MySQL Authentification Backend

This backend uses a MySQL Database to store user data and passwords.

Any database that contains basic user and group information could be used with Dokuwiki. How you adapt the SQL statements to match your favorite database will be discussed in this pages. All configuration and SQL statements are tested with MySQL 4.0 and are based on the example database structure. The backend is able to work with MySQL 3.23, too, but needs slightly modified SQL statements.

The backend is used in some real world configurations that uses the flexibility SQL is offering.

• Phorum - a message board / forum
• FUDforum - a message board / forum
• InvisionBoard - a message board / forum
• phpBB Board - a message board / forum
• Flyspray - a bug tracker
• Drupal - a fine content management system (CMS)
• Nucleus - a powerfull blogging system
• Gallery2 - a gallery: Gallery
• Nuked Klan - a CMS for gamers :Nuked Klan
• PostNuke - a CMS http://www.postnuke.org
• Simple Machines Forum - Simple Machines Forum http://www.simplemachines.org
• ProjectPier - collaboration system: http://projectpier.org
• WordPress - Add WordPress blogging system!: WordPress, Example for DW 2006-03-09d + WP 2.0.4
• Add S9Y blogging system! (pls wait a few days)

Add these configuration options to conf/local.php to use MySQL as your Auth information store.

At least as of release 2006-03-09, all options below are in the distribution in /conf/mysql.conf.php.example. Rename the file to mysql.conf.php, edit it for your settings, and then add the line

require_once('mysql.conf.php');

to your conf/local.protected.php file and not in conf/local.php, cause there it would be eventually overwritten by the configuration manager. (This way you don't have to try and copy/paste all the below code.)

The version included in the distribution does split up the first and last name fields, as a user mentioned below in an improved example.

It will be enabled with the configuration option

$conf['authtype'] = "mysql";

This option defines the MySQL server to connect to. If you are running MySQL on the same server as your Dokuwiki installation, 'localhost' would be sufficient. Otherwise put in your remote MySQL server here. Keep in mind that the remote database server must allow access from your Dokuwiki server. See MySQL documentation for details on this issue.

$conf['auth']['mysql']['server'] = 'localhost';

This option defines which user Dokuwiki should use to access the database.

$conf['auth']['mysql']['user'] = 'dbuser';

Set the database password for 'user' here. Because it is entered in clear text some additional security prophylaxes should be performed.

$conf['auth']['mysql']['password'] = 'dbpassword';

Last but not least you need to specify the database that stores all the user information.

$conf['auth']['mysql']['database'] = 'users';

Normally password encryption is done by DokuWiki (recommended) but for some reasons it might be useful to let the database do the encryption. Set 'forwardClearPass' to '0' and Dokuwiki do the password encryption. Different encryption algorithms are possible. See Chapter Configuration for full list

If you set 'forwardClearPass' to 1 the backend expects the database to do the crypting. It will forward the clear text password to the database. Be aware of the security risk.

$conf['auth']['mysql']['forwardClearPass'] = 0;

Multiple table operations will be protected by locks. This array tells the module which tables to lock. If you use any aliases for table names the array must also contain these aliases. Any not named alias will cause a warning during operation.

MySQL 3.23 doesn't support transactions so that this mechanism is simulated with LOCK TABLES to be downwards compatible. Future versions of this backend may support transactions natively.

$conf['auth']['mysql']['TablesToLock']= array("users", "users AS u",
              "groups", "groups AS g", "usergroup", "usergroup AS ug");

The SQL statements in this section are necessary to use dokuwiki with the MySQL authentication backend. They are the minimum set you have to define.

This statement is used to grant or deny access to the wiki. The result should be a table with exact one line containing at least the password of the user. If the result table is empty or contains more than one row, access will be denied. The module access the password as 'pass' so an alias might be necessary.

If you set 'forwardClearPass = 1' the password must be verified from the database. An additional WHERE clause will do the job: ”AND pass = MD5('%p')”. A much better way is and I really recommend to do it this way is to set 'forwardClearPass = 0' and let Dokuwiki do the crypting.

• '%{user}' will be replaced by a user name
• '%{pass}' will be replaced by an encrypted or clear text password (depends on 'forwardClearPass')
• '%{dgroup}' will be replaced by the default group name

$conf['auth']['mysql']['checkPass']   = "SELECT pass
                                         FROM usergroup AS ug
                                         JOIN users AS u ON u.uid=ug.uid
                                         JOIN groups AS g ON g.gid=ug.gid
                                         WHERE login='%{user}'
                                         AND name='%{dgroup}'";

If you share the user database with other applications it might be useful to be able to define which user may access the Wiki. Ok, the main spirit of a Wiki is it not to limit the access and give all users the possibility to participate. But hey, you are reading an article about access control, what did you expect? So let us get the donkey from the ice.

As already mentioned we have a user database but not every user in this database should be allowed to log into the wiki. The easiest way to check this is the DokuWiki defaultgroup. Every new DokuWiki user will automatically be a member of this group so all we have to do is to check the group besides the password at login time.

The above SQL statement already does this with “name='%{dgroup}'”.

This statement should return a table with exact one row containing information about one user. The field needed are:

• 'pass' containing the encrypted or clear text password
• 'name' the user's full name
• 'mail' the user's email address

Keep in mind that Dokuwiki will access these information through the names listed above so aliases might be necessary.

• '%{user}' will be replaced by a user name

$conf['auth']['mysql']['getUserInfo'] = "SELECT pass, fullname AS name, email AS mail
                                         FROM users
                                         WHERE login='%{user}'";

This statement is used to get all groups a user is member of. The result should be a table containing all groups the given user is member of. The module access the group name as 'group' so an alias might be necessary.

• '%{user}' will be replaced by a user name

$conf['auth']['mysql']['getGroups']   = "SELECT name as `group`
                                         FROM groups g, users u, usergroup ug
                                         WHERE u.uid = ug.uid
                                         AND g.gid = ug.gid
                                         AND u.login='%{user}'";

The SQL statements in this section are necessary to use the user manager plugin. They set up only basic support and you will only be able to get and display the user list.

This statement should return a table containing all user login names that meet certain filter criteria. The filter expressions will be added case dependent by the module. At the end a sort expression will be added.

Important is that this list contains no double entries to a user. Each user name is only allowed once in the table.

The login name will be accessed as 'user' to an alias might be necessary. No patterns will be replaced in this statement but following patters will be replaced in the filter expressions:

• '%{user}' in FilterLogin will be replaced by a user name
• '%{name}' in FilterName will be replaced by user's full name
• '%{email}' in FilterEmail will be replaced by user's email address
• '%{group}' in FilterGroup will be replaced by a group name

$conf['auth']['mysql']['getUsers']    = "SELECT DISTINCT login AS user
                                         FROM users AS u 
                                         LEFT JOIN usergroup AS ug ON u.uid=ug.uid
                                         LEFT JOIN groups AS g ON ug.gid=g.gid";
$conf['auth']['mysql']['FilterLogin'] = "login LIKE '%{user}'";
$conf['auth']['mysql']['FilterName']  = "fullname LIKE '%{name}'";
$conf['auth']['mysql']['FilterEmail'] = "email LIKE '%{email}'";
$conf['auth']['mysql']['FilterGroup'] = "name LIKE '%{group}'";
$conf['auth']['mysql']['SortOrder']   = "ORDER BY login";

You additionally need the SQL statements in this section if you want to add new users in the database with the user manager.

This statement should add a user to the database. Minimum information to store are: login name, password, email address and full name.

• '%{user}' will be replaced by the user name
• '%{pass}' will be replaced by the password (encrypted or clear text, depends on 'forwardClearPass')
• '%{email}' will be replaced by user's email address
• '%{name}' will be replaced by user's full name

$conf['auth']['mysql']['addUser']     = "INSERT INTO users
                                         (login, pass, email, fullname)
                                         VALUES ('%{user}', '%{pass}', '%{email}', '%{name}')";

Please keep in mind that if you set 'forwardClearPass = 1' the clear text password is filled in here. You should at least replace '%p' with MD5('%p') or better set 'forwardClearPass = 0' and let Dokuwiki do the crypting. I really recommend the second method.

This statement should add a group to the database.

• '%{group}' will be replaced by a group name

$conf['auth']['mysql']['addGroup']    = "INSERT INTO groups (name)
                                         VALUES ('%{group}')";

This statement should connect a user to a group (a user become member of that group).

• '%{user}' will be replaced by a user name
• '%{uid}' will be replaced by the id of a user data-set
• '%{group}' will be replaced by a group name
• '%{gid}' will be replaced by the id of a group data-set

$conf['auth']['mysql']['addUserGroup']= "INSERT INTO usergroup (uid, gid)
                                         VALUES ('%{uid}', '%{gid}')";

This statement should remove a group from the database.

• '%{group}' will be replaced by the group name
• '%{gid}' will be replaced by the id of a group data-set

$conf['auth']['mysql']['delGroup']    = "DELETE FROM groups
                                         WHERE gid='%{gid}'";

This statement should return the database index of a given user name. The module will access the index with the name 'id' so an alias might be necessary.

• '%{user}' will be replaced by the user name

$conf['auth']['mysql']['getUserID']   = "SELECT uid AS id FROM users WHERE login='%{user}'";

This statement should return the database index of a given group name. The module will access the index with the name 'id' so an alias might be necessary.

• '%{group}' will be replaced by the group name

$conf['auth']['mysql']['getGroupID']  = "SELECT gid AS id FROM groups WHERE name='%{group}'";

You additionally need the SQL statements in this section if you want to remove users from the database with the user manager.

This statement should remove a user from the database.

• '%{user}' will be replaced by the user name
• '%{uid}' will be replaced by the id of a user data-set

$conf['auth']['mysql']['delUser']     = "DELETE FROM users
                                         WHERE uid='%{uid}'";

This statement should remove all connections from a user to any group (a user quits membership of all groups).

• '%{uid}' will be replaced by the id of a user data-set

$conf['auth']['mysql']['delUserRefs'] = "DELETE FROM usergroup
                                         WHERE uid='%{uid}'";

This statements should modify a user entry in the database. The statements UpdateLogin, UpdatePass, UpdateEmail and UpdateName will be added to updateUser on demand. Only changed parameters will be used.

• '%{user}' will be replaces by the user name
• '%{pass}' will be replaced by the encrypted or clear text password (depends on 'forwardClearPass')
• '%{email}' will be replaced by the email address
• '%{name}' will be replaced by the user's full name
• '%{uid}' will be replaced by the user id that should be updated

$conf['auth']['mysql']['updateUser']  = "UPDATE users SET";
$conf['auth']['mysql']['UpdateLogin'] = "login='%{user}'";
$conf['auth']['mysql']['UpdatePass']  = "pass='%{pass}'";
$conf['auth']['mysql']['UpdateEmail'] = "email='%{email}'";
$conf['auth']['mysql']['UpdateName']  = "fullname='%{name}'";
$conf['auth']['mysql']['UpdateTarget']= "WHERE uid=%{uid}";

This statement should remove a single connection from a user to a group (a user quits membership of that group).

• '%{user}' will be replaced by a user name
• '%{uid}' will be replaced by the id of a user data-set
• '%{group}' will be replaced by a group name
• '%{gid}' will be replaced by the id of a group data-set

$conf['auth']['mysql']['delUserGroup']= "DELETE FROM usergroup
                                         WHERE uid='%{uid}'
                                         AND gid='%{gid}'";

This is a very simple example database.

CREATE TABLE `users` (
  `uid` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `login` varchar(20) NOT NULL DEFAULT '',
  `pass` varchar(60) NOT NULL DEFAULT '',
  `fullname` varchar(255) NOT NULL DEFAULT '',
  `email` varchar(255) NOT NULL DEFAULT '',
  PRIMARY KEY  (`uid`),
  UNIQUE KEY `login` (`login`)
) TYPE = MYISAM;
 
CREATE TABLE `groups` (
  `gid` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `name` varchar(50) NOT NULL DEFAULT '',
  PRIMARY KEY  (`gid`),
  UNIQUE KEY `name` (`name`)
) TYPE = MYISAM;
 
CREATE TABLE `usergroup` (
  `uid` int(10) UNSIGNED NOT NULL DEFAULT '0',
  `gid` int(10) UNSIGNED NOT NULL DEFAULT '0',
  PRIMARY KEY  (`uid`,`gid`)
) TYPE = MYISAM;

Storing the fullname in one single database field may be sufficient for some basic tasks but it has a lot of advantages to split the name up in firstname and lastname. Only one table of the above example need some tuning to get this to work:

CREATE TABLE `users` (
  `uid` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `login` varchar(20) NOT NULL DEFAULT '',
  `pass` varchar(60) NOT NULL DEFAULT '',
  `firstname` varchar(255) NOT NULL DEFAULT '',
  `lastname` varchar(255) NOT NULL DEFAULT '',
  `email` varchar(255) NOT NULL DEFAULT '',
  PRIMARY KEY  (`uid`),
  UNIQUE KEY `login` (`login`)
) TYPE = MYISAM;

To use this slightly changed structure without the need to recode major parts of DokuWiki, it becomes necessary to modify some of our SQL statements:

$conf['auth']['mysql']['getUserInfo'] = "SELECT pass, CONCAT(firstname,' ',lastname) AS name, email AS mail
                                         FROM users
                                         WHERE login='%{user}'";
$conf['auth']['mysql']['addUser']     = "INSERT INTO users
                                         (login, pass, email, firstname, lastname)
                                         VALUES ('%{user}', '%{pass}', '%{email}',
                                         SUBSTRING('%{name}', 1, LOCATE(' ', '%{name}')),
                                         SUBSTRING('%{name}', LOCATE(' ', '%{name}') + 1) )";
$conf['auth']['mysql']['FilterName']  = "CONCAT(firstname,' ',lastname) LIKE '%{name}'";
$conf['auth']['mysql']['UpdateName']  = "firstname=SUBSTRING_INDEX('%{name}',' ', 1),
                                         lastname=SUBSTRING_INDEX('%{name}',' ', -1)";

This modifications in the first statement and also in the FilterName join the firstname and the lastname to fullname used by DokuWiki and the second statement splits the given fullname up into two parts: firstname and lastname. This should also work if the last name consists of multiply words like “de la Cruz”. And anyone who registers with a one-word name will have all of it put into the “lastname” field of the database.

Please keep in mind that if you set 'forwardClearPass = 1' the cleartext password is filled in here. You should at least replace '%p' with MD5('%p') or better set 'forwardClearPass = 0' and let Dokuwiki do the crypting. I really recommend the second method.

It seems that you're using MyISAM tables. At least there are no foreign keys constraints in the example database structure although they'd be needed for the usergroup table to ensure referential integrity. Anyway, you should always explicitly specify the table type you want to use in any CREATE TABLE statement otherwise the results are dependent on a config-setting of the DBMS you often don't know. While MyISAM is the default setting in the public MySQL distribution this setting is quite often changed to InnoDB to allow for transactions, foreign keys, automatic referential integrity and other improvements. On such an optimized system your CREATE TABLE statements would actually create tables of a type you're not expecting …

Ok. I added the type explicitly
— Matthias Grimm 2006-01-31 19:40

Another point is that in the SQL snippets above I can't find the handling of the usergroup table's fields in case of adding/deleting records to/from the respective master table: The addUserGroup and delUserGroup statements are seperated and since there are neither transactions nor FK contraints involved the whole construct is not safe. While this could be left to the DBMS (provided that you're using InnoDB tables with the correct FK/DELETE/UPDATE contraints, which would obsolete as well application level table locking and for example delUserGroup), here (i.e. when using MyISAM) you have to do this on application level.

Table usergroup is handled by addUserGroup and delUserGroup. Multi-statement commands will be protected by table locks. This backend must also work with mysql 3.23 and because neither transaction are well supported nor innoDB work without a lot of tweaking in 3.23, transactions aren't used here. This may change in future.
— Matthias Grimm 2006-01-31 19:44

Hence you should either make sure that there's no way to add/remove records to/from the users / groups tables without updating the usergroup table appropriately or consequently use the DBMS features provided by the InnoDB table type as mentioned above. In any case, however, whatever you choose, always specify the table type you want to use!
– 2005-12-04 Matthias Watermann

I'm developing a wiki (using 2006-03-09b) with acl integrated into a phpBB database on a XAMPP for Windows system, which has MySQL 5.0.18. It seems to work except when I log in I get an error at the top of the page: Warning: Invalid argument supplied for foreach() in C:\Program Files\XAMPP\xampp\htdocs\wiki\inc\auth\mysql.class.php on line 491

I wondered if this might be an issue with MySQL 5? Any thoughts appreciated.

• I didn't get exactly this error, but at another line of the file. It was about having a filter on users which led to an empty result. This is not particulary a problem of mysql, but of php. Well, it's a bug in the code, but I guess older versions of php silently ignored foreach on undefined / empty / non-array variables, but newer versions do complain about it. This should be fixed, though (see below). – Johannes Jordan
• Easy workaround: surround the foreach() statement with if ($result) { }

Dokuwiki uses the standard MySQL PHP library. However, some Apache web servers may be configured to use only the MySQLi PHP library. Patching Dokuwiki to use MySQLi instead of MySQL is very straight forward. The script below will patch Dokuwiki to use PHP MySQLi instead MySQL

(
cat < 'EOF'
26c26
<      * checks if the mysql interface is available, otherwise it will
---
>      * checks if the mysqli interface is available, otherwise it will
38c38
<       if(!function_exists('mysql_connect')) {
---
>       if(!function_exists('mysqli_connect')) {
712c712
<         $con = @mysql_connect ($this->cnf['server'], $this->cnf['user'], $this->cnf['password']);
---
>         $con = @mysqli_connect ($this->cnf['server'], $this->cnf['user'], $this->cnf['password']);
714,715c714,715
<           if ((mysql_select_db($this->cnf['database'], $con))) {
<             if ((preg_match("/^(\d+)\.(\d+)\.(\d+).*/", mysql_get_server_info ($con), $result)) == 1) {
---
>           if ((mysqli_select_db($con, $this->cnf['database']))) {
>             if ((preg_match("/^(\d+)\.(\d+)\.(\d+).*/", mysqli_get_server_info ($con), $result)) == 1) {
723c723
<             mysql_close ($con);
---
>             mysqli_close ($con);
743c743
<         mysql_close ($this->dbcon);
---
>         mysqli_close ($this->dbcon);
763c763
<         $result = @mysql_query($query,$this->dbcon);
---
>         $result = @mysqli_query($this->dbcon,$query);
765c765
<           while (($t = mysql_fetch_assoc($result)) !== false)
---
>           while ($t = mysqli_fetch_assoc($result))
767c767
<           mysql_free_result ($result);
---
>           mysqli_free_result ($result);
771c771
<           msg('MySQL err: '.mysql_error($this->dbcon),-1,__LINE__,__FILE__);
---
>           msg('MySQL err: '.mysqli_error($this->dbcon),-1,__LINE__,__FILE__);
789c789
<         $result = @mysql_query($query,$this->dbcon);
---
>         $result = @mysqli_query($this->dbcon,$query);
791c791
<           $rc = mysql_insert_id($this->dbcon); //give back ID on insert
---
>           $rc = mysqli_insert_id($this->dbcon); //give back ID on insert
795c795
<           msg('MySQL err: '.mysql_error($this->dbcon),-1,__LINE__,__FILE__);
---
>           msg('MySQL err: '.mysqli_error($this->dbcon),-1,__LINE__,__FILE__);
906c906
<         $string = mysql_real_escape_string($string, $this->dbcon);
---
>         $string = mysqli_real_escape_string($this->dbcon,$string);
EOF
) > /home/apache/dokuwiki-2006-11-06/inc/auth/mysql.class.php.patch
patch /home/apache/dokuwiki-2006-11-06/inc/auth/mysql.class.php /home/apache/dokuwiki-2006-11-06/inc/auth/mysql.class.php.patch
rm /home/apache/dokuwiki-2006-11-06/inc/auth/mysql.class.php.patch