def request_authentication(username, sock, sip, sport, password):
a = util.get_random_number()
A = util.get_public_ephemeral(a)
message = {}
message.update({'username': username})
message.update({'A': A})
try:
msg = util.encrypt_message_PSK(message, SERVER_KEY)
except Exception as e:
print "An error occured while encrypting the text message - ", message, "! %s" %e
try:
#start_new_thread(receiveMessages, (sock,))
sock.connect((sip, int(sport)))
send_message(sock, msg, sip, sport)
progress[username] = 1
t1 = Thread(target=receiveMessages, args=(sock, username, sip, sport, A, password, a))
t1.start()
t1.join()
if(EXIT_IN_ERROR):
sys.exit()
except ServerConnectionBroken:
print 'Connection broken !!'
sys.exit()
def receiveMessages(sock, username, sip, sport, A, password, a):
while(1):
try:
# try to receive messages from the server
msg = sock.recv(40960) # changed here akshay
if msg != '':
msg1 = pickle.loads(msg)
#print("Received message:%s" %(msg1))
status = progress[username]
if(status == 1):
if(msg1 == 'ERROR'):
global EXIT_IN_ERROR
EXIT_IN_ERROR = True
sys.exit()
value = find_value_from_hash(msg1)
send_message(sock, value, sip, sport)
progress[username] = 2
if(status == 2):
challenge_pk_data = {}
data_for_kas = {}
final_to_server = {}
global shared_key
shared_key = compute_shared_key(A, msg1, username, password, a)
final_kas = util.MD5_HASH(shared_key)
challenge = util.get_random_number()
global NONCE_SENT
NONCE_SENT = challenge
data_for_kas.update({'CHALLENGE': challenge , 'PK_CLIENT': CLIENT_PUBLIC_KEY_STR})
Kas_encrypted_data = util.encrypt_message_KAS(data_for_kas, final_kas, GENERATED_IV)
# add IV here
challenge_pk_data.update({'CHALLENGE_PK': Kas_encrypted_data, 'CHALLENGE': challenge, 'IV': GENERATED_IV})
data_to_server = util.encrypt_message_PSK(challenge_pk_data, SERVER_KEY)
send_message(sock, data_to_server, sip, sport)
progress[username] = 3
if(status == 3):
hash_shared_key = util.MD5_HASH(shared_key)
nonce = util.decrypt_using_Kas(msg1, hash_shared_key, GENERATED_IV)
incremented_nonce = long(nonce) + 1
if incremented_nonce == NONCE_SENT:
print ("Login Success !")
return True
else:
print("Authentication pending!")
return False
else:
print("Connection with server is broken...")
sys.exit()
except KeyboardInterrupt:
sock.close()
# handling socket errors
except socket.error, s_error:
sock.close()
error_code = s_error[0]
error_message = s_error[1]
print('Error in reading messages: ', error_code, ' - ', error_message)
except Exception as e:
print('Error occured:', e)
sock.close()
sys.exit()
