root/lib/session.php @ 152

<?
// To use:
// include_once "session.php"
// $mysession = new Session;
// 
// $mysession->loggedin is TRUE if they have logged in
//
// other attributes are :
// username   - the username they logged in with
// fullname   - whatever full name we know for them
// last   - unix timestamp for their previous page access
// data   - var/array for persistant data, commit by calling the 'save' method


// Session management and authentication mechanism.
class Session {
public    $loggedin=FALSE;    // Is this a valid logged in user ?
public    $username='';        // Username
public    $fullname;        // Fullname
public  $email=0;        // Email waiting?
public  $groups  =array();    // users groups
public    $data='';        // Var/array for session persistant data
public    $token='';        // session identifier
public    $last='';        // Time of last page request
private    $timeout = 300;        // Idle timeout limit in minutes
private    $table = "session";    // session storage table (const)
private $datahash='';        // hash of data field

    // Create a new session id
    private function newsession()
    {
        global $DB;
        $try = 0;

        do {
            $tt=date("D M d H:i:s Y");
            $ip = $_SERVER['REMOTE_ADDR'];
            $token = md5("$ip$tt$try");
            $old = $DB->GetAll("select hash from session where hash=?", array($token));
        }while ($old);
        $DB->Execute("insert into session (hash, time, ip) values (?,NOW(),?)", array($token, $ip));
        setcookie("session", $token, NULL, "/");
        $this->token = $token;
        return;
    }

    // Public Object constructor
    function __construct()
    {
        global $DB;
        unset($token);

        // The possible form elements
        $submit = @$_POST['Login'];
        $logout = @$_POST['Logout'];
        $session_user = strtolower(@$_POST['session_user']);
        $session_pass = @$_POST['session_pass'];

        // We havent logged them in yet
        $this->loggedin = FALSE;

        // Time out any old sessions
        $DB->Execute("delete from {$this->table} where time < NOW() - '{$this->timeout} minutes'::reltime");

        // Log them out if they ask
        if ($logout=="Logout") {
            $this->logout();
            return;
        }

        // the possible token data passed from a form
        if (isset($_REQUEST['token'])) 
            $token = $_REQUEST['token'];

        // Check if we were handed a specific token identifier
        // Otherwise use the value from the cookie we gave out
        if (!isset($token) && isset($_COOKIE['session'])) 
            $token=@$_COOKIE['session'];

        if (isset($token)) $this->token = $token;

        // Okay, so we still dont have a session id
        // so issue a new one and go back to core
        if (!isset($token))  
        {
            $this->newsession();
            return;
        }

        // Is this a login attempt ?
        if ($submit != '' && $session_user != '' && $session_pass != '')
        {
            $this->session_init($session_user, $session_pass);
        }

        // Retrieve session information
        $oldsess=$DB->GetAll("select * from {$this->table} where hash=?", array($this->token));

        if (!$oldsess || count($oldsess) < 1) {
            $this->errormsg="Session timed out";
            $this->newsession();
            return;
        }

        // Extract detail of session for pass-back
        $detail = $oldsess[0];
        $this->data = unserialize((string)$detail['data']);
        $this->last = strtotime($detail['time']);
        $this->datahash = md5(serialize($this->data));

        // are we actually logged in, fill in more
        if ($detail['username']) {
            // Are we using HTTPS?
            if (!isset($_SERVER['HTTPS'])) {
                $this->errormsg = "Insecure Connection";
                $this->loggedin = FALSE;
                return;
            }
            // User is valid but they're coming from the wrong IP
            if ($detail['ip'] != $_SERVER['REMOTE_ADDR']) {
                $this->errormsg = "Invalid IP";
                $this->loggedin = FALSE;
                return;
            }
            $this->username=$detail['username'];
            $this->fetch_detail($detail['username']);
            $this->loggedin = TRUE;
        }

        // update time stamp
        $DB->Execute( "update {$this->table} set time=NOW() where hash=?", array($this->token));
    }

    // Public function: Store the session data away in the database
    public function save( )
    {
        global $DB;
        $newhash = md5(serialize($this->data));
        if ($newhash == $this->datahash) {
            // no change in data, dont save
            return;
        }

        $DB->Execute("update {$this->table} set data=? where hash=?", array(serialize($this->data),$this->token));

    }

    // Public function: force a logout of the session
    public function logout( )
    {
        global $DB;
        $DB->Execute("delete from session where hash=?", array($this->token));
        $this->newsession();
        $this->loggedin = FALSE;
    }

    // Fill out any extra details we know about the user
    private function fetch_detail( $user )
    {
        if (!($ldap = @ldap_connect("ldap://localhost"))) {
            $this->errormsg="LDAP connect failed";
            return FALSE;
        }
        $info = $this->ldap_getuser($ldap, $user);
        if (!$info) return FALSE;

        ldap_close($ldap);

        // Check the user's email status
        $mailstat = stat("/var/spool/mail/".$user);
        if ($mailstat[size]>0) {
            if ($mailstat[mtime]>$mailstat[atime]) $this->email = 2;
            else $this->email = 1;
        }

        $this->fullname = $info['cn'][0];
        $this->groups = $info['grouplist'];

    }

    /* check using mod_auth_externals helper 
    private function check_pass($user, $pass)
    {

        if ($fd === FALSE) {
            $this->errormsg = "Auth system error";
            return FALSE;
        }

        fwrite($fd, "$user\n");
        fwrite($fd, "$pass\n");
        $ret = pclose($fd);
        if ($ret == 0) return TRUE;

        $this->autherror = "u='$user' p='$pass' ret=$ret";
        $this->errormsg = "Invalid Username or Password";
        return FALSE;
    }
    */

    // Get a users full record from ldap
    private function ldap_getuser($ldap, $user)
    {
        // publically bind to find user
        if (!($bind=@ldap_bind($ldap, "", ""))) {
            $this->errormsg="LDAP bind failed";
            return NULL;
        }
        // find the user
        if (!($search=@ldap_search($ldap, "dc=sucs,dc=org", "(&(uid=$user))"))) {
            $this->errormsg="LDAP search fail";
            return NULL;
        }
        $n = ldap_count_entries($ldap, $search);
        if ($n < 1) {
            $this->errormsg = "Username or Password Incorrect";
            return NULL;
        }
        $info = ldap_get_entries($ldap, $search);

        if (($grpsearch=@ldap_search($ldap, "ou=Group,dc=sucs,dc=org", "memberuid=$user"))) {
            $gn = ldap_count_entries($ldap,$grpsearch);
            $gpile = ldap_get_entries($ldap, $grpsearch);
            $glist=array();
            for ($i=0;$i<$gn;$i++) {
                $glist[  $gpile[$i]['cn'][0] ] = $gpile[$i]['gidnumber'][0];
            }
            $info[0]['grouplist'] = $glist;
        }
        return $info[0];
    }

    /* check using ldap directly */
    private function check_pass($user, $pass)
    {
        // Open connection
        if (!($ldap = @ldap_connect("ldap://localhost"))) {
            $this->errormsg="LDAP connect failed";
            return FALSE;
        }
        $info = $this->ldap_getuser($ldap, $user);
        if (!$info) return FALSE;

        $real = @ldap_bind($ldap, $info['dn'], $pass);

        ldap_close($ldap);
        if ($real) return TRUE;
        $this->errormsg="Username or Password Incorrect";
        return FALSE;

    }

    // Private function: process login form
    private function session_init($user, $pass)
    {
        global $DB;
        // Check that this is a valid session start
        // This prevents replay attacks
        $sess = $DB->GetAll("select * from {$this->table} where hash=? and username is NULL", array($this->token));
        if (!$sess || count($sess)<1) {
            $this->errormsg = "Invalid session, login again.";
            return;
        }

        if (!$this->check_pass($user, $pass)) return;
        $this->username = $user;

        // Update the session, filling in the blanks
        $DB->Execute("update {$this->table} set username=?, time='NOW()', ip=? where hash=?", array($this->username, $_SERVER['REMOTE_ADDR'], $this->token));

        // Return back to normal session retrieval
    }

} // end of Class