lib.php

<?PHP  // $Id$
//CHANGELOG:
//21.09.2004 Added support for multiple ldap-servers.
//           Theres no nedd to use auth_ldap_bind,
//           Anymore auth_ldap_connect does this for you
//19.09.2004 Lot of changes are coming from Martin Langhoff
//           Current code is working but can change a lot. Be warned...
//15.08.2004 Added support for user syncronization
//24.02.2003 Added support for coursecreators
//20.02.2003 Added support for user creation
//12.10.2002 Reformatted source for consistency
//03.10.2002 First version to CVS
//29.09.2002 Clean up and splitted code to functions v. 0.02
//29.09.2002 LDAP authentication functions v. 0.01
//Distributed under GPL (c)Petri Asikainen 2002-2004

/* README!
Module is quite complete and  most functinality can be configured from
configinterfave /admin/auth.php. Some of latest additions/features need to
be configured by modifying source code.
 
USER CREATION FEATURE
User-creation makes posible that your current 
users can authenticate with existings usernames/password and new users can 
create own accounts to LDAP-directory. I'm using this feature and new users
are created to LDAP different context, without rights to other system. When
user-creation feature is set like that, there's no known security issues.

If you plan to use user creation feature, look function auth_user_create
and modify it for your needs.
You have to change all hardcoded attribute values to fit your LDAP-server.

I write ldap-module on Novell E-directory / Linux & Solaris , 
so all default values are for it.

LDAP USER SYNCRONIZATION
!!!! Following comlete outdated as guid-field is not used anymorein moodeles user-table
!!!! I'll update this documentation as soon ldap-code get more stabile.

BACKUP
This is first version of usersync so backup your database, if you like to test this feature!

BINARY FIELDS
I'm testing this against Novell eDirectory where guid field is binary
so I have to use bin2hex() in function auth_get_users (), If your guid field is not binary
comment that line out.

EXISTING USERS
For existing systems there no way to figure out is account from ldap or not.
So sysadmin,  you have to update 'auth' and 'guid' fields for your existing ldap-users by hand (or scripting)
If your users usernamed are stabile, you can use auth_get_users() for this.

AUTOMATING SYNCRONIZATION
Right now moodle does not automaticly run auth_sync_users() so you have to create
your own script like:
auth/ldap/cron.php
<?
    require_once("../../config.php");
    require_once("../../course/lib.php");
    require_once('../../lib/blocklib.php');
    require_once("../../mod/resource/lib.php");
    require_once("lib.php");
    require_once("../../mod/forum/lib.php");
    auth_sync_users();
?>

Usersync is quite heavy process, it could be good idea to place that script outside of webroot and run it  with cron.
                            

Any feedback is wellcome,

Petri Asikainen paca@sci.fi


*/
function auth_user_login ($username, $password) {
/// Returns true if the username and password work
/// and false if they don't

    global $CFG;

    if (!$username or !$password) {    // Don't allow blank usernames or passwords
        return false;
    }
 
    $ldapconnection  = auth_ldap_connect();

    if ($ldapconnection) {
        $ldap_user_dn = auth_ldap_find_userdn($ldapconnection, $username);
      
        //if ldap_user_dn is empty, user does not exist
        if(!$ldap_user_dn){
            ldap_close($ldapconnection);
            return false;
        }

        // Try to bind with current username and password
        $ldap_login = @ldap_bind($ldapconnection, $ldap_user_dn, $password);
        ldap_close($ldapconnection);
        if ($ldap_login) {
            return true;
        }
    } else {
        @ldap_close($ldapconnection);
        error("LDAP-module cannot connect to server: $CFG->ldap_host_url");
    }
    return false;
}


 
function auth_get_userinfo($username){
/// reads userinformation from ldap and return it in array()
    global $CFG;

    $config = (array)$CFG;
    $attrmap = auth_ldap_attributes();
   
    $ldapconnection=auth_ldap_connect();

    $result = array();
    $search_attribs = array();
  
    foreach ($attrmap as $key=>$value) {
        if (!in_array($value, $search_attribs)) {
            array_push($search_attribs, $value);
        }    
    }

    $user_dn = auth_ldap_find_userdn($ldapconnection, $username);

    if (empty($CFG->ldap_objectclass)) {        // Can't send empty filter
        $CFG->ldap_objectclass="objectClass=*";
    }
  
    $user_info_result = ldap_read($ldapconnection,$user_dn,$CFG->ldap_objectclass, $search_attribs);

    if ($user_info_result) {
        $user_entry = ldap_get_entries($ldapconnection, $user_info_result);
        foreach ($attrmap as $key=>$value){
            if(isset($user_entry[0][strtolower($value)][0])){
                $result[$key]=utf8_decode($user_entry[0][strtolower($value)][0]);
            }
        }
    }

    @ldap_close($ldapconnection);
    
    return $result;
}

function auth_get_userlist () {
    global $CFG;
    return auth_ldap_get_userlist("($CFG->ldap_user_attribute=*)");
}
function auth_user_exists ($username) {
   global $CFG; 
   //returns true if given usernname exist on ldap
   $users = auth_ldap_get_userlist("($CFG->ldap_user_attribute=$username)");
   return count($users); 
}

function auth_user_create ($userobject,$plainpass) {
//create new user to ldap
//use auth_user_exists to prevent dublicate usernames
//return true if user is created, false on error
	global $CFG;
    $attrmap = auth_ldap_attributes();
    $ldapconnection = auth_ldap_connect();
    
    $newuser = array();
     
    foreach ($attrmap as $key=>$value){
            if(!empty($userobject->$key) ){
                if (isset($CFG->{auth_user_.$key._updateremote}) && $CFG->{auth_user_.$key._updateremote} == "1" ) { 
                    $newuser[$value]=utf8_encode($userobject->$key);
                }     
            }
    }
    
    //Following sets all mandatory and other forced attribute values
    //MODIFY following to suite your enviroment
    $newuser['objectClass']= array("inetOrgPerson","organizationalPerson","person","top");
    $newuser['uniqueId']= $userobject->username;
    $newuser['logindisabled']="TRUE";
    $newuser['userpassword']=$plainpass;
        
    $uadd = ldap_add($ldapconnection, $CFG->ldap_user_attribute."=$userobject->username,".$CFG->ldap_create_context, $newuser);

    ldap_close($ldapconnection);
    return $uadd;
    
}

function auth_get_users($filter='*') {
//returns all userobjects from external database
    global $CFG;

    $fresult = array();
    $ldapconnection = auth_ldap_connect();

    if (empty($CFG->ldap_objectclass)) {
        $CFG->ldap_objectclass="objectClass=*";
    }

    if ($filter=="*") {
       $filter = "(&(".$CFG->ldap_user_attribute."=*)(".$CFG->ldap_objectclass."))";
    }

    $contexts = explode(";",$CFG->ldap_contexts);
 
    if (!empty($CFG->ldap_create_context)){
          array_push($contexts, $CFG->ldap_create_context);
    }

    $attrmap = auth_ldap_attributes();
   
    $search_attribs = array();
  
    foreach ($attrmap as $key=>$value) {
        if (!in_array($value, $search_attribs)) {
            array_push($search_attribs, $value);
        }    
    }


    foreach ($contexts as $context) {

        if ($CFG->ldap_search_sub) {
            //use ldap_search to find first user from subtree
            $ldap_result = ldap_search($ldapconnection, $context,
                                       $filter,
                                       $search_attribs);
        } else {
            //search only in this context
            $ldap_result = ldap_list($ldapconnection, $context,
                                     $filter,
                                     $search_attribs);
        }

        $users = auth_ldap_get_entries($ldapconnection, $ldap_result);

        //add found users to list
        foreach ($users as $ldapuser=>$attribs) {
            $user = new object();
            foreach ($attrmap as $key=>$value){
                if(isset($users[$ldapuser][$value][0])){
                    $user->$key=$users[$ldapuser][$value][0];
                }
            }    
            //quick way to get around binarystrings
            $user->guid=bin2hex($user->guid);
            //add authentication source stamp 
            $user->auth='ldap';
            $fresult[$user->username]=$user;

        }
    }
   
    return $fresult;
}

function auth_sync_users ($unsafe_optimizations = false, $bulk_insert_records = 1) {
//Syncronizes userdb with ldap
//This will add, rename 
/// OPTIONAL PARAMETERS
/// $unsafe_optimizations = true  // will skip over moodle standard DB interfaces and use very optimized
///             and non-portable SQL -- useful only for mysql or postgres7
/// $bulk_insert_records = 1 // will insert $bulkinsert_records per insert statement
///                         valid only with $unsafe. increase to a couple thousand for
///                         blinding fast inserts -- but test it: you may hit mysqld's 
///                         max_allowed_packet limit.

    global $CFG ;
    $ldapusers     = auth_get_users();
    $usedidnumbers = Array();

    // these are only populated if we managed to find added/removed users
    $add_users    = false;
    $remove_users = false;
    
    if($unsafe_optimizations){
        // create a temp table
        if(strtolower($CFG->dbtype) === 'mysql'){
            // help old mysql versions cope with large temp tables
            execute_sql('SET SQL_BIG_TABLES=1'); 
            execute_sql('CREATE TEMPORARY TABLE ' . $CFG->prefix .'extuser (idnumber VARCHAR(12), PRIMARY KEY (idnumber)) TYPE=MyISAM'); 
        } elseif (strtolower($CFG->dbtype) === 'postgres7'){
            execute_sql('CREATE TEMPORARY TABLE '.$CFG->prefix.'extuser (idnumber VARCHAR(12), PRIMARY KEY (idnumber))'); 
        }
        
        $userids = array_keys($ldapusers);
        // bulk insert -- superfast with $bulk_insert_records
        while(count($userids)){
            $sql = 'INSERT INTO '.$CFG->prefix.'extuser (idnumber) VALUES ';
            $values = array_splice($userids, -($bulk_insert_records) ); 
            // make those values safe
            array_map('addslashes', $values);
            // join and quote the whole lot
            $sql = $sql . '(\'' . join('\'),(\'', $values) . '\')';
            execute_sql($sql); 
        }
        
        /// REMOVE execute_sql('delete from mdl_user where idnumber like \'%s\'');
        
        // find users in DB that aren't in ldap -- to be removed!
        $sql = 'SELECT u.* 
                FROM ' . $CFG->prefix .'user u LEFT JOIN ' . $CFG->prefix .'extuser e 
                        ON u.idnumber = e.idnumber 
                WHERE u.auth=\'ldap\' AND u.deleted=\'0\' AND e.idnumber IS NULL';
        $remove_users = get_records_sql($sql); 
        print "User entries to remove: ". count($remove_users) . "\n";
        
        // find users missing in DB that are in LDAP
        // note that get_records_sql wants at least 2 fields returned,
        // and gives me a nifty object I don't want.
        $sql = 'SELECT e.idnumber,1 
                FROM ' . $CFG->prefix .'extuser e  LEFT JOIN ' . $CFG->prefix .'user u
                        ON e.idnumber = u.idnumber 
                WHERE  u.id IS NULL';
        $add_users = array_keys(get_records_sql($sql)) || array(); // get rid of the fat        
        print "User entries to add: ". count($add_users). "\n";
    }
    
    foreach ($ldapusers as $user) {
    
        $usedidnumbers[] = $user->idnumber; //we will need all used idnumbers later
        //update modified time
        $user->modified = time();
        //All users are confirmed
        $user->confirmed = 1;
        // if user does not exist create it
        if ( ($unsafe_optimizations && is_array($add_users) && in_array($user->idnumber, $add_users) )
              || (!$unsafe_optimizations  &&!record_exists('user','auth', 'ldap', 'idnumber', $user->idnumber)) ) {
            if (insert_record ('user',$user)) {
                echo "inserted user $user->username with idnumber $user->idnumber \n";
            } else {
                echo "error inserting user $user->username with idnumber $user->idnumber \n";
            }
            update_user_record($user->username);
            continue ;
        } else {
           //update username
           set_field('user', 'username', $user->username , 'auth', 'ldap', 'idnumber', $user->idnumber);
           //no id-information in ldap so get now
           update_user_record($user->username);
           $userid = get_field('user', 'id', 'auth', 'ldap', 'idnumber', $user->idnumber);
           
           if (auth_iscreator($user->username)) {
                 if (! record_exists("user_coursecreators", "userid", $userid)) {
                      $cdata['userid']=$userid;
                      $creator = insert_record("user_coursecreators",$cdata);
                      if (! $creator) {
                          error("Cannot add user to course creators.");
                      }
                  }
            } else {
                 if ( record_exists("user_coursecreators", "userid", $userid)) {
                      $creator = delete_records("user_coursecreators", "userid", $userid);
                      if (! $creator) {
                          error("Cannot remove user from course creators.");
                      }
                 }
            }
        }
    }    
    
    if($unsafe_optimizations){
        $result=(is_array($remove_users) ? $remove_users : array());
    } else{
        //find nonexisting users from moodles userdb
        $sql = "SELECT * FROM ".$CFG->prefix."user WHERE deleted = '0' AND auth = 'ldap' AND idnumber  NOT IN ('".implode('\' , \'',$usedidnumbers)."');" ;
        $result = get_records_sql($sql);
    }

    if (!empty($result)){
        foreach ($result as $user) {
            //following is copy pasted from admin/user.php
            //maybe this should moved to function in lib/datalib.php
            unset($updateuser);
            $updateuser->id = $user->id;
            $updateuser->deleted = "1";
            $updateuser->username = "$user->email.".time();  // Remember it just in case
            $updateuser->email = "";               // Clear this field to free it up
            $updateuser->timemodified = time();
            if (update_record("user", $updateuser)) {
                unenrol_student($user->id);  // From all courses
                remove_teacher($user->id);   // From all courses
                remove_admin($user->id);
                notify(get_string("deletedactivity", "", fullname($user, true)) );
            } else {
                notify(get_string("deletednot", "", fullname($user, true)));
            }
            //copy pasted part ends
        }     
    }    
}

function auth_user_activate ($username) {
//activate new ldap-user after email-address is confirmed
	global $CFG;

    $ldapconnection = auth_ldap_connect();

    $userdn = auth_ldap_find_userdn($ldapconnection, $username);
    
    $newinfo['loginDisabled']="FALSE";

    $result = ldap_modify($ldapconnection, $userdn, $newinfo);
    ldap_close($ldapconnection);
    return $result;
}

function auth_user_disable ($username) {
//activate new ldap-user after email-address is confirmed
	global $CFG;

    $ldapconnect = auth_ldap_connect();

    $userdn = auth_ldap_find_userdn($ldapconnection, $username);
    $newinfo['loginDisabled']="TRUE";

    $result = ldap_modify($ldapconnection, $userdn, $newinfo);
    ldap_close($ldapconnection);
    return $result;
}

function auth_iscreator($username=0) {
///if user is member of creator group return true
    global $USER , $CFG; 
    if (! $username) {
        $username=$USER->username;
    }
   
    if ((! $CFG->ldap_creators) OR (! $CFG->ldap_memberattribute)) {
        return false;
    } 

    return auth_ldap_isgroupmember($username, $CFG->ldap_creators);
 
}

function auth_user_update($olduser, $newuser) {
/// called when the user record is updated. push fields to 
/// the LDAP database if configured to do so...

    global $USER , $CFG;
    
    $ldapconnection = auth_ldap_connect();
    
    $result = array();
    $search_attribs = array();

    $attrmap = auth_ldap_attributes();  
    foreach ($attrmap as $key=>$value) {
        if (!in_array($value, $search_attribs)) {
            array_push($search_attribs, $value);
        }    
    }

    $user_dn = auth_ldap_find_userdn($ldapconnection, $olduser->username);

    if (empty($CFG->ldap_objectclass)) {
        $CFG->ldap_objectclass="objectClass=*";
    }
  
    $user_info_result = ldap_read($ldapconnection,$user_dn,$CFG->ldap_objectclass, $search_attribs);

    if ($user_info_result){

        $user_entry = ldap_get_entries($ldapconnection, $user_info_result);
        //error_log(var_export($user_entry) . 'fpp' );

        foreach ($attrmap as $key=>$ldapkey){
            if (isset($CFG->{'auth_user_'. $key.'_updateremote'}) && $CFG->{'auth_user_'. $key.'_updateremote'}){
                // skip update if the values already match
                if( !($newuser->$key === $user_entry[0][strtolower($ldapkey)][0]) ){
                    ldap_modify($ldapconnection, $user_dn, array($ldapkey => utf8_encode($newuser->$key)));
                } else { 
                    error_log("Skip updating field $key for entry $user_dn: it seems to be already same on LDAP. " . 
                              "  old moodle value: '" . $olduser->$key . 
                              "' new value '" . $newuser->$key . 
                              "' current value in ldap entry " . $user_entry[0][strtolower($ldapkey)][0]);
                }
            }
        }
        

    } else {
        error_log("ERROR:No user found in LDAP");
        @ldap_close($ldapconnection);
        return false;
    }

    @ldap_close($ldapconnection);
        
    return true;

}

function auth_user_update_password($username, $newpassword) {
/// called when the user password is updated -- it assumes it is called by an admin
/// or that you've otherwise checked the user's credentials
/// IMPORTANT: $newpassword must be cleartext, not crypted/md5'ed

    global $CFG;
    $result = false;
     
    $ldapconnection = auth_ldap_connect();

    $user_dn = auth_ldap_find_userdn($ldapconnection, $username);
    
    if(!$user_dn){
        error_log('LDAP Error in auth_user_update_password(). No DN for: ' . $username); 
        return false;
    }
    // send ldap the password in cleartext, it will md5 it itself
    $result = ldap_modify($ldapconnection, $user_dn, array('userPassword' => $newpassword));
    
    if(!$result){
        error_log('LDAP Error in auth_user_update_password(). Error code: ' 
                  . ldap_errno($ldapconnection) . '; Error string : '
                  . ldap_err2str(ldap_errno($ldapconnection)));
    }
    
    @ldap_close($ldapconnection);

    return $result;
}

//PRIVATE FUNCTIONS starts
//private functions are named as auth_ldap*

function auth_ldap_isgroupmember ($username='', $groupdns='') {
// Takes username and groupdn(s) , separated by ;
// Returns true if user is member of any given groups

    global $CFG, $USER;

   
    if (empty($username) OR empty($groupdns)) {
        return false;
    }
    
    $groups = explode(";",$groupdns);

    //build filter
    $filter = "(& ($CFG->ldap_user_attribute=$username)(|";
    foreach ($groups as $group){
        $filter .= "($CFG->ldap_memberattribute=$group)";
    }
    $filter .= "))";
    //search
    $result = auth_ldap_get_userlist($filter);
   
    return count($result);

}
function auth_ldap_connect(){
/// connects  and binds to ldap-server
/// Returns connection result

    global $CFG;
    $urls = explode(";",$CFG->ldap_host_url);

    foreach ($urls as $server){
        $connresult = ldap_connect($server);
        //ldap_connect returns ALWAYS true

        if (!empty($CFG->ldap_version)) {
            ldap_set_option($connresult, LDAP_OPT_PROTOCOL_VERSION, $CFG->ldap_version);
        }

        if ($CFG->ldap_bind_dn){
            //bind with search-user
            $bindresult=@ldap_bind($connresult, $CFG->ldap_bind_dn,$CFG->ldap_bind_pw);
        } else {
            //bind anonymously
            $bindresult=@ldap_bind($connresult);
        }    

        if ($bindresult) {
            return $connresult;
        }
    }    
    
    //If any of servers are alive we have already returned connection
    error("LDAP-module cannot connect any LDAP servers : $CFG->ldap_host_url");
    return false;
}





function auth_ldap_find_userdn ($ldapconnection, $username){
/// return dn of username
/// like: cn=username,ou=suborg,o=org
/// or false if username not found

    global $CFG;

    //default return value
    $ldap_user_dn = FALSE;

    //get all contexts and look for first matching user
    $ldap_contexts = explode(";",$CFG->ldap_contexts);
    
    if (!empty($CFG->ldap_create_context)){
	  array_push($ldap_contexts, $CFG->ldap_create_context);
    }
  
    foreach ($ldap_contexts as $context) {

        $context == trim($context);

        if ($CFG->ldap_search_sub){
            //use ldap_search to find first user from subtree
            $ldap_result = ldap_search($ldapconnection, $context, "(".$CFG->ldap_user_attribute."=".$username.")",array($CFG->ldap_user_attribute));

        } else {
            //search only in this context
            $ldap_result = ldap_list($ldapconnection, $context, "(".$CFG->ldap_user_attribute."=".$username.")",array($CFG->ldap_user_attribute));
        }
 
        $entry = ldap_first_entry($ldapconnection,$ldap_result);

        if ($entry){
            $ldap_user_dn = ldap_get_dn($ldapconnection, $entry);
            break ;
        }
    }

    return $ldap_user_dn;
}

function auth_ldap_attributes (){
//returns array containg attribute mappings between Moodle and ldap
	global $CFG;

    $config = (array)$CFG;
    $fields = array("firstname", "lastname", "email", "phone1", "phone2", 
                    "department", "address", "city", "country", "description", 
                    "idnumber", "lang" );

    $moodleattributes = array();
    foreach ($fields as $field) {
        if (!empty($config["auth_user_$field"])) {
            $moodleattributes[$field] = $config["auth_user_$field"];
        }
    }
    $moodleattributes['username']=$config["ldap_user_attribute"];
	return $moodleattributes;
}

function auth_ldap_get_userlist($filter="*") {
/// returns all users from ldap servers
    global $CFG;

    $fresult = array();

    $ldapconnection = auth_ldap_connect();

    if (empty($CFG->ldap_objectclass)) {
        $CFG->ldap_objectclass="objectClass=*";
    }

    if ($filter=="*") {
       $filter = "(&(".$CFG->ldap_user_attribute."=*)(".$CFG->ldap_objectclass."))";
    }

    $contexts = explode(";",$CFG->ldap_contexts);
 
    if (!empty($CFG->ldap_create_context)){
          array_push($contexts, $CFG->ldap_create_context);
    }

    foreach ($contexts as $context) {

        if ($CFG->ldap_search_sub) {
            //use ldap_search to find first user from subtree
            $ldap_result = ldap_search($ldapconnection, $context,
                                       $filter,
                                       array($CFG->ldap_user_attribute));
        } else {
            //search only in this context
            $ldap_result = ldap_list($ldapconnection, $context,
                                     $filter,
                                     array($CFG->ldap_user_attribute));
        }

        $users = ldap_get_entries($ldapconnection, $ldap_result);

        //add found users to list
        for ($i=0;$i<$users['count'];$i++) {
            array_push($fresult, ($users[$i][$CFG->ldap_user_attribute][0]) );
        }
    }
   
    return $fresult;
}

function auth_ldap_get_entries($conn, $searchresult){
//Returns values like ldap_get_entries but is
//binary compatible
    $i=0;
    $fresult=array();
    $entry = ldap_first_entry($conn, $searchresult);
    do {
        $attributes = ldap_get_attributes($conn, $entry);
        for($j=0; $j<$attributes['count']; $j++) {
            $values = ldap_get_values_len($conn, $entry,$attributes[$j]);
            $fresult[$i][$attributes[$j]] = $values;
        }         
        $i++;               
    }
    while ($entry = ldap_next_entry($conn, $entry));
    //were done
    return ($fresult);
}




?>