path: root/cryptech_console

#!/usr/bin/env python
#
# Copyright (c) 2017, NORDUnet A/S All rights reserved.
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# modification, are permitted provided that the following conditions are
# met:
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#   this list of conditions and the following disclaimer.
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# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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"""
Console client shim to work with Cryptech Python multiplexer.
"""

import os
import sys
import socket
import atexit
import termios
import argparse

import tornado.iostream
import tornado.ioloop
import tornado.gen

class FemtoTerm(object):

    def __init__(self, s):
        self.termios_setup()
        self.stdin_stream  = tornado.iostream.PipeIOStream(sys.stdin.fileno())
        self.stdout_stream = tornado.iostream.PipeIOStream(sys.stdout.fileno())
        self.socket_stream = tornado.iostream.IOStream(s)
        self.closed = False

    def close(self):
        self.termios_teardown()
        self.stdin_stream.close()
        self.stdout_stream.close()
        self.socket_stream.close()
        self.closed = True

    @tornado.gen.coroutine
    def run(self):
        yield [self.stdout_loop(), self.stdin_loop()]

    def termios_setup(self):
        self.fd = sys.stdin.fileno()
        self.old_tcattr = termios.tcgetattr(self.fd)
        self.new_tcattr = termios.tcgetattr(self.fd)
        atexit.register(self.termios_teardown)
        self.new_tcattr[3] &= ~(termios.ICANON | termios.ECHO) #  | termios.ISIG
        self.new_tcattr[6][termios.VMIN] = 1
        self.new_tcattr[6][termios.VTIME] = 0
        termios.tcsetattr(self.fd, termios.TCSANOW, self.new_tcattr)

    def termios_teardown(self):
        if self.fd is not None:
            termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old_tcattr)
            self.fd = None

    @tornado.gen.coroutine
    def copy_loop(self, stream1, stream2, text1, text2, buffer_size = 1024):
        try:
            while not self.closed:
                buffer = yield stream1.read_bytes(buffer_size, partial = True)
                yield stream2.write(buffer.replace(text1, text2))
        except tornado.iostream.StreamClosedError:
            self.close()

    def stdin_loop(self):
        return self.copy_loop(self.stdin_stream, self.socket_stream, b"\n", b"\r")

    def stdout_loop(self):
        return self.copy_loop(self.socket_stream, self.stdout_stream, b"\r\n", b"\n")

def main():
    parser = argparse.ArgumentParser(formatter_class = argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument("cty_socket",
                        nargs = "?",
                        help = "CTY PF_UNIX socket name",
                        default = os.getenv("CRYPTECH_CTY_CLIENT_SOCKET_NAME",
                                            "/tmp/.cryptech_muxd.cty"))
    args = parser.parse_args()

    s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    try:
        s.connect(args.cty_socket)
    except socket.error:
        sys.exit("Couldn't connect to socket {}".format(args.cty_socket))
    tornado.ioloop.IOLoop.current().run_sync(FemtoTerm(s).run)

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass