TokenController

Complexity

Total Complexity

26

Size/Duplication

Total Lines	140
Duplicated Lines	0 %

Importance

Changes	1
Bugs	0	Features	0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	_create_token_for_user()	0	3	1
A	__init__()	0	7	2
A	_handle_proxy_auth()	0	15	3
F	_handle_standalone_auth()	0	93	15
A	post()	0	6	3
A	_process_successful_response()	0	4	1
A	_abort_request()	0	3	1

# Licensed to the StackStorm, Inc ('StackStorm') under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.

import base64

import pecan
from pecan import rest
from six.moves import http_client
from oslo_config import cfg

from st2common.exceptions.auth import TokenNotFoundError, TokenExpiredError
from st2common.exceptions.auth import TTLTooLargeException, UserNotFoundError
from st2common.exceptions.auth import NoNicknameOriginProvidedError, AmbiguousUserError
from st2common.exceptions.auth import NotServiceUserError
from st2common.models.api.base import jsexpose
from st2common.models.api.auth import TokenAPI
from st2common.persistence.auth import User
from st2common.services.access import create_token
from st2common.util import auth as auth_utils
from st2common import log as logging
from st2auth.backends import get_backend_instance


LOG = logging.getLogger(__name__)


class TokenValidationController(rest.RestController):

    @jsexpose(body_cls=TokenAPI, status_code=http_client.OK)
    def post(self, request, **kwargs):
        token = getattr(request, 'token', None)

        if not token:
            pecan.abort(http_client.BAD_REQUEST, 'Token is not provided.')

        try:
            return {'valid': auth_utils.validate_token(token) is not None}
        except (TokenNotFoundError, TokenExpiredError):
            return {'valid': False}
        except Exception:
            msg = 'Unexpected error occurred while verifying token.'
            LOG.exception(msg)
            pecan.abort(http_client.INTERNAL_SERVER_ERROR, msg)


class TokenController(rest.RestController):
    validate = TokenValidationController()

    def __init__(self, *args, **kwargs):
        super(TokenController, self).__init__(*args, **kwargs)

        if cfg.CONF.auth.mode == 'standalone':
            self._auth_backend = get_backend_instance(name=cfg.CONF.auth.backend)
        else:
            self._auth_backend = None

    @jsexpose(body_cls=TokenAPI, status_code=http_client.CREATED)
    def post(self, request, **kwargs):
        if cfg.CONF.auth.mode == 'proxy':
            return self._handle_proxy_auth(request=request, **kwargs)
        elif cfg.CONF.auth.mode == 'standalone':
            return self._handle_standalone_auth(request=request, **kwargs)

    def _handle_proxy_auth(self, request, **kwargs):
        remote_addr = pecan.request.headers.get('x-forwarded-for', pecan.request.remote_addr)
        extra = {'remote_addr': remote_addr}

        if pecan.request.remote_user:
            ttl = getattr(request, 'ttl', None)
            try:
                token = self._create_token_for_user(username=pecan.request.remote_user, ttl=ttl)
            except TTLTooLargeException as e:
                self._abort_request(status_code=http_client.BAD_REQUEST,
                                    message=e.message)
            return self._process_successful_response(token=token)

        LOG.audit('Access denied to anonymous user.', extra=extra)
        self._abort_request()

    def _handle_standalone_auth(self, request, **kwargs):
        authorization = pecan.request.authorization

        auth_backend = self._auth_backend.__class__.__name__
        remote_addr = pecan.request.remote_addr
        extra = {'auth_backend': auth_backend, 'remote_addr': remote_addr}

        if not authorization:
            LOG.audit('Authorization header not provided', extra=extra)
            self._abort_request()
            return

        auth_type, auth_value = authorization
        if auth_type.lower() not in ['basic']:
            extra['auth_type'] = auth_type
            LOG.audit('Unsupported authorization type: %s' % (auth_type), extra=extra)
            self._abort_request()
            return

        try:
            auth_value = base64.b64decode(auth_value)
        except Exception:
            LOG.audit('Invalid authorization header', extra=extra)
            self._abort_request()
            return

        split = auth_value.split(':')
        if len(split) != 2:
            LOG.audit('Invalid authorization header', extra=extra)
            self._abort_request()
            return

        username, password = split
        result = self._auth_backend

        result = self._auth_backend.authenticate(username=username, password=password)
        if result is True:
            ttl = getattr(request, 'ttl', None)
            impersonate_user = getattr(request, 'user', None)

            if impersonate_user is not None:
                # check this is a service account
                if not User.get_by_name(username).is_service:
                    message = "Current user is not a service and cannot " \
                              "request impersonated tokens"
                    self._abort_request(status_code=http_client.BAD_REQUEST,
                                        message=message)
                    return
                username = impersonate_user
            else:
                impersonate_user = getattr(request, 'impersonate_user', None)
                nickname_origin = getattr(request, 'nickname_origin', None)
                if impersonate_user is not None:
                    try:
                        # check this is a service account
                        if not User.get_by_name(username).is_service:
                            raise NotServiceUserError()
                        username = User.get_by_nickname(impersonate_user,
                                                        nickname_origin).name
                    except NotServiceUserError:
                        message = "Current user is not a service and cannot " \
                                  "request impersonated tokens"
                        self._abort_request(status_code=http_client.BAD_REQUEST,
                                            message=message)
                        return
                    except UserNotFoundError:
                        message = "Could not locate user %s@%s" % \
                                  (impersonate_user, nickname_origin)
                        self._abort_request(status_code=http_client.BAD_REQUEST,
                                            message=message)
                        return
                    except NoNicknameOriginProvidedError:
                        message = "Nickname origin is not provided for nickname '%s'" % \
                                  impersonate_user
                        self._abort_request(status_code=http_client.BAD_REQUEST,
                                            message=message)
                        return
                    except AmbiguousUserError:
                        message = "%s@%s matched more than one username" % \
                                  (impersonate_user, nickname_origin)
                        self._abort_request(status_code=http_client.BAD_REQUEST,
                                            message=message)
                        return
            try:
                token = self._create_token_for_user(username=username, ttl=ttl)
                return self._process_successful_response(token=token)
            except TTLTooLargeException as e:
                self._abort_request(status_code=http_client.BAD_REQUEST,
                                    message=e.message)
                return

        LOG.audit('Invalid credentials provided', extra=extra)
        self._abort_request()

    def _abort_request(self, status_code=http_client.UNAUTHORIZED,
                       message='Invalid or missing credentials'):
        pecan.abort(status_code, message)

    def _process_successful_response(self, token):
        api_url = cfg.CONF.auth.api_url
        pecan.response.headers['X-API-URL'] = api_url
        return token

    def _create_token_for_user(self, username, ttl=None):
        tokendb = create_token(username=username, ttl=ttl)
        return TokenAPI.from_model(tokendb)