client.py

#!/usr/bin/env python
#
# -*- coding: utf-8 -*-
#
# client.py
#
# Copyright (C) 2006-2020 wolfSSL Inc.
#
# This file is part of wolfSSL. (formerly known as CyaSSL)
#
# wolfSSL is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# wolfSSL is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

# pylint: disable=missing-docstring, invalid-name, import-error

import sys
import socket
import argparse

try:
    import wolfssl
except ImportError:
    print("You must run 'python setup.py install' to use the examples")
    sys.exit()

def build_arg_parser():
    parser = argparse.ArgumentParser(add_help=False)

    parser.add_argument(
        "-?", "--help", action="help",
        help="show this help message and exit"
    )

    parser.add_argument(
        "-h", metavar="host", default="127.0.0.1",
        help="Host to connect to, default 127.0.0.1"
    )

    parser.add_argument(
        "-p", metavar="port", type=int, default=11111,
        help="Port to connect on, not 0, default 11111"
    )

    parser.add_argument(
        "-v", metavar="version", type=int, choices=[0, 1, 2, 3, 4], default=4,
        help="SSL version [0-4] (SSLv3, TLSv1, TLSv1.1, TLSv1.2, SSLv23)"
    )

    parser.add_argument(
        "-l", metavar="ciphers", type=str, default="",
        help="Cipher suite list (: delimited)"
    )

    parser.add_argument(
        "-c", metavar="certificate", default="./certs/client-cert.pem",
        help="Certificate file,           default ./certs/client-cert.pem"
    )

    parser.add_argument(
        "-k", metavar="key", default="./certs/client-key.pem",
        help="Key file,                   default ./certs/client-key.pem"
    )

    parser.add_argument(
        "-A", metavar="ca_file", default="./certs/ca-cert.pem",
        help="Certificate Authority file, default ./certs/ca-cert.pem"
    )

    parser.add_argument(
        "-d", action="store_true",
        help="Disable client cert check"
    )

    parser.add_argument(
        "-g", action="store_true",
        help="Send server HTTP GET"
    )

    return parser


def get_method(index):
    return (
        wolfssl.PROTOCOL_SSLv3,
        wolfssl.PROTOCOL_TLSv1,
        wolfssl.PROTOCOL_TLSv1_1,
        wolfssl.PROTOCOL_TLSv1_2,
        wolfssl.PROTOCOL_SSLv23
    )[index]


# Callback for wolfssl/certs/client-keyEnc.pem (yassl123 password)
# sz is the max size of password allowed
# rw is type i.e PEM_PASS_READ
# userdata is a void pointer potentially set by user
def password_cb(sz, rw, userdata):
    return "yassl123"


def main():
    args = build_arg_parser().parse_args()

    bind_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)

    # enable debug, if native wolfSSL has been compiled with '--enable-debug'
    wolfssl.WolfSSL.enable_debug()

    context = wolfssl.SSLContext(get_method(args.v))

    context.set_passwd_cb(password_cb)
    context.load_cert_chain(args.c, args.k)

    if args.d:
        context.verify_mode = wolfssl.CERT_NONE
    else:
        context.verify_mode = wolfssl.CERT_REQUIRED
        context.load_verify_locations(args.A)

    if args.l:
        context.set_ciphers(args.l)

    try:
        secure_socket = context.wrap_socket(bind_socket)

        secure_socket.connect((args.h, args.p))

        if args.g:
            secure_socket.write(b"GET / HTTP/1.1\n\n")
        else:
            secure_socket.write(b"hello wolfssl")

        print("\n", secure_socket.read(), "\n")

    except KeyboardInterrupt:
        print()

    finally:
        secure_socket.close()


if __name__ == '__main__':
    main()