seg/trabalho4/as.py

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2023-10-22 19:56:01 +00:00
from common import *
from hashlib import sha256
import socket
from AES import AESCipher
import os
HOST = "127.0.0.1"
PORT = AS_PORT
def process_message(message):
print(message)
message = message.split("||")
if message[0] == "register":
body = message[1].split(",")
username = body[0]
password = body[1]
password = sha256(password.encode()).hexdigest()
key = message[3]
return register_user(username, password, key)
elif message[0] == "login":
body = message[1].split(",")
username = body[0]
password = body[1]
password = sha256(password.encode()).hexdigest()
return login(username, password)
elif message[0] == "request":
"""
M1 = [ID_C + {ID_S + T_R + N1}Kc]
T_c_tgs = {ID_C + T_R + K_c_tgs}K_tgs
M2 = [{K_c_tgs + N_1}Kc + T_c_tgs]
"""
body = message[1].split(",")
ID_C = body[0]
key = get_key(ID_C)
AES = AESCipher(key)
K_tgs = C_K_tgs
M2_AES = AESCipher(K_tgs)
inner_message = AES.decrypt(body[1])
inner_message = inner_message.split(",")
T_R = inner_message[1]
N1 = inner_message[2]
K_c_tgs = os.urandom(16)
T_c_tgs = f"{ID_C},{T_R},{K_c_tgs}"
T_c_tgs = M2_AES.encrypt(T_c_tgs)
M2 = f"{K_c_tgs},{N1}"
M2 = AES.encrypt(M2)
M2 = f"{M2},{T_c_tgs}"
print('sending m2', M2)
return M2
else:
print("Invalid message")
def register_user(username, password, key):
with open("users.data", "a") as f:
f.write(f"{username},{password},{key.encode()}\n")
return f"success,{key}"
def login(username, password):
with open("users.data", "r", newline='\n') as f:
for line in f:
line = line.strip()
line = line.replace("\n", "")
user, pw, key = line.split(",")
if user == username and pw == password:
key = eval(key)
print(f"Login succeeded!")
return f"success,{key}"
print("Login failed!")
return "failure"
def get_key(username):
return C_User_Key
with open("users.data", "r", newline='\n') as f:
for line in f:
line = line.strip()
line = line.replace("\n", "")
user, _, key = line.split(",")
if user == username:
return eval(key)
def main():
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
while True:
conn, addr = s.accept()
with conn:
print(f"Connected by {addr}")
data = conn.recv(4096)
data = data.decode()
response = process_message(data)
conn.sendall(response.encode())
if __name__ == "__main__":
main()