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Diffstat (limited to 'soledad_server/src/leap/soledad_server/auth.py')
| -rw-r--r-- | soledad_server/src/leap/soledad_server/auth.py | 431 |
1 files changed, 0 insertions, 431 deletions
diff --git a/soledad_server/src/leap/soledad_server/auth.py b/soledad_server/src/leap/soledad_server/auth.py deleted file mode 100644 index 3bcfcf04..00000000 --- a/soledad_server/src/leap/soledad_server/auth.py +++ /dev/null @@ -1,431 +0,0 @@ -# -*- coding: utf-8 -*- -# auth.py -# Copyright (C) 2013 LEAP -# -# This program is free software: you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation, either version 3 of the License, or -# (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program. If not, see <http://www.gnu.org/licenses/>. - - -""" -Authentication facilities for Soledad Server. -""" - - -import httplib -import simplejson as json - - -from u1db import DBNAME_CONSTRAINTS -from abc import ABCMeta, abstractmethod -from routes.mapper import Mapper -from couchdb.client import Server -from twisted.python import log - - -#----------------------------------------------------------------------------- -# Authentication -#----------------------------------------------------------------------------- - -class Unauthorized(Exception): - """ - User authentication failed. - """ - - -class URLToAuthorization(object): - """ - Verify if actions can be performed by a user. - """ - - HTTP_METHOD_GET = 'GET' - HTTP_METHOD_PUT = 'PUT' - HTTP_METHOD_DELETE = 'DELETE' - HTTP_METHOD_POST = 'POST' - - def __init__(self, uuid, shared_db_name, user_db_prefix): - """ - Initialize the mapper. - - The C{uuid} is used to create the rules that will either allow or - disallow the user to perform specific actions. - - @param uuid: The user uuid. - @type uuid: str - @param shared_db_name: The name of the shared database that holds - user's encrypted secrets. - @type shared_db_name: str - @param user_db_prefix: The string prefix of users' databases. - @type user_db_prefix: str - """ - self._map = Mapper(controller_scan=None) - self._user_db_prefix = user_db_prefix - self._shared_db_name = shared_db_name - self._register_auth_info(self._uuid_dbname(uuid)) - - def is_authorized(self, environ): - """ - Return whether an HTTP request that produced the CGI C{environ} - corresponds to an authorized action. - - @param environ: Dictionary containing CGI variables. - @type environ: dict - - @return: Whether the action is authorized or not. - @rtype: bool - """ - return self._map.match(environ=environ) is not None - - def _register(self, pattern, http_methods): - """ - Register a C{pattern} in the mapper as valid for C{http_methods}. - - @param pattern: The URL pattern that corresponds to the user action. - @type pattern: str - @param http_methods: A list of authorized HTTP methods. - @type http_methods: list of str - """ - self._map.connect( - None, pattern, http_methods=http_methods, - conditions=dict(method=http_methods), - requirements={'dbname': DBNAME_CONSTRAINTS}) - - def _uuid_dbname(self, uuid): - """ - Return the database name corresponding to C{uuid}. - - @param uuid: The user uid. - @type uuid: str - - @return: The database name corresponding to C{uuid}. - @rtype: str - """ - return '%s%s' % (self._user_db_prefix, uuid) - - def _register_auth_info(self, dbname): - """ - Register the authorization info in the mapper using C{dbname} as the - user's database name. - - This method sets up the following authorization rules: - - URL path | Authorized actions - -------------------------------------------------- - / | GET - /shared-db | GET - /shared-db/docs | - - /shared-db/doc/{id} | GET, PUT, DELETE - /shared-db/sync-from/{source} | - - /user-db | GET, PUT, DELETE - /user-db/docs | - - /user-db/doc/{id} | - - /user-db/sync-from/{source} | GET, PUT, POST - - @param dbname: The name of the user's database. - @type dbname: str - """ - # auth info for global resource - self._register('/', [self.HTTP_METHOD_GET]) - # auth info for shared-db database resource - self._register( - '/%s' % self._shared_db_name, - [self.HTTP_METHOD_GET]) - # auth info for shared-db doc resource - self._register( - '/%s/doc/{id:.*}' % self._shared_db_name, - [self.HTTP_METHOD_GET, self.HTTP_METHOD_PUT, - self.HTTP_METHOD_DELETE]) - # auth info for user-db database resource - self._register( - '/%s' % dbname, - [self.HTTP_METHOD_GET, self.HTTP_METHOD_PUT, - self.HTTP_METHOD_DELETE]) - # auth info for user-db sync resource - self._register( - '/%s/sync-from/{source_replica_uid}' % dbname, - [self.HTTP_METHOD_GET, self.HTTP_METHOD_PUT, - self.HTTP_METHOD_POST]) - # generate the regular expressions - self._map.create_regs() - - -class SoledadAuthMiddleware(object): - """ - Soledad Authentication WSGI middleware. - - This class must be extended to implement specific authentication methods - (see SoledadTokenAuthMiddleware below). - - It expects an HTTP_AUTHORIZATION header containing the the concatenation of - the following strings: - - 1. The authentication scheme. It will be verified by the - _verify_authentication_scheme() method. - - 2. A space character. - - 3. The base64 encoded string of the concatenation of the user uuid with - the authentication data, separated by a collon, like this: - - base64("<uuid>:<auth_data>") - - After authentication check, the class performs an authorization check to - verify whether the user is authorized to perform the requested action. - - On client-side, 2 methods must be implemented so the soledad client knows - how to send authentication headers to server: - - * set_<method>_credentials: store authentication credentials in the - class. - - * _sign_request: format and include custom authentication data in - the HTTP_AUTHORIZATION header. - - See leap.soledad.auth and u1db.remote.http_client.HTTPClient to understand - how to do it. - """ - - __metaclass__ = ABCMeta - - HTTP_AUTH_KEY = "HTTP_AUTHORIZATION" - PATH_INFO_KEY = "PATH_INFO" - - CONTENT_TYPE_JSON = ('content-type', 'application/json') - - def __init__(self, app): - """ - Initialize the Soledad Authentication Middleware. - - @param app: The application to run on successfull authentication. - @type app: u1db.remote.http_app.HTTPApp - @param prefix: Auth app path prefix. - @type prefix: str - """ - self._app = app - - def _error(self, start_response, status, description, message=None): - """ - Send a JSON serialized error to WSGI client. - - @param start_response: Callable of the form start_response(status, - response_headers, exc_info=None). - @type start_response: callable - @param status: Status string of the form "999 Message here" - @type status: str - @param response_headers: A list of (header_name, header_value) tuples - describing the HTTP response header. - @type response_headers: list - @param description: The error description. - @type description: str - @param message: The error message. - @type message: str - - @return: List with JSON serialized error message. - @rtype list - """ - start_response("%d %s" % (status, httplib.responses[status]), - [self.CONTENT_TYPE_JSON]) - err = {"error": description} - if message: - err['message'] = message - return [json.dumps(err)] - - def _unauthorized_error(self, start_response, message): - """ - Send a unauth error. - - @param message: The error message. - @type message: str - @param start_response: Callable of the form start_response(status, - response_headers, exc_info=None). - @type start_response: callable - - @return: List with JSON serialized error message. - @rtype list - """ - return self._error( - start_response, - 401, - "unauthorized", - message) - - def __call__(self, environ, start_response): - """ - Handle a WSGI call to the authentication application. - - @param environ: Dictionary containing CGI variables. - @type environ: dict - @param start_response: Callable of the form start_response(status, - response_headers, exc_info=None). - @type start_response: callable - - @return: Target application results if authentication succeeds, an - error message otherwise. - @rtype: list - """ - # check for authentication header - auth = environ.get(self.HTTP_AUTH_KEY) - if not auth: - return self._unauthorized_error( - start_response, "Missing authentication header.") - - # get authentication data - scheme, encoded = auth.split(None, 1) - uuid, auth_data = encoded.decode('base64').split(':', 1) - if not self._verify_authentication_scheme(scheme): - return self._unauthorized_error("Wrong authentication scheme") - - # verify if user is athenticated - if not self._verify_authentication_data(uuid, auth_data): - return self._unauthorized_error( - start_response, - self._get_auth_error_string()) - - # verify if user is authorized to perform action - if not self._verify_authorization(environ, uuid): - return self._unauthorized_error( - start_response, - "Unauthorized action.") - - # move on to the real Soledad app - del environ[self.HTTP_AUTH_KEY] - return self._app(environ, start_response) - - @abstractmethod - def _verify_authentication_scheme(self, scheme): - """ - Verify if authentication scheme is valid. - - @param scheme: Auth scheme extracted from the HTTP_AUTHORIZATION - header. - @type scheme: str - - @return: Whether the authentitcation scheme is valid. - """ - return None - - @abstractmethod - def _verify_authentication_data(self, uuid, auth_data): - """ - Verify valid authenticatiion for this request. - - @param uuid: The user's uuid. - @type uuid: str - @param auth_data: Authentication data. - @type auth_data: str - - @return: Whether the token is valid for authenticating the request. - @rtype: bool - """ - return None - - def _verify_authorization(self, environ, uuid): - """ - Verify if the user is authorized to perform the requested action over - the requested database. - - @param environ: Dictionary containing CGI variables. - @type environ: dict - @param uuid: The user's uuid. - @type uuid: str - - @return: Whether the user is authorize to perform the requested action - over the requested db. - @rtype: bool - """ - return URLToAuthorization( - uuid, self._app.SHARED_DB_NAME, - self._app.USER_DB_PREFIX - ).is_authorized(environ) - - @abstractmethod - def _get_auth_error_string(self): - """ - Return an error string specific for each kind of authentication method. - - @return: The error string. - """ - return None - - -class SoledadTokenAuthMiddleware(SoledadAuthMiddleware): - """ - Token based authentication. - """ - - TOKENS_DB = "tokens" - TOKENS_TYPE_KEY = "type" - TOKENS_TYPE_DEF = "Token" - TOKENS_USER_ID_KEY = "user_id" - - TOKEN_AUTH_ERROR_STRING = "Incorrect address or token." - - def _verify_authentication_scheme(self, scheme): - """ - Verify if authentication scheme is valid. - - @param scheme: Auth scheme extracted from the HTTP_AUTHORIZATION - header. - @type scheme: str - - @return: Whether the authentitcation scheme is valid. - """ - if scheme.lower() != 'token': - return False - return True - - def _verify_authentication_data(self, uuid, auth_data): - """ - Extract token from C{auth_data} and proceed with verification of - C{uuid} authentication. - - @param uuid: The user UID. - @type uuid: str - @param auth_data: Authentication data (i.e. the token). - @type auth_data: str - - @return: Whether the token is valid for authenticating the request. - @rtype: bool - """ - token = auth_data # we expect a cleartext token at this point - return self._verify_token_in_couchdb(uuid, token) - - def _verify_token_in_couchdb(self, uuid, token): - """ - Query couchdb to decide if C{token} is valid for C{uuid}. - - @param uuid: The user uuid. - @type uuid: str - @param token: The token. - @type token: str - """ - server = Server(url=self._app.state.couch_url) - try: - dbname = self.TOKENS_DB - db = server[dbname] - token = db.get(token) - if token is None: - return False - return token[self.TOKENS_TYPE_KEY] == self.TOKENS_TYPE_DEF and \ - token[self.TOKENS_USER_ID_KEY] == uuid - except Exception as e: - log.err(e) - return False - return True - - def _get_auth_error_string(self): - """ - Get the error string for token auth. - - @return: The error string. - """ - return self.TOKEN_AUTH_ERROR_STRING |