def setup_key_distribution(self, receiver_ID, N, receiver_ip):
sender_key_10 = np.concatenate(
(DES.byte_to_arr(self.key_), np.zeros(2)))
receiver_key_10 = np.concatenate(
(DES.byte_to_arr(KEYS[receiver_ID]), np.zeros(2)))
session_key = random.getrandbits(8)
session_key_enc_a = DES.full_encrypt(str(session_key), sender_key_10)
receiver_ID_enc_a = DES.full_encrypt(str(receiver_ip), sender_key_10)
N_enc_a = DES.full_encrypt(str(N), sender_key_10)
session_key_enc_b = DES.full_encrypt(str(session_key), receiver_key_10)
sender_id_enc_b = DES.full_encrypt(str(self.id_), receiver_key_10)
timestamp = datetime.datetime.now()
timestamp_str = timestamp.strftime('%Y-%m-%d %H:%M:%S')
timestamp_str_enc_b = DES.full_encrypt(timestamp_str, receiver_key_10)
timestamp_str_enc_a = DES.full_encrypt(timestamp_str, sender_key_10)
return str(session_key_enc_a) + "," + str(receiver_ID_enc_a) + "," + \
str(N_enc_a) + "," + \
str(timestamp_str_enc_a) + "," + str(session_key_enc_b) + "," + \
str(sender_id_enc_b) + "," + str(timestamp_str_enc_b)
import socket
import DES
import datetime
import numpy as np
port = 8888
if __name__ == "__main__":
KDC_ip = '127.0.0.1'
print(sys.argv)
if len(sys.argv) >= 2:
KDC_ip = sys.argv[1]
u = b"BOB"
key = 192
key10 = np.concatenate((DES.byte_to_arr(key), np.zeros(2)))
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.connect((KDC_ip, port))
s.sendall(u)
R = s.recv(1024)
R = R.decode("utf-8")
if R == "200 OK":
print("Everyone connected to KDC.")
else:
raise RuntimeError("ERROR - Not everyone connected to KDC.")
# should have both Alice and Bob connected!!! send 200 OK to start symmetric key distribution.
for conn in conn_dict.values():
conn[1].sendall(b"200 OK")
fds.append(conn[1])
# wait patiently for a request to make a symmetric session key.
readable, writable, exceptional = select.select(fds, [], [])
for C in readable:
ID = C.recv(1024)
ID = ID.decode("utf-8")
# ID user is going to request a session key!
# beyond the ID, everything is going to be encrypted with
# KDC and user's personal key.
request_enc = C.recv(1024).decode("utf-8")
print(connection.KEYS[ID])
key10 = np.concatenate(
(DES.byte_to_arr(connection.KEYS[ID]), np.zeros(2)))
print(key10)
request = DES.full_decrypt(request_enc, key10)
info = request.split(',')
C.sendall(
str.encode(
Alice.setup_key_distribution(info[0], int(info[1]),
conn_dict[info[0]][0])))
# session key is sent. my work here is done.
s.close()