class VClientSocketAgent(VClientSocket):
"""A :class:`VClientSocket` with a byte producer/consumer interface.
:param max_read: max bytes fetched per socket read
:type max_read: int
:param max_write: max bytes written per socket send
:type max_write: int
:param wbuf_len: buffer size of data held for writing (or None)
:type wbuf_len: int
*max_read* is also the maximum size of the buffer for data read
from the socket (so maximum bytes read in one read operation is
*max_read* minus the amount of data currently held in the receive
buffer).
If *wbuf_len* is None then *max_write* is used as the buffer size.
"""
def __init__(self,
reactor,
sock=None,
hc_pol=None,
close_cback=None,
connected=False,
max_read=0x4000,
max_write=0x4000,
wbuf_len=None):
self._max_read = max_read
self._max_write = max_write
self._wbuf = VByteBuffer()
if wbuf_len is None:
wbuf_len = max_write
self._wbuf_len = wbuf_len
self._ci = None
self._ci_eod = False
self._ci_eod_clean = None
self._ci_producer = None
self._ci_consumed = 0
self._ci_lim_sent = 0
self._ci_aborted = False
self._pi = None
self._pi_closed = False
self._pi_consumer = None
self._pi_produced = 0
self._pi_prod_lim = 0
self._pi_buffer = VByteBuffer()
self._pi_aborted = False
# Parent __init__ must be called after local attributes are
# initialized due to overloaded methods called during construction
super_init = super(VClientSocketAgent, self).__init__
super_init(reactor=reactor,
sock=sock,
hc_pol=hc_pol,
close_cback=close_cback,
connected=connected)
@property
def byte_consume(self):
"""Holds a :class:`IVByteConsumer` interface to the socket."""
if not self._ci:
ci = _VSocketConsumer(self)
self._ci = weakref.ref(ci)
return ci
else:
ci = self._ci()
if ci:
return ci
else:
ci = _VSocketConsumer(self)
self._ci = weakref.ref(ci)
return ci
@property
def byte_produce(self):
"""Holds a :class:`IVByteProducer` interface to the socket."""
if not self._pi:
pi = _VSocketProducer(self)
self._pi = weakref.ref(pi)
return pi
else:
pi = self._pi()
if pi:
return pi
else:
pi = _VSocketProducer(self)
self._pi = weakref.ref(pi)
return pi
@property
def byte_io(self):
"""Byte interface (\ :class:`versile.reactor.io.VByteIOPair`\ )."""
return VByteIOPair(self.byte_consume, self.byte_produce)
def _can_connect(self, peer):
"""Called internally to validate whether a connection can be made.
:param peer: peer to connect to
:type peer: :class:`versile.common.peer.VPeer`
:returns: True if connection is allowed
:rtype: bool
If the socket is connected to a byte consumer, sends a control
request for 'can_connect(peer)'. If that control message
returns a boolean, this is used as the _can_connect
result. Otherwise, True is returned.
"""
if self._pi_consumer:
try:
return self._pi_consumer.control.can_connect(peer)
except VIOMissingControl:
return True
else:
return True
def _sock_was_connected(self):
super(VClientSocketAgent, self)._sock_was_connected()
if self._p_consumer:
# Notify producer-connected chain about 'connected' status
control = self._p_consumer.control
def notify():
try:
control.connected(self._sock_peer)
except VIOMissingControl:
pass
self.reactor.schedule(0.0, notify)
@peer
def _c_consume(self, buf, clim):
if self._ci_eod:
raise VIOClosed('Consumer already reached end-of-data')
elif not self._ci_producer:
raise VIOError('No connected producer')
elif self._ci_consumed >= self._ci_lim_sent:
raise VIOError('Consume limit exceeded')
elif not buf:
raise VIOError('No data to consume')
max_cons = self._wbuf_len - len(self._wbuf)
max_cons = min(max_cons, self._ci_lim_sent - self._ci_consumed)
if clim is not None and clim > 0:
max_cons = min(max_cons, clim)
was_empty = not self._wbuf
indata = buf.pop(max_cons)
self._wbuf.append(indata)
self._ci_consumed += len(indata)
if was_empty:
self.start_writing(internal=True)
return self._ci_lim_sent
def _c_end_consume(self, clean):
if self._ci_eod:
return
self._ci_eod = True
self._ci_eod_clean = clean
if not self._wbuf:
self.close_output(VFIOCompleted())
if self._ci_producer:
self._ci_producer.abort()
self._c_detach()
def _c_abort(self, force=False):
if not self._ci_aborted or force:
self._ci_aborted = True
self._ci_eod = True
self._ci_consumed = self._ci_lim_sent = 0
self._wbuf.clear()
if not self._sock_out_closed:
self.close_output(VFIOCompleted())
if self._ci_producer:
self._ci_producer.abort()
self._c_detach()
def _c_attach(self, producer, rthread=False):
# Ensure 'attach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._c_attach, producer, rthread=True)
return
if self._ci_producer is producer:
return
elif self._ci_producer:
raise VIOError('Producer already attached')
self._ci_producer = producer
if self._sock_out_closed:
self.reactor.schedule(0.0, self._c_abort, True)
else:
self._ci_consumed = self._ci_lim_sent = 0
producer.attach(self.byte_consume)
self._ci_lim_sent = self._wbuf_len
producer.can_produce(self._ci_lim_sent)
# Notify attached chain
try:
producer.control.notify_consumer_attached(self.byte_consume)
except VIOMissingControl:
pass
def _c_detach(self, rthread=False):
# Ensure 'detach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._c_detach, rthread=True)
return
if self._ci_producer:
prod, self._ci_producer = self._ci_producer, None
prod.detach()
self._ci_consumed = self._ci_lim_sent = 0
def active_do_write(self):
if self._wbuf:
data = self._wbuf.peek(self._max_write)
try:
num_written = self.write_some(data)
except VIOException:
self._c_abort()
else:
if num_written > 0:
self._wbuf.remove(num_written)
if self._ci_producer:
self._ci_lim_sent = (self._ci_consumed +
self._wbuf_len - len(self._wbuf))
self._ci_producer.can_produce(self._ci_lim_sent)
if not self._wbuf:
self.stop_writing()
if self._ci_eod:
self._c_abort()
else:
self.stop_writing()
def _output_was_closed(self, reason):
# No more output will be written, abort consumer
self._c_abort()
@property
def _c_control(self):
return self._c_get_control()
# Implements _c_control in order to be able to override _c_control
# behavior by overloading as a regular method
def _c_get_control(self):
return VIOControl()
@property
def _c_producer(self):
return self._ci_producer
@property
def _c_flows(self):
return tuple()
@property
def _c_twoway(self):
return True
@property
def _c_reverse(self):
return self.byte_produce()
@peer
def _p_can_produce(self, limit):
if not self._pi_consumer:
raise VIOError('No connected consumer')
if limit is None or limit < 0:
if (not self._pi_prod_lim is None and not self._pi_prod_lim < 0):
if self._pi_produced >= self._pi_prod_lim:
self.start_reading(internal=True)
self._pi_prod_lim = limit
else:
if (self._pi_prod_lim is not None
and 0 <= self._pi_prod_lim < limit):
if self._pi_produced >= self._pi_prod_lim:
self.start_reading(internal=True)
self._pi_prod_lim = limit
def _p_abort(self, force=False):
if not self._pi_aborted or force:
self._pi_aborted = True
self._pi_produced = self._pi_prod_lim = 0
if not self._sock_in_closed:
self.close_input(VFIOCompleted())
if self._pi_consumer:
self._pi_consumer.abort()
self._p_detach()
def _p_attach(self, consumer, rthread=False):
# Ensure 'attach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._p_attach, consumer, rthread=True)
return
if self._pi_consumer is consumer:
return
elif self._pi_consumer:
raise VIOError('Consumer already attached')
self._pi_produced = self._pi_prod_lim = 0
self._pi_consumer = consumer
consumer.attach(self.byte_produce)
# Notify attached chain
try:
consumer.control.notify_producer_attached(self.byte_produce)
except VIOMissingControl:
pass
# If closed, pass notification
if self._sock_in_closed:
self.reactor.schedule(0.0, self._p_abort, True)
def _p_detach(self, rthread=False):
# Ensure 'detach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._p_detach, rthread=True)
return
if self._pi_consumer:
cons, self._pi_consumer = self._pi_consumer, None
cons.detach()
self._pi_produced = self._pi_prod_lim = 0
def active_do_read(self):
if not self._pi_consumer:
self.stop_reading()
if self._pi_prod_lim is not None and self._pi_prod_lim >= 0:
max_read = self._pi_prod_lim - self._pi_produced
else:
max_read = self._max_read
max_read = min(max_read, self._max_read)
if max_read <= 0:
self.stop_reading()
return
try:
data = self.read_some(max_read)
except Exception as e:
self._p_abort()
else:
self._pi_buffer.append(data)
if self._pi_buffer:
self.pi_prod_lim = self._pi_consumer.consume(self._pi_buffer)
def _input_was_closed(self, reason):
if self._pi_consumer:
# Notify consumer about end-of-data
clean = isinstance(reason, VFIOCompleted)
self._pi_consumer.end_consume(clean)
else:
self._p_abort()
@property
def _p_control(self):
return self._p_get_control()
# Implements _p_control in order to be able to override _p_control
# behavior by overloading as a regular method
def _p_get_control(self):
class _Control(VIOControl):
def __init__(self, sock):
self.__sock = sock
def req_producer_state(self, consumer):
# Send notification of socket connect status
def notify():
if self.__sock._sock_peer:
try:
consumer.control.connected(self.__sock._sock_peer)
except VIOMissingControl:
pass
self.__sock.reactor.schedule(0.0, notify)
return _Control(self)
@property
def _p_consumer(self):
return self._pi_consumer
@property
def _p_flows(self):
return tuple()
@property
def _p_twoway(self):
return True
@property
def _p_reverse(self):
return self.byte_consume()
class VMessageDecrypter(object):
"""Decrypter for encrypted messages with data integrity check.
Decodes encrypted plaintext messages in the format encrypted by
:class:`VMessageEncrypter`\ .
:param decrypter: transform for decryption
:type decrypter: :class:`versile.crypto.VBlockTransform`
:param hash_cls: hash class for message integrity hash
:type hash_cls: :class:`versile.crypto.VHash`
:param mac_secret: secret data for package authentication
:type mac_secret: bytes
"""
def __init__(self, decrypter, hash_cls, mac_secret):
self._decrypter = decrypter
self._hash_cls = hash_cls
self._mac_secret = mac_secret
self._max_plaintext_len = 0x10000 # HARDCODED 2-byte message length
self._cipher_blocksize = decrypter.blocksize
self._hash_len = hash_cls.digest_size()
self._read_buf = VByteBuffer()
self._in_buf = VByteBuffer()
self._msg_buf = VByteBuffer()
self._have_len = False
self._plaintext_blocksize = None
self._plaintext_len = None
self._invalid = False
self._result = None
self._msg_num = 0
def reset(self):
"""Resets the decrypter to read a new message.
:raises: :class:`VCryptoException`
Raises an exception if ongoing decryption is not completed.
"""
if self._result is None:
raise VCryptoException('Ongoing decryption not completed')
self._read_buf.remove()
self._in_buf.remove()
self._msg_buf.remove()
self._have_len = False
self._plaintext_len = None
self._invalid = False
self._result = None
def read(self, data):
"""Reads encrypted message data.
:param data: input data to decrypt and decode
:type data: bytes, :class:`versile.common.util.VByteBuffer`
:returns: number of bytes read
:rtype: int
Reads only as much data as is required to complete processing
a complete single message. If data is of type
:class:`versile.common.util.VByteBuffer` then the data that
was read will be popped off the buffer.
.. note::
When decryption of one message has completed,
:meth:`reset` must be called before a new message can be
read.
"""
if isinstance(data, bytes):
read_buf = self._read_buf
read_buf.remove()
read_buf.append(data)
elif isinstance(data, VByteBuffer):
read_buf = data
else:
raise TypeError('Input must be bytes or VByteBuffer')
num_read = 0
_pbsize = self._plaintext_blocksize
_cbsize = self._cipher_blocksize
while read_buf and self._result is None and not self._invalid:
# First decode single block to get blocksize
if not self._have_len:
max_read = _cbsize - len(self._in_buf)
enc_data = read_buf.pop(max_read)
self._in_buf.append(enc_data)
num_read += len(enc_data)
if len(self._in_buf) == _cbsize:
enc_data = self._in_buf.pop()
block = self._decrypter(enc_data)
if _pbsize is None:
_pbsize = len(block)
self._plaintext_blocksize = _pbsize
self._msg_buf.append(block)
len_bytes = self._msg_buf.peek(2)
if _pyver == 2:
self._plaintext_len = 1 + (
(_b_ord(len_bytes[0]) << 8) + _b_ord(len_bytes[1]))
else:
self._plaintext_len = 1 + (
(len_bytes[0] << 8) + len_bytes[1])
self._have_len = True
# If we have first block, decrypt more blocks as available/needed
if self._have_len:
msg_len = 2 + self._plaintext_len + self._hash_len
pad_len = msg_len % _pbsize
if pad_len:
pad_len = _pbsize - pad_len
msg_len += pad_len
msg_left = msg_len - len(self._msg_buf)
blocks_left = msg_left // _pbsize
input_left = (blocks_left * _cbsize - len(self._in_buf))
in_data = read_buf.pop(input_left)
num_read += len(in_data)
self._in_buf.append(in_data)
num_decode = len(self._in_buf)
num_decode -= num_decode % _cbsize
if num_decode > 0:
enc_data = self._in_buf.pop(num_decode)
self._msg_buf.append(self._decrypter(enc_data))
elif len(self._msg_buf) != msg_len:
break
if self._have_len and len(self._msg_buf) == msg_len:
len_bytes = self._msg_buf.pop(2)
plaintext = self._msg_buf.pop(self._plaintext_len)
padding = self._msg_buf.pop(pad_len)
msg_hash = self._msg_buf.pop(self._hash_len)
_mac_msg = b''.join((posint_to_bytes(self._msg_num), len_bytes,
plaintext, padding))
if msg_hash == self._hash_cls.hmac(self._mac_secret, _mac_msg):
self._result = plaintext
self._msg_num += 1
else:
self._invalid = True
return num_read
def done(self):
"""Returns True if decryption and decoding of a message was done.
:returns: True if reading is done
:rtype: bool
:raises: :exc:`versile.crypto.VCryptoException`
Raises an exception if the message failed to verify against
the message hash, meaning the message cannot be trusted and
could have been tampered with.
"""
if self._invalid:
raise VCryptoException('Message failed to verify')
return (self._result is not None)
def result(self):
"""Returns plaintext of a decrypted and decoded message.
:returns: decoded plaintext
:rtype: bytes
:raises: :exc:`versile.crypto.VCryptoException`
Should only be called if :meth:`done` indicates message
parsing was completed, otherwise an exception may be raised
due to incomplete message.
Raises an exception if the message failed to verify against
the message hash, meaning the message cannot be trusted and
may have been tampered with.
"""
if self._invalid:
raise VCryptoException('Message failed to verify')
elif self._result is None:
raise VCryptoException('Message not yet fully decoded')
return self._result
def has_data(self):
"""Returns True if object holds any data
:returns: True if holds data
:rtype: bool
Returns False only if no data has been read since the object
was instantiated or since the most recent :meth:`reset`\ .
"""
return bool(self._read_buf or self._in_buf or self._msg_buf
or self._result)
@property
def max_plaintext_len(self):
"""Maximum plaintext length allowed in a message."""
return self._max_plaintext_len
class VPipeAgent(object):
"""Byte producer/consumer interface to a pipe reader/writer pair.
:param read_fd: read pipe file descriptor
:type read_fd: int
:param write_fd: write pipe file descriptor
:type write_fd: int
:param max_read: max bytes fetched per pipe read
:type max_read: int
:param max_write: max bytes written per pipe write
:type max_write: int
:param wbuf_len: buffer size of data held for writing (or None)
:type wbuf_len: int
The agent creates a :class:`VPipeReader` and :class:`VPipeWriter`
for the provided pipe read/write descriptors which it uses for
reactor driven pipe I/O communication.
*max_read* is also the maximum size of the buffer for data read
from the socket (so maximum bytes read in one read operation is
*max_read* minus the amount of data currently held in the receive
buffer).
If *wbuf_len* is None then *max_write* is used as the buffer size.
"""
def __init__(self,
reactor,
read_fd,
write_fd,
max_read=0x4000,
max_write=0x4000,
wbuf_len=None):
self.__reactor = reactor
self._reader = _VAgentReader(self, reactor, read_fd)
self._writer = _VAgentWriter(self, reactor, write_fd)
self._reader.set_pipe_peer(self._writer)
self._writer.set_pipe_peer(self._reader)
self._max_read = max_read
self._max_write = max_write
self._wbuf = VByteBuffer()
if wbuf_len is None:
wbuf_len = max_write
self._wbuf_len = wbuf_len
self._ci = None
self._ci_eod = False
self._ci_eod_clean = None
self._ci_producer = None
self._ci_consumed = 0
self._ci_lim_sent = 0
self._ci_aborted = False
self._pi = None
self._pi_closed = False
self._pi_consumer = None
self._pi_produced = 0
self._pi_prod_lim = 0
self._pi_buffer = VByteBuffer()
self._pi_aborted = False
@property
def byte_consume(self):
"""Holds a :class:`IVByteConsumer` interface to the pipe reader."""
if not self._ci:
ci = _VPipeConsumer(self)
self._ci = weakref.ref(ci)
return ci
else:
ci = self._ci()
if ci:
return ci
else:
ci = _VPipeConsumer(self)
self._ci = weakref.ref(ci)
return ci
@property
def byte_produce(self):
"""Holds a :class:`IVByteProducer` interface to the pipe writer."""
if not self._pi:
pi = _VPipeProducer(self)
self._pi = weakref.ref(pi)
return pi
else:
pi = self._pi()
if pi:
return pi
else:
pi = _VPipeProducer(self)
self._pi = weakref.ref(pi)
return pi
@property
def byte_io(self):
"""Byte interface (\ :class:`versile.reactor.io.VByteIOPair`\ )."""
return VByteIOPair(self.byte_consume, self.byte_produce)
@property
def reactor(self):
"""Holds the reactor of the associated reader."""
return self.__reactor
@peer
def _c_consume(self, buf, clim):
if self._ci_eod:
raise VIOClosed('Consumer already reached end-of-data')
elif not self._ci_producer:
raise VIOError('No connected producer')
elif self._ci_consumed >= self._ci_lim_sent:
raise VIOError('Consume limit exceeded')
elif not buf:
raise VIOError('No data to consume')
max_cons = self._wbuf_len - len(self._wbuf)
max_cons = min(max_cons, self._ci_lim_sent - self._ci_consumed)
if clim is not None and clim > 0:
max_cons = min(max_cons, clim)
was_empty = not self._wbuf
indata = buf.pop(max_cons)
self._wbuf.append(indata)
self._ci_consumed += len(indata)
if was_empty:
self._writer.start_writing(internal=True)
return self._ci_lim_sent
def _c_end_consume(self, clean):
if self._ci_eod:
return
self._ci_eod = True
self._ci_eod_clean = clean
if not self._wbuf:
self._writer.close_output(VFIOCompleted())
if self._ci_producer:
self._ci_producer.abort()
self._c_detach()
def _c_abort(self):
if not self._ci_aborted:
self._ci_aborted = True
self._ci_eod = True
self._ci_consumed = self._ci_lim_sent = 0
self._wbuf.clear()
self._writer.close_output(VFIOCompleted())
if self._ci_producer:
self._ci_producer.abort()
self._c_detach()
def _c_attach(self, producer, rthread=False):
# Ensure 'attach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._c_attach, producer, rthread=True)
return
if self._ci_producer is producer:
return
elif self._ci_producer:
raise VIOError('Producer already attached')
self._ci_producer = producer
self._ci_consumed = self._ci_lim_sent = 0
producer.attach(self.byte_consume)
self._ci_lim_sent = self._wbuf_len
producer.can_produce(self._ci_lim_sent)
# Notify attached chain
try:
producer.control.notify_consumer_attached(self.byte_consume)
except VIOMissingControl:
pass
def _c_detach(self, rthread=False):
# Ensure 'detach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._c_detach, rthread=True)
return
if self._ci_producer:
prod, self._ci_producer = self._ci_producer, None
prod.detach()
self._ci_consumed = self._ci_lim_sent = 0
def _do_write(self):
if self._wbuf:
data = self._wbuf.peek(self._max_write)
try:
num_written = self._writer.write_some(data)
except VIOException:
self._c_abort()
else:
if num_written > 0:
self._wbuf.remove(num_written)
if self._ci_producer:
self._ci_lim_sent = (self._ci_consumed +
self._wbuf_len - len(self._wbuf))
self._ci_producer.can_produce(self._ci_lim_sent)
if not self._wbuf:
self._writer.stop_writing()
if self._ci_eod:
self._c_abort()
else:
self._writer.stop_writing()
def _output_was_closed(self, reason):
# No more output will be written, abort consumer
self._c_abort()
@property
def _c_control(self):
return VIOControl()
@property
def _c_producer(self):
return self._ci_producer
@property
def _c_flows(self):
return tuple()
@property
def _c_twoway(self):
return True
@property
def _c_reverse(self):
return self.byte_produce()
@peer
def _p_can_produce(self, limit):
if not self._pi_consumer:
raise VIOError('No connected consumer')
if limit is None or limit < 0:
if (not self._pi_prod_lim is None and not self._pi_prod_lim < 0):
if self._pi_produced >= self._pi_prod_lim:
self._reader.start_reading(internal=True)
self._pi_prod_lim = limit
else:
if (self._pi_prod_lim is not None
and 0 <= self._pi_prod_lim < limit):
if self._pi_produced >= self._pi_prod_lim:
self._reader.start_reading(internal=True)
self._pi_prod_lim = limit
def _p_abort(self):
if not self._pi_aborted:
self._pi_aborted = True
self._pi_produced = self._pi_prod_lim = 0
self._reader.close_input(VFIOCompleted())
if self._pi_consumer:
self._pi_consumer.abort()
self._p_detach()
def _p_attach(self, consumer, rthread=False):
# Ensure 'attach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._p_attach, consumer, rthread=True)
return
if self._pi_consumer is consumer:
return
elif self._pi_consumer:
raise VIOError('Consumer already attached')
self._pi_produced = self._pi_prod_lim = 0
self._pi_consumer = consumer
consumer.attach(self.byte_produce)
# Notify attached chain
try:
consumer.control.notify_producer_attached(self.byte_produce)
except VIOMissingControl:
pass
def _p_detach(self, rthread=False):
# Ensure 'detach' is performed in reactor thread
if not rthread:
self.reactor.execute(self._p_detach, rthread=True)
return
if self._pi_consumer:
cons, self._pi_consumer = self._pi_consumer, None
cons.detach()
self._pi_produced = self._pi_prod_lim = 0
def _do_read(self):
if not self._pi_consumer:
self._reader.stop_reading()
if self._pi_prod_lim is not None and self._pi_prod_lim >= 0:
max_read = self._pi_prod_lim - self._pi_produced
else:
max_read = self._max_read
max_read = min(max_read, self._max_read)
if max_read <= 0:
self._reader.stop_reading()
return
try:
data = self._reader.read_some(max_read)
except Exception as e:
self._p_abort()
else:
self._pi_buffer.append(data)
if self._pi_buffer:
self.pi_prod_lim = self._pi_consumer.consume(self._pi_buffer)
def _input_was_closed(self, reason):
if self._pi_consumer:
# Notify consumer about end-of-data
clean = isinstance(reason, VFIOCompleted)
self._pi_consumer.end_consume(clean)
else:
self._p_abort()
@property
def _p_control(self):
class _Control(VIOControl):
def __init__(self, obj):
self._obj = obj
def req_producer_state(self, consumer):
# Send 'connected' notification if pipe is not closed
def notify():
if (self._obj._reader._fd >= 0
and self._obj._writer._fd >= 0):
try:
consumer.control.connected(VPipePeer())
except VIOMissingControl:
pass
self._obj.reactor.schedule(0.0, notify)
return _Control(self)
@property
def _p_consumer(self):
return self._pi_consumer
@property
def _p_flows(self):
return tuple()
@property
def _p_twoway(self):
return True
@property
def _p_reverse(self):
return self.byte_consume()
