NAME

       CGI::Application::Plugin::Authentication::Driver - Base module for building driver classes for
       CGI::Application::Plugin::Authentication

SYNOPSIS

        package CGI::Application::Plugin::Authentication::Driver::MyDriver;
        use base qw(CGI::Application::Plugin::Authentication::Driver);

         sub verify_credentials {
             my $self = shift;
             my @credentials = @_;

             if ( >>> Validate Credentials <<< ) {
                 return $credentials[0];
             }
             return;
         }

DESCRIPTION

       This module is a base class for all driver classes for the CGI::Application::Plugin::Authentication
       plugin.  Each driver class is required to provide only one method to validate the given credentials.
       Normally only two credentials will be passed in (username and password), but you can configure the plugin
       to handle any number of credentials (for example you may require the user to enter a group name, or
       domain name as well as a username and password).

FIELD FILTERS

       It is quite common for passwords to be stored using some form of one way encryption.  Unix crypt being
       the old standard in the Unix community, however MD5 or SHA1 hashes are more popular today.  In order to
       simplify the validation routines some methods have been provided to help test these passwords.  When
       configuring a Driver (and if the driver supports it), you can specify which fields are encoded, and which
       method is used for the encoding by specifying a filter on the field in question.

        CREDENTIALS => ['authen_username', 'authen_password'],
        DRIVERS     => [ 'DBI',
                           DSN         => '...',
                           TABLE       => 'users',
                           CONSTRAINTS => {
                               username       => '__CREDENTIAL_1__',
                               'MD5:password' => '__CREDENTIAL_2__',
                           }
                       ],

       Here we are saying that the password field is encoded using an MD5 hash, and should be checked
       accordingly.

   Filter options
       Some of the filters may have multiple forms.  For example there are three forms of MD5 hashes:  binary,
       base64 and hex.  You can specify these extra options by using an underscore to separate it from the
       filter name.

        'MD5_base64:password'

   Chained Filters
       it is possible to chain multiple filters.  This can be useful if your MD5 strings are stored in hex
       format.  Hex numbers are case insensitive, so the may be stored in either upper or lower case.  To make
       this consistent, you can MD5 encode the password first, and then upper case the results.  The filters are
       applied from the inside out:

        'uc:MD5_hex:password'

   Custom Filters
       If your field is encoded using a custom technique, then you can provide a custom filter function.  This
       can be be done by providing a FILTERS option that contains a hash of filter subroutines that are keyed by
       their name.  You can then use the filter name on any of the fields as if it was a builtin filter.

        CREDENTIALS => ['authen_username', 'authen_password'],
        DRIVERS     => [ 'DBI',
                           DSN      => '...',
                           TABLE    => 'users',
                           CONSTRAINTS => {
                               username         => '__CREDENTIAL_1__',
                               'rot13:password' => '__CREDENTIAL_2__',
                           }
                           FILTERS => { rot13 => \&rot13_filter },
                       ],

        sub rot13_filter {
            my $param = shift;
            my $value = shift;
            $value =~ tr/A-Za-z/N-ZA-Mn-za-m/;
            return $value;
        }

       Please see the documentation for the driver that you are using to make sure that it supports encoded
       fields.

   Builtin Filters
       Here is a list of the filters that are provided with this module:

       crypt - provided by perl "crypt" function
       MD5 - requires Digest::MD5
       SHA1 - requires Digest::SHA1
       uc - provided by the perl "uc" function
       lc - provided by the perl "lc" function
       trim - removed whitespace from the start and end of the field

METHODS

   new
       This is a constructor that can create a new Driver object.  It requires an Authentication object as its
       first parameter, and any number of other parameters that will be used as options depending on which
       Driver object is being created.  You shouldn't need to call this as the Authentication plugin takes care
       of creating Driver objects.

   initialize
       This method will be called right after a new Driver object is created.  So any startup customizations can
       be dealt with here.

   options
       This will return a list of options that were provided when this driver was configured by the user.

   authen
       This will return the underlying CGI::Application::Plugin::Authentication object.  In most cases it will
       not be necessary to access this.

   find_option
       This method will search the Driver options for a specific key and return the value it finds.

   verify_credentials
       This method needs to be provided by the driver class.  It needs to be an object method that accepts a
       list of credentials, and will verify that the credentials are valid, and return a username that will be
       used to identify this login (usually you will just return the value of the first credential, however you
       are not bound to that)..

   filter
       This method can be used to filter a field (usually password fields) using a number of standard or custom
       encoding techniques.  See the section on Builtin Filters above to see what filters are available When
       using a custom filter, you will need to provide a FILTERS option in the configuration of the DRIVER (See
       the section on FIELD FILTERS above for an example).  By default, if no filter is specified, it is
       returned as is.  This means that you can run all fields through this function even if they don't have any
       filters to simplify the driver code.

        my $filtered = $self->filter('MD5_hex:password', 'foobar');

        - or -

        # custom filter
        my $filtered = $self->filter('foobar:password', 'foo');

        - or -

        # effectively a noop
        my $filtered = $self->filter('username', 'foo');

   check_filtered
       This method can be used to test filtered fields (usually password fields) against a number of standard or
       custom encoding techniques.  The following encoding techniques are provided:  plain, MD5, SHA1, crypt.
       When using a custom encoder, you will need to provide it in the configuration of the DRIVERS (See the
       section on ENCODED PASSWORDS above for an example).  By default, if no encoding is specified, it is
       assumed to be 'plain'.  This means that you can run all fields through this function even if they don't
       have any encoding to simplify the driver code.

        my $verified = $self->check_filtered('MD5:password', 'foobar', 'OFj2IjCsPJFfMAxmQxLGPw');

        - or -

        # custom encoder
        my $verified = $self->check_filtered('foobar:password', 'foo', 'bar');

        - or -

        # a field that isn't filtered (effectively just checks for equality on second and third args)
        my $verified = $self->check_filtered('username', 'foobar', 'foobar');
        my $verified = $self->check_filtered('plain:username', 'foobar', 'foobar');

   strip_field_names
       This method will take a field name (or list of names) and strip off the leading encoding type.  For
       example if you passed in 'MD5:password' the method would return 'password'.

        my $fieldname = $self->strip_field_names('MD5:password');

SEE ALSO

       CGI::Application::Plugin::Authentication, perl(1)

AUTHOR

       Cees Hek <ceeshek@gmail.com>

LICENCE AND COPYRIGHT

       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.

DISCLAIMER OF WARRANTY

       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT
       PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
       PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
       PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE
       SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY
       OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
       THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE
       WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
       DAMAGES.

perl v5.26.1                                       2018-01-CGI::Application::Plugin::Authentication::Driver(3pm)