``repoze.who``
==============

.. image:: https://travis-ci.org/repoze/repoze.who.png?branch=master
        :target: https://travis-ci.org/repoze/repoze.who

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        :target: http://repozewho.readthedocs.org/en/latest/
        :alt: Documentation Status

Overview
--------

``repoze.who`` is an identification and authentication framework
for arbitrary WSGI applications.  ``repoze.who`` can be configured
either as WSGI middleware or as an API for use by an application.

``repoze.who`` is inspired by Zope 2's Pluggable Authentication
Service (PAS) (but ``repoze.who`` is not dependent on Zope in any
way; it is useful for any WSGI application).  It provides no facility
for authorization (ensuring whether a user can or cannot perform the
operation implied by the request).  This is considered to be the
domain of the WSGI application.


repoze.who Changelog
====================

2.3 (2016-05-31)
----------------

- Add support for Python 3.4, Python 3.5, and PyPy3.

- Drop support for Python 2.6 and 3.2.

- ``middleware``:  avoid passing extracted ``identity`` to ``remember``
  during egress (the app may have called ``api.forget()``).  See #21.

- ``_auth_tkt`` / ``plugins.auth_tkt``:  add support for any hash algorithm
  supported by the ``hashlib`` module in Python's standard library.
  Fixes #22 via #23.

- ``plugins.auth_tkt``:  Fix storage of "userdata" to save dict.  Fixes
  #14 via #18.

- middleware:  avoid UnboundLocalError when wrapped generater yields no
  items.  See:  http://bugs.repoze.org/issue184

- Make cookie expiration date RFC-2616 compliant (independent of locale,
  including 'GMT' zone). See #11.

2.2 (2013-05-17)
----------------

- Parse INI-file configuration using ``SafeConfigParser``:  allows
  escaping the ``'%'`` so that e.g. a query template using for a DB-API
  connection using ``pyformat`` preserves the template.

- Added support for Python 3.3, PyPy.


2.1 (2013-03-20)
----------------

- ``_compat`` module:  tolerate missing ``CONTENT_TYPE`` key in the WSGI
  environment.  Thanks to Dag Hoidal for the patch.

- ``htpasswd`` plugin:  add a ``sha1_check`` checker function (the ``crypt``
  module is not available on Windows).  Thanks to Chandrashekar Jayaraman
  for the patch.

- Documentation typo fixes from Carlos de la Guardia and Atsushi Odagiri.


2.1b1 (2012-11-05)
------------------

- Ported to Py3k using the "compatible subset" mode.
  - Dropped support for Python < 2.6.x.
  - Dropped dependency on Paste (forking some code from it).
  - Added dependency on WebOb instead.
  Thanks to Atsushi Odagiri (aodag) for the initial effort.


2.0 (2011-09-28)
----------------

- ``auth_tkt`` plugin:  strip any port number from the 'Domain' of generated
  cookies.  http://bugs.repoze.org/issue66

- Further harden middleware, calling ``close()`` on the iterable even if
  raising an exception for a missing challenger.
  http://bugs.repoze.org/issue174


2.0b1 (2011-05-24)
------------------

- Enabled standard use of logging module's configuration mechanism. 
  See http://docs.python.org/dev/howto/logging.html#configuring-logging-for-a-library
  Thanks to jgoldsmith for the patch: http://bugs.repoze.org/issue178


- ``repoze.who.plugins.htpasswd``:  defend against timing-based attacks.


2.0a4 (2011-02-02)
------------------

- Ensure that the middleware calls ``close()`` (if it exists) on the
  iterable returned from thw wrapped application, as required by PEP 333.
  http://bugs.repoze.org/issue174

- Make ``make_api_factory_with_config`` tolerant of invalid filenames /
  content for the config file:  in such cases, the API factory will have
  *no* configured plugins or policies:  it will only be useful for retrieving
  the API from an environment populated by middleware.

- Fix bug in ``repoze.who.api`` where the ``remember()`` or ``forget()``
  methods could return a None if the identifier plugin returned a None.

- Fix ``auth_tkt`` plugin to not hand over tokens as strings to paste. See
  http://lists.repoze.org/pipermail/repoze-dev/2010-November/003680.html

- Fix ``auth_tkt`` plugin to add "secure" and "HttpOnly" to cookies when
  configured with ``secure=True``:  these attributes prevent the browser from
  sending cookies over insecure channels, which could be vulnerable to some
  XSS attacks.

- Avoid propagating unicode 'max_age' value into cookie headers.  See
  https://bugs.launchpad.net/bugs/674123 .

- Added a single-file example BFG application demonstrating the use of
  the new 'login' and 'logout' methods of the API object.

- Add ``login`` and ``logout`` methods to the ``repoze.who.api.API`` object,
  as a convenience for application-driven login / logout code, which would
  otherwise need to use private methods of the API, and reach down into
  its plugins.


2.0a3 (2010-09-30)
------------------

- Deprecated the following plugins, moving their modules, tests, and docs
  to a new project, ``repoze.who.deprecatedplugins``:

  - ``repoze.who.plugins.cookie.InsecureCookiePlugin``

  - ``repoze.who.plugins.form.FormPlugin``

  - ``repoze.who.plugins.form.RedirectingFormPlugin``

- Made the ``repoze.who.plugins.cookie.InsecureCookiePlugin`` take a
  ``charset`` argument, and use to to encode / decode login and password.
  See http://bugs.repoze.org/issue155

- Updated ``repoze.who.restrict`` to return headers as a list, to keep
  ``wsgiref`` from complaining.

- Helped default request classifier cope with xml submissions with an
  explicit charset defined: http://bugs.repoze.org/issue145 (Lorenzo
  M. Catucci)

- Corrected the handling of type and subtype when matching an XML post
  to ``xmlpost`` in the default classifier, which, according to RFC
  2045, must be matched case-insensitively:
  http://bugs.repoze.org/issue145 (Lorenzo M. Catucci)

- Added ``repoze.who.config:make_api_factory_with_config``, a convenience
  method for applications which want to set up their own API Factory from
  a configuration file.

- Fixed example call to ``repoze.who.config:make_middleware_with_config``
  (added missing ``global_config`` argument).  See
  http://bugs.repoze.org/issue114


2.0a2 (2010-03-25)
------------------

Bugs Fixed
~~~~~~~~~~

- Fixed failure to pass substution values in log message string formatting
  for ``repoze.who.api:API.challenge``.  Fix included adding tests for all
  logging done by the API object.  See http://bugs.repoze.org/issue122

Backward Incompatibilities
~~~~~~~~~~~~~~~~~~~~~~~~~~

- Adjusted logging level for some lower-level details from ``info``
  to ``debug``.



2.0a1 (2010-02-24)
------------------

Features
~~~~~~~~

- Restored the ability to create the middleware using the old ``classifier``
  argument.  That argument is now a deprecated-but-will-work-forever alias for
  ``request_classifier``.

- The ``auth_tkt`` plugin now implements the ``IAuthenticator`` interface,
  and should normally be used both as an ``IIdentifier`` and an
  ``IAuthenticator``.

- Factored out the API of the middleware object to make it useful from
  within the application.  Applications using ``repoze.who``` now fall into
  one of three catgeories:

  - "middleware-only" applications are configured with middleware, and
    use either ``REMOTE_USER`` or ``repoze.who.identity`` from the environment
    to determing the authenticated user.

  - "bare metal" applications use no ``repoze.who`` middleware at all:
    instead, they configure and an ``APIFactory`` object at startup, and
    use it to create an ``API`` object when needed on a per-request basis.

  - "hybrid" applications are configured with ``repoze.who`` middleware,
    but use a new library function to fetch the ``API`` object from the
    environ, e.g. to permit calling ``remember`` after a signup or successful
    login.

Bugs Fixed
~~~~~~~~~~

- Fix http://bugs.repoze.org/issue102: when no challengers existed,
  logging would cause an exception.

- Remove ``ez_setup.py`` and dependency on it in setup.py (support
  distribute).

Backward Incompatibilities
~~~~~~~~~~~~~~~~~~~~~~~~~~

- The middleware used to allow identifier plugins to "pre-authenticate"
  an identity.  This feature is no longer supported: the ``auth_tkt`` 
  plugin, which used to use the feature, is now configured to work as
  an authenticator plugin (as well as an identifier).

- The ``repoze.who.middleware:PluggableAuthenticationMiddleware`` class
  no longer has the following (non-API) methods (now made API methods
  of the ``repoze.who.api:API`` class):

  - ``add_metadata``
  - ``authenticate``
  - ``challenge``
  - ``identify``

- The following (non-API) functions moved from ``repoze.who.middleware`` to
  ``repoze.who.api``:

  - ``make_registries``
  - ``match_classification``
  - ``verify``



1.0.18 (2009-11-05)
-------------------

- Issue #104:  AuthTkt plugin was passing an invalid cookie value in
  headers from ``forget``, and was not setting the ``Max-Age`` and 
  ``Expires`` attributes of those cookies.



1.0.17 (2009-11-05)
-------------------

- Fixed the ``repoze.who.plugins.form.make_plugin`` factory's ``formcallable``
  argument handling, to allow passing in a dotted name (e.g., from a config
  file).



1.0.16 (2009-11-04)
-------------------

- Exposed ``formcallable`` argument for ``repoze.who.plugins.form.FormPlugin``
  to the callers of the ``repoze.who.plugins.form.make_plugin`` factory.
  Thanks to Roland Hedburg for the report.

- Fixed an issue that caused the following symptom when using the
  ini configuration parser::

   TypeError: _makePlugin() got multiple values for keyword argument 'name'

  See http://bugs.repoze.org/issue92 for more details.  Thanks to vaab
  for the bug report and initial fix.


1.0.15 (2009-06-25)
-------------------

- If the form post value ``max_age`` exists while in the ``identify``
  method is handling the ``login_handler_path``, pass the max_age
  value in the returned identity dictionary as ``max_age``.  See the
  below bullet point for why.

- If the ``identity`` dict passed to the ``auth_tkt`` ``remember``
  method contains a ``max_age`` key with a string (or integer) value,
  treat it as a cue to set the ``Max-Age`` and ``Expires`` headers in
  the returned cookies.  The cookie ``Max-Age`` is set to the value
  and the ``Expires`` is computed from the current time.


1.0.14 (2009-06-17)
-------------------

- Fix test breakage on Windows.  See http://bugs.repoze.org/issue79 .

- Documented issue with using ``include_ip`` setting in the ``auth_tkt``
  plugin.  See http://bugs.repoze.org/issue81 .

- Added 'passthrough_challenge_decider', which avoids re-challenging 401
  responses which have been "pre-challenged" by the application.

- One-hundred percent unit test coverage.

- Add ``timeout`` and ``reissue_time`` arguments to the auth_tkt
  identifier plugin, courtesty of Paul Johnston.

- Add a ``userid_checker`` argument to the auth_tkt identifier plugin,
  courtesty of Gustavo Narea.

  If ``userid_checker`` is provided, it must be a dotted Python name
  that resolves to a function which accepts a userid and returns a
  boolean True or False, indicating whether that user exists in a
  database.  This is a workaround.  Due to a design bug in repoze.who,
  the only way who can check for user existence is to use one or more
  IAuthenticator plugin ``authenticate`` methods.  If an
  IAuthenticator's ``authenticate`` method returns true, it means that
  the user exists.  However most IAuthenticator plugins expect *both*
  a username and a password, and will return False unconditionally if
  both aren't supplied.  This means that an authenticator can't be
  used to check if the user "only" exists.  The identity provided by
  an auth_tkt does not contain a password to check against.  The
  actual design bug in repoze.who is this: when a user presents
  credentials from an auth_tkt, he is considered "preauthenticated".
  IAuthenticator.authenticate is just never called for a
  "preauthenticated" identity, which works fine, but it means that the
  user will be considered authenticated even if you deleted the user's
  record from whatever database you happen to be using.  However, if
  you use a userid_checker, you can ensure that a user exists for the
  auth_tkt supplied userid.  If the userid_checker returns False, the
  auth_tkt credentials are considered "no good".


1.0.13 (2009-04-24)
-------------------

- Added a paragraph to ``IAuthenticator`` docstring, documenting that plugins
  are allowed to add keys to the ``identity`` dictionary (e.g., to save a
  second database query in an ``IMetadataProvider`` plugin).

- Patch supplied for issue #71 (http://bugs.repoze.org/issue71)
  whereby a downstream app can return a generator, relying on an
  upstream component to call start_response.  We do this because the
  challenge decider needs the status and headers to decide what to do.


1.0.12 (2009-04-19)
-------------------
- auth_tkt plugin tried to append REMOTE_USER_TOKENS data to
  existing tokens data returned by auth_tkt.parse_tkt; this was
  incorrect; just overwrite.

- Extended auth_tkt plugin factory to allow passing secret in a separate
  file from the main config file.  See http://bugs.repoze.org/issue40 .


1.0.11 (2009-04-10)
-------------------

- Fix auth_tkt plugin; cookie values are now quoted, making it possible
  to put spaces and other whitespace, etc in usernames. (thanks to Michael
  Pedersen).

- Fix corner case issue of an exception raised when attempting to log
  when there are no identifiers or authenticators.


1.0.10 (2009-01-23)
-------------------

- The RedirectingFormPlugin now passes along SetCookie headers set
  into the response by the application within the NotFound response
  (fixes TG2 "flash" issue).


1.0.9 (2008-12-18)
------------------

- The RedirectingFormPlugin now attempts to find a header named
  ``X-Authentication-Failure-Reason`` among the response headers set
  by the application when a challenge is issued.  If a value for this
  header exists (and is non-blank), the value is attached to the
  redirect URL's query string as the ``reason`` parameter (or a
  user-settable key).  This makes it possible for downstream
  applications to issue a response that initiates a challenge with
  this header and subsequently display the reason in the login form
  rendered as a result of the challenge.


1.0.8 (2008-12-13)
------------------

- The ``PluggableAuthenticationMiddleware`` constructor accepts a
  ``log_stream`` argument, which is typically a file.  After this
  release, it can also be a PEP 333 ``Logger`` instance; if it is a
  PEP 333 ``Logger`` instance, this logger will be used as the
  repoze.who logger (instead of one being constructed by the
  middleware, as was previously always the case).  When the
  ``log_stream`` argument is a PEP 333 Logger object, the
  ``log_level`` argument is ignored.


1.0.7 (2008-08-28)
------------------

- ``repoze.who`` and ``repoze.who.plugins`` were not added to the
  ``namespace_packages`` list in setup.py, potentially making 1.0.6 a
  brownbag release, given that making these packages namespace
  packages was the only reason for its release.


1.0.6 (2008-08-28)
------------------

- Make repoze.who and repoze.who.plugins into namespace packages
  mainly so we can allow plugin authors to distribute packages in the
  repoze.who.plugins namespace.


1.0.5 (2008-08-23)
------------------

- Fix auth_tkt plugin to set the same cookies in its ``remember``
  method that it does in its ``forget`` method.  Previously, logging
  out and relogging back in to a site that used auth_tkt identifier
  plugin was slightly dicey and would only work sometimes.

- The FormPlugin plugin has grown a redirect-on-unauthorized feature.
  Any response from a downstream application that causes a challenge
  and includes a Location header will cause a redirect to the value of
  the Location header.


1.0.4 (2008-08-22)
------------------

- Added a key to the '[general]' config section: ``remote_user_key``.
  If you use this key in the config file, it tells who to 1) not
  perform any authentication if it exists in the environment during
  ingress and 2) to set the key in the environment for the downstream
  app to use as the REMOTE_USER variable.  The default is
  ``REMOTE_USER``.

- Using unicode user ids in combination with the auth_tkt plugin would
  cause problems under mod_wsgi.

- Allowed 'cookie_path' argument to InsecureCookiePlugin (and config
  constructor).  Thanks to Gustavo Narea.


1.0.3 (2008-08-16)
------------------

- A bug in the middleware's ``authenticate`` method made it impossible
  to authenticate a user with a userid that was null (e.g. 0, False),
  which are valid identifiers.  The only invalid userid is now None.

- Applied patch from Olaf Conradi which logs an error when an invalid
  filename is passed to the HTPasswdPlugin.


1.0.2 (2008-06-16)
------------------

- Fix bug found by Chris Perkins: the auth_tkt plugin's "remember"
  method didn't handle userids which are Python "long" instances
  properly.  Symptom: TypeError: cannot concatenate 'str' and 'long'
  objects in "paste.auth.auth_tkt".

- Added predicate-based "restriction" middleware support
  (repoze.who.restrict), allowing configuratio-driven authorization as
  a WSGI filter.  One example predicate, 'authenticated_predicate', is
  supplied, which requires that the user be authenticated either via
  'REMOTE_USER' or via 'repoze.who.identity'.  To use the filter to
  restrict access::

     [filter:authenticated_only]
     use = egg:repoze.who#authenticated

   or::

     [filter:some_predicate]
     use = egg:repoze.who#predicate
     predicate = my.module:some_predicate
     some_option = a value


1.0.1 (2008-05-24)
------------------

- Remove dependency-link to dist.repoze.org to prevent easy_install
  from inserting that path into its search paths (the dependencies are
  available from PyPI).


1.0 (2008-05-04)
-----------------

- The plugin at plugins.form.FormPlugin didn't redirect properly after
  collecting identification information.  Symptom: a downstream app
  would receive a POST request with a blank body, which would
  sometimes result in a Bad Request error.

- Fixed interface declarations of
  'classifiers.default_request_classifier' and
  'classifiers.default_password_compare'.

- Added actual config-driven middleware factory,
  'config.make_middleware_with_config'

- Removed fossilized 'who_conf' argument from plugin factory functions.

- Added ConfigParser-based WhoConfig, implementing the spec outlined at
  http://www.plope.com/static/misc/sphinxtest/intro.html#middleware-configuration-via-config-file,
  with the following changes:

  - "Bare" plugins (requiring no configuration options) may be specified
     as either egg entry points (e.g., 'egg:distname#entry_point_name') or
     as dotted-path-with-colon (e.g., 'dotted.name:object_id').

  - Therefore, the separator between a plugin and its classifier is now
    a semicolon, rather than a colon. E.g.::

     [plugins:id_plugin]
     use = egg:another.package#identify_with_frobnatz
     frobnatz = baz

     [identifiers]
     plugins =
       egg:my.egg#identify;browser
       dotted.name:identifier
       id_plugin


0.9.1 (2008-04-27)
------------------

- Fix auth_tkt plugin to be able to encode and decode integer user
  ids.


0.9 (2008-04-01)
----------------

- Fix bug introduced in FormPlugin in 0.8 release (rememberer headers
  not set).

- Add PATH_INFO to started and ended log info.

- Add a SQLMetadataProviderPlugin (in plugins/sql).

- Change constructor of SQLAuthenticatorPlugin: it now accepts only
  "query", "conn_factory", and "compare_fn".  The old constructor
  accepted a DSN, but some database systems don't use DBAPI DSNs.  The
  new constructor accepts no DSN; the conn_factory is assumed to do
  all the work to make a connection, including knowing the DSN if one
  is required.  The "conn_factory" should return something that, when
  called with no arguments, returns a database connection.

- The "make_plugin" helper in plugins/sql has been renamed
  "make_authenticator_plugin".  When called, this helper will return a
  SQLAuthenticatorPlugin.  A bit of helper logic in the
  "make_authenticator_plugin" allows a connection factory to be
  computed.  The top-level callable referred to by conn_factory in
  this helper should return a function that, when called with no
  arguments, returns a datbase connection.  The top-level callable
  itself is called with "who_conf" (global who configuration) and any
  number of non-top-level keyword arguments as they are passed into
  the helper, to allow for a DSN or URL or whatever to be passed in.

- A "make_metatata_plugin" helper has been added to plugins/sql. When
  called, this will make a SQLMetadataProviderPlugin.  See the
  implementation for details.  It is similar to the
  "make_authenticator_plugin" helper.


0.8 (2008-03-27)
----------------

- Add a RedirectingFormIdentifier plugin.  This plugin is willing to
  redirect to an external (or downstream application) login form to
  perform identification.  The external login form must post to the
  "login_handler_path" of the plugin (optimally with a "came_from"
  value to tell the plugin where to redirect the response to if the
  authentication works properly).  The "logout_handler_path" of this
  plugin can be visited to perform a logout.  The "came_from" value
  also works there.

- Identifier plugins are now permitted to set a key in the environment
  named 'repoze.who.application' on ingress (in 'identify').  If an
  identifier plugin does so, this application is used instead of the
  "normal" downstream application.  This feature was added to more
  simply support the redirecting form identifier plugin.


0.7 (2008-03-26)
----------------

- Change the IMetadataProvider interface: this interface used to have
  a "metadata" method which returned a dictionary.  This method is not
  part of that API anymore.  It's been replaced with an "add_metadata"
  method which has the signature::

    def add_metadata(environ, identity):
        """
        Add metadata to the identity (which is a dictionary)
        """

   The return value is ignored.  IMetadataProvider plugins are now
   assumed to be responsible for 'scribbling' directly on the identity
   that is passed in (it's a dictionary).  The user id can always be
   retrieved from the identity via identity['repoze.who.userid'] for
   metadata plugins that rely on that value.


0.6 (2008-03-20)
----------------

- Renaming: repoze.pam is now repoze.who

- Bump ez_setup.py version.

- Add IMetadataProvider plugin type.  Chris says 'Whit rules'.


0.5 (2008-03-09)
----------------

- Allow "remote user key" (default: REMOTE_USER) to be overridden
  (pass in remote_user_key to middleware constructor).

- Allow form plugin to override the default form.

- API change: IIdentifiers are no longer required to put both 'login'
  and 'password' in a returned identity dictionary.  Instead, an
  IIdentifier can place arbitrary key/value pairs in the identity
  dictionary (or return an empty dictionary).

- API return value change: the "failure" identity which IIdentifiers
  return is now None rather than an empty dictionary.

- The IAuthenticator interface now specifies that IAuthenticators must
  not raise an exception when evaluating an identity that does not
  have "expected" key/value pairs (e.g. when an IAuthenticator that
  expects login and password inspects an identity returned by an
  IP-based auth system which only puts the IP address in the
  identity); instead they fail gracefully by returning None.

- Add (cookie) "auth_tkt" identification plugin.

- Stamp identity dictionaries with a userid by placing a key named
  'repoze.pam.userid' into the identity for each authenticated
  identity.

- If an IIdentifier plugin inserts a 'repoze.pam.userid' key into the
  identity dictionary, consider this identity "preauthenticated".  No
  authenticator plugins will be asked to authenticate this identity.
  This is designed for things like the recently added auth_tkt plugin,
  which embeds the user id into the ticket.  This effectively alllows
  an IIdentifier plugin to become an IAuthenticator plugin when
  breaking apart the responsibility into two separate plugins is
  "make-work".  Preauthenticated identities will be selected first
  when deciding which identity to use for any given request.

- Insert a 'repoze.pam.identity' key into the WSGI environment on
  ingress if an identity is found.  Its value will be the identity
  dictionary related to the identity selected by repoze.pam on
  ingress.  Downstream consumers are allowed to mutate this
  dictionary; this value is passed to "remember" and "forget", so its
  main use is to do a "credentials reset"; e.g. a user has changed his
  username or password within the application, but we don't want to
  force him to log in again after he does so.


0.4 (03-07-2008)
----------------

- Allow plugins to specify a classifiers list per interface (instead
  of a single classifiers list per plugin).


0.3 (03-05-2008)
----------------

- Make SQLAuthenticatorPlugin's default_password_compare use hexdigest
  sha instead of base64'ed binary sha for simpler conversion.


0.2 (03-04-2008)
----------------

- Added SQLAuthenticatorPlugin (see plugins/sql.py).


0.1 (02-27-2008)
----------------

- Initial release (no configuration file support yet).


