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quay/data/users/externaljwt.py
2019-11-12 11:09:47 -05:00

128 lines
4.7 KiB
Python

import logging
import json
import os
from data.users.federated import FederatedUsers, UserInformation
from util.security import jwtutil
logger = logging.getLogger(__name__)
class ExternalJWTAuthN(FederatedUsers):
""" Delegates authentication to a REST endpoint that returns JWTs. """
PUBLIC_KEY_FILENAME = 'jwt-authn.cert'
def __init__(self, verify_url, query_url, getuser_url, issuer, override_config_dir, http_client,
max_fresh_s, public_key_path=None, requires_email=True):
super(ExternalJWTAuthN, self).__init__('jwtauthn', requires_email)
self.verify_url = verify_url
self.query_url = query_url
self.getuser_url = getuser_url
self.issuer = issuer
self.client = http_client
self.max_fresh_s = max_fresh_s
self.requires_email = requires_email
default_key_path = os.path.join(override_config_dir, ExternalJWTAuthN.PUBLIC_KEY_FILENAME)
public_key_path = public_key_path or default_key_path
if not os.path.exists(public_key_path):
error_message = ('JWT Authentication public key file "%s" not found' % public_key_path)
raise Exception(error_message)
self.public_key_path = public_key_path
with open(public_key_path) as public_key_file:
self.public_key = public_key_file.read()
def has_password_set(self, username):
return True
def ping(self):
result = self.client.get(self.getuser_url, timeout=2)
# We expect a 401 or 403 of some kind, since we explicitly don't send an auth header
if result.status_code // 100 != 4:
return (False, result.text or 'Could not reach JWT authn endpoint')
return (True, None)
def get_user(self, username_or_email):
if self.getuser_url is None:
return (None, 'No endpoint defined for retrieving user')
(payload, err_msg) = self._execute_call(self.getuser_url, 'quay.io/jwtauthn/getuser',
params=dict(username=username_or_email))
if err_msg is not None:
return (None, err_msg)
if not 'sub' in payload:
raise Exception('Missing sub field in JWT')
if self.requires_email and not 'email' in payload:
raise Exception('Missing email field in JWT')
# Parse out the username and email.
user_info = UserInformation(username=payload['sub'], email=payload.get('email'),
id=payload['sub'])
return (user_info, None)
def query_users(self, query, limit=20):
if self.query_url is None:
return (None, self.federated_service, 'No endpoint defined for querying users')
(payload, err_msg) = self._execute_call(self.query_url, 'quay.io/jwtauthn/query',
params=dict(query=query, limit=limit))
if err_msg is not None:
return (None, self.federated_service, err_msg)
query_results = []
for result in payload['results'][0:limit]:
user_info = UserInformation(username=result['username'], email=result.get('email'),
id=result['username'])
query_results.append(user_info)
return (query_results, self.federated_service, None)
def verify_credentials(self, username_or_email, password):
(payload, err_msg) = self._execute_call(self.verify_url, 'quay.io/jwtauthn',
auth=(username_or_email, password))
if err_msg is not None:
return (None, err_msg)
if not 'sub' in payload:
raise Exception('Missing sub field in JWT')
if self.requires_email and not 'email' in payload:
raise Exception('Missing email field in JWT')
user_info = UserInformation(username=payload['sub'], email=payload.get('email'),
id=payload['sub'])
return (user_info, None)
def _execute_call(self, url, aud, auth=None, params=None):
""" Executes a call to the external JWT auth provider. """
result = self.client.get(url, timeout=2, auth=auth, params=params)
if result.status_code != 200:
return (None, result.text or 'Could not make JWT auth call')
try:
result_data = json.loads(result.text)
except ValueError:
raise Exception('Returned JWT body for url %s does not contain JSON', url)
# Load the JWT returned.
encoded = result_data.get('token', '')
exp_limit_options = jwtutil.exp_max_s_option(self.max_fresh_s)
try:
payload = jwtutil.decode(encoded, self.public_key, algorithms=['RS256'],
audience=aud, issuer=self.issuer,
options=exp_limit_options)
return (payload, None)
except jwtutil.InvalidTokenError:
logger.exception('Exception when decoding returned JWT for url %s', url)
return (None, 'Exception when decoding returned JWT')