Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/internet/_newtls.py

@@ -0,0 +1,271 @@
+# -*- test-case-name: twisted.test.test_ssl -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+This module implements memory BIO based TLS support.  It is the preferred
+implementation and will be used whenever pyOpenSSL 0.10 or newer is installed
+(whenever L{twisted.protocols.tls} is importable).
+
+@since: 11.1
+"""
+
+from __future__ import division, absolute_import
+
+from zope.interface import implementer
+from zope.interface import directlyProvides
+
+from twisted.internet.interfaces import ITLSTransport, ISSLTransport
+from twisted.internet.abstract import FileDescriptor
+
+from twisted.protocols.tls import TLSMemoryBIOFactory, TLSMemoryBIOProtocol
+
+
+class _BypassTLS(object):
+    """
+    L{_BypassTLS} is used as the transport object for the TLS protocol object
+    used to implement C{startTLS}.  Its methods skip any TLS logic which
+    C{startTLS} enables.
+
+    @ivar _base: A transport class L{_BypassTLS} has been mixed in with to which
+        methods will be forwarded.  This class is only responsible for sending
+        bytes over the connection, not doing TLS.
+
+    @ivar _connection: A L{Connection} which TLS has been started on which will
+        be proxied to by this object.  Any method which has its behavior
+        altered after C{startTLS} will be skipped in favor of the base class's
+        implementation.  This allows the TLS protocol object to have direct
+        access to the transport, necessary to actually implement TLS.
+    """
+    def __init__(self, base, connection):
+        self._base = base
+        self._connection = connection
+
+
+    def __getattr__(self, name):
+        """
+        Forward any extra attribute access to the original transport object.
+        For example, this exposes C{getHost}, the behavior of which does not
+        change after TLS is enabled.
+        """
+        return getattr(self._connection, name)
+
+
+    def write(self, data):
+        """
+        Write some bytes directly to the connection.
+        """
+        return self._base.write(self._connection, data)
+
+
+    def writeSequence(self, iovec):
+        """
+        Write a some bytes directly to the connection.
+        """
+        return self._base.writeSequence(self._connection, iovec)
+
+
+    def loseConnection(self, *args, **kwargs):
+        """
+        Close the underlying connection.
+        """
+        return self._base.loseConnection(self._connection, *args, **kwargs)
+
+
+    def registerProducer(self, producer, streaming):
+        """
+        Register a producer with the underlying connection.
+        """
+        return self._base.registerProducer(self._connection, producer, streaming)
+
+
+    def unregisterProducer(self):
+        """
+        Unregister a producer with the underlying connection.
+        """
+        return self._base.unregisterProducer(self._connection)
+
+
+
+def startTLS(transport, contextFactory, normal, bypass):
+    """
+    Add a layer of SSL to a transport.
+
+    @param transport: The transport which will be modified.  This can either by
+        a L{FileDescriptor<twisted.internet.abstract.FileDescriptor>} or a
+        L{FileHandle<twisted.internet.iocpreactor.abstract.FileHandle>}.  The
+        actual requirements of this instance are that it have:
+
+          - a C{_tlsClientDefault} attribute indicating whether the transport is
+            a client (C{True}) or a server (C{False})
+          - a settable C{TLS} attribute which can be used to mark the fact
+            that SSL has been started
+          - settable C{getHandle} and C{getPeerCertificate} attributes so
+            these L{ISSLTransport} methods can be added to it
+          - a C{protocol} attribute referring to the L{IProtocol} currently
+            connected to the transport, which can also be set to a new
+            L{IProtocol} for the transport to deliver data to
+
+    @param contextFactory: An SSL context factory defining SSL parameters for
+        the new SSL layer.
+    @type contextFactory: L{twisted.internet.interfaces.IOpenSSLContextFactory}
+
+    @param normal: A flag indicating whether SSL will go in the same direction
+        as the underlying transport goes.  That is, if the SSL client will be
+        the underlying client and the SSL server will be the underlying server.
+        C{True} means it is the same, C{False} means they are switched.
+    @type param: L{bool}
+
+    @param bypass: A transport base class to call methods on to bypass the new
+        SSL layer (so that the SSL layer itself can send its bytes).
+    @type bypass: L{type}
+    """
+    # Figure out which direction the SSL goes in.  If normal is True,
+    # we'll go in the direction indicated by the subclass.  Otherwise,
+    # we'll go the other way (client = not normal ^ _tlsClientDefault,
+    # in other words).
+    if normal:
+        client = transport._tlsClientDefault
+    else:
+        client = not transport._tlsClientDefault
+
+    # If we have a producer, unregister it, and then re-register it below once
+    # we've switched to TLS mode, so it gets hooked up correctly:
+    producer, streaming = None, None
+    if transport.producer is not None:
+        producer, streaming = transport.producer, transport.streamingProducer
+        transport.unregisterProducer()
+
+    tlsFactory = TLSMemoryBIOFactory(contextFactory, client, None)
+    tlsProtocol = TLSMemoryBIOProtocol(tlsFactory, transport.protocol, False)
+    transport.protocol = tlsProtocol
+
+    transport.getHandle = tlsProtocol.getHandle
+    transport.getPeerCertificate = tlsProtocol.getPeerCertificate
+
+    # Mark the transport as secure.
+    directlyProvides(transport, ISSLTransport)
+
+    # Remember we did this so that write and writeSequence can send the
+    # data to the right place.
+    transport.TLS = True
+
+    # Hook it up
+    transport.protocol.makeConnection(_BypassTLS(bypass, transport))
+
+    # Restore producer if necessary:
+    if producer:
+        transport.registerProducer(producer, streaming)
+
+
+
+@implementer(ITLSTransport)
+class ConnectionMixin(object):
+    """
+    A mixin for L{twisted.internet.abstract.FileDescriptor} which adds an
+    L{ITLSTransport} implementation.
+
+    @ivar TLS: A flag indicating whether TLS is currently in use on this
+        transport.  This is not a good way for applications to check for TLS,
+        instead use L{twisted.internet.interfaces.ISSLTransport}.
+    """
+
+    TLS = False
+
+    def startTLS(self, ctx, normal=True):
+        """
+        @see: L{ITLSTransport.startTLS}
+        """
+        startTLS(self, ctx, normal, FileDescriptor)
+
+
+    def write(self, bytes):
+        """
+        Write some bytes to this connection, passing them through a TLS layer if
+        necessary, or discarding them if the connection has already been lost.
+        """
+        if self.TLS:
+            if self.connected:
+                self.protocol.write(bytes)
+        else:
+            FileDescriptor.write(self, bytes)
+
+
+    def writeSequence(self, iovec):
+        """
+        Write some bytes to this connection, scatter/gather-style, passing them
+        through a TLS layer if necessary, or discarding them if the connection
+        has already been lost.
+        """
+        if self.TLS:
+            if self.connected:
+                self.protocol.writeSequence(iovec)
+        else:
+            FileDescriptor.writeSequence(self, iovec)
+
+
+    def loseConnection(self):
+        """
+        Close this connection after writing all pending data.
+
+        If TLS has been negotiated, perform a TLS shutdown.
+        """
+        if self.TLS:
+            if self.connected and not self.disconnecting:
+                self.protocol.loseConnection()
+        else:
+            FileDescriptor.loseConnection(self)
+
+
+    def registerProducer(self, producer, streaming):
+        """
+        Register a producer.
+
+        If TLS is enabled, the TLS connection handles this.
+        """
+        if self.TLS:
+            # Registering a producer before we're connected shouldn't be a
+            # problem. If we end up with a write(), that's already handled in
+            # the write() code above, and there are no other potential
+            # side-effects.
+            self.protocol.registerProducer(producer, streaming)
+        else:
+            FileDescriptor.registerProducer(self, producer, streaming)
+
+
+    def unregisterProducer(self):
+        """
+        Unregister a producer.
+
+        If TLS is enabled, the TLS connection handles this.
+        """
+        if self.TLS:
+            self.protocol.unregisterProducer()
+        else:
+            FileDescriptor.unregisterProducer(self)
+
+
+
+class ClientMixin(object):
+    """
+    A mixin for L{twisted.internet.tcp.Client} which just marks it as a client
+    for the purposes of the default TLS handshake.
+
+    @ivar _tlsClientDefault: Always C{True}, indicating that this is a client
+        connection, and by default when TLS is negotiated this class will act as
+        a TLS client.
+    """
+    _tlsClientDefault = True
+
+
+
+class ServerMixin(object):
+    """
+    A mixin for L{twisted.internet.tcp.Server} which just marks it as a server
+    for the purposes of the default TLS handshake.
+
+    @ivar _tlsClientDefault: Always C{False}, indicating that this is a server
+        connection, and by default when TLS is negotiated this class will act as
+        a TLS server.
+    """
+    _tlsClientDefault = False