encode(tag).decode('UTF-8')
nonce = b64encode(cipher.nonce).decode('UTF-8')
ct = b64encode(ciphertext).decode('UTF-8')
sendjson = json.dumps(
{'header': b64encode(header).decode('UTF-8'), 'nonce': nonce, 'message': ct, 'tag': b64tag}).encode(
'UTF-8')
self.network.send_msg(self.clientAddr, sendjson)
self.sendTypedMessage(message, "AUT")
return linsuccess
except Exception:
print("Incorrect decryption")
print("Login failed")
return False
def initClientConnection(self, msg: bytes) -> bytes:
@ -137,7 +127,7 @@ class NetWrapper:
if not self.clientAddr:
return self.initClientConnection(msg)
else:
return self.recieveEncryptedMessage(msg)
return self.recieveEncryptedMessage(msg, "CMD")
def logout(self) -> None:
self.clientAddr = ""
@ -146,7 +136,9 @@ class NetWrapper:
self.currentUser = ""
self.homeDirectory = ""
def recieveEncryptedMessage(self, msg: bytes) -> bytes:
def recieveEncryptedMessage(self, msg: bytes, type: str) -> bytes:
if not (type == "IDY" or type == "DH" or type == "CMD"):
raise Exception('Unknown message type')
try:
b64 = json.loads(msg.decode('UTF-8'))
retheader = json.loads(b64decode(b64['header']).decode('UTF-8'))
@ -156,7 +148,7 @@ class NetWrapper:
retcipher = ChaCha20_Poly1305.new(key=self.cipherkey, nonce=retnonce)
retcipher.update(b64decode(b64['header']))
plaintext = retcipher.decrypt_and_verify(retciphertext, rettag)
if not (retheader['source'] == self.clientAddr and retheader['type'] == 'CMD'):
if not (retheader['source'] == self.clientAddr and retheader['type'] == type):
return "ERROR".encode('UTF-8')
else:
return plaintext