secure-chat/client/main.py

#!/usr/bin/env python3
# coding: utf8

import json
import logging
import logging.config
import os
import socket

try:
    # noinspection PyUnresolvedReferences
    from Crypto.PublicKey import RSA as RSA
    # noinspection PyUnresolvedReferences
    from Crypto.Cipher import PKCS1_OAEP
    pycryptodome = False
except ModuleNotFoundError:  # Pycryptodomex
    from Cryptodome.PublicKey import RSA as RSA
    from Cryptodome.Cipher import PKCS1_OAEP
    pycryptodome = True


def setup_logging(default_path='log_config.json', default_level=logging.INFO, env_key='LOG_CFG'):
    """Setup logging configuration
    """
    path = default_path
    value = os.getenv(env_key, None)
    if value:
        path = value
    if os.path.exists(path):
        with open(path, 'rt') as f:
            config = json.load(f)
        logging.config.dictConfig(config)
    else:
        logging.basicConfig(level=default_level)


setup_logging()

log_server = logging.getLogger('server')

debug = log_server.debug
info = log_server.info
warning = log_server.warning
error = log_server.error
critical = log_server.critical

#### Variables ####
HOST = '127.0.0.1'
PORT = 8888
BUFFER_SIZE = 4096
CHUNK_SIZE = int(BUFFER_SIZE / 8)

clientSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
clientSocket.connect((HOST, PORT))


# ET ICI ON MET LE CLIENT

def send(to_send):
    clientSocket.send(BEGIN_MESSAGE)
    i = 0
    for to_send_text in [to_send[i:i + BUFFER_SIZE - 2] for i in range(0, len(to_send), BUFFER_SIZE - 2)]:
        print((len(to_send_text)).to_bytes(2, byteorder='big'))
        print((len(to_send_text)).to_bytes(2, byteorder='big') + to_send_text.ljust(BUFFER_SIZE, b";"))
        clientSocket.send((len(to_send_text)).to_bytes(2, byteorder='big') + to_send_text.ljust(BUFFER_SIZE - 2, b";"))
        i += 1
    print(i)
    clientSocket.send(END_MESSAGE)


BEGIN_MESSAGE = bytes("debut", "ascii").ljust(BUFFER_SIZE, b";")
END_MESSAGE = bytes("fin", "ascii").ljust(BUFFER_SIZE, b";")
HEADER_TXT = """\
EICP2P2 V1
type: RSASend"""
HEADER = bytes(HEADER_TXT, "ascii").ljust(BUFFER_SIZE, b";")

## création des clef RSA
RSA_KEY_SIZE = CHUNK_SIZE * 2
key = RSA.generate(BUFFER_SIZE * 2)
private_key = key.export_key()
file_out = open("private.pem", "wb")
file_out.write(private_key)
public_key = key.publickey().export_key()
file_out = open("receiver.pem", "wb")
file_out.write(public_key)
to_send = public_key.ljust(BUFFER_SIZE, b';')

clientSocket.send(BEGIN_MESSAGE)
clientSocket.send(HEADER)
clientSocket.send(to_send)
clientSocket.send(END_MESSAGE)

print('ok')
chunk = bytes("", "ascii")
while chunk != BEGIN_MESSAGE:
    chunk = clientSocket.recv(BUFFER_SIZE)
last_chunk = chunk
while last_chunk != END_MESSAGE:
    last_chunk = clientSocket.recv(BUFFER_SIZE)
    chunk += last_chunk

print(len(chunk[BUFFER_SIZE:-BUFFER_SIZE]))
chunk = chunk[BUFFER_SIZE:-BUFFER_SIZE]

# HEADER+AES key are encypted in same time, so decrypt time at same time
cipher_rsa = PKCS1_OAEP.new(key)
texte_to_decrypt = b''

for ligne in [chunk[i:i + BUFFER_SIZE] for i in range(0, len(chunk), BUFFER_SIZE)]:
    to_decrypt = ligne[2:]
    to_decrypt = to_decrypt[:int.from_bytes(ligne[:2], byteorder='big')]
    texte_to_decrypt += to_decrypt
print(len(texte_to_decrypt))
texte = b''
for to_decrypt in [texte_to_decrypt[i:i + RSA_KEY_SIZE] for i in range(0, len(texte_to_decrypt), RSA_KEY_SIZE)]:
    print(len(to_decrypt))
    print(to_decrypt)
    print(texte)
    print(len(texte))
    texte += cipher_rsa.decrypt(to_decrypt)
print(texte)