223 lines
8.8 KiB
Python
223 lines
8.8 KiB
Python
"""passbook app_gw request handler"""
|
|
import mimetypes
|
|
from logging import getLogger
|
|
from random import SystemRandom
|
|
from urllib.parse import urlparse
|
|
|
|
import certifi
|
|
import urllib3
|
|
from django.core.cache import cache
|
|
from django.utils.http import urlencode
|
|
|
|
from passbook.app_gw.models import ApplicationGatewayProvider
|
|
from passbook.app_gw.proxy.exceptions import InvalidUpstream
|
|
from passbook.app_gw.proxy.response import get_django_response
|
|
from passbook.app_gw.proxy.utils import encode_items, normalize_request_headers
|
|
from passbook.app_gw.rewrite import Rewriter
|
|
from passbook.core.models import Application
|
|
from passbook.core.policies import PolicyEngine
|
|
|
|
SESSION_UPSTREAM_KEY = 'passbook_app_gw_upstream'
|
|
IGNORED_HOSTNAMES_KEY = 'passbook_app_gw_ignored'
|
|
LOGGER = getLogger(__name__)
|
|
QUOTE_SAFE = r'<.;>\(}*+|~=-$/_:^@)[{]&\'!,"`'
|
|
ERRORS_MESSAGES = {
|
|
'upstream-no-scheme': ("Upstream URL scheme must be either "
|
|
"'http' or 'https' (%s).")
|
|
}
|
|
HTTP_NO_VERIFY = urllib3.PoolManager()
|
|
HTTP = urllib3.PoolManager(
|
|
cert_reqs='CERT_REQUIRED',
|
|
ca_certs=certifi.where())
|
|
IGNORED_HOSTS = cache.get(IGNORED_HOSTNAMES_KEY, [])
|
|
|
|
|
|
class RequestHandler:
|
|
"""Forward requests"""
|
|
|
|
_parsed_url = None
|
|
_request_headers = None
|
|
|
|
def __init__(self, app_gw, request):
|
|
self.app_gw = app_gw
|
|
self.request = request
|
|
|
|
@staticmethod
|
|
def find_app_gw_for_request(request):
|
|
"""Check if a request should be proxied or forwarded to passbook"""
|
|
# Check if hostname is in cached list of ignored hostnames
|
|
# This saves us having to query the database on each request
|
|
host_header = request.META.get('HTTP_HOST')
|
|
if host_header in IGNORED_HOSTS:
|
|
LOGGER.debug("%s is ignored", host_header)
|
|
return False
|
|
# Look through all ApplicationGatewayProviders and check hostnames
|
|
matches = ApplicationGatewayProvider.objects.filter(
|
|
server_name__contains=[host_header],
|
|
enabled=True)
|
|
if not matches.exists():
|
|
# Mo matching Providers found, add host header to ignored list
|
|
IGNORED_HOSTS.append(host_header)
|
|
cache.set(IGNORED_HOSTNAMES_KEY, IGNORED_HOSTS)
|
|
LOGGER.debug("Ignoring %s", host_header)
|
|
return False
|
|
# At this point we're certain there's a matching ApplicationGateway
|
|
if len(matches) > 1:
|
|
# This should never happen
|
|
raise ValueError
|
|
app_gw = matches.first()
|
|
try:
|
|
# Check if ApplicationGateway is associated with application
|
|
getattr(app_gw, 'application')
|
|
if app_gw:
|
|
return app_gw
|
|
except Application.DoesNotExist:
|
|
LOGGER.debug("ApplicationGateway not associated with Application")
|
|
return True
|
|
|
|
def _get_upstream(self):
|
|
"""Choose random upstream and save in session"""
|
|
if SESSION_UPSTREAM_KEY not in self.request.session:
|
|
self.request.session[SESSION_UPSTREAM_KEY] = {}
|
|
if self.app_gw.pk not in self.request.session[SESSION_UPSTREAM_KEY]:
|
|
upstream_index = int(SystemRandom().random() * len(self.app_gw.upstream))
|
|
self.request.session[SESSION_UPSTREAM_KEY][self.app_gw.pk] = upstream_index
|
|
return self.app_gw.upstream[self.request.session[SESSION_UPSTREAM_KEY][self.app_gw.pk]]
|
|
|
|
def get_upstream(self):
|
|
"""Get upstream as parsed url"""
|
|
upstream = self._get_upstream()
|
|
|
|
self._parsed_url = urlparse(upstream)
|
|
|
|
if self._parsed_url.scheme not in ('http', 'https'):
|
|
raise InvalidUpstream(ERRORS_MESSAGES['upstream-no-scheme'] %
|
|
upstream)
|
|
|
|
return upstream
|
|
|
|
def _format_path_to_redirect(self):
|
|
LOGGER.debug("Path before: %s", self.request.get_full_path())
|
|
rewriter = Rewriter(self.app_gw, self.request)
|
|
after = rewriter.build()
|
|
LOGGER.debug("Path after: %s", after)
|
|
return after
|
|
|
|
def get_proxy_request_headers(self):
|
|
"""Get normalized headers for the upstream
|
|
Gets all headers from the original request and normalizes them.
|
|
Normalization occurs by removing the prefix ``HTTP_`` and
|
|
replacing and ``_`` by ``-``. Example: ``HTTP_ACCEPT_ENCODING``
|
|
becames ``Accept-Encoding``.
|
|
.. versionadded:: 0.9.1
|
|
:param request: The original HTTPRequest instance
|
|
:returns: Normalized headers for the upstream
|
|
"""
|
|
return normalize_request_headers(self.request)
|
|
|
|
def get_request_headers(self):
|
|
"""Return request headers that will be sent to upstream.
|
|
The header REMOTE_USER is set to the current user
|
|
if AuthenticationMiddleware is enabled and
|
|
the view's add_remote_user property is True.
|
|
.. versionadded:: 0.9.8
|
|
"""
|
|
request_headers = self.get_proxy_request_headers()
|
|
if not self.app_gw.authentication_header:
|
|
return request_headers
|
|
request_headers[self.app_gw.authentication_header] = self.request.user.get_username()
|
|
LOGGER.info("%s set", self.app_gw.authentication_header)
|
|
|
|
return request_headers
|
|
|
|
def check_permission(self):
|
|
"""Check if user is authenticated and has permission to access app"""
|
|
if not hasattr(self.request, 'user'):
|
|
return False
|
|
if not self.request.user.is_authenticated:
|
|
return False
|
|
policy_engine = PolicyEngine(self.app_gw.application.policies.all())
|
|
policy_engine.for_user(self.request.user).with_request(self.request).build()
|
|
passing, _messages = policy_engine.result
|
|
|
|
return passing
|
|
|
|
def get_encoded_query_params(self):
|
|
"""Return encoded query params to be used in proxied request"""
|
|
get_data = encode_items(self.request.GET.lists())
|
|
return urlencode(get_data)
|
|
|
|
def _created_proxy_response(self, path):
|
|
request_payload = self.request.body
|
|
|
|
LOGGER.debug("Request headers: %s", self._request_headers)
|
|
|
|
request_url = self.get_upstream() + path
|
|
LOGGER.debug("Request URL: %s", request_url)
|
|
|
|
if self.request.GET:
|
|
request_url += '?' + self.get_encoded_query_params()
|
|
LOGGER.debug("Request URL: %s", request_url)
|
|
|
|
http = HTTP
|
|
if not self.app_gw.upstream_ssl_verification:
|
|
http = HTTP_NO_VERIFY
|
|
|
|
try:
|
|
proxy_response = http.urlopen(self.request.method,
|
|
request_url,
|
|
redirect=False,
|
|
retries=None,
|
|
headers=self._request_headers,
|
|
body=request_payload,
|
|
decode_content=False,
|
|
preload_content=False)
|
|
LOGGER.debug("Proxy response header: %s",
|
|
proxy_response.getheaders())
|
|
except urllib3.exceptions.HTTPError as error:
|
|
LOGGER.exception(error)
|
|
raise
|
|
|
|
return proxy_response
|
|
|
|
def _replace_host_on_redirect_location(self, proxy_response):
|
|
location = proxy_response.headers.get('Location')
|
|
if location:
|
|
if self.request.is_secure():
|
|
scheme = 'https://'
|
|
else:
|
|
scheme = 'http://'
|
|
request_host = scheme + self.request.META.get('HTTP_HOST')
|
|
|
|
upstream_host_http = 'http://' + self._parsed_url.netloc
|
|
upstream_host_https = 'https://' + self._parsed_url.netloc
|
|
|
|
location = location.replace(upstream_host_http, request_host)
|
|
location = location.replace(upstream_host_https, request_host)
|
|
proxy_response.headers['Location'] = location
|
|
LOGGER.debug("Proxy response LOCATION: %s",
|
|
proxy_response.headers['Location'])
|
|
|
|
def _set_content_type(self, proxy_response):
|
|
content_type = proxy_response.headers.get('Content-Type')
|
|
if not content_type:
|
|
content_type = (mimetypes.guess_type(self.request.path)[0] or
|
|
self.app_gw.default_content_type)
|
|
proxy_response.headers['Content-Type'] = content_type
|
|
LOGGER.debug("Proxy response CONTENT-TYPE: %s",
|
|
proxy_response.headers['Content-Type'])
|
|
|
|
def get_response(self):
|
|
"""Pass request to upstream and return response"""
|
|
self._request_headers = self.get_request_headers()
|
|
|
|
path = self._format_path_to_redirect()
|
|
proxy_response = self._created_proxy_response(path)
|
|
|
|
self._replace_host_on_redirect_location(proxy_response)
|
|
self._set_content_type(proxy_response)
|
|
response = get_django_response(proxy_response, strict_cookies=False)
|
|
|
|
LOGGER.debug("RESPONSE RETURNED: %s", response)
|
|
return response
|