Theo van Hoesel
and 1 contributors

NAME

Dancer2::Plugin::HTTP::Auth::Extensible - extensible authentication framework for Dancer2 apps

DESCRIPTION

A user authentication and authorisation framework plugin for Dancer2 apps.

Makes it easy to require a user to be logged in to access certain routes, provides role-based access control, and supports various authentication methods/sources (config file, database, Unix system users, etc).

Designed to support multiple authentication realms and to be as extensible as possible, and to make secure password handling easy (the base class for auth providers makes handling RFC2307-style hashed passwords really simple, so you have no excuse for storing plain-text passwords).

SYNOPSIS

Configure the plugin to use the authentication provider class you wish to use:

  plugins:
        HTTP::Auth::Extensible:
            realms:
                users:
                    provider: Example
                    ....

The configuration you provide will depend on the authentication provider module in use. For a simple example, see Dancer2::Plugin::Auth::Extensible::Provider::Config.

Define that a user must be logged in and have the proper permissions to access a route:

    get '/secret' => http_require_role Confidant => sub { tell_secrets(); };

Define that a user must be logged in to access a route - and find out who is logged in with the logged_in_user keyword:

    get '/users' => http_require_authentication sub {
        my $user = http_authenticated_user;
        return "Hi there, $user->{username}";
    };

AUTHENTICATION PROVIDERS

This framework builds on top of Dancer2::Plugin::Auth::Extensible. For a full explenation of the providers check that manual.

For flexibility, that authentication framework uses simple authentication provider classes, which implement a simple interface and do whatever is required to authenticate a user against the chosen source of authentication.

For an example of how simple provider classes are, so you can build your own if required or just try out this authentication framework plugin easily, see Dancer2::Plugin::Auth::Extensible::Provider::Example.

That framework supplies the following providers out-of-the-box:

Dancer2::Plugin::Auth::Extensible::Provider::Unix

Authenticates users using system accounts on Linux/Unix type boxes

Dancer2::Plugin::Auth::Extensible::Provider::Database

Authenticates users stored in a database table

Dancer2::Plugin::Auth::Extensible::Provider::Config

Authenticates users stored in the app's config

Need to write your own? Just subclass Dancer2::Plugin::Auth::Extensible::Provider::Base and implement the required methods, and you're good to go!

CONTROLLING ACCESS TO ROUTES

Keywords are provided to check if a user is logged in / has appropriate roles.

http_require_authentication - require the user to be authenticated
    get '/dashboard' => http_require_authentication sub { .... };

If the user can not be authenticated, they will be recieve a HTTP response status of /401 Not Authorized. Remember, it should actualy say 'Not Authenticated'.

Optionally, a realm name can be specified as an extra argument:

    get 'outer_space'
        => http_require_authentication 'outer_space'
        => sub { .... };
http_require_role - require the user to have a specified role
    get '/beer' => http_require_role BeerDrinker => sub { ... };

Requires that the user can be authenticated as a user who has the specified role. If the user can not be authenticated, they will get a 401 Unautorized response. If they are logged in, but do not have the required role, they will recieve a 403 Forbidden response.

http_require_any_roles - require the user to have one of a list of roles
    get '/drink' => require_any_role [qw(BeerDrinker VodaDrinker)] => sub {
        ...
    };

Same as http_require_role except that a user has any one (or more) of the roles listed.

require_all_roles - require the user to have all roles listed
    get '/foo' => require_all_roles [qw(Foo Bar)] => sub { ... };

Same as http_require_role except that a user has all of the roles listed.

Replacing the Default 401 and 403 Pages

Keywords

http_require_authentication

Used to wrap a route which requires a user can be authenticated to access it.

    get '/secret' => http_require_authentication sub { .... };
    get '/secret' => http_require_authentication 'realm-name' sub { .... };
require_role

Used to wrap a route which requires a user can be authenticated with the specified role in order to access it.

    get '/beer' => require_role BeerDrinker => sub { ... };
    get '/beer' => require_role BeerDrinker 'realm-name' => sub { ... };

You can also provide a regular expression, if you need to match the role using a regex - for example:

    get '/beer' => http_require_role qr/Drinker$/ => sub { ... };
http_require_any_role

Used to wrap a route which requires a user can be authenticated with any one (or more) of the specified roles in order to access it.

    get '/foo' => http_require_any_role [qw(Foo Bar)] => sub { ... };
    get '/foo' => http_require_any_role [qw(Foo Bar)] 'realm-name' => sub { ... };
http_require_all_roles

Used to wrap a route which requires a user can be authenticated with all of the roles listed in order to access it.

    get '/foo' => http_require_all_roles [qw(Foo Bar)] => sub { ... };
    get '/foo' => http_require_all_roles [qw(Foo Bar)] 'realm-name' => sub { ... };
authenticated_user

Returns a hashref of details of the currently authenticated user, if there is one.

The details you get back will depend upon the authentication provider in use.

user_has_role

Check if a user has the role named.

By default, the currently-logged-in user will be checked, so you need only name the role you're looking for:

    if (user_has_role('BeerDrinker')) { pour_beer(); }

You can also provide the username to check;

    if (user_has_role($user, $role)) { .... }
user_roles

Returns a list of the roles of a user.

By default, roles for the currently-logged-in user will be checked; alternatively, you may supply a username to check.

Returns a list or arrayref depending on context.

authenticate_user

Usually you'll want to let the built-in authentication handling code deal with authenticating users, but in case you need to do it yourself, this keyword accepts a username and password, and optionally a specific realm, and checks whether the username and password are valid.

For example:

    if (authenticate_user($username, $password)) {
        ...
    }

If you are using multiple authentication realms, by default each realm will be consulted in turn. If you only wish to check one of them (for instance, you're authenticating an admin user, and there's only one realm which applies to them), you can supply the realm as an optional third parameter.

In boolean context, returns simply true or false; in list context, returns ($success, $realm).

http_username - gets or sets the name of the authenticated user

WARNING: setting the username will issue a "SECURITY BREACH" warning. You rarely want to impersonate another user.

    $my username = http_username;
    http_username('new name');
    http_username 'new name';

If not inside an authenticated route (there is no authenticated user), http_username returns undef.

http_realm - gets or sets the real of the current request

WARNING: setting the realm will issue a "SECURITY BREACH" warning. You rarely want to switch to another realm

    $my realm = http_realm;
    http_realm('new name');
    http_realm 'new name';

If not inside an authenticated route (there is no authenticated user), http_realm returns undef.

SAMPLE CONFIGURATION

In your application's configuation file:

    plugins:
        HTTP::Auth::Extensible:
            # Set to 1 if you want to disable the use of roles (0 is default)
            disable_roles: 0
            # After /login: If no return_url is given: land here ('/' is default)
            user_home_page: '/user'
            # After /logout: If no return_url is given: land here (no default)
            exit_page: '/'
            
            # List each authentication realm, with the provider to use and the
            # provider-specific settings (see the documentation for the provider
            # you wish to use)
            realms:
                realm_one:
                    provider: Database
                        db_connection_name: 'foo'
            
            default_realm: realm_xxx
            # If there is more than one realm, is needed if no 'realm' is
            # specified in http_requires_authentication.

Please note that you not have to have a session provider configured. The authentication framework does not require sessions in order to track information about the currently logged in user.

AUTHOR

Theo van Hoesel, <Th.J.v.Hoesel at THEMA-MEDIA dot nl>

HTTP Autneticate implementation based on:

David Precious, <davidp at preshweb.co.uk>

Dancer2 port of Dancer::Plugin::Auth::Extensible by:

Stefan Hornburg (Racke), <racke at linuxia.de>

BUGS / FEATURE REQUESTS

This is an early version; there may still be bugs present or features missing.

This is developed on GitHub - please feel free to raise issues or pull requests against the repo at: https://github.com/THEMA-MEDIA/Dancer2-Plugin-HTTP-Auth-Extensible

ACKNOWLEDGEMENTS

Valuable feedback on the early design of this module came from many people, including Matt S Trout (mst), David Golden (xdg), Damien Krotkine (dams), Daniel Perrett, and others.

Configurable login/logout URLs added by Rene (hertell)

Regex support for require_role by chenryn

Support for user_roles looking in other realms by Colin Ewen (casao)

LDAP provider added by Mark Meyer (ofosos)

Config options for default login/logout handlers by Henk van Oers (hvoers)

LICENSE AND COPYRIGHT

Copyright 2014 THEMA-MEDIA, Th.J. van Hoesel

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.