[[!template id=plugin name=unixauth core=0 author="[[schmonz]]"]]
[[!tag type/auth]]
+[[!template id=gitbranch branch=unixauth author="[[schmonz]]"]]
+
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.
To authenticate, either [checkpassword](http://cr.yp.to/checkpwd.html) or [pwauth](http://www.unixpapa.com/pwauth/) must be installed and configured. `checkpassword` is strongly preferred. If your web server runs as an unprivileged user -- as it darn well should! -- then `checkpassword` needs to be setuid root. (Or your ikiwiki CGI wrapper, I guess, but don't do that.) Other checkpassword implementations are available, notably [checkpassword-pam](http://checkpasswd-pam.sourceforge.net/).
__Security__: [As with passwordauth](/security/#index14h2), be wary of sending usernames and passwords in cleartext. Unlike passwordauth, sniffing `unixauth` credentials can get an attacker much further than mere wiki access. Therefore, this plugin defaults to not even _displaying_ the login form fields unless we're running under SSL. Nobody should be able to do anything remotely dumb until the admin has done at least a little thinking. After that, dumb things are always possible. ;-)
-`unixauth` tests for the presence of the `HTTPS` environment variable. `Wrapper.pm` needs to be tweaked to pass it through; without that, the plugin fails closed.
-
-[[!toggle id="diff" text="Wrapper.pm.diff"]]
-
-[[!toggleable id="diff" text="""
-
- --- Wrapper.pm.orig 2008-07-29 00:09:10.000000000 -0400
- +++ Wrapper.pm
- @@ -28,7 +28,7 @@ sub gen_wrapper () { #{{{
- my @envsave;
- push @envsave, qw{REMOTE_ADDR QUERY_STRING REQUEST_METHOD REQUEST_URI
- CONTENT_TYPE CONTENT_LENGTH GATEWAY_INTERFACE
- - HTTP_COOKIE REMOTE_USER} if $config{cgi};
- + HTTP_COOKIE REMOTE_USER HTTPS} if $config{cgi};
- my $envsave="";
- foreach my $var (@envsave) {
- $envsave.=<<"EOF"
-
-"""]]
-
-[[!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 => "getsetup", id => "unixauth", call => \&getsetup);
- hook(type => "formbuilder_setup", id => "unixauth",
- call => \&formbuilder_setup);
- hook(type => "formbuilder", id => "unixauth",
- call => \&formbuilder);
- hook(type => "sessioncgi", id => "unixauth", call => \&sessioncgi);
- } # }}}
-
- sub getsetup () { #{{{
- return
- unixauth_type => {
- type => "string",
- example => "checkpassword",
- description => "type of authenticator; can be 'checkpassword' or 'pwauth'",
- safe => 0,
- rebuild => 1,
- },
- unixauth_command => {
- type => "string",
- example => "/path/to/checkpassword",
- description => "full path and any arguments",
- safe => 0,
- rebuild => 1,
- },
- unixauth_requiressl => {
- type => "boolean",
- example => "1",
- description => "require SSL? strongly recommended",
- safe => 0,
- rebuild => 1,
- },
- plugin => {
- description => "Unix user authentication",
- safe => 0,
- rebuild => 1,
- },
- } #}}}
-
- # 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{unixauth_type}) {
- # admin needs to carefully think over his configuration
- return 0;
- }
- elsif ($config{unixauth_type} eq "checkpassword") {
- open UNIXAUTH, "|$config{unixauth_command} true 3<&0" or die("Could not run $config{unixauth_type}");
- print UNIXAUTH "$user\0$password\0Y123456\0";
- close UNIXAUTH;
- $ret=!($?>>8);
- }
- elsif ($config{unixauth_type} eq "pwauth") {
- open UNIXAUTH, "|$config{unixauth_command}" or die("Could not run $config{unixauth_type}");
- print UNIXAUTH "$user\n$password\n";
- close UNIXAUTH;
- $ret=!($?>>8);
- }
- else {
- # no such authentication type
- return 0;
- }
-
- 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 not under SSL, die before even showing a login form,
- # unless the admin explicitly says it's fine
- if (! exists $config{unixauth_requiressl}) {
- $config{unixauth_requiressl} = 1;
- }
- if ($config{unixauth_requiressl}) {
- if ((! $config{sslcookie}) || (! exists $ENV{'HTTPS'})) {
- die("SSL required to login. Contact your administrator.<br>");
- }
- }
-
- 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);
- },
- );
- }
-
- # XXX is this reachable? looks like no
- 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
+`unixauth` needs the `HTTPS` environment variable, available in ikiwiki 2.67 or later (fixed in #[502047](http://bugs.debian.org/502047)), without which it fails closed.
-"""]]
+The plugin has not been tested with newer versions of ikiwiki. [[schmonz]] hopes to have time to polish this plugin soon.