Authorization framework for cgi::application
use base qw(CGI::Application);
use CGI::Application::Plugin::Authentication;
use CGI::Application::Plugin::Authorization;
# default config for runmode authorization
_\|_PACKAGE_\|_->authz->config(
DRIVER => [ 'HTGroup', FILE => 'htgroup' ],
);
# Using a named configuration to distinguish it from
# the above configuration
_\|_PACKAGE_\|_->authz('dbaccess')->config(
DRIVER => [ 'DBI',
DBH => $self->dbh,
TABLES => ['user', 'access'],
JOIN_ON => 'user.id = access.user_id',
CONSTRAINTS => {
'user.name' => '_\|_USERNAME_\|_',
'access.table' => '_\|_PARAM_1_\|_',
'access.item_id' => '_\|_PARAM_2_\|_'
}
],
);
sub admin_runmode {
my $self = shift;
# User must be in the admin group to have access to this runmode
return $self->authz->forbidden unless $self->authz->authorize('admin');
# rest of the runmode
...
}
sub update_widget {
my $self = shift;
my $widget = $self->query->param('widget_id');
# Can this user edit this widget in the widgets table?
return $self->authz->forbidden unless $self->authz('dbaccess')->authorize(widgets => $widget);
# save changes to the widget
...
}
CGI::Application::Plugin::Authorization adds the ability to authorize users for specific tasks. Once a user has been authenticated and you know who you are dealing with, you can then use this plugin to control what that user has access to. It imports two methods (\*(C`authz\*(C' and \*(C`authorization\*(C') into your CGI::Application module. Both of these methods are interchangeable, so you should choose one and use it consistently throughout your code. Through the authz method you can call all the methods of the CGI::Application::Plugin::Authorization plugin.
There could be multiple ways that you may want to authorize actions in different parts of your code. These differences may conflict with each other. For example you may have runmode level authorization that requires that the user belongs to a certain group. But secondly, you may have row level database authorization that requires that the username column of the table contains the name of the current user. These configurations would conflict with each other since they are authorizing using different information. To solve this you can create multiple named configurations, by specifying a unique name to the c<authz> method.
_\|_PACKAGE_\|_->authz('dbaccess')->config( DRIVER => [ 'DBI', ... ], ); # later $self->authz('dbaccess')->authorize(widgets => $widget_id);
These methods are interchangeable and provided for users that either prefer brevity, or clarity. Everything is controlled through this method call, which will return a CGI::Application::Plugin::Authorization object, or just the class name if called as a class method. When using the plugin, you will always first call $self->authz or _\|_PACKAGE_\|_->authz and then the method you wish to invoke. You can create multiple named authorization modules by providing a unique name to the call to authz. This will allow you to handle different types of authorization in your modules. For example, you could use the main configuration to do runmode level authorization, and use a named configuration to manage database row level authorization.
This method is used to configure the CGI::Application::Plugin::Authorization module. It can be called as an object method, or as a class method.
The following parameters are accepted:
Here you can choose which authorization module(s) you want to use to perform the authorization. For simplicity, you can leave off the CGI::Application::Plugin::Authorization::Driver:: part when specifying the \s-1DRIVER\s0 parameter. If this module requires extra parameters, you can pass an array reference that contains as the first parameter the name of the module, and the required parameters as the rest of the array. You can provide multiple drivers which will be used, in order, to check the permissions until a valid response is received. DRIVER => [ 'DBI', dbh => $self->dbh ],
- or -
DRIVER => [ [ 'HTGroup', file => '.htgroup' ], [ 'LDAP', binddn => '...', host => 'localhost', ... ] ],
Here you can specify a runmode that the user will be redirected to if they fail the authorization checks. FORBIDDEN_RUNMODE => 'forbidden'
If your forbidden page is external to this module, then you can use this option to specify a \s-1URL\s0 that the user will be redirected to when they fail the authorization checks. If both \s-1FORBIDDEN_URL\s0 and \s-1FORBIDDEN_RUNMODE\s0 are specified, then the latter will take precedence. FORBIDDEN_URL => 'http://example.com/forbidden.html'
This option allows you to provide a method that should return us the username of the currently logged in user. It will be passed the current authz objects as the only parameter. This is not a required option, and can be omitted if you use the Authentication plugin, or if your authentication system sets $ENV{\s-1REMOTE_USER\s0}. GET_USERNAME => sub { my $authz = shift; return $authz->cgiapp->my_username }
This method takes a list of runmodes that are to be authorized, and the authorization rules for said runmodes. If a user tries to access one of these runmodes, then they will be redirected to the forbidden page unless authorization is granted.
The runmode names can be simple strings, regular expressions, coderefs (which are passed the name of the runmode as their only parameter), or special directives that start with a colon.
The authorization rules can be simple strings representing the name of the group that the user must be a member of, as a list-ref of group names (of which the user only has to be a member of any one of the groups, or as a code-ref that will be called (with no parameters).
This method is cumulative, so if it is called multiple times, the new values are appended to the list of existing entries. It returns a list containing all of the entries that have been configured thus far.
\s-1NOTE:\s0 compatibility with the interface as was defined in 0.06 is preserved. 0.06 allowed for runmodes to be passed in as a list-ref of two-element lists to specify authorization rules. Although this interface is supported, the extra list-refs aren't necessary.
# match all runmodes _\|_PACKAGE_\|_->authz->authz_runmodes( ':all' => 'admin', );
# only protect runmodes one and two _\|_PACKAGE_\|_->authz->authz_runmodes( one => 'admin', two => 'admin', );
# protect only runmodes that start with auth_ _\|_PACKAGE_\|_->authz->authz_runmodes( qr/^authz_/ => 'admin', );
# protect all runmodes that *do not* start with public_ _\|_PACKAGE_\|_->authz->authz_runmodes( qr/^(?!public_)/ => 'admin', );
# preserve the interface from 0.06: _\|_PACKAGE_\|_->authz->authz_runmodes( [':all' => 'admin'], );
This method accepts the name of a runmode, and if that runmode requires authorization (ie the user needs to be a member of a particular group or has to satisfy some other authorization rule) then this method returns the corresponding authorization rule which must be satisfied (which could be either a scalar, a list-ref, or a code-ref, depending on how the rules were defined).
This method creates a new CGI::Application::Plugin::Authorization object. It requires as it's only parameter a CGI::Application object. This method should never be called directly, since the \*(C`authz\*(C' method that is imported into the CGI::Application module will take care of creating the CGI::Application::Plugin::Authorization object when it is required.
This method works the same way as \*(C`new\*(C', except that it returns the same Authorization object for the duration of the request. This method should never be called directly, since the \*(C`authz\*(C' method that is imported into the CGI::Application module will take care of creating the CGI::Application::Plugin::Authorization object when it is required.
This method will test to see if the current user has access to the given resource. It will take the given parameters and test them against the \s-1DRIVER\s0 classes that have been configured. A true return value means the user should have access to the given resource.
# is the current user in the admin group if ($self->authz->authorize('admingroup')) { # perform an admin action }
This method will return the name of the currently logged in user. It uses three different methods to figure out the username:
Use the subroutine provided by the \s-1GET_USERNAME\s0 option to figure out the current username
See if the CGI::Application::Plugin::Authentication plugin is being used, and retrieve the username through this plugin
See if the \s-1REMOTE_USER\s0 environment variable is set and use that value
This method will return a list of driver objects that are used for this authorization instance.
This will return the underlying CGI::Application object.
This method is called during the prerun stage to register some custom runmodes that the Authentication plugin requires in order to function.
We'll automatically add the \*(C`authz_forbidden\*(C' run mode if you are using CGI::Application 4.0 or greater.
If you are using an older version of CGI::Application you will need to add it yourself.
sub cgiapp_prerun { my $self = shift;
$self->run_modes( authz_forbidden => \&CGI::Application::Plugin::Authorization::authz_forbidden, ); }
This method is a CGI::Application prerun callback that will be automatically registered for you if you are using CGI::Application 4.0 or greater. If you are using an older version of CGI::Application you will have to create your own cgiapp_prerun method and make sure you call this method from there.
sub cgiapp_prerun { my $self = shift;
$self->CGI::Application::Plugin::Authorization::prerun_callback(); }
This method is be called during the prerun stage if the current user is not authorized, and they are trying to access an authz runmode. It will redirect to the page that has been configured as the forbidden page, based on the value of \s-1FORBIDDEN_RUNMODE\s0 or \s-1FORBIDDEN_URL\s0 If nothing is configured then the default forbidden page will be used.
This will return a forbidden page. It checks the configuration to see if there is a custom runmode or \s-1URL\s0 to redirect to, otherwise it calls the builtin authz_forbidden runmode.
This runmode is provided if you do not want to create your own forbidden runmode. It will display a simple error page to the user.
This runmode is provided for convenience when an external redirect needs to be done. It just returns an empty string.
In a CGI::Application module:
package MyCGIApp;
use base qw(CGI::Application); use CGI::Application::Plugin::AutoRunmode; use CGI::Application::Plugin::Authentication; use CGI::Application::Plugin::Authorization;
# Configure Authentication MyCGIApp->authen->config( DRIVER => 'Dummy', ); MyCGIApp->authen->protected_runmodes(qr/^admin_/);
# Configure Authorization (manages runmode authorization) MyCGIApp->authz->config( DRIVER => [ 'DBI', DBH => $self->dbh, TABLES => ['user', 'usergroup', 'group'], JOIN_ON => 'user.id = usergroup.user_id AND usergroup.group_id = group.id', CONSTRAINTS => { 'user.name' => '_\|_USERNAME_\|_', 'group.name' => '_\|_GROUP_\|_', } ], ); MyCGIApp->authz->authz_runmodes( [a_runmode => 'a_group'], [qr/^admin_/ => 'admin'], [':all' => 'all_group'], [sub {my $rm = shift; return ($rm eq "dangerous_rm")} => 'super_group'], );
# Configure second Authorization module using a named configuration _\|_PACKAGE_\|_->authz('dbaccess')->config( DRIVER => [ 'DBI', DBH => $self->dbh, TABLES => ['user', 'access'], JOIN_ON => 'user.id = access.user_id', CONSTRAINTS => { 'user.name' => '_\|_USERNAME_\|_', 'access.table' => '_\|_PARAM_1_\|_', 'access.item_id' => '_\|_PARAM_2_\|_' } ], );
sub start : Runmode { my $self = shift;
}
sub admin_one : Runmode { my $self = shift; # The user will only get here if they are logged in and # belong to the admin group
}
sub admin_widgets : Runmode { my $self = shift; # The user will only get here if they are logged in and # belong to the admin group
# Can this user edit this widget in the widgets table? my $widget_id = $self->query->param('widget_id'); return $self->authz->forbidden unless $self->authz('dbaccess')->authorize(widgets => $widget_id);
}
The module is definitely in a usable state, but there are still some parts missing that I would like to add in:
This is alpha software and as such, the features and interface are subject to change. So please check the Changes file when upgrading.
CGI::Application::Plugin::Authentication, CGI::Application, perl\|(1)
Cees Hek <[email protected]>
Thanks to SiteSuite (http://www.sitesuite.com.au) for funding the development of this plugin and for releasing it to the world.
Copyright (c) 2005, SiteSuite. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
\s-1BECAUSE\s0 \s-1THIS\s0 \s-1SOFTWARE\s0 \s-1IS\s0 \s-1LICENSED\s0 \s-1FREE\s0 \s-1OF\s0 \s-1CHARGE\s0, \s-1THERE\s0 \s-1IS\s0 \s-1NO\s0 \s-1WARRANTY\s0 \s-1FOR\s0 \s-1THE\s0 \s-1SOFTWARE\s0, \s-1TO\s0 \s-1THE\s0 \s-1EXTENT\s0 \s-1PERMITTED\s0 \s-1BY\s0 \s-1APPLICABLE\s0 \s-1LAW\s0. \s-1EXCEPT\s0 \s-1WHEN\s0 \s-1OTHERWISE\s0 \s-1STATED\s0 \s-1IN\s0 \s-1WRITING\s0 \s-1THE\s0 \s-1COPYRIGHT\s0 \s-1HOLDERS\s0 \s-1AND/OR\s0 \s-1OTHER\s0 \s-1PARTIES\s0 \s-1PROVIDE\s0 \s-1THE\s0 \s-1SOFTWARE\s0 \*(L"\s-1AS\s0 \s-1IS\s0\*(R" \s-1WITHOUT\s0 \s-1WARRANTY\s0 \s-1OF\s0 \s-1ANY\s0 \s-1KIND\s0, \s-1EITHER\s0 \s-1EXPRESSED\s0 \s-1OR\s0 \s-1IMPLIED\s0, \s-1INCLUDING\s0, \s-1BUT\s0 \s-1NOT\s0 \s-1LIMITED\s0 \s-1TO\s0, \s-1THE\s0 \s-1IMPLIED\s0 \s-1WARRANTIES\s0 \s-1OF\s0 \s-1MERCHANTABILITY\s0 \s-1AND\s0 \s-1FITNESS\s0 \s-1FOR\s0 A \s-1PARTICULAR\s0 \s-1PURPOSE\s0. \s-1THE\s0 \s-1ENTIRE\s0 \s-1RISK\s0 \s-1AS\s0 \s-1TO\s0 \s-1THE\s0 \s-1QUALITY\s0 \s-1AND\s0 \s-1PERFORMANCE\s0 \s-1OF\s0 \s-1THE\s0 \s-1SOFTWARE\s0 \s-1IS\s0 \s-1WITH\s0 \s-1YOU\s0. \s-1SHOULD\s0 \s-1THE\s0 \s-1SOFTWARE\s0 \s-1PROVE\s0 \s-1DEFECTIVE\s0, \s-1YOU\s0 \s-1ASSUME\s0 \s-1THE\s0 \s-1COST\s0 \s-1OF\s0 \s-1ALL\s0 \s-1NECESSARY\s0 \s-1SERVICING\s0, \s-1REPAIR\s0, \s-1OR\s0 \s-1CORRECTION\s0.
\s-1IN\s0 \s-1NO\s0 \s-1EVENT\s0 \s-1UNLESS\s0 \s-1REQUIRED\s0 \s-1BY\s0 \s-1APPLICABLE\s0 \s-1LAW\s0 \s-1OR\s0 \s-1AGREED\s0 \s-1TO\s0 \s-1IN\s0 \s-1WRITING\s0 \s-1WILL\s0 \s-1ANY\s0 \s-1COPYRIGHT\s0 \s-1HOLDER\s0, \s-1OR\s0 \s-1ANY\s0 \s-1OTHER\s0 \s-1PARTY\s0 \s-1WHO\s0 \s-1MAY\s0 \s-1MODIFY\s0 \s-1AND/OR\s0 \s-1REDISTRIBUTE\s0 \s-1THE\s0 \s-1SOFTWARE\s0 \s-1AS\s0 \s-1PERMITTED\s0 \s-1BY\s0 \s-1THE\s0 \s-1ABOVE\s0 \s-1LICENCE\s0, \s-1BE\s0 \s-1LIABLE\s0 \s-1TO\s0 \s-1YOU\s0 \s-1FOR\s0 \s-1DAMAGES\s0, \s-1INCLUDING\s0 \s-1ANY\s0 \s-1GENERAL\s0, \s-1SPECIAL\s0, \s-1INCIDENTAL\s0, \s-1OR\s0 \s-1CONSEQUENTIAL\s0 \s-1DAMAGES\s0 \s-1ARISING\s0 \s-1OUT\s0 \s-1OF\s0 \s-1THE\s0 \s-1USE\s0 \s-1OR\s0 \s-1INABILITY\s0 \s-1TO\s0 \s-1USE\s0 \s-1THE\s0 \s-1SOFTWARE\s0 (\s-1INCLUDING\s0 \s-1BUT\s0 \s-1NOT\s0 \s-1LIMITED\s0 \s-1TO\s0 \s-1LOSS\s0 \s-1OF\s0 \s-1DATA\s0 \s-1OR\s0 \s-1DATA\s0 \s-1BEING\s0 \s-1RENDERED\s0 \s-1INACCURATE\s0 \s-1OR\s0 \s-1LOSSES\s0 \s-1SUSTAINED\s0 \s-1BY\s0 \s-1YOU\s0 \s-1OR\s0 \s-1THIRD\s0 \s-1PARTIES\s0 \s-1OR\s0 A \s-1FAILURE\s0 \s-1OF\s0 \s-1THE\s0 \s-1SOFTWARE\s0 \s-1TO\s0 \s-1OPERATE\s0 \s-1WITH\s0 \s-1ANY\s0 \s-1OTHER\s0 \s-1SOFTWARE\s0), \s-1EVEN\s0 \s-1IF\s0 \s-1SUCH\s0 \s-1HOLDER\s0 \s-1OR\s0 \s-1OTHER\s0 \s-1PARTY\s0 \s-1HAS\s0 \s-1BEEN\s0 \s-1ADVISED\s0 \s-1OF\s0 \s-1THE\s0 \s-1POSSIBILITY\s0 \s-1OF\s0 \s-1SUCH\s0 \s-1DAMAGES\s0.