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NAME

       Catalyst::Plugin::Authentication - Infrastructure plugin for the Catalyst authentication
       framework.

SYNOPSIS

           use Catalyst qw/
               Authentication
           /;

           # later on ...
           $c->authenticate({ username => 'myusername',
                              password => 'mypassword' });
           my $age = $c->user->get('age');
           $c->logout;

DESCRIPTION

       The authentication plugin provides generic user support for Catalyst apps. It is the basis
       for both authentication (checking the user is who they claim to be), and authorization
       (allowing the user to do what the system authorises them to do).

       Using authentication is split into two parts. A Store is used to actually store the user
       information, and can store any amount of data related to the user. Credentials are used to
       verify users, using information from the store, given data from the frontend. A Credential
       and a Store are paired to form a 'Realm'. A Catalyst application using the authentication
       framework must have at least one realm, and may have several.

       To implement authentication in a Catalyst application you need to add this module, and
       specify at least one realm in the configuration.

       Authentication data can also be stored in a session, if the application is using the
       Catalyst::Plugin::Session module.

       NOTE in version 0.10 of this module, the interface to this module changed.  Please see
       "COMPATIBILITY ROUTINES" for more information.

INTRODUCTION

   The Authentication/Authorization Process
       Web applications typically need to identify a user - to tell the user apart from other
       users. This is usually done in order to display private information that is only that
       user's business, or to limit access to the application so that only certain entities can
       access certain parts.

       This process is split up into several steps. First you ask the user to identify
       themselves. At this point you can't be sure that the user is really who they claim to be.

       Then the user tells you who they are, and backs this claim with some piece of information
       that only the real user could give you. For example, a password is a secret that is known
       to both the user and you. When the user tells you this password you can assume they're in
       on the secret and can be trusted (ignore identity theft for now). Checking the password,
       or any other proof is called credential verification.

       By this time you know exactly who the user is - the user's identity is authenticated. This
       is where this module's job stops, and your application or other plugins step in.

       The next logical step is authorization, the process of deciding what a user is (or isn't)
       allowed to do. For example, say your users are split into two main groups - regular users
       and administrators. You want to verify that the currently logged in user is indeed an
       administrator before performing the actions in an administrative part of your application.
       These decisions may be made within your application code using just the information
       available after authentication, or it may be facilitated by a number of plugins.

   The Components In This Framework
       Realms

       Configuration of the Catalyst::Plugin::Authentication framework is done in terms of
       realms. In simplest terms, a realm is a pairing of a Credential verifier and a User
       storage (Store) backend. As of version 0.10003, realms are now objects that you can create
       and customize.

       An application can have any number of Realms, each of which operates independent of the
       others. Each realm has a name, which is used to identify it as the target of an
       authentication request. This name can be anything, such as 'users' or 'members'. One realm
       must be defined as the default_realm, which is used when no realm name is specified. More
       information about configuring realms is available in the configuration section.

       Credential Verifiers

       When user input is transferred to the Catalyst application (typically via form inputs) the
       application may pass this information into the authentication system through the
       "$c->authenticate()" method.  From there, it is passed to the appropriate Credential
       verifier.

       These plugins check the data, and ensure that it really proves the user is who they claim
       to be.

       Credential verifiers compatible with versions of this module 0.10x and upwards should be
       in the namespace "Catalyst::Authentication::Credential".

       Storage Backends

       The authentication data also identifies a user, and the Storage backend modules use this
       data to locate and return a standardized object-oriented representation of a user.

       When a user is retrieved from a store it is not necessarily authenticated.  Credential
       verifiers accept a set of authentication data and use this information to retrieve the
       user from the store they are paired with.

       Storage backends compatible with versions of this module 0.10x and upwards should be in
       the namespace "Catalyst::Authentication::Store".

       The Core Plugin

       This plugin on its own is the glue, providing realm configuration, session integration,
       and other goodness for the other plugins.

       Other Plugins

       More layers of plugins can be stacked on top of the authentication code. For example,
       Catalyst::Plugin::Session::PerUser provides an abstraction of browser sessions that is
       more persistent per user.  Catalyst::Plugin::Authorization::Roles provides an accepted way
       to separate and group users into categories, and then check which categories the current
       user belongs to.

EXAMPLE

       Let's say we were storing users in a simple Perl hash. Users are verified by supplying a
       password which is matched within the hash.

       This means that our application will begin like this:

           package MyApp;

           use Catalyst qw/
               Authentication
           /;

           __PACKAGE__->config( 'Plugin::Authentication' =>
                       {
                           default => {
                               credential => {
                                   class => 'Password',
                                   password_field => 'password',
                                   password_type => 'clear'
                               },
                               store => {
                                   class => 'Minimal',
                                   users => {
                                       bob => {
                                           password => "s00p3r",
                                           editor => 'yes',
                                           roles => [qw/edit delete/],
                                       },
                                       william => {
                                           password => "s3cr3t",
                                           roles => [qw/comment/],
                                       }
                                   }
                               }
                           }
                       }
           );

       This tells the authentication plugin what realms are available, which credential and store
       modules are used, and the configuration of each. With this code loaded, we can now attempt
       to authenticate users.

       To show an example of this, let's create an authentication controller:

           package MyApp::Controller::Auth;

           sub login : Local {
               my ( $self, $c ) = @_;

               if (    my $user     = $c->req->params->{user}
                   and my $password = $c->req->params->{password} )
               {
                   if ( $c->authenticate( { username => $user,
                                            password => $password } ) ) {
                       $c->res->body( "hello " . $c->user->get("name") );
                   } else {
                       # login incorrect
                   }
               }
               else {
                   # invalid form input
               }
           }

       This code should be self-explanatory. If all the necessary fields are supplied, call the
       "authenticate" method on the context object. If it succeeds the user is logged in.

       The credential verifier will attempt to retrieve the user whose details match the
       authentication information provided to "$c->authenticate()". Once it fetches the user the
       password is checked and if it matches the user will be authenticated and "$c->user" will
       contain the user object retrieved from the store.

       In the above case, the default realm is checked, but we could just as easily check an
       alternate realm. If this were an admin login, for example, we could authenticate on the
       admin realm by simply changing the "$c->authenticate()" call:

           if ( $c->authenticate( { username => $user,
                                    password => $password }, 'admin' ) ) {
               $c->res->body( "hello " . $c->user->get("name") );
           } ...

       Now suppose we want to restrict the ability to edit to a user with an 'editor' value of
       yes.

       The restricted action might look like this:

           sub edit : Local {
               my ( $self, $c ) = @_;

               $c->detach("unauthorized")
                 unless $c->user_exists
                 and $c->user->get('editor') eq 'yes';

               # do something restricted here
           }

       (Note that if you have multiple realms, you can use "$c->user_in_realm('realmname')" in
       place of "$c->user_exists();" This will essentially perform the same verification as
       user_exists, with the added requirement that if there is a user, it must have come from
       the realm specified.)

       The above example is somewhat similar to role based access control.
       Catalyst::Authentication::Store::Minimal treats the roles field as an array of role names.
       Let's leverage this. Add the role authorization plugin:

           use Catalyst qw/
               ...
               Authorization::Roles
           /;

           sub edit : Local {
               my ( $self, $c ) = @_;

               $c->detach("unauthorized") unless $c->check_user_roles("edit");

               # do something restricted here
           }

       This is somewhat simpler and will work if you change your store, too, since the role
       interface is consistent.

       Let's say your app grows, and you now have 10,000 users. It's no longer efficient to
       maintain a hash of users, so you move this data to a database.  You can accomplish this
       simply by installing the DBIx::Class Store and changing your config:

           __PACKAGE__->config( 'Plugin::Authentication' =>
                           {
                               default_realm => 'members',
                               members => {
                                   credential => {
                                       class => 'Password',
                                       password_field => 'password',
                                       password_type => 'clear'
                                   },
                                   store => {
                                       class => 'DBIx::Class',
                                       user_model => 'MyApp::Users',
                                       role_column => 'roles',
                                   }
                               }
                           }
           );

       The authentication system works behind the scenes to load your data from the new source.
       The rest of your application is completely unchanged.

CONFIGURATION

           # example
           __PACKAGE__->config( 'Plugin::Authentication' =>
                       {
                           default_realm => 'members',

                           members => {
                               credential => {
                                   class => 'Password',
                                   password_field => 'password',
                                   password_type => 'clear'
                               },
                               store => {
                                   class => 'DBIx::Class',
                                   user_model => 'MyApp::Users',
                                   role_column => 'roles',
                               }
                           },
                           admins => {
                               credential => {
                                   class => 'Password',
                                   password_field => 'password',
                                   password_type => 'clear'
                               },
                               store => {
                                   class => '+MyApp::Authentication::Store::NetAuth',
                                   authserver => '192.168.10.17'
                               }
                           }
                       }
           );

       NOTE: Until version 0.10008 of this module, you would need to put all the realms inside a
       "realms" key in the configuration. Please see "COMPATIBILITY CONFIGURATION" for more
       information

       use_session
           Whether or not to store the user's logged in state in the session, if the application
           is also using Catalyst::Plugin::Session. This value is set to true per default.

           However, even if use_session is disabled, if any code touches $c->session, a session
           object will be auto-vivified and session Cookies will be sent in the headers. To
           prevent accidental session creation, check if a session already exists with if
           ($c->sessionid) { ... }. If the session doesn't exist, then don't place anything in
           the session to prevent an unecessary session from being created.

       default_realm
           This defines which realm should be used as when no realm is provided to methods that
           require a realm such as authenticate or find_user.

       realm refs
           The Plugin::Authentication config hash contains the series of realm configurations you
           want to use for your app. The only rule here is that there must be at least one. A
           realm consists of a name, which is used to reference the realm, a credential and a
           store.  You may also put your realm configurations within a subelement called 'realms'
           if you desire to separate them from the remainder of your configuration.  Note that if
           you use a 'realms' subelement, you must put ALL of your realms within it.

           You can also specify a realm class to instantiate instead of the default
           Catalyst::Authentication::Realm class using the 'class' element within the realm
           config.

           Each realm config contains two hashes, one called 'credential' and one called 'store',
           each of which provide configuration details to the respective modules.  The contents
           of these hashes is specific to the module being used, with the exception of the
           'class' element, which tells the core Authentication module the classname to
           instantiate.

           The 'class' element follows the standard Catalyst mechanism of class specification. If
           a class is prefixed with a +, it is assumed to be a complete class name. Otherwise it
           is considered to be a portion of the class name. For credentials, the classname
           'Password', for example, is expanded to
           Catalyst::Authentication::Credential::Password. For stores, the classname 'storename'
           is expanded to: Catalyst::Authentication::Store::storename.

METHODS

   $c->authenticate( $userinfo [, $realm ])
       Attempts to authenticate the user using the information in the $userinfo hash reference
       using the realm $realm. $realm may be omitted, in which case the default realm is checked.

   $c->user( )
       Returns the currently logged in user, or undef if there is none.  Normally the user is re-
       retrieved from the store.  For Catalyst::Authentication::Store::DBIx::Class the user is
       re-restored using the primary key of the user table.  Thus user can throw an error even
       though user_exists returned true.

   $c->user_exists( )
       Returns true if a user is logged in right now. The difference between user_exists and user
       is that user_exists will return true if a user is logged in, even if it has not been yet
       retrieved from the storage backend. If you only need to know if the user is logged in,
       depending on the storage mechanism this can be much more efficient.  user_exists only
       looks into the session while user is trying to restore the user.

   $c->user_in_realm( $realm )
       Works like user_exists, except that it only returns true if a user is both logged in right
       now and was retrieved from the realm provided.

   $c->logout( )
       Logs the user out. Deletes the currently logged in user from "$c->user" and the session.
       It does not delete the session.

   $c->find_user( $userinfo, $realm )
       Fetch a particular users details, matching the provided user info, from the realm
       specified in $realm.

           $user = $c->find_user({ id => $id });
           $c->set_authenticated($user); # logs the user in and calls persist_user

   persist_user()
       Under normal circumstances the user data is only saved to the session during initial
       authentication.  This call causes the auth system to save the currently authenticated
       user's data across requests.  Useful if you have changed the user data and want to ensure
       that future requests reflect the most current data.  Assumes that at the time of this
       call, $c->user contains the most current data.

   find_realm_for_persisted_user()
       Private method, do not call from user code!

INTERNAL METHODS

       These methods are for Catalyst::Plugin::Authentication INTERNAL USE only.  Please do not
       use them in your own code, whether application or credential / store modules. If you do,
       you will very likely get the nasty shock of having to fix / rewrite your code when things
       change. They are documented here only for reference.

   $c->set_authenticated( $user, $realmname )
       Marks a user as authenticated. This is called from within the authenticate routine when a
       credential returns a user. $realmname defaults to 'default'.  You can use find_user to get
       $user

   $c->auth_restore_user( $user, $realmname )
       Used to restore a user from the session. In most cases this is called without arguments to
       restore the user via the session. Can be called with arguments when restoring a user from
       some other method.  Currently not used in this way.

   $c->auth_realms( )
       Returns a hashref containing realmname -> realm instance pairs. Realm instances contain an
       instantiated store and credential object as the 'store' and 'credential' elements,
       respectively

   $c->get_auth_realm( $realmname )
       Retrieves the realm instance for the realmname provided.

   $c->update_user_in_session
       This was a short-lived method to update user information - you should use persist_user
       instead.

   $c->setup_auth_realm( )

OVERRIDDEN METHODS

   $c->setup( )

SEE ALSO

       This list might not be up to date.  Below are modules known to work with the updated API
       of 0.10 and are therefore compatible with realms.

   Realms
       Catalyst::Authentication::Realm

   User Storage Backends
       Catalyst::Authentication::Store::Minimal
       Catalyst::Authentication::Store::DBIx::Class
       Catalyst::Authentication::Store::LDAP
       Catalyst::Authentication::Store::RDBO
       Catalyst::Authentication::Store::Model::KiokuDB
       Catalyst::Authentication::Store::Jifty::DBI
       Catalyst::Authentication::Store::Htpasswd

   Credential verification
       Catalyst::Authentication::Credential::Password
       Catalyst::Authentication::Credential::HTTP
       Catalyst::Authentication::Credential::OpenID
       Catalyst::Authentication::Credential::Authen::Simple
       Catalyst::Authentication::Credential::Flickr
       Catalyst::Authentication::Credential::Testing
       Catalyst::Authentication::Credential::AuthTkt
       Catalyst::Authentication::Credential::Kerberos

   Authorization
       Catalyst::Plugin::Authorization::ACL, Catalyst::Plugin::Authorization::Roles

   Internals Documentation
       Catalyst::Plugin::Authentication::Internals

   Misc
       Catalyst::Plugin::Session, Catalyst::Plugin::Session::PerUser

DON'T SEE ALSO

       This module along with its sub plugins deprecate a great number of other modules. These
       include Catalyst::Plugin::Authentication::Simple, Catalyst::Plugin::Authentication::CDBI.

INCOMPATABILITIES

       The realms-based configuration and functionality of the 0.10 update of
       Catalyst::Plugin::Authentication required a change in the API used by credentials and
       stores.  It has a compatibility mode which allows use of modules that have not yet been
       updated. This, however, completely mimics the older api and disables the new realm-based
       features. In other words you cannot mix the older credential and store modules with
       realms, or realm-based configs. The changes required to update modules are relatively
       minor and are covered in Catalyst::Plugin::Authentication::Internals.  We hope that most
       modules will move to the compatible list above very quickly.

COMPATIBILITY CONFIGURATION

       Until version 0.10008 of this module, you needed to put all the realms inside a "realms"
       key in the configuration.

           # example
           __PACKAGE__->config( 'Plugin::Authentication' =>
                       {
                           default_realm => 'members',
                           realms => {
                               members => {
                                   ...
                               },
                           },
                       }
           );

       If you use the old, deprecated "__PACKAGE__->config( 'authentication' )" configuration
       key, then the realms key is still required.

COMPATIBILITY ROUTINES

       In version 0.10 of Catalyst::Plugin::Authentication, the API changed. For app developers,
       this change is fairly minor, but for Credential and Store authors, the changes are
       significant.

       Please see the documentation in version 0.09 of Catalyst::Plugin::Authentication for a
       better understanding of how the old API functioned.

       The items below are still present in the plugin, though using them is deprecated. They
       remain only as a transition tool, for those sites which can not yet be upgraded to use the
       new system due to local customizations or use of Credential / Store modules that have not
       yet been updated to work with the new API.

       These routines should not be used in any application using realms functionality or any of
       the methods described above. These are for reference purposes only.

   $c->login( )
       This method is used to initiate authentication and user retrieval. Technically this is
       part of the old Password credential module and it still resides in the Password class. It
       is included here for reference only.

   $c->default_auth_store( )
       Return the store whose name is 'default'.

       This is set to "$c->config( 'Plugin::Authentication' => { store => # Store} )" if that
       value exists, or by using a Store plugin:

           # load the Minimal authentication store.
           use Catalyst qw/Authentication Authentication::Store::Minimal/;

       Sets the default store to Catalyst::Plugin::Authentication::Store::Minimal.

   $c->get_auth_store( $name )
       Return the store whose name is $name.

   $c->get_auth_store_name( $store )
       Return the name of the store $store.

   $c->auth_stores( )
       A hash keyed by name, with the stores registered in the app.

   $c->register_auth_stores( %stores_by_name )
       Register stores into the application.

   $c->auth_store_names( )
   $c->get_user( )

SUPPORT

       Please use the rt.cpan.org bug tracker, and git patches are wecome.

       Questions on usage should be directed to the Catalyst mailing list or the #catalyst irc
       channel.

AUTHORS

       Yuval Kogman, "nothingmuch@woobling.org" - original author

       Jay Kuri, "jayk@cpan.org" - Large rewrite

PRIMARY MAINTAINER

       Tomas Doran (t0m), "bobtfish@bobtfish.net"

ADDITIONAL CONTRIBUTORS

       Jess Robinson
       David Kamholz
       kmx
       Nigel Metheringham
       Florian Ragwitz "rafl@debian.org"
       Stephan Jauernick "stephanj@cpan.org"
       Oskari Ojala (Okko), "perl@okko.net"
       John Napiorkowski (jnap) "jjnapiork@cpan.org"

COPYRIGHT & LICENSE

       Copyright (c) 2005 - 2012 the Catalyst::Plugin::Authentication "AUTHORS", "PRIMARY
       MAINTAINER" and "ADDITIONAL CONTRIBUTORS" as listed above.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.