repoze.who 2.0a3

repoze.who is an identification and authentication framework for WSGI.

``repoze.who`` -- WSGI Authentication Middleware / API
======================================================

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.

See the ``docs`` subdirectory of this package (also available at least
provisionally at http://static.repoze.org/whodocs) for more
information.


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

2.0a3 (2010-09030)
------------------

- 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).