Plack::Middleware::Auth::WebID - authentication middleware for WebID
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; };
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.
$env->{WEBID}
$env->{WEBID_OBJECT}
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.
get
set
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.)
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.
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.
new
The key within $env where Plack::Middleware::Auth::WebID can find a PEM-encoded client SSL certificate.
$env
Apache keeps this information in $env->{'SSL_CLIENT_CERT'}, so it should be no surprise that this setting defaults to 'SSL_CLIENT_CERT'.
$env->{'SSL_CLIENT_CERT'}
Suppresses setting $env->{WEBID_OBJECT}. $env->{WEBID} will still be set as usual.
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.
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.
ExportCertData
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.
Please report any bugs to http://rt.cpan.org/Dist/Display.html?Queue=Web-ID.
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.
Toby Inkster <tobyink@cpan.org>.
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.
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.
To install Web::ID, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Web::ID
CPAN shell
perl -MCPAN -e shell install Web::ID
For more information on module installation, please visit the detailed CPAN module installation guide.