add ydb deps

1 files changed, 922 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Lib/asyncio/sslproto.py b/contrib/tools/python3/src/Lib/asyncio/sslproto.py
new file mode 100644
index 0000000000..488e17d8bc
--- /dev/null
+++ b/contrib/tools/python3/src/Lib/asyncio/sslproto.py
@@ -0,0 +1,922 @@
+import collections
+import enum
+import warnings
+try:
+    import ssl
+except ImportError:  # pragma: no cover
+    ssl = None
+
+from . import constants
+from . import exceptions
+from . import protocols
+from . import transports
+from .log import logger
+
+if ssl is not None:
+    SSLAgainErrors = (ssl.SSLWantReadError, ssl.SSLSyscallError)
+
+
+class SSLProtocolState(enum.Enum):
+    UNWRAPPED = "UNWRAPPED"
+    DO_HANDSHAKE = "DO_HANDSHAKE"
+    WRAPPED = "WRAPPED"
+    FLUSHING = "FLUSHING"
+    SHUTDOWN = "SHUTDOWN"
+
+
+class AppProtocolState(enum.Enum):
+    # This tracks the state of app protocol (https://git.io/fj59P):
+    #
+    #     INIT -cm-> CON_MADE [-dr*->] [-er-> EOF?] -cl-> CON_LOST
+    #
+    # * cm: connection_made()
+    # * dr: data_received()
+    # * er: eof_received()
+    # * cl: connection_lost()
+
+    STATE_INIT = "STATE_INIT"
+    STATE_CON_MADE = "STATE_CON_MADE"
+    STATE_EOF = "STATE_EOF"
+    STATE_CON_LOST = "STATE_CON_LOST"
+
+
+def _create_transport_context(server_side, server_hostname):
+    if server_side:
+        raise ValueError('Server side SSL needs a valid SSLContext')
+
+    # Client side may pass ssl=True to use a default
+    # context; in that case the sslcontext passed is None.
+    # The default is secure for client connections.
+    # Python 3.4+: use up-to-date strong settings.
+    sslcontext = ssl.create_default_context()
+    if not server_hostname:
+        sslcontext.check_hostname = False
+    return sslcontext
+
+
+def add_flowcontrol_defaults(high, low, kb):
+    if high is None:
+        if low is None:
+            hi = kb * 1024
+        else:
+            lo = low
+            hi = 4 * lo
+    else:
+        hi = high
+    if low is None:
+        lo = hi // 4
+    else:
+        lo = low
+
+    if not hi >= lo >= 0:
+        raise ValueError('high (%r) must be >= low (%r) must be >= 0' %
+                         (hi, lo))
+
+    return hi, lo
+
+
+class _SSLProtocolTransport(transports._FlowControlMixin,
+                            transports.Transport):
+
+    _start_tls_compatible = True
+    _sendfile_compatible = constants._SendfileMode.FALLBACK
+
+    def __init__(self, loop, ssl_protocol):
+        self._loop = loop
+        self._ssl_protocol = ssl_protocol
+        self._closed = False
+
+    def get_extra_info(self, name, default=None):
+        """Get optional transport information."""
+        return self._ssl_protocol._get_extra_info(name, default)
+
+    def set_protocol(self, protocol):
+        self._ssl_protocol._set_app_protocol(protocol)
+
+    def get_protocol(self):
+        return self._ssl_protocol._app_protocol
+
+    def is_closing(self):
+        return self._closed
+
+    def close(self):
+        """Close the transport.
+
+        Buffered data will be flushed asynchronously.  No more data
+        will be received.  After all buffered data is flushed, the
+        protocol's connection_lost() method will (eventually) called
+        with None as its argument.
+        """
+        if not self._closed:
+            self._closed = True
+            self._ssl_protocol._start_shutdown()
+        else:
+            self._ssl_protocol = None
+
+    def __del__(self, _warnings=warnings):
+        if not self._closed:
+            self._closed = True
+            _warnings.warn(
+                "unclosed transport <asyncio._SSLProtocolTransport "
+                "object>", ResourceWarning)
+
+    def is_reading(self):
+        return not self._ssl_protocol._app_reading_paused
+
+    def pause_reading(self):
+        """Pause the receiving end.
+
+        No data will be passed to the protocol's data_received()
+        method until resume_reading() is called.
+        """
+        self._ssl_protocol._pause_reading()
+
+    def resume_reading(self):
+        """Resume the receiving end.
+
+        Data received will once again be passed to the protocol's
+        data_received() method.
+        """
+        self._ssl_protocol._resume_reading()
+
+    def set_write_buffer_limits(self, high=None, low=None):
+        """Set the high- and low-water limits for write flow control.
+
+        These two values control when to call the protocol's
+        pause_writing() and resume_writing() methods.  If specified,
+        the low-water limit must be less than or equal to the
+        high-water limit.  Neither value can be negative.
+
+        The defaults are implementation-specific.  If only the
+        high-water limit is given, the low-water limit defaults to an
+        implementation-specific value less than or equal to the
+        high-water limit.  Setting high to zero forces low to zero as
+        well, and causes pause_writing() to be called whenever the
+        buffer becomes non-empty.  Setting low to zero causes
+        resume_writing() to be called only once the buffer is empty.
+        Use of zero for either limit is generally sub-optimal as it
+        reduces opportunities for doing I/O and computation
+        concurrently.
+        """
+        self._ssl_protocol._set_write_buffer_limits(high, low)
+        self._ssl_protocol._control_app_writing()
+
+    def get_write_buffer_limits(self):
+        return (self._ssl_protocol._outgoing_low_water,
+                self._ssl_protocol._outgoing_high_water)
+
+    def get_write_buffer_size(self):
+        """Return the current size of the write buffers."""
+        return self._ssl_protocol._get_write_buffer_size()
+
+    def set_read_buffer_limits(self, high=None, low=None):
+        """Set the high- and low-water limits for read flow control.
+
+        These two values control when to call the upstream transport's
+        pause_reading() and resume_reading() methods.  If specified,
+        the low-water limit must be less than or equal to the
+        high-water limit.  Neither value can be negative.
+
+        The defaults are implementation-specific.  If only the
+        high-water limit is given, the low-water limit defaults to an
+        implementation-specific value less than or equal to the
+        high-water limit.  Setting high to zero forces low to zero as
+        well, and causes pause_reading() to be called whenever the
+        buffer becomes non-empty.  Setting low to zero causes
+        resume_reading() to be called only once the buffer is empty.
+        Use of zero for either limit is generally sub-optimal as it
+        reduces opportunities for doing I/O and computation
+        concurrently.
+        """
+        self._ssl_protocol._set_read_buffer_limits(high, low)
+        self._ssl_protocol._control_ssl_reading()
+
+    def get_read_buffer_limits(self):
+        return (self._ssl_protocol._incoming_low_water,
+                self._ssl_protocol._incoming_high_water)
+
+    def get_read_buffer_size(self):
+        """Return the current size of the read buffer."""
+        return self._ssl_protocol._get_read_buffer_size()
+
+    @property
+    def _protocol_paused(self):
+        # Required for sendfile fallback pause_writing/resume_writing logic
+        return self._ssl_protocol._app_writing_paused
+
+    def write(self, data):
+        """Write some data bytes to the transport.
+
+        This does not block; it buffers the data and arranges for it
+        to be sent out asynchronously.
+        """
+        if not isinstance(data, (bytes, bytearray, memoryview)):
+            raise TypeError(f"data: expecting a bytes-like instance, "
+                            f"got {type(data).__name__}")
+        if not data:
+            return
+        self._ssl_protocol._write_appdata((data,))
+
+    def writelines(self, list_of_data):
+        """Write a list (or any iterable) of data bytes to the transport.
+
+        The default implementation concatenates the arguments and
+        calls write() on the result.
+        """
+        self._ssl_protocol._write_appdata(list_of_data)
+
+    def write_eof(self):
+        """Close the write end after flushing buffered data.
+
+        This raises :exc:`NotImplementedError` right now.
+        """
+        raise NotImplementedError
+
+    def can_write_eof(self):
+        """Return True if this transport supports write_eof(), False if not."""
+        return False
+
+    def abort(self):
+        """Close the transport immediately.
+
+        Buffered data will be lost.  No more data will be received.
+        The protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
+        """
+        self._closed = True
+        if self._ssl_protocol is not None:
+            self._ssl_protocol._abort()
+
+    def _force_close(self, exc):
+        self._closed = True
+        self._ssl_protocol._abort(exc)
+
+    def _test__append_write_backlog(self, data):
+        # for test only
+        self._ssl_protocol._write_backlog.append(data)
+        self._ssl_protocol._write_buffer_size += len(data)
+
+
+class SSLProtocol(protocols.BufferedProtocol):
+    max_size = 256 * 1024   # Buffer size passed to read()
+
+    _handshake_start_time = None
+    _handshake_timeout_handle = None
+    _shutdown_timeout_handle = None
+
+    def __init__(self, loop, app_protocol, sslcontext, waiter,
+                 server_side=False, server_hostname=None,
+                 call_connection_made=True,
+                 ssl_handshake_timeout=None,
+                 ssl_shutdown_timeout=None):
+        if ssl is None:
+            raise RuntimeError("stdlib ssl module not available")
+
+        self._ssl_buffer = bytearray(self.max_size)
+        self._ssl_buffer_view = memoryview(self._ssl_buffer)
+
+        if ssl_handshake_timeout is None:
+            ssl_handshake_timeout = constants.SSL_HANDSHAKE_TIMEOUT
+        elif ssl_handshake_timeout <= 0:
+            raise ValueError(
+                f"ssl_handshake_timeout should be a positive number, "
+                f"got {ssl_handshake_timeout}")
+        if ssl_shutdown_timeout is None:
+            ssl_shutdown_timeout = constants.SSL_SHUTDOWN_TIMEOUT
+        elif ssl_shutdown_timeout <= 0:
+            raise ValueError(
+                f"ssl_shutdown_timeout should be a positive number, "
+                f"got {ssl_shutdown_timeout}")
+
+        if not sslcontext:
+            sslcontext = _create_transport_context(
+                server_side, server_hostname)
+
+        self._server_side = server_side
+        if server_hostname and not server_side:
+            self._server_hostname = server_hostname
+        else:
+            self._server_hostname = None
+        self._sslcontext = sslcontext
+        # SSL-specific extra info. More info are set when the handshake
+        # completes.
+        self._extra = dict(sslcontext=sslcontext)
+
+        # App data write buffering
+        self._write_backlog = collections.deque()
+        self._write_buffer_size = 0
+
+        self._waiter = waiter
+        self._loop = loop
+        self._set_app_protocol(app_protocol)
+        self._app_transport = None
+        self._app_transport_created = False
+        # transport, ex: SelectorSocketTransport
+        self._transport = None
+        self._ssl_handshake_timeout = ssl_handshake_timeout
+        self._ssl_shutdown_timeout = ssl_shutdown_timeout
+        # SSL and state machine
+        self._incoming = ssl.MemoryBIO()
+        self._outgoing = ssl.MemoryBIO()
+        self._state = SSLProtocolState.UNWRAPPED
+        self._conn_lost = 0  # Set when connection_lost called
+        if call_connection_made:
+            self._app_state = AppProtocolState.STATE_INIT
+        else:
+            self._app_state = AppProtocolState.STATE_CON_MADE
+        self._sslobj = self._sslcontext.wrap_bio(
+            self._incoming, self._outgoing,
+            server_side=self._server_side,
+            server_hostname=self._server_hostname)
+
+        # Flow Control
+
+        self._ssl_writing_paused = False
+
+        self._app_reading_paused = False
+
+        self._ssl_reading_paused = False
+        self._incoming_high_water = 0
+        self._incoming_low_water = 0
+        self._set_read_buffer_limits()
+        self._eof_received = False
+
+        self._app_writing_paused = False
+        self._outgoing_high_water = 0
+        self._outgoing_low_water = 0
+        self._set_write_buffer_limits()
+        self._get_app_transport()
+
+    def _set_app_protocol(self, app_protocol):
+        self._app_protocol = app_protocol
+        # Make fast hasattr check first
+        if (hasattr(app_protocol, 'get_buffer') and
+                isinstance(app_protocol, protocols.BufferedProtocol)):
+            self._app_protocol_get_buffer = app_protocol.get_buffer
+            self._app_protocol_buffer_updated = app_protocol.buffer_updated
+            self._app_protocol_is_buffer = True
+        else:
+            self._app_protocol_is_buffer = False
+
+    def _wakeup_waiter(self, exc=None):
+        if self._waiter is None:
+            return
+        if not self._waiter.cancelled():
+            if exc is not None:
+                self._waiter.set_exception(exc)
+            else:
+                self._waiter.set_result(None)
+        self._waiter = None
+
+    def _get_app_transport(self):
+        if self._app_transport is None:
+            if self._app_transport_created:
+                raise RuntimeError('Creating _SSLProtocolTransport twice')
+            self._app_transport = _SSLProtocolTransport(self._loop, self)
+            self._app_transport_created = True
+        return self._app_transport
+
+    def connection_made(self, transport):
+        """Called when the low-level connection is made.
+
+        Start the SSL handshake.
+        """
+        self._transport = transport
+        self._start_handshake()
+
+    def connection_lost(self, exc):
+        """Called when the low-level connection is lost or closed.
+
+        The argument is an exception object or None (the latter
+        meaning a regular EOF is received or the connection was
+        aborted or closed).
+        """
+        self._write_backlog.clear()
+        self._outgoing.read()
+        self._conn_lost += 1
+
+        # Just mark the app transport as closed so that its __dealloc__
+        # doesn't complain.
+        if self._app_transport is not None:
+            self._app_transport._closed = True
+
+        if self._state != SSLProtocolState.DO_HANDSHAKE:
+            if (
+                self._app_state == AppProtocolState.STATE_CON_MADE or
+                self._app_state == AppProtocolState.STATE_EOF
+            ):
+                self._app_state = AppProtocolState.STATE_CON_LOST
+                self._loop.call_soon(self._app_protocol.connection_lost, exc)
+        self._set_state(SSLProtocolState.UNWRAPPED)
+        self._transport = None
+        self._app_transport = None
+        self._app_protocol = None
+        self._wakeup_waiter(exc)
+
+        if self._shutdown_timeout_handle:
+            self._shutdown_timeout_handle.cancel()
+            self._shutdown_timeout_handle = None
+        if self._handshake_timeout_handle:
+            self._handshake_timeout_handle.cancel()
+            self._handshake_timeout_handle = None
+
+    def get_buffer(self, n):
+        want = n
+        if want <= 0 or want > self.max_size:
+            want = self.max_size
+        if len(self._ssl_buffer) < want:
+            self._ssl_buffer = bytearray(want)
+            self._ssl_buffer_view = memoryview(self._ssl_buffer)
+        return self._ssl_buffer_view
+
+    def buffer_updated(self, nbytes):
+        self._incoming.write(self._ssl_buffer_view[:nbytes])
+
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            self._do_handshake()
+
+        elif self._state == SSLProtocolState.WRAPPED:
+            self._do_read()
+
+        elif self._state == SSLProtocolState.FLUSHING:
+            self._do_flush()
+
+        elif self._state == SSLProtocolState.SHUTDOWN:
+            self._do_shutdown()
+
+    def eof_received(self):
+        """Called when the other end of the low-level stream
+        is half-closed.
+
+        If this returns a false value (including None), the transport
+        will close itself.  If it returns a true value, closing the
+        transport is up to the protocol.
+        """
+        self._eof_received = True
+        try:
+            if self._loop.get_debug():
+                logger.debug("%r received EOF", self)
+
+            if self._state == SSLProtocolState.DO_HANDSHAKE:
+                self._on_handshake_complete(ConnectionResetError)
+
+            elif self._state == SSLProtocolState.WRAPPED:
+                self._set_state(SSLProtocolState.FLUSHING)
+                if self._app_reading_paused:
+                    return True
+                else:
+                    self._do_flush()
+
+            elif self._state == SSLProtocolState.FLUSHING:
+                self._do_write()
+                self._set_state(SSLProtocolState.SHUTDOWN)
+                self._do_shutdown()
+
+            elif self._state == SSLProtocolState.SHUTDOWN:
+                self._do_shutdown()
+
+        except Exception:
+            self._transport.close()
+            raise
+
+    def _get_extra_info(self, name, default=None):
+        if name in self._extra:
+            return self._extra[name]
+        elif self._transport is not None:
+            return self._transport.get_extra_info(name, default)
+        else:
+            return default
+
+    def _set_state(self, new_state):
+        allowed = False
+
+        if new_state == SSLProtocolState.UNWRAPPED:
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.UNWRAPPED and
+            new_state == SSLProtocolState.DO_HANDSHAKE
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.DO_HANDSHAKE and
+            new_state == SSLProtocolState.WRAPPED
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.WRAPPED and
+            new_state == SSLProtocolState.FLUSHING
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.FLUSHING and
+            new_state == SSLProtocolState.SHUTDOWN
+        ):
+            allowed = True
+
+        if allowed:
+            self._state = new_state
+
+        else:
+            raise RuntimeError(
+                'cannot switch state from {} to {}'.format(
+                    self._state, new_state))
+
+    # Handshake flow
+
+    def _start_handshake(self):
+        if self._loop.get_debug():
+            logger.debug("%r starts SSL handshake", self)
+            self._handshake_start_time = self._loop.time()
+        else:
+            self._handshake_start_time = None
+
+        self._set_state(SSLProtocolState.DO_HANDSHAKE)
+
+        # start handshake timeout count down
+        self._handshake_timeout_handle = \
+            self._loop.call_later(self._ssl_handshake_timeout,
+                                  lambda: self._check_handshake_timeout())
+
+        self._do_handshake()
+
+    def _check_handshake_timeout(self):
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            msg = (
+                f"SSL handshake is taking longer than "
+                f"{self._ssl_handshake_timeout} seconds: "
+                f"aborting the connection"
+            )
+            self._fatal_error(ConnectionAbortedError(msg))
+
+    def _do_handshake(self):
+        try:
+            self._sslobj.do_handshake()
+        except SSLAgainErrors:
+            self._process_outgoing()
+        except ssl.SSLError as exc:
+            self._on_handshake_complete(exc)
+        else:
+            self._on_handshake_complete(None)
+
+    def _on_handshake_complete(self, handshake_exc):
+        if self._handshake_timeout_handle is not None:
+            self._handshake_timeout_handle.cancel()
+            self._handshake_timeout_handle = None
+
+        sslobj = self._sslobj
+        try:
+            if handshake_exc is None:
+                self._set_state(SSLProtocolState.WRAPPED)
+            else:
+                raise handshake_exc
+
+            peercert = sslobj.getpeercert()
+        except Exception as exc:
+            self._set_state(SSLProtocolState.UNWRAPPED)
+            if isinstance(exc, ssl.CertificateError):
+                msg = 'SSL handshake failed on verifying the certificate'
+            else:
+                msg = 'SSL handshake failed'
+            self._fatal_error(exc, msg)
+            self._wakeup_waiter(exc)
+            return
+
+        if self._loop.get_debug():
+            dt = self._loop.time() - self._handshake_start_time
+            logger.debug("%r: SSL handshake took %.1f ms", self, dt * 1e3)
+
+        # Add extra info that becomes available after handshake.
+        self._extra.update(peercert=peercert,
+                           cipher=sslobj.cipher(),
+                           compression=sslobj.compression(),
+                           ssl_object=sslobj)
+        if self._app_state == AppProtocolState.STATE_INIT:
+            self._app_state = AppProtocolState.STATE_CON_MADE
+            self._app_protocol.connection_made(self._get_app_transport())
+        self._wakeup_waiter()
+        self._do_read()
+
+    # Shutdown flow
+
+    def _start_shutdown(self):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN,
+                SSLProtocolState.UNWRAPPED
+            )
+        ):
+            return
+        if self._app_transport is not None:
+            self._app_transport._closed = True
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            self._abort()
+        else:
+            self._set_state(SSLProtocolState.FLUSHING)
+            self._shutdown_timeout_handle = self._loop.call_later(
+                self._ssl_shutdown_timeout,
+                lambda: self._check_shutdown_timeout()
+            )
+            self._do_flush()
+
+    def _check_shutdown_timeout(self):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN
+            )
+        ):
+            self._transport._force_close(
+                exceptions.TimeoutError('SSL shutdown timed out'))
+
+    def _do_flush(self):
+        self._do_read()
+        self._set_state(SSLProtocolState.SHUTDOWN)
+        self._do_shutdown()
+
+    def _do_shutdown(self):
+        try:
+            if not self._eof_received:
+                self._sslobj.unwrap()
+        except SSLAgainErrors:
+            self._process_outgoing()
+        except ssl.SSLError as exc:
+            self._on_shutdown_complete(exc)
+        else:
+            self._process_outgoing()
+            self._call_eof_received()
+            self._on_shutdown_complete(None)
+
+    def _on_shutdown_complete(self, shutdown_exc):
+        if self._shutdown_timeout_handle is not None:
+            self._shutdown_timeout_handle.cancel()
+            self._shutdown_timeout_handle = None
+
+        if shutdown_exc:
+            self._fatal_error(shutdown_exc)
+        else:
+            self._loop.call_soon(self._transport.close)
+
+    def _abort(self):
+        self._set_state(SSLProtocolState.UNWRAPPED)
+        if self._transport is not None:
+            self._transport.abort()
+
+    # Outgoing flow
+
+    def _write_appdata(self, list_of_data):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN,
+                SSLProtocolState.UNWRAPPED
+            )
+        ):
+            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
+                logger.warning('SSL connection is closed')
+            self._conn_lost += 1
+            return
+
+        for data in list_of_data:
+            self._write_backlog.append(data)
+            self._write_buffer_size += len(data)
+
+        try:
+            if self._state == SSLProtocolState.WRAPPED:
+                self._do_write()
+
+        except Exception as ex:
+            self._fatal_error(ex, 'Fatal error on SSL protocol')
+
+    def _do_write(self):
+        try:
+            while self._write_backlog:
+                data = self._write_backlog[0]
+                count = self._sslobj.write(data)
+                data_len = len(data)
+                if count < data_len:
+                    self._write_backlog[0] = data[count:]
+                    self._write_buffer_size -= count
+                else:
+                    del self._write_backlog[0]
+                    self._write_buffer_size -= data_len
+        except SSLAgainErrors:
+            pass
+        self._process_outgoing()
+
+    def _process_outgoing(self):
+        if not self._ssl_writing_paused:
+            data = self._outgoing.read()
+            if len(data):
+                self._transport.write(data)
+        self._control_app_writing()
+
+    # Incoming flow
+
+    def _do_read(self):
+        if (
+            self._state not in (
+                SSLProtocolState.WRAPPED,
+                SSLProtocolState.FLUSHING,
+            )
+        ):
+            return
+        try:
+            if not self._app_reading_paused:
+                if self._app_protocol_is_buffer:
+                    self._do_read__buffered()
+                else:
+                    self._do_read__copied()
+                if self._write_backlog:
+                    self._do_write()
+                else:
+                    self._process_outgoing()
+            self._control_ssl_reading()
+        except Exception as ex:
+            self._fatal_error(ex, 'Fatal error on SSL protocol')
+
+    def _do_read__buffered(self):
+        offset = 0
+        count = 1
+
+        buf = self._app_protocol_get_buffer(self._get_read_buffer_size())
+        wants = len(buf)
+
+        try:
+            count = self._sslobj.read(wants, buf)
+
+            if count > 0:
+                offset = count
+                while offset < wants:
+                    count = self._sslobj.read(wants - offset, buf[offset:])
+                    if count > 0:
+                        offset += count
+                    else:
+                        break
+                else:
+                    self._loop.call_soon(lambda: self._do_read())
+        except SSLAgainErrors:
+            pass
+        if offset > 0:
+            self._app_protocol_buffer_updated(offset)
+        if not count:
+            # close_notify
+            self._call_eof_received()
+            self._start_shutdown()
+
+    def _do_read__copied(self):
+        chunk = b'1'
+        zero = True
+        one = False
+
+        try:
+            while True:
+                chunk = self._sslobj.read(self.max_size)
+                if not chunk:
+                    break
+                if zero:
+                    zero = False
+                    one = True
+                    first = chunk
+                elif one:
+                    one = False
+                    data = [first, chunk]
+                else:
+                    data.append(chunk)
+        except SSLAgainErrors:
+            pass
+        if one:
+            self._app_protocol.data_received(first)
+        elif not zero:
+            self._app_protocol.data_received(b''.join(data))
+        if not chunk:
+            # close_notify
+            self._call_eof_received()
+            self._start_shutdown()
+
+    def _call_eof_received(self):
+        try:
+            if self._app_state == AppProtocolState.STATE_CON_MADE:
+                self._app_state = AppProtocolState.STATE_EOF
+                keep_open = self._app_protocol.eof_received()
+                if keep_open:
+                    logger.warning('returning true from eof_received() '
+                                   'has no effect when using ssl')
+        except (KeyboardInterrupt, SystemExit):
+            raise
+        except BaseException as ex:
+            self._fatal_error(ex, 'Error calling eof_received()')
+
+    # Flow control for writes from APP socket
+
+    def _control_app_writing(self):
+        size = self._get_write_buffer_size()
+        if size >= self._outgoing_high_water and not self._app_writing_paused:
+            self._app_writing_paused = True
+            try:
+                self._app_protocol.pause_writing()
+            except (KeyboardInterrupt, SystemExit):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.pause_writing() failed',
+                    'exception': exc,
+                    'transport': self._app_transport,
+                    'protocol': self,
+                })
+        elif size <= self._outgoing_low_water and self._app_writing_paused:
+            self._app_writing_paused = False
+            try:
+                self._app_protocol.resume_writing()
+            except (KeyboardInterrupt, SystemExit):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.resume_writing() failed',
+                    'exception': exc,
+                    'transport': self._app_transport,
+                    'protocol': self,
+                })
+
+    def _get_write_buffer_size(self):
+        return self._outgoing.pending + self._write_buffer_size
+
+    def _set_write_buffer_limits(self, high=None, low=None):
+        high, low = add_flowcontrol_defaults(
+            high, low, constants.FLOW_CONTROL_HIGH_WATER_SSL_WRITE)
+        self._outgoing_high_water = high
+        self._outgoing_low_water = low
+
+    # Flow control for reads to APP socket
+
+    def _pause_reading(self):
+        self._app_reading_paused = True
+
+    def _resume_reading(self):
+        if self._app_reading_paused:
+            self._app_reading_paused = False
+
+            def resume():
+                if self._state == SSLProtocolState.WRAPPED:
+                    self._do_read()
+                elif self._state == SSLProtocolState.FLUSHING:
+                    self._do_flush()
+                elif self._state == SSLProtocolState.SHUTDOWN:
+                    self._do_shutdown()
+            self._loop.call_soon(resume)
+
+    # Flow control for reads from SSL socket
+
+    def _control_ssl_reading(self):
+        size = self._get_read_buffer_size()
+        if size >= self._incoming_high_water and not self._ssl_reading_paused:
+            self._ssl_reading_paused = True
+            self._transport.pause_reading()
+        elif size <= self._incoming_low_water and self._ssl_reading_paused:
+            self._ssl_reading_paused = False
+            self._transport.resume_reading()
+
+    def _set_read_buffer_limits(self, high=None, low=None):
+        high, low = add_flowcontrol_defaults(
+            high, low, constants.FLOW_CONTROL_HIGH_WATER_SSL_READ)
+        self._incoming_high_water = high
+        self._incoming_low_water = low
+
+    def _get_read_buffer_size(self):
+        return self._incoming.pending
+
+    # Flow control for writes to SSL socket
+
+    def pause_writing(self):
+        """Called when the low-level transport's buffer goes over
+        the high-water mark.
+        """
+        assert not self._ssl_writing_paused
+        self._ssl_writing_paused = True
+
+    def resume_writing(self):
+        """Called when the low-level transport's buffer drains below
+        the low-water mark.
+        """
+        assert self._ssl_writing_paused
+        self._ssl_writing_paused = False
+        self._process_outgoing()
+
+    def _fatal_error(self, exc, message='Fatal error on transport'):
+        if self._transport:
+            self._transport._force_close(exc)
+
+        if isinstance(exc, OSError):
+            if self._loop.get_debug():
+                logger.debug("%r: %s", self, message, exc_info=True)
+        elif not isinstance(exc, exceptions.CancelledError):
+            self._loop.call_exception_handler({
+                'message': message,
+                'exception': exc,
+                'transport': self._transport,
+                'protocol': self,
+            })