def read(conn, mask):
data = conn.recv(1024)
client_infos = clients_information[conn]
if data:
data = json.loads(data)
#client has done dh shandshake
if client_infos["dh_handshake"]:
data["header"] = symmetriccrypt.decrypt(
client_infos["common_secret"], data["header"].encode(),
"AES-128", "CBC").decode()
if data["header"] == "CN": #client name
#receive client name
do_CN(conn, data, client_infos)
elif data["header"] == "NM": #new message
do_NM(conn, data, client_infos)
#client has not done the dh handshake yet
else:
#client confirm received dh parameters
if data["header"] == "RDHP":
#send my dh public numbers to client
conn.send(
json.dumps({
"header": "SDHN",
"data": client_infos["my_dh_public_number"]
}).encode())
logger.debug("sended dh public number to new client")
#do dh handshake
else:
do_CDHN(conn, data, client_infos)
#empty data closing client connection
else:
logger.info('closing {}'.format(client_infos["addr"]))
response = "{} leave on chat".format(client_infos["name"])
clients_connection.remove(conn)
del clients_information[conn]
sel.unregister(conn)
conn.close()
#inform others who leave
for participant in clients_connection:
if not (clients_information[participant]["dh_handshake"]):
continue
response = {
"header":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"], "SM",
"AES-128", "CBC").decode(),
"data":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"],
response, "AES-128", "CBC").decode()
}
participant.send(json.dumps(response).encode())
def server_message_received(conn):
data = conn.recv(1024)
#client has done dh shandshake
if server_connection["dh_handshake"]:
data = json.loads(data)
data["header"] = symmetriccrypt.decrypt(server_connection["common_secret"], data["header"].encode(), "AES-128", "CBC").decode()
#message chat settings
if data["header"] == "SM":
do_SM(conn, data)
#chat messages
elif data["header"] == "OM":
do_OM(conn, data)
#this client has not done the dh handshake yet
else:
if server_connection["have_dh_parameters"]:
#receive server dh public numbers
do_SDHN(conn, data)
else:
#receive dh parameters from server
do_DHP(conn, data)
def do_CN(conn, data, client_infos):
data["data"] = symmetriccrypt.decrypt(client_infos["common_secret"],
data["data"].encode(), "AES-128",
"CBC").decode()
clients_information[conn]["name"] = data["data"]
#introduces the new client to others
sey_to_others = "now {} is connected".format(client_infos["name"])
for participant in clients_connection:
if participant == conn or not (
clients_information[participant]["dh_handshake"]):
continue
response = {
"header":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"], "SM",
"AES-128", "CBC").decode(),
"data":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"],
sey_to_others, "AES-128", "CBC").decode()
}
participant.send(json.dumps(response).encode())
logger.debug("fineshed do_CN, client name is {}".format(data["data"]))
def do_NM(conn, data, client_infos):
data["data"] = symmetriccrypt.decrypt(client_infos["common_secret"],
data["data"].encode(), "AES-128",
"CBC").decode()
now = datetime.datetime.now()
now = "{}:{}".format(now.hour, now.minute)
data["data"] = "{};{};{}".format(client_infos["name"], data["data"], now)
for participant in clients_connection:
if participant == conn or not (
clients_information[participant]["dh_handshake"]):
continue
response = {
"header":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"], "OM",
"AES-128", "CBC").decode(),
"data":
symmetriccrypt.encrypt(
clients_information[participant]["common_secret"],
data["data"], "AES-128", "CBC").decode()
}
participant.send(json.dumps(response).encode())
logger.debug("finished do_NM")
def do_OM(conn, data):
data = symmetriccrypt.decrypt(server_connection["common_secret"], data["data"].encode(), "AES-128", "CBC").decode()
data = data.split(";")
window.manager.current_screen.receive_chat_participants_message(data)
def do_SM(conn, data):
data = symmetriccrypt.decrypt(server_connection["common_secret"], data["data"].encode(), "AES-128", "CBC").decode()
window.manager.current_screen.receive_server_nofication(data)