class documentation

TLSMemoryBIOProtocol is a protocol wrapper which uses OpenSSL via a memory BIO to encrypt bytes written to it before sending them on to the underlying transport and decrypts bytes received from the underlying transport before delivering them to the wrapped protocol.

In addition to producer events from the underlying transport, the need to wait for reads before a write can proceed means the TLSMemoryBIOProtocol may also want to pause a producer. Pause/resume events are therefore merged using the _ProducerMembrane wrapper. Non-streaming (pull) producers are supported by wrapping them with _PullToPush.

Because TLS may need to wait for reads before writing, some writes may be buffered until a read occurs.

Method __init__ Undocumented
Method abortConnection Tear down TLS state so that if the connection is aborted mid-handshake we don't deliver any further data from the application.
Method connectionLost Handle the possible repetition of calls to this method (due to either the underlying transport going away or due to an error at the TLS layer) and make sure the base implementation only gets invoked once.
Method dataReceived Deliver any received bytes to the receive BIO and then read and deliver to the application any application-level data which becomes available as a result of this.
Method failVerification Abort the connection during connection setup, giving a reason that certificate verification failed.
Method getHandle Return the OpenSSL.SSL.Connection object being used to encrypt and decrypt this connection.
Method getPeerCertificate Return an object with the peer's certificate info.
Method loseConnection Send a TLS close alert and close the underlying connection.
Method makeConnection Connect this wrapper to the given transport and initialize the necessary OpenSSL.SSL.Connection with a memory BIO.
Method registerProducer Undocumented
Method unregisterProducer Undocumented
Method write Process the given application bytes and send any resulting TLS traffic which arrives in the send BIO.
Method writeSequence Write a sequence of application bytes by joining them into one string and passing them to write.
Instance Variable connected Undocumented
Instance Variable disconnecting Undocumented
Property negotiatedProtocol No summary
Method _bufferedWrite Put the given octets into TLSMemoryBIOProtocol._appSendBuffer, and tell any listening producer that it should pause because we are now buffering.
Method _checkHandshakeStatus Ask OpenSSL to proceed with a handshake in progress.
Method _flushReceiveBIO Try to receive any application-level bytes which are now available because of a previous write into the receive BIO. This will take care of delivering any application-level bytes which are received to the protocol, as well as handling of the various exceptions which can come from trying to get such bytes.
Method _flushSendBIO Read any bytes out of the send BIO and write them to the underlying transport.
Method _shutdownTLS Initiate, or reply to, the shutdown handshake of the TLS layer.
Method _tlsShutdownFinished Called when TLS connection has gone away; tell underlying transport to disconnect.
Method _unbufferPendingWrites Un-buffer all waiting writes in TLSMemoryBIOProtocol._appSendBuffer.
Method _write Process the given application bytes and send any resulting TLS traffic which arrives in the send BIO.
Instance Variable _aborted abortConnection has been called. No further data will be received to the wrapped protocol's dataReceived.
Instance Variable _appSendBuffer application-level (cleartext) data that is waiting to be transferred to the TLS buffer, but can't be because the TLS connection is handshaking.
Instance Variable _connectWrapped A flag indicating whether or not to call makeConnection on the wrapped protocol. This is for the reactor's twisted.internet.interfaces.ITLSTransport.startTLS implementation, since it has a protocol which it has already called ...
Instance Variable _handshakeDone A flag indicating whether or not the handshake is known to have completed successfully (True) or not (False). This is used to control error reporting behavior. If the handshake has not completed, the underlying ...
Instance Variable _lostTLSConnection A flag indicating whether connection loss has already been dealt with (True) or not (False). TLS disconnection is distinct from the underlying connection being lost.
Instance Variable _producer The current producer registered via registerProducer, or None if no producer has been registered or a previous one was unregistered.
Instance Variable _producerPaused Undocumented
Instance Variable _reason If an unexpected OpenSSL.SSL.Error occurs which causes the connection to be lost, it is saved here. If appropriate, this may be used as the reason passed to the application protocol's connectionLost method.
Instance Variable _tlsConnection The OpenSSL.SSL.Connection instance which is encrypted and decrypting this connection.

Inherited from ProtocolWrapper:

Method __getattr__ Undocumented
Method getHost Undocumented
Method getPeer Undocumented
Method logPrefix Use a customized log prefix mentioning both the wrapped protocol and the current one.
Method stopConsuming Undocumented
Instance Variable factory The WrappingFactory which created this ProtocolWrapper.
Instance Variable wrappedProtocol An IProtocol provider to which IProtocol method calls onto this ProtocolWrapper will be proxied.

Inherited from BaseProtocol (via ProtocolWrapper, Protocol):

Method connectionMade Called when a connection is made.
Instance Variable transport Undocumented
def __init__(self, factory, wrappedProtocol, _connectWrapped=True): (source)
def abortConnection(self): (source)

Tear down TLS state so that if the connection is aborted mid-handshake we don't deliver any further data from the application.

def connectionLost(self, reason): (source)

Handle the possible repetition of calls to this method (due to either the underlying transport going away or due to an error at the TLS layer) and make sure the base implementation only gets invoked once.

def dataReceived(self, bytes): (source)

Deliver any received bytes to the receive BIO and then read and deliver to the application any application-level data which becomes available as a result of this.

def failVerification(self, reason): (source)

Abort the connection during connection setup, giving a reason that certificate verification failed.

Parameters
reason:FailureThe reason that the verification failed; reported to the application protocol's connectionLost method.
def getHandle(self): (source)

Return the OpenSSL.SSL.Connection object being used to encrypt and decrypt this connection.

This is done for the benefit of twisted.internet.ssl.Certificate's peerFromTransport and hostFromTransport methods only. A different system handle may be returned by future versions of this method.

def getPeerCertificate(self): (source)

Return an object with the peer's certificate info.

def loseConnection(self): (source)
def makeConnection(self, transport): (source)

Connect this wrapper to the given transport and initialize the necessary OpenSSL.SSL.Connection with a memory BIO.

def registerProducer(self, producer, streaming): (source)
def write(self, bytes): (source)

Process the given application bytes and send any resulting TLS traffic which arrives in the send BIO.

If loseConnection was called, subsequent calls to write will drop the bytes on the floor.

def writeSequence(self, iovec): (source)

Write a sequence of application bytes by joining them into one string and passing them to write.

def _bufferedWrite(self, octets): (source)

Put the given octets into TLSMemoryBIOProtocol._appSendBuffer, and tell any listening producer that it should pause because we are now buffering.

def _checkHandshakeStatus(self): (source)

Ask OpenSSL to proceed with a handshake in progress.

Initially, this just sends the ClientHello; after some bytes have been stuffed in to the Connection object by dataReceived, it will then respond to any Certificate or KeyExchange messages.

def _flushReceiveBIO(self): (source)

Try to receive any application-level bytes which are now available because of a previous write into the receive BIO. This will take care of delivering any application-level bytes which are received to the protocol, as well as handling of the various exceptions which can come from trying to get such bytes.

def _flushSendBIO(self): (source)

Read any bytes out of the send BIO and write them to the underlying transport.

def _shutdownTLS(self): (source)

Initiate, or reply to, the shutdown handshake of the TLS layer.

def _tlsShutdownFinished(self, reason): (source)

Called when TLS connection has gone away; tell underlying transport to disconnect.

Parameters
reason:Failure or Nonea Failure whose value is an Exception if we want to report that failure through to the wrapped protocol's connectionLost, or None if the reason that connectionLost should receive should be coming from the underlying transport.
def _unbufferPendingWrites(self): (source)

Un-buffer all waiting writes in TLSMemoryBIOProtocol._appSendBuffer.

def _write(self, bytes): (source)

Process the given application bytes and send any resulting TLS traffic which arrives in the send BIO.

This may be called by dataReceived with bytes that were buffered before loseConnection was called, which is why this function doesn't check for disconnection but accepts the bytes regardless.

_aborted: bool = (source)

abortConnection has been called. No further data will be received to the wrapped protocol's dataReceived.

_appSendBuffer: list of bytes = (source)

application-level (cleartext) data that is waiting to be transferred to the TLS buffer, but can't be because the TLS connection is handshaking.

_connectWrapped = (source)

A flag indicating whether or not to call makeConnection on the wrapped protocol. This is for the reactor's twisted.internet.interfaces.ITLSTransport.startTLS implementation, since it has a protocol which it has already called makeConnection on, and which has no interest in a new transport. See #3821.

_handshakeDone: bool = (source)

A flag indicating whether or not the handshake is known to have completed successfully (True) or not (False). This is used to control error reporting behavior. If the handshake has not completed, the underlying OpenSSL.SSL.Error will be passed to the application's connectionLost method. If it has completed, any unexpected OpenSSL.SSL.Error will be turned into a ConnectionLost. This is weird; however, it is simply an attempt at a faithful re-implementation of the behavior provided by twisted.internet.ssl.

_lostTLSConnection: bool = (source)

A flag indicating whether connection loss has already been dealt with (True) or not (False). TLS disconnection is distinct from the underlying connection being lost.

_producer = (source)

The current producer registered via registerProducer, or None if no producer has been registered or a previous one was unregistered.

_producerPaused: bool = (source)

Undocumented

If an unexpected OpenSSL.SSL.Error occurs which causes the connection to be lost, it is saved here. If appropriate, this may be used as the reason passed to the application protocol's connectionLost method.

_tlsConnection = (source)

The OpenSSL.SSL.Connection instance which is encrypted and decrypting this connection.