edouard@3884: #!/usr/bin/env python
edouard@3884: # -*- coding: utf-8 -*-
edouard@3884: 
edouard@3884: # This file is part of Beremiz, a Integrated Development Environment for
edouard@3884: # programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
edouard@3884: #
edouard@3884: # Copyright (C) 2019: Edouard TISSERANT
edouard@3884: #
edouard@3884: # See COPYING file for copyrights details.
edouard@3884: #
edouard@3884: # This program is free software; you can redistribute it and/or
edouard@3884: # modify it under the terms of the GNU General Public License
edouard@3884: # as published by the Free Software Foundation; either version 2
edouard@3884: # of the License, or (at your option) any later version.
edouard@3884: #
edouard@3884: # This program is distributed in the hope that it will be useful,
edouard@3884: # but WITHOUT ANY WARRANTY; without even the implied warranty of
edouard@3884: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
edouard@3884: # GNU General Public License for more details.
edouard@3884: #
edouard@3884: # You should have received a copy of the GNU General Public License
edouard@3884: # along with this program; if not, write to the Free Software
edouard@3884: # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
edouard@3884: 
edouard@3884: 
edouard@3884: """
edouard@3884: The TLS-PSK adapter that handles SSL connections instead of regular sockets,
edouard@3884: but using Pre Shared Keys instead of Certificates
edouard@3884: """
edouard@3884: 
edouard@3884: import socket
edouard@3884: import ssl
edouard@3884: 
edouard@3884: try:
edouard@3884:     import sslpsk
edouard@3884: except ImportError as e:
edouard@3884:     sslpsk = None
edouard@3884: 
edouard@3884: from erpc.transport import TCPTransport
edouard@3884: 
edouard@3884: class SSLPSKClientTransport(TCPTransport):
edouard@3884:     def __init__(self, host, port, psk):
edouard@3884:         """ overrides TCPTransport's __init__ to wrap socket in SSl wrapper """
edouard@3884:         super(TCPTransport, self).__init__()
edouard@3884:         self._host = host
edouard@3884:         self._port = port
edouard@3884:         self._isServer = isServer
edouard@3884:         self._sock = None
edouard@3884: 
edouard@3884:         if sslpsk is None:
edouard@3884:              raise ImportError("sslpsk module is not available")
edouard@3884: 
edouard@3884:         raw_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
edouard@3884:         raw_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
edouard@3884:         raw_sock.connect((self._host, self._port))
edouard@3884:         self._sock = sslpsk.wrap_socket(
edouard@3884:                 raw_sock, psk=psk, server_side=False,
edouard@3884:                 ciphers="PSK-AES256-CBC-SHA",  # available in openssl 1.0.2
edouard@3884:                 ssl_version=ssl.PROTOCOL_TLSv1)
edouard@3884: 
edouard@3884: