Add community auth v2 provider for mediawiki

tools/communityauth/sample/php/mediawiki/README.rst

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+Mediawiki login provider
+------------------------
+
+This provider implements a (fairly ugly) community auth v2 provider
+for mediawiki. Since the mediawiki API doesn't support external
+authentication (it reqiures there to be a username and password,
+which isn't always true, and can only pass those on to external
+services), this has to be done by browser interception. Basically,
+we intercept the mediawiki login URL and redirect it. Upon receiving
+the data back from the authentication system, we inject it into the
+mediawiki session and redirect back. It appears to work so far...
+
+Installation
+++++++++++++
+Copy all the PHP files to `/var/lib/mediawiki/pgauth/`, and
+edit as necessary to have the correct URLs and keys.
+
+Server configuration
+++++++++++++++++++++
+The webserver needs to be configured to intercept and redirect
+the mediawiki URLs. The following configuration is required on
+lighttpd::
+
+        url.rewrite-once = (
+		"^/wiki/([^?]*)(?:\?(.*))?" => "/index.php?title=$1&$2",
+		"^/index.php\?title=Special:UserLogin&returnto=(.*)" => "/pgauth/login.php?r=$1",
+		"^/index.php\?title=Special:UserLogout&returnto=(.*)" => "/pgauth/logout.php",
+        )
+
+It should be added after the regular mediawiki rewrites (included here
+for reference on the first row).
+
+Configuration
++++++++++++++
+Edit the settings in `pgauth_conf.php` to set steid, key and URLs. The
+database connectoin string configured here is for the authentication
+provider to connect to the mediawiki database, not to the community auth
+database.

tools/communityauth/sample/php/mediawiki/auth.php

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+<?php
+require 'pgauth_conf.php';
+
+if ($_GET['s'] == "logout") {
+  /*
+   * Redirect back from the authentication system after a
+   * distributed logout. Just send it back to the frontpage for now.
+   */
+  header("Location: ${pgauth_logoutsite}/");
+  exit(0);
+}
+
+session_name('wikidb_session');
+session_start();
+
+$iv = $_GET['i'];
+$d = $_GET['d'];
+
+$key = base64_decode(strtr(${pgauth_key}, '-_', '+/'), true);
+$iv = base64_decode(strtr($iv, '-_', '+/'), true);
+$d = base64_decode(strtr($d, '-_', '+/'), true);
+if ($key == FALSE || $iv == FALSE || $d == FALSE) {
+  print "Invalid authentication data";
+  exit(0);
+}
+
+$td = mcrypt_module_open("rijndael-128", "", "cbc", "");
+if (!$td) {
+  print "Unable to open mcrypt module";
+  exit(0);
+}
+
+$r = mcrypt_generic_init($td, $key, $iv);
+/* Docs say FALSE or <0 is incorrect. But it returns FALSE when it works.. */
+if ($r < 0) {
+  print "Unable to initialize encryption module: $r";
+  exit(0);
+}
+
+$decrypted = rtrim(mdecrypt_generic($td, $d));
+mcrypt_generic_deinit($td);
+mcrypt_module_close($td);
+parse_str($decrypted, $data);
+
+if ($data['t'] < time() - 10) {
+  print "Authentication token too old";
+  exit(0);
+}
+
+// User found, and we read a reasonable authenticaiton time.
+// Look for the user in the mediawiki database
+$db = pg_connect(${pgauth_connstr});
+$q = pg_query_params($db, "SELECT user_token, user_id, user_real_name, user_email FROM mwuser WHERE user_name=$1", array(ucfirst(strtolower($data['u']))));
+if (pg_num_rows($q) == 0) {
+  /*
+   * Create a token the same way mediawiki does (ish).
+   * We cheat on some points though, but that shouldn't
+   * be an issue really - it's random enough.
+   */
+  $token = md5(microtime() . mt_rand(0, 0x7fffffff));
+
+  /* Hardcoded default options.. Ugly, but it works.. */
+  $options=<<<EOT
+quickbar=1
+underline=2
+cols=80
+rows=25
+searchlimit=20
+contextlines=5
+contextchars=50
+skin=postgresql
+math=1
+rcdays=7
+rclimit=50
+wllimit=250
+highlightbroken=1
+stubthreshold=0
+previewontop=1
+editsection=1
+editsectiononrightclick=0
+showtoc=1
+showtoolbar=1
+date=ISO 8601
+imagesize=2
+thumbsize=2
+rememberpassword=0
+enotifwatchlistpages=1
+enotifusertalkpages=1
+enotifminoredits=1
+enotifrevealaddr=0
+shownumberswatching=0
+fancysig=0
+externaleditor=0
+externaldiff=0
+showjumplinks=1
+numberheadings=0
+uselivepreview=0
+watchlistdays=3
+variant=
+language=en
+searchNs0=1
+nickname=
+timecorrection=
+ajaxsearch=
+searchNs1=0
+searchNs2=0
+searchNs3=0
+searchNs4=0
+searchNs5=0
+searchNs6=0
+searchNs7=0
+searchNs8=0
+searchNs9=0
+searchNs10=0
+searchNs11=0
+searchNs12=0
+searchNs13=0
+searchNs14=0
+searchNs15=0
+disablemail=1
+justify=0
+hideminor=0
+extendwatchlist=0
+usenewrc=0
+editondblclick=0
+editwidth=0
+watchcreations=0
+watchdefault=0
+watchmoves=0
+watchdeletion=0
+minordefault=0
+previewonfirst=0
+nocache=0
+forceeditsummary=0
+watchlisthideown=0
+watchlisthidebots=0
+watchlisthideminor=0
+ccmeonemails=1
+diffonly=0
+EOT;
+
+  /*
+   * Try to create a user..
+   */
+  $q = pg_query_params($db, "INSERT INTO mwuser (user_name, user_real_name, user_password, user_newpassword, user_newpass_time, user_token, user_email, user_email_token, user_email_token_expires, user_email_authenticated, user_options, user_touched, user_registration, user_editcount, user_hidden) VALUES ($1, $2, NULL, NULL, NULL, $3, $4, NULL, '2000-01-01 00:00:00', CURRENT_TIMESTAMP, $5, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP, 0, 0) RETURNING user_token, user_id, user_real_name, user_email", array(ucfirst(strtolower($data['u'])), $data['f'] . ' ' . $data['l'], $token, $data['e'], $options));
+  if (pg_num_rows($q) != 1) {
+    print "Failed to add user!";
+    pg_close($db);
+    exit(0);
+  }
+}
+else if (pg_num_rows($q) != 1) {
+  print "Invalid data returned!";
+  pg_close($db);
+  exit(0);
+}
+
+/*
+ * Update email and real name, if they changed in the community
+ * auth system. Community auth always overwrites whatever is
+ * in the wiki.
+ */
+$r = pg_fetch_assoc($q);
+if ($r['user_email'] != $data['e']) {
+  $q = pg_query_params($db, "UPDATE mwuser SET user_email=$1 WHERE user_name=$2", array($data['e'], ucfirst(strtolower($data['u']))));
+  if (pg_result_status($q) != PGSQL_COMMAND_OK) {
+    print "Failed to update email!";
+    pg_close($db);
+    exit(0);
+  }
+}
+if ($r['user_real_name'] != $data['f'] . ' ' . $data['l']) {
+  $q = pg_query_params($db, "UPDATE mwuser SET user_real_name=$1 WHERE user_name=$2", array($data['f'] . ' ' . $data['l'], ucfirst(strtolower($data['u']))));
+  print "'$q'";
+  if (pg_result_status($q) != PGSQL_COMMAND_OK) {
+    print "Failed to update real name!";
+    pg_close($db);
+    exit(0);
+  }
+}
+
+pg_close($db);
+
+// Now inject this data into the mediawiki session
+$_SESSION['wsUserID'] = $r['user_id'];
+$_SESSION['wsToken'] = $r['user_token'];
+$_SESSION['wsUserName'] = ucfirst(strtolower($data['u']));
+session_write_close();
+
+if ($data['su']) {
+  $redir = $data['su'];
+} else {
+  $redir = '/wiki/Main_Page';
+}
+
+/* Add ?nocache=... or &nocache=... to avoid mediawiki caching */
+$redir .= strpos($redir, "?")==false?"?":"&";
+$redir .= "nocache=" . urlencode(microtime());
+header("Location: ${pgauth_rootsite}$redir");
+header("Cache-control: private, must-revalidate, max-age=0");
+?>

tools/communityauth/sample/php/mediawiki/login.php

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+<?
+require 'pgauth_conf.php';
+/* Redirect authentication request */
+
+$su = "/wiki/" . $_GET['r'];
+header("Location: https://www.postgresql.org/account/auth/${pgauth_siteid}/?su=" . urlencode($su));
+?>

tools/communityauth/sample/php/mediawiki/logout.php

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+<?
+require 'pgauth_conf.php';
+/* Log the user out locally */
+
+session_name('wikidb_session');
+session_start();
+
+unset($_SESSION['wsUserID']);
+unset($_SESSION['wsToken']);
+unset($_SESSION['wsUserName']);
+setcookie('wikidbLoggedOut', time());
+
+/* Redirect logout request too */
+header("Location: https://www.postgresql.org/account/auth/${pgauth_siteid}/logout/");
+?>

tools/communityauth/sample/php/mediawiki/pgauth_conf.php

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+<?
+$pgauth_siteid=12321432432;
+$pgauth_key = 'puSOAmUPWlZvVvnQtkUpwjxj7U4NT7sW0FhBqo/OkgA=';
+$pgauth_rootsite = 'https://wikitest.postgresql.org';
+$pgauth_logoutsite = 'http://wikitest.postgresql.org';
+$pgauth_connstr = "dbname=wikidb";
+?>