NAME

       Plack::Middleware::Auth::WebID - authentication middleware for WebID

SYNOPSIS

         use Plack::Builder;

         my $app   = sub { ... };
         my $cache = CHI->new( ... );

         sub unauthenticated
         {
           my ($self, $env) = @_;
           return [
             403,
             [ 'Content-Type' => 'text/plain' ],
             [ '403 Forbidden' ],
           ];
         }

         builder
         {
           enable "Auth::WebID",
               cache     => $cache,
               on_unauth => \&unauthenticated;
           $app;
         };

DESCRIPTION

       Plack::Middleware::Auth::WebID is a WebID handler for Plack.

       If authentication is successful, then the handler sets "$env->{WEBID}" to the user's WebID
       URI, and sets "$env->{WEBID_OBJECT}" to a Web::ID object.

CONFIGURATION

       cache
           This may be set to an object that will act as a cache for Web::ID objects.

           Plack::Middleware::Auth::WebID does not care what package you use for your caching
           needs. CHI, Cache::Cache and Cache should all work. In fact, any package that provides
           a similar one-argument "get" and a two-argument "set" ought to work. Which should you
           use? Well CHI seems to be best, however it's Moose-based, so usually too slow for CGI
           applications. Use Cache::Cache for CGI, and CHI otherwise.

           You don't need to set a cache at all, but if there's no cache, then reauthentication
           (which is computationally expensive) happens for every request. Use of a cache with an
           expiration time of around 15 minutes should significantly speed up the responsiveness
           of a WebID-secured site. (For forking servers you probably want a cache that is shared
           between processes, such as a memcached cache.)

       on_unauth
           Coderef that will be called if authentication is not successful. You can use this to
           return a "403 Forbidden" page for example, or try an alternative authentication
           method.

           The default coderef used will simply run the application as normal, but setting
           "$env->{WEBID}" to the empty string.

       webid_class
           Name of an alternative class to use for WebID authentication instead of Web::ID. Note
           that any such class would need to provide a compatible "new" constructor.

       certificate_env_key
           The key within $env where Plack::Middleware::Auth::WebID can find a PEM-encoded client
           SSL certificate.

           Apache keeps this information in "$env->{'SSL_CLIENT_CERT'}", so it should be no
           surprise that this setting defaults to 'SSL_CLIENT_CERT'.

       no_object_please
           Suppresses setting "$env->{WEBID_OBJECT}". "$env->{WEBID}" will still be set as usual.

SERVER SUPPORT

       WebID is an authentication system based on the Semantic Web and HTTPS.  It relies on
       client certificates (but not on certification authorities; self-signed certificates are
       OK).

       So for this authentication module to work...

       •   You need to be using a server which supports HTTPS.

           Many web PSGI web servers (e.g. HTTP::Server::Simple, Starman, etc) do not support
           HTTPS natively. In some cases these are used with an HTTPS proxy in front of them.

       •   Your HTTPS server needs to request a client certificate from the client.

       •   Your HTTPS server needs to expose the client certificate to Plack via $env.

           If you're using an HTTPS proxy in front of a non-HTTPS web server, then you might need
           to be creative to find a way to forward this information to your backend web server.

       •   The client browser needs to have a WebID-compatible certificate installed.

           Nuff said.

   Apache2 (mod_perl and CGI)
       The SSLVerifyClient directive can be used to tell Apache that you want it to request a
       certificate from the client.

       Apache is able to deposit the certifcate in an environment variable called
       SSL_CLIENT_CERT. However by default it might not. Check out the SSLOptions directive and
       enable the "ExportCertData" option, or if you're using mod_perl try
       Plack::Middleware::Apache2::ModSSL.

   Gepok
       Gepok is one of a very small number of PSGI-compatible web servers that supports HTTPS
       natively. As of 0.20 it will request client certificates, but you will need to use
       Plack::Middleware::GepokX::ModSSL in order to make the certificate available in the PSGI
       $env hashref.

BUGS

       Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=Web-ID>.

SEE ALSO

       Plack, Web::ID, Web::ID::FAQ.

       General WebID information: <http://webid.info/>, <http://www.w3.org/wiki/WebID>,
       <http://www.w3.org/2005/Incubator/webid/spec/>,
       <http://lists.foaf-project.org/mailman/listinfo/foaf-protocols>.

       Apache mod_ssl: Plack::Middleware::Apache2::ModSSL, Apache2::ModSSL,
       <http://httpd.apache.org/docs/2.0/mod/mod_ssl.html>.

       Gepok: Gepok, Plack::Middleware::GepokX::ModSSL.

AUTHOR

       Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

       This software is copyright (c) 2012 by Toby Inkster.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES

       THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
       WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
       PURPOSE.