iniciando trab 4

2023-10-22 16:56:01 -03:00
parent 8ce9fbd1f0
commit c8799ed37a
7 changed files with 460 additions and 0 deletions
@@ -0,0 +1,104 @@
+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()