Provided by: libcatalyst-plugin-authentication-perl_0.10023-2_all 
NAME
Catalyst::Authentication::Credential::Remote - Let the webserver (e.g. Apache)
authenticate Catalyst application users
SYNOPSIS
# in your MyApp.pm
__PACKAGE__->config(
'Plugin::Authentication' => {
default_realm => 'remoterealm',
realms => {
remoterealm => {
credential => {
class => 'Remote',
allow_regexp => '^(user.*|admin|guest)$',
deny_regexp => 'test',
},
store => {
class => 'Null',
# if you want to have some additional user attributes
# like user roles, user full name etc. you can specify
# here the store where you keep this data
}
},
},
},
);
# in your Controller/Root.pm you can implement "auto-login" in this way
sub begin : Private {
my ( $self, $c ) = @_;
unless ($c->user_exists) {
# authenticate() for this module does not need any user info
# as the username is taken from $c->req->remote_user and
# password is not needed
unless ($c->authenticate( {} )) {
# return 403 forbidden or kick out the user in other way
};
}
}
# or you can implement in any controller an ordinary login action like this
sub login : Global {
my ( $self, $c ) = @_;
$c->authenticate( {} );
}
DESCRIPTION
This module allows you to authenticate the users of your Catalyst application on
underlaying webserver. The complete list of authentication method available via this
module depends just on what your webserver (e.g. Apache, IIS, Lighttpd) is able to handle.
Besides the common methods like HTTP Basic and Digest authentication you can also use
sophisticated ones like so called "integrated authentication" via NTLM or Kerberos
(popular in corporate intranet applications running in Windows Active Directory
environment) or even the SSL authentication when users authenticate themself using their
client SSL certificates.
The main idea of this module is based on a fact that webserver passes the name of
authenticated user into Catalyst application as REMOTE_USER variable (or in case of SSL
client authentication in other variables like SSL_CLIENT_S_DN on Apache + mod_ssl) - from
this point referenced as WEBUSER. This module simply takes this value - perfoms some
optional checks (see below) - and if everything is OK the WEBUSER is declared as
authenticated on Catalyst level. In fact this module does not perform any check for
password or other credential; it simply believes the webserver that user was properly
authenticated.
CONFIG
class
This config item is REQUIRED.
class is part of the core Catalyst::Plugin::Authentication module, it contains the class
name of the store to be used.
The classname used for Credential. This is part of Catalyst::Plugin::Authentication and is
the method by which Catalyst::Authentication::Credential::Remote is loaded as the
credential validator. For this module to be used, this must be set to 'Remote'.
source
This config item is OPTIONAL - default is REMOTE_USER.
source contains a name of a variable passed from webserver that contains the user
identification.
Supported values: REMOTE_USER, SSL_CLIENT_*, CERT_*, AUTH_USER
BEWARE: Support for using different variables than REMOTE_USER does not work properly with
Catalyst 5.8004 and before (if you want details see source code).
Note1: Apache + mod_ssl uses SSL_CLIENT_S_DN, SSL_CLIENT_S_DN_* etc. (has to be enabled by
'SSLOption +StdEnvVars') or you can also let Apache make a copy of this value into
REMOTE_USER (Apache option 'SSLUserName SSL_CLIENT_S_DN').
Note2: Microsoft IIS uses CERT_SUBJECT, CERT_SERIALNUMBER etc. for storing info about
client authenticated via SSL certificate. AUTH_USER on IIS seems to have the same value as
REMOTE_USER (but there might be some differences I am not aware of).
deny_regexp
This config item is OPTIONAL - no default value.
deny_regexp contains a regular expression used for check against WEBUSER (see details
below)
allow_regexp
This config item is OPTIONAL - no default value.
deny_regexp contains a regular expression used for check against WEBUSER.
Allow/deny checking of WEBUSER values goes in this way:
1) If deny_regexp is defined and WEBUSER matches deny_regexp then authentication FAILS
otherwise continues with next step. If deny_regexp is not defined or is an empty string we
skip this step.
2) If allow_regexp is defined and WEBUSER matches allow_regexp then authentication PASSES
otherwise FAILS. If allow_regexp is not defined or is an empty string we skip this step.
The order deny-allow is fixed.
cutname_regexp
This config item is OPTIONAL - no default value.
If param cutname_regexp is specified we try to cut the final usename passed to Catalyst
application as a substring from WEBUSER. This is useful for example in case of SSL
authentication when WEBUSER looks like this 'CN=john, OU=Unit Name, O=Company, C=CZ' -
from this format we can simply cut pure usename by cutname_regexp set to 'CN=(.*), OU=Unit
Name, O=Company, C=CZ'.
Substring is always taken as '$1' regexp substring. If WEBUSER does not match
cutname_regexp at all or if '$1' regexp substring is empty we pass the original WEBUSER
value (without cutting) to Catalyst application.
username_field
This config item is OPTIONAL - default is username
The key name in the authinfo hash that the user's username is mapped into. This is useful
for using a store which requires a specific unusual field name for the username. The
username is additionally mapped onto the id key.
METHODS
new ( $config, $app, $realm )
Instantiate a new Catalyst::Authentication::Credential::Remote object using the
configuration hash provided in $config. In case of invalid value of any configuration
parameter (e.g. invalid regular expression) throws an exception.
authenticate ( $realm, $authinfo )
Takes the username form WEBUSER set by webserver, performs additional checks using
optional allow_regexp/deny_regexp configuration params, optionaly takes substring from
WEBUSER and the sets the resulting value as a Catalyst username.
COMPATIBILITY
It is strongly recommended to use this module with Catalyst 5.80005 and above as previous
versions have some bugs related to $c->engine->env and do not support
$c->req->remote_user.
This module tries some workarounds when it detects an older version and should work as
well.
USING WITH A REVERSE PROXY
If you are using a reverse proxy, then the WEBUSER will not be directly accessible by the
Catalyst server. To use remote authentication, you will have to modify the web server to
set a header containing the WEBUSER. You would then need to modify the PSGI configuration
to map the header back to the WEBUSER variable.
For example, in Apache you would add the configuration
RequestHeader unset X-Forwarded-User
RewriteEngine On
RewriteCond %{LA-U:REMOTE_USER} (.+)
RewriteRule . - [E=RU:%1]
RequestHeader set X-Forwarded-User %{RU}e
You then need to create a Plack::Middleware module to map the header back to the WEBUSER:
package Plack::Middleware::MyRemote;
use parent qw( Plack::Middleware );
use Plack::Util;
sub call {
my ($self, $env) = @_;
my $user = $env->{HTTP_X_FORWARDED_USER} // "";
$env->{REMOTE_USER} = $user
if ($user && ($user ne '(null)'));
my $res = $self->app->($env);
return $res;
}
1;
Finally, you need to modify myapp.psgi to use the custom middleware:
use strict;
use warnings;
use MyApp;
use Plack::Builder;
my $app = Drain->apply_default_middlewares(Drain->psgi_app);
builder {
enable "Plack::Middleware::MyRemote";
$app;
};
perl v5.18.2 2013Catalyst::Authentication::Credential::Remote(3pm)