summaryrefslogtreecommitdiff
path: root/soledad_server
diff options
context:
space:
mode:
authordrebs <drebs@leap.se>2013-07-23 23:12:27 -0300
committerdrebs <drebs@leap.se>2013-07-24 18:22:11 -0300
commit7feefdc283d896fdccee8067d867c14f674a912c (patch)
treed290f58447cfbcd9ccd8956cfea00ecf096d502a /soledad_server
parentb5f9e0ce679c87075d04db0645f18281feeeb01d (diff)
Refactor authentication to make it adaptable.
Diffstat (limited to 'soledad_server')
-rw-r--r--soledad_server/changes/2621-refactor-audh-to-make-it-adaptable2
-rw-r--r--soledad_server/src/leap/soledad_server/__init__.py272
-rw-r--r--soledad_server/src/leap/soledad_server/auth.py431
3 files changed, 436 insertions, 269 deletions
diff --git a/soledad_server/changes/2621-refactor-audh-to-make-it-adaptable b/soledad_server/changes/2621-refactor-audh-to-make-it-adaptable
new file mode 100644
index 00000000..775f7e8d
--- /dev/null
+++ b/soledad_server/changes/2621-refactor-audh-to-make-it-adaptable
@@ -0,0 +1,2 @@
+ o Refactor server side auth classes to make it possible for other kinds of
+ authentication to be easily implemented. Closes #2621.
diff --git a/soledad_server/src/leap/soledad_server/__init__.py b/soledad_server/src/leap/soledad_server/__init__.py
index 471ac30f..afbb057e 100644
--- a/soledad_server/src/leap/soledad_server/__init__.py
+++ b/soledad_server/src/leap/soledad_server/__init__.py
@@ -24,12 +24,7 @@ This should be run with:
"""
import configparser
-import httplib
-import simplejson as json
-
-from routes.mapper import Mapper
-from u1db import DBNAME_CONSTRAINTS
from u1db.remote import http_app
@@ -40,8 +35,6 @@ old_tsafe = tsafe
from twisted.web.wsgi import WSGIResource
from twisted.internet import reactor
-from twisted.python import log
-
from twisted import version
if version.base() == "12.0.0":
# Put OpenSSL's tsafe back into place. This can probably be removed if we
@@ -49,271 +42,12 @@ if version.base() == "12.0.0":
import sys
sys.modules['OpenSSL.tsafe'] = old_tsafe
-from couchdb.client import Server
+from leap.soledad_server.auth import SoledadTokenAuthMiddleware
from leap.soledad_server.couch import CouchServerState
#-----------------------------------------------------------------------------
-# Authentication
-#-----------------------------------------------------------------------------
-
-class Unauthorized(Exception):
- """
- User authentication failed.
- """
-
-
-class URLToAuth(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):
- """
- 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
- """
- self._map = Mapper(controller_scan=None)
- 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' % (SoledadApp.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' % SoledadApp.SHARED_DB_NAME,
- [self.HTTP_METHOD_GET])
- # auth info for shared-db doc resource
- self._register(
- '/%s/doc/{id:.*}' % SoledadApp.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.
-
- In general, databases are accessed using a token provided by the LEAP API.
- Some special databases can be read without authentication.
- """
-
- TOKENS_DB = "tokens"
- TOKENS_TYPE_KEY = "type"
- TOKENS_TYPE_DEF = "Token"
- TOKENS_USER_ID_KEY = "user_id"
-
- 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 __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
- """
- unauth_err = lambda msg: self._error(start_response,
- 401,
- "unauthorized",
- msg)
-
- auth = environ.get(self.HTTP_AUTH_KEY)
- if not auth:
- return unauth_err("Missing Token Authentication.")
-
- scheme, encoded = auth.split(None, 1)
- if scheme.lower() != 'token':
- return unauth_err("Missing Token Authentication")
-
- uuid, token = encoded.decode('base64').split(':', 1)
- if not self.verify_token(environ, uuid, token):
- return unauth_err("Incorrect address or token.")
-
- if not self.verify_action(uuid, environ):
- return unauth_err("Unauthorized action.")
-
- del environ[self.HTTP_AUTH_KEY]
-
- return self._app(environ, start_response)
-
- def verify_token(self, environ, uuid, token):
- """
- Verify if token is valid for authenticating this request.
-
- @param environ: Dictionary containing CGI variables.
- @type environ: dict
- @param uuid: The user's uuid.
- @type uuid: str
- @param token: The authentication token.
- @type token: str
-
- @return: Whether the token is valid for authenticating the request.
- @rtype: bool
- """
-
- 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 verify_action(self, uuid, environ):
- """
- Verify if the user is authorized to perform the requested action over
- the requested database.
-
- @param uuid: The user's uuid.
- @type uuid: str
- @param environ: Dictionary containing CGI variables.
- @type environ: dict
-
- @return: Whether the user is authorize to perform the requested action
- over the requested db.
- @rtype: bool
- """
- return URLToAuth(uuid).is_authorized(environ)
-
-
-#-----------------------------------------------------------------------------
# Soledad WSGI application
#-----------------------------------------------------------------------------
@@ -386,6 +120,6 @@ conf = load_configuration('/etc/leap/soledad-server.conf')
state = CouchServerState(conf['couch_url'])
# WSGI application that may be used by `twistd -web`
-application = SoledadAuthMiddleware(SoledadApp(state))
+application = SoledadTokenAuthMiddleware(SoledadApp(state))
-resource = WSGIResource(reactor, reactor.getThreadPool(), application)
+resource = WSGIResource(reactor, reactor.getThreadPool(), application) \ No newline at end of file
diff --git a/soledad_server/src/leap/soledad_server/auth.py b/soledad_server/src/leap/soledad_server/auth.py
new file mode 100644
index 00000000..e0169523
--- /dev/null
+++ b/soledad_server/src/leap/soledad_server/auth.py
@@ -0,0 +1,431 @@
+# -*- 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