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¶

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 unnecessary 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¶

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

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.

OVERRIDDEN METHODS¶

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.

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.

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

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.