iniciando trab 4

trabalho4/service.py

@@ -0,0 +1,67 @@
+import socket
+from common import *
+import socket
+from AES import AESCipher
+import os
+from random import randint
+
+HOST = "127.0.0.1"
+PORT = SERVICE_PORT
+
+def process_message(message):
+    print(message)
+    message = message.split("||")
+
+    if message[0] == "request":
+        """
+        T_c_s = {ID_C + T_A + K_c_s}K_s
+
+        M5 = [{ID_C + T_A + S_R + N3}K_c_s + T_c_s]
+        M6 = [{Resposta, N3}K_c_s]
+        """
+        body = message[1].split(",")
+        K_s = C_K_s
+        T_c_s_AES = AESCipher(K_s)
+
+        M5_inner = body[0]
+        T_c_s = body[1]
+
+        T_c_s = T_c_s_AES.decrypt(T_c_s)
+        T_c_s = T_c_s.split(",")
+        ID_C = T_c_s[0]
+        T_A = T_c_s[1]
+        K_c_s = T_c_s[2]
+
+        M5_inner_AES = AESCipher(K_c_s)
+        M5_inner = M5_inner_AES.decrypt(M5_inner)
+        M5_inner = M5_inner.split(",")
+        ID_S = M5_inner[2]
+        N3 = M5_inner[3]
+
+        # generate M6
+
+        M6_inner = f"{randint(0, 100)},{N3}"
+        M6_inner_AES = AESCipher(K_c_s)
+        M6_inner = M6_inner_AES.encrypt(M6_inner)
+
+        M6 = f"{M6_inner}"
+        return M6
+
+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}")
+                all_data = ""
+                data = conn.recv(4096)
+                all_data += data.decode()
+
+                response = process_message(all_data)
+
+                conn.sendall(response.encode())
+
+if __name__ == "__main__":
+    main()