glare/glare/api/middleware/keycloak_auth.py

205 lines
7.4 KiB
Python

# Copyright 2017 - Nokia Networks
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from cachetools import cached
from cachetools import LRUCache
import json
import jwt
import memcache
from oslo_config import cfg
from oslo_log import log as logging
from oslo_middleware import base as base_middleware
import pprint
import requests
from six.moves import urllib
import webob.dec
from glare.common import exception
from glare.common import utils
from glare.i18n import _
from jwt.algorithms import RSAAlgorithm
LOG = logging.getLogger(__name__)
keycloak_oidc_opts = [
cfg.StrOpt(
'auth_url',
default='http://127.0.0.1:8080/auth',
help='Keycloak base url (e.g. https://my.keycloak:8443/auth)'
),
cfg.StrOpt(
'user_info_endpoint_url',
default='/realms/%s/protocol/openid-connect/userinfo',
help='Endpoint against which authorization will be performed'
),
cfg.StrOpt(
'certfile',
help='Required if identity server requires client certificate'
),
cfg.StrOpt(
'keyfile',
help='Required if identity server requires client certificate'
),
cfg.StrOpt(
'cafile',
help='A PEM encoded Certificate Authority to use when verifying '
'HTTPs connections. Defaults to system CAs.'
),
cfg.BoolOpt(
'insecure',
default=False,
help='If True, SSL/TLS certificate verification is disabled'
),
cfg.StrOpt(
'memcached_server',
default=None,
help='Url of memcached server to use for caching'
),
cfg.IntOpt(
'token_cache_time',
default=60,
min=0,
help='In order to prevent excessive effort spent validating '
'tokens, the middleware caches previously-seen tokens '
'for a configurable duration (in seconds).'
),
cfg.StrOpt(
'public_cert_url',
default="/realms/%s/protocol/openid-connect/certs",
help="URL to get the public key for perticualar realm"
),
cfg.StrOpt(
'keycloak_iss',
help="keycloak issuer(iss) url Ex: https://ip_add:port/auth/realms/%s"
)
]
CONF = cfg.CONF
CONF.register_opts(keycloak_oidc_opts, group="keycloak_oidc")
class KeycloakAuthMiddleware(base_middleware.Middleware):
def __init__(self, app):
super(KeycloakAuthMiddleware, self).__init__(application=app)
mcserv_url = CONF.keycloak_oidc.memcached_server
self.mcclient = memcache.Client(mcserv_url) if mcserv_url else None
self.certfile = CONF.keycloak_oidc.certfile
self.keyfile = CONF.keycloak_oidc.keyfile
self.cafile = CONF.keycloak_oidc.cafile or utils.get_system_ca_file()
self.insecure = CONF.keycloak_oidc.insecure
def authenticate(self, access_token, realm_name, audience):
info = None
if self.mcclient:
info = self.mcclient.get(access_token)
user_info_endpoint_url = CONF.keycloak_oidc.user_info_endpoint_url
if info is None:
if user_info_endpoint_url.startswith(('http://', 'https://')):
info = self.send_request_to_auth_server(
url=user_info_endpoint_url, access_token=access_token)
else:
public_key = self.get_public_key(realm_name)
keycloak_iss = None
try:
if CONF.keycloak_oidc.keycloak_iss:
keycloak_iss = \
CONF.keycloak_oidc.keycloak_iss % realm_name
jwt.decode(access_token, public_key, audience=audience,
issuer=keycloak_iss, algorithms=['RS256'],
verify=True)
except Exception as e:
LOG.error("Exception in access_token validation %s", e)
raise exception.Unauthorized()
return info
@webob.dec.wsgify
def __call__(self, request):
if 'X-Auth-Token' not in request.headers:
msg = _("Auth token must be provided in 'X-Auth-Token' header.")
LOG.error(msg)
raise exception.Unauthorized()
access_token = request.headers.get('X-Auth-Token')
try:
decoded = jwt.decode(access_token, algorithms=['RS256'],
verify=False)
except Exception as e:
msg = _("Token can't be decoded because of wrong format %s")\
% str(e)
LOG.error(msg)
raise exception.Unauthorized()
# Get user realm from parsed token
# Format is "iss": "http://<host>:<port>/auth/realms/<realm_name>",
__, __, realm_name = decoded['iss'].strip().rpartition('/realms/')
audience = decoded.get('aud')
# Get roles from from parsed token
roles = ','.join(decoded['realm_access']['roles']) \
if 'realm_access' in decoded else ''
self.authenticate(access_token, realm_name, audience)
request.headers["X-Identity-Status"] = "Confirmed"
request.headers["X-Project-Id"] = realm_name
request.headers["X-Roles"] = roles
return request.get_response(self.application)
@cached(LRUCache(maxsize=32))
def get_public_key(self, realm_name):
keycloak_key_url = CONF.keycloak_oidc.auth_url + \
CONF.keycloak_oidc.public_cert_url % realm_name
response_json = self.send_request_to_auth_server(keycloak_key_url)
public_key = RSAAlgorithm.from_jwk(json.dumps(
response_json.get("keys")[0]))
return public_key
def send_request_to_auth_server(self, url, access_token=None):
verify = None
if urllib.parse.urlparse(url).scheme == "https":
verify = False if self.insecure else self.cafile
cert = (self.certfile, self.keyfile) \
if self.certfile and self.keyfile else None
headers = {}
if access_token:
headers["Authorization"] = "Bearer %s" % access_token
try:
resp = requests.get(
url,
headers=headers,
verify=verify,
cert=cert
)
except requests.ConnectionError as e:
msg = _("Can't connect to keycloak server with address '%s'."
) % url
LOG.error(msg, e)
raise exception.GlareException(message=msg)
if resp.status_code == 400:
raise exception.BadRequest(message=resp.text)
if resp.status_code == 401:
LOG.warning("HTTP response from OIDC provider:"
" [%s] with WWW-Authenticate: [%s]",
pprint.pformat(resp.text),
resp.headers.get("WWW-Authenticate"))
raise exception.Unauthorized(message=resp.text)
if resp.status_code == 403:
raise exception.Forbidden(message=resp.text)
elif resp.status_code > 400:
raise exception.GlareException(message=resp.text)
return resp.json()