2a04b4dadf
Introduce a framework to the websocketproxy to allow a security negotiation to take place between the proxy and the target service, prior to connecting the client tenant to the target service. Based on earlier work by Solly Ross <sross@redhat.com> Change-Id: Ifb9360be73864ab45129c758bd1323a9bab8e48c Co-authored-by: Stephen Finucane <sfinucan@redhat.com> Implements: bp websocket-proxy-to-host-security
261 lines
10 KiB
Python
261 lines
10 KiB
Python
# Copyright (c) 2012 OpenStack Foundation
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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'''
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Websocket proxy that is compatible with OpenStack Nova.
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Leverages websockify.py by Joel Martin
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'''
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import socket
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import sys
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from oslo_log import log as logging
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import six
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from six.moves import http_cookies as Cookie
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import six.moves.urllib.parse as urlparse
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import websockify
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import nova.conf
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from nova.consoleauth import rpcapi as consoleauth_rpcapi
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from nova import context
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from nova import exception
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from nova.i18n import _
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LOG = logging.getLogger(__name__)
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CONF = nova.conf.CONF
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class TenantSock(object):
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"""A socket wrapper for communicating with the tenant.
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This class provides a socket-like interface to the internal
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websockify send/receive queue for the client connection to
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the tenant user. It is used with the security proxy classes.
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"""
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def __init__(self, reqhandler):
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self.reqhandler = reqhandler
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self.queue = []
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def recv(self, cnt):
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# NB(sross): it's ok to block here because we know
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# exactly the sequence of data arriving
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while len(self.queue) < cnt:
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# new_frames looks like ['abc', 'def']
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new_frames, closed = self.reqhandler.recv_frames()
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# flatten frames onto queue
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for frame in new_frames:
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# The socket returns (byte) strings in Python 2...
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if six.PY2:
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self.queue.extend(frame)
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# ...and integers in Python 3. For the Python 3 case, we need
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# to convert these to characters using 'chr' and then, as this
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# returns unicode, convert the result to byte strings.
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else:
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self.queue.extend(
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[six.binary_type(chr(c), 'ascii') for c in frame])
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if closed:
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break
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popped = self.queue[0:cnt]
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del self.queue[0:cnt]
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return b''.join(popped)
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def sendall(self, data):
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self.reqhandler.send_frames([data])
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def finish_up(self):
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self.reqhandler.send_frames([b''.join([self.queue])])
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def close(self):
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self.finish_up()
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self.reqhandler.send_close()
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class NovaProxyRequestHandlerBase(object):
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def address_string(self):
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# NOTE(rpodolyaka): override the superclass implementation here and
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# explicitly disable the reverse DNS lookup, which might fail on some
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# deployments due to DNS configuration and break VNC access completely
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return str(self.client_address[0])
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def verify_origin_proto(self, connection_info, origin_proto):
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access_url = connection_info.get('access_url')
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if not access_url:
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detail = _("No access_url in connection_info. "
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"Cannot validate protocol")
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raise exception.ValidationError(detail=detail)
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expected_protos = [urlparse.urlparse(access_url).scheme]
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# NOTE: For serial consoles the expected protocol could be ws or
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# wss which correspond to http and https respectively in terms of
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# security.
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if 'ws' in expected_protos:
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expected_protos.append('http')
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if 'wss' in expected_protos:
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expected_protos.append('https')
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return origin_proto in expected_protos
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def new_websocket_client(self):
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"""Called after a new WebSocket connection has been established."""
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# Reopen the eventlet hub to make sure we don't share an epoll
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# fd with parent and/or siblings, which would be bad
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from eventlet import hubs
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hubs.use_hub()
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# The nova expected behavior is to have token
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# passed to the method GET of the request
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parse = urlparse.urlparse(self.path)
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if parse.scheme not in ('http', 'https'):
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# From a bug in urlparse in Python < 2.7.4 we cannot support
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# special schemes (cf: http://bugs.python.org/issue9374)
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if sys.version_info < (2, 7, 4):
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raise exception.NovaException(
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_("We do not support scheme '%s' under Python < 2.7.4, "
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"please use http or https") % parse.scheme)
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query = parse.query
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token = urlparse.parse_qs(query).get("token", [""]).pop()
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if not token:
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# NoVNC uses it's own convention that forward token
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# from the request to a cookie header, we should check
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# also for this behavior
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hcookie = self.headers.get('cookie')
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if hcookie:
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cookie = Cookie.SimpleCookie()
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for hcookie_part in hcookie.split(';'):
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hcookie_part = hcookie_part.lstrip()
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try:
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cookie.load(hcookie_part)
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except Cookie.CookieError:
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# NOTE(stgleb): Do not print out cookie content
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# for security reasons.
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LOG.warning('Found malformed cookie')
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else:
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if 'token' in cookie:
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token = cookie['token'].value
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ctxt = context.get_admin_context()
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rpcapi = consoleauth_rpcapi.ConsoleAuthAPI()
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connect_info = rpcapi.check_token(ctxt, token=token)
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if not connect_info:
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raise exception.InvalidToken(token=token)
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# Verify Origin
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expected_origin_hostname = self.headers.get('Host')
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if ':' in expected_origin_hostname:
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e = expected_origin_hostname
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if '[' in e and ']' in e:
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expected_origin_hostname = e.split(']')[0][1:]
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else:
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expected_origin_hostname = e.split(':')[0]
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expected_origin_hostnames = CONF.console.allowed_origins
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expected_origin_hostnames.append(expected_origin_hostname)
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origin_url = self.headers.get('Origin')
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# missing origin header indicates non-browser client which is OK
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if origin_url is not None:
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origin = urlparse.urlparse(origin_url)
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origin_hostname = origin.hostname
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origin_scheme = origin.scheme
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if origin_hostname == '' or origin_scheme == '':
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detail = _("Origin header not valid.")
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raise exception.ValidationError(detail=detail)
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if origin_hostname not in expected_origin_hostnames:
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detail = _("Origin header does not match this host.")
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raise exception.ValidationError(detail=detail)
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if not self.verify_origin_proto(connect_info, origin_scheme):
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detail = _("Origin header protocol does not match this host.")
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raise exception.ValidationError(detail=detail)
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self.msg(_('connect info: %s'), str(connect_info))
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host = connect_info['host']
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port = int(connect_info['port'])
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# Connect to the target
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self.msg(_("connecting to: %(host)s:%(port)s") % {'host': host,
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'port': port})
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tsock = self.socket(host, port, connect=True)
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# Handshake as necessary
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if connect_info.get('internal_access_path'):
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tsock.send("CONNECT %s HTTP/1.1\r\n\r\n" %
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connect_info['internal_access_path'])
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end_token = "\r\n\r\n"
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while True:
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data = tsock.recv(4096, socket.MSG_PEEK)
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token_loc = data.find(end_token)
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if token_loc != -1:
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if data.split("\r\n")[0].find("200") == -1:
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raise exception.InvalidConnectionInfo()
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# remove the response from recv buffer
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tsock.recv(token_loc + len(end_token))
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break
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if self.server.security_proxy is not None:
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tenant_sock = TenantSock(self)
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try:
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tsock = self.server.security_proxy.connect(tenant_sock, tsock)
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except exception.SecurityProxyNegotiationFailed:
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LOG.exception("Unable to perform security proxying, shutting "
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"down connection")
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tenant_sock.close()
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tsock.shutdown(socket.SHUT_RDWR)
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tsock.close()
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raise
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tenant_sock.finish_up()
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# Start proxying
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try:
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self.do_proxy(tsock)
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except Exception:
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if tsock:
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tsock.shutdown(socket.SHUT_RDWR)
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tsock.close()
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self.vmsg(_("%(host)s:%(port)s: "
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"Websocket client or target closed") %
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{'host': host, 'port': port})
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raise
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class NovaProxyRequestHandler(NovaProxyRequestHandlerBase,
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websockify.ProxyRequestHandler):
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def __init__(self, *args, **kwargs):
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websockify.ProxyRequestHandler.__init__(self, *args, **kwargs)
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def socket(self, *args, **kwargs):
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return websockify.WebSocketServer.socket(*args, **kwargs)
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class NovaWebSocketProxy(websockify.WebSocketProxy):
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def __init__(self, *args, **kwargs):
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""":param security_proxy: instance of
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nova.console.securityproxy.base.SecurityProxy
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Create a new web socket proxy, optionally using the
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@security_proxy instance to negotiate security layer
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with the compute node.
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"""
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self.security_proxy = kwargs.pop('security_proxy', None)
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super(NovaWebSocketProxy, self).__init__(*args, **kwargs)
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@staticmethod
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def get_logger():
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return LOG
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