ch2_netcat_example.py

ch2_netcat_example.py

#netcat example
import sys
import socket
import getopt
global target
global port
target = ""
port = 0
def usage():
    print("                                                           ")
    print("********************** Python Netcat **********************")
    print("Usage: python3 ch2_netcat_example.py -t 192.168.0.1 -p 9999")
    print("-t --target=                             target destination")
    print("-p --port=                                      target port")
    print("-h --help                                    this help menu")
    print("                                                           ")
    sys.exit(0)
if not len(sys.argv[1:]):
    usage()
try:
    opts, args = getopt.getopt(sys.argv[1:], "t:p:h", ["target=", "port=", "help"])
except getopt.GetoptError as err:
    print(str(err))
    sys.exit(1)
#check options and arguments
for o, a in opts:
    if o in ("-h", "--help"):
        usage()
    elif o in ("-t", "--target") and len(a):
        target = a
    elif o in ("-p", "--port") and int(a) in range(1, 65536):
        port = int(a)
    else:
        print("Invalid Arguments")
        usage()
#read buffer from stdin
print("Enter buffer data (CTRL-D to send/ CTRL-C to quit)")
buffer = sys.stdin.read()
#create the tcp client socket, connect and send buffer data
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((target, port))
#CTRL-C to stop python netcat
while True:
    #send buffer data
    client_socket.send(buffer.encode())
#get 4096 bytes from destination
    response = client_socket.recv(4096)
    bytes = len(response)
    total_bytes = bytes
#get all remaining bytes from destination
    while bytes == 4096:
        data = client_socket.recv(4096)
        response += data
        bytes = len(data)
        total_bytes += bytes
#Show the full response
    print(f"Response ({total_bytes} Bytes):")
    print(response)
#read buffer from stdin
    print("Enter buffer data (CTRL-D to send/ CTRL-C to quit)")
    buffer = sys.stdin.read()