[[!template id=plugin name=unixauth core=0 author="[[schmonz]]"]]
[[!tag type/auth]]

This plugin authenticates users against the Unix user database. It presents a similar UI to [[plugins/passwordauth]], but simpler, as there's no need to be able to register or change one's password.

[pwauth](http://www.unixpapa.com/pwauth/) must be installed and working. In particular, it must be configured to recognize the UID of the calling web server, or authentication will always fail. Set `pwauth_path` to the full path of your pwauth binary.

As [with passwordauth](/security/#index14h2), be wary of sending usernames and passwords in cleartext. Unlike with passwordauth, sniffing these credentials can get an attacker much further than mere wiki access. SSL with this plugin is a __must__.

[[!toggle id="code" text="unixauth.pm"]]

[[!toggleable id="code" text="""

    #!/usr/bin/perl
    # Ikiwiki unixauth authentication.
    package IkiWiki::Plugin::unixauth;
    
    use warnings;
    use strict;
    use IkiWiki 2.00;
    
    sub import { #{{{
            hook(type => "formbuilder_setup", id => "unixauth",
                call => \&formbuilder_setup);
            hook(type => "formbuilder", id => "unixauth",
                call => \&formbuilder);
        hook(type => "sessioncgi", id => "unixauth", call => \&sessioncgi);
    } # }}}
    
    # Checks if a string matches a user's password, and returns true or false.
    sub checkpassword ($$;$) { #{{{
        my $user=shift;
        my $password=shift;
        my $field=shift || "password";
    
        # It's very important that the user not be allowed to log in with
        # an empty password!
        if (! length $password) {
                return 0;
        }
    
        my $ret=0;
        if (! exists $config{pwauth_path}) {
                $config{pwauth_path}="/usr/libexec/pwauth";
        }
        open PWAUTH, "|$config{pwauth_path}" or die("Could not run pwauth");
        print PWAUTH "$user\n$password\n";
        close PWAUTH;
        $ret=!($?>>8);
    
        if ($ret) {
            my $userinfo=IkiWiki::userinfo_retrieve();
            if (! length $user || ! defined $userinfo ||
                ! exists $userinfo->{$user} || ! ref $userinfo->{$user}) {
                    IkiWiki::userinfo_setall($user, {
                        'email' => '',
                        'regdate' => time,
                    });
            }
        }
    
        return $ret;
    } #}}}
    
    sub formbuilder_setup (@) { #{{{
        my %params=@_;
    
        my $form=$params{form};
        my $session=$params{session};
        my $cgi=$params{cgi};
    
        if ($form->title eq "signin") {
                $form->field(name => "name", required => 0);
                $form->field(name => "password", type => "password", required => 0);
                
                if ($form->submitted) {
                        my $submittype=$form->submitted;
                        # Set required fields based on how form was submitted.
                        my %required=(
                                "Login" => [qw(name password)],
                        );
                        foreach my $opt (@{$required{$submittype}}) {
                                $form->field(name => $opt, required => 1);
                        }
        
                        # Validate password against name for Login.
                        if ($submittype eq "Login") {
                                $form->field(
                                        name => "password",
                                        validate => sub {
                                                checkpassword($form->field("name"), shift);
                                        },
                                );
                        }
                        
                        elsif ($submittype eq "Login") {
                                $form->field( 
                                        name => "name",
                                        validate => sub {
                                                my $name=shift;
                                                length $name &&
                                                IkiWiki::userinfo_get($name, "regdate");
                                        },
                                );
                        }
                }
                else {
                        # First time settings.
                        $form->field(name => "name");
                        if ($session->param("name")) {
                                $form->field(name => "name", value => $session->param("name"));
                        }
                }
        }
        elsif ($form->title eq "preferences") {
                $form->field(name => "name", disabled => 1, 
                        value => $session->param("name"), force => 1,
                        fieldset => "login");
                $form->field(name => "password", disabled => 1, type => "password",
                        fieldset => "login"),
        }
    }
    
    sub formbuilder (@) { #{{{
        my %params=@_;
    
        my $form=$params{form};
        my $session=$params{session};
        my $cgi=$params{cgi};
        my $buttons=$params{buttons};
    
        if ($form->title eq "signin") {
                if ($form->submitted && $form->validate) {
                        if ($form->submitted eq 'Login') {
                                $session->param("name", $form->field("name"));
                                IkiWiki::cgi_postsignin($cgi, $session);
                        }
                }
        }
        elsif ($form->title eq "preferences") {
                if ($form->submitted eq "Save Preferences" && $form->validate) {
                        my $user_name=$form->field('name');
                }
        }
    } #}}}
    
    sub sessioncgi ($$) { #{{{
        my $q=shift;
        my $session=shift;
    } #}}}
    
    1

"""]]