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#!/usr/local/bin/python -O
from __future__ import print_function
"""Implements a [hopefully] non-blocking SSL Dispatcher on top of M2Crypto.
Written by Ilya Etingof <ilya@glas.net>, 05/2001
"""
import asyncore # type: ignore # https://github.com/python/typeshed/issues/356
import socket
# M2Crypto
from M2Crypto import SSL # type: ignore # we are not in proper directory
class NBConnection(SSL.Connection):
"""Functional equivalent of SSL.Connection class.
Facilitates possibly delayed socket.connect() and socket.accept()
termination.
"""
def __init__(self, ctx, sock):
SSL.Connection.__init__(self, ctx, sock)
def connect(self, addr):
self._setup_ssl(addr)
# FIXME SSL.Connection doesn't have _check_ssl_return method
return self._check_ssl_return(SSL.m2.ssl_connect(self.ssl))
def accept(self, addr):
self._setup_ssl(addr)
self.accept_ssl()
class Dispatcher(asyncore.dispatcher_with_send):
"""A non-blocking SSL Dispatcher that mimics the asyncode.dispatcher API"""
def __init__(self, cert, key, sock=None, serving=None):
asyncore.dispatcher_with_send.__init__(self)
self.__serving = serving
# XXX
if sock:
if self.__serving:
self.set_socket(sock)
else:
self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
self.ctx = SSL.Context()
self.ctx.set_verify(SSL.verify_none, 10)
self.ctx.load_cert(cert, key)
self.ctx.set_info_callback()
self.ssl = NBConnection(self.ctx, self.socket)
self.peer = None
self.__output = ''
self.__want_write = 1
#
# The following are asyncore overloaded methods
#
def handle_connect(self):
"""Initiate SSL connection negotiation"""
if self.__serving:
self.ssl.accept(self.addr)
self.peer = self.ssl.get_peer_cert()
self.handle_ssl_accept()
else:
self.ssl.connect(self.addr)
self.handle_ssl_connect()
def handle_read(self):
"""Read user and/or SSL protocol data from SSL connection"""
ret = self.ssl._read_nbio()
if ret:
self.handle_ssl_read(ret)
else:
# Assume write is wanted
self.__want_write = 1
def handle_write(self):
"""Write pending user or SSL protocol data down to SSL connection"""
self.__want_write = 0
ret = self.ssl._write_nbio(self.__output)
if ret < 0:
try:
err = SSL.m2.ssl_get_error(self.ssl.ssl, ret)
except SSL.SSLError:
return
if err == SSL.m2.ssl_error_want_write:
self.__want_write = 1
else:
self.__output = self.__output[ret:]
def writable(self):
"""Indicate that write is desired.
Happens if there's some user and/or SSL protocol data.
"""
if self.__output or self.__want_write:
return 1
return self.ssl_writable()
def handle_close(self):
"""Shutdown SSL connection."""
self.ssl = None
self.ctx = None
self.close()
self.handle_ssl_close()
def handle_error(self, *info):
"""A trap for asyncore errors"""
self.handle_ssl_error(info)
#
# The following are ssl.dispatcher API
#
def ssl_connect(self, server):
"""Initiate SSL connection"""
self.connect(server)
def ssl_write(self, data):
"""Write data to SSL connection"""
self.__output = self.__output + data
def ssl_close(self):
"""Close SSL connection"""
self.handle_close()
def handle_ssl_connect(self):
"""Invoked on SSL connection establishment (whilst in Client mode)"""
print('Unhandled handle_ssl_connect()')
def handle_ssl_accept(self):
"""Invoked on SSL connection establishment (whilst in server mode)"""
print('Unhandled handle_ssl_accept()')
def handle_ssl_read(self, data):
"""Invoked on new data arrival to SSL connection"""
print('Unhandled handle_ssl_read event')
def handle_ssl_close(self):
"""Invoked on SSL connection termination"""
pass
def ssl_writable(self):
"""Invoked prior to every select() call"""
return 0
if __name__ == '__main__':
"""Give it a test run"""
class Client(Dispatcher):
"""SSL Client class"""
def __init__(self, cert, key):
Dispatcher.__init__(self, cert, key)
def handle_ssl_read(self, data):
print(data)
self.ssl_write('test write')
ssl = Client('test.cert', 'test.key')
ssl.ssl_connect(('localhost', 7777))
asyncore.loop()
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