<?php
/*
+-----------------------------------------------------------------------+
| Roundcube/rcube_ldap_generic.php |
| |
| This file is part of the Roundcube Webmail client |
| Copyright (C) 2006-2013, The Roundcube Dev Team |
| Copyright (C) 2012-2013, Kolab Systems AG |
| |
| Licensed under the GNU General Public License version 3 or |
| any later version with exceptions for skins & plugins. |
| See the README file for a full license statement. |
| |
| PURPOSE: |
| Provide basic functionality for accessing LDAP directories |
| |
+-----------------------------------------------------------------------+
| Author: Thomas Bruederli < roundcube @ gmail . com > |
| Aleksander Machniak < machniak @ kolabsys . com > |
+-----------------------------------------------------------------------+
*/
/*
LDAP connection properties
--------------------------
$prop = array(
'host' => '< ldap-server-address > ',
// or
'hosts' => array('directory.verisign.com'),
'port' => 389,
'use_tls' => true|false,
'ldap_version' => 3, // using LDAPv3
'auth_method' => '', // SASL authentication method (for proxy auth), e.g. DIGEST-MD5
'attributes' => array('dn'), // List of attributes to read from the server
'vlv' => false, // Enable Virtual List View to more efficiently fetch paginated data (if server supports it)
'config_root_dn' => 'cn=config', // Root DN to read config (e.g. vlv indexes) from
'numsub_filter' => '(objectClass=organizationalUnit)', // with VLV, we also use numSubOrdinates to query the total number of records. Set this filter to get all numSubOrdinates attributes for counting
'sizelimit' => '0', // Enables you to limit the count of entries fetched. Setting this to 0 means no limit.
'timelimit' => '0', // Sets the number of seconds how long is spend on the search. Setting this to 0 means no limit.
'network_timeout' => 10, // The timeout (in seconds) for connect + bind arrempts. This is only supported in PHP >= 5.3.0 with OpenLDAP 2.x
'referrals' => true|false, // Sets the LDAP_OPT_REFERRALS option. Mostly used in multi-domain Active Directory setups
);
*/
/**
* Model class to access an LDAP directories
*
* @package Framework
* @subpackage LDAP
*/
class rcube_ldap_generic
{
const UPDATE_MOD_ADD = 1;
const UPDATE_MOD_DELETE = 2;
const UPDATE_MOD_REPLACE = 4;
const UPDATE_MOD_FULL = 7;
public $conn;
public $vlv_active = false;
/** private properties */
protected $cache = null;
protected $config = array();
protected $attributes = array('dn');
protected $entries = null;
protected $result = null;
protected $debug = false;
protected $list_page = 1;
protected $page_size = 10;
protected $vlv_config = null;
/**
* Object constructor
*
* @param array $p LDAP connection properties
*/
function __construct($p)
{
$this->config = $p;
if (is_array($p['attributes']))
$this->attributes = $p['attributes'];
if (!is_array($p['hosts']) & & !empty($p['host']))
$this->config['hosts'] = array($p['host']);
}
/**
* Activate/deactivate debug mode
*
* @param boolean $dbg True if LDAP commands should be logged
*/
public function set_debug($dbg = true)
{
$this->debug = $dbg;
}
/**
* Set connection options
*
* @param mixed $opt Option name as string or hash array with multiple options
* @param mixed $val Option value
*/
public function set_config($opt, $val = null)
{
if (is_array($opt))
$this->config = array_merge($this->config, $opt);
else
$this->config[$opt] = $value;
}
/**
* Enable caching by passing an instance of rcube_cache to be used by this object
*
* @param object rcube_cache Instance or False to disable caching
*/
public function set_cache($cache_engine)
{
$this->cache = $cache_engine;
}
/**
* Set properties for VLV-based paging
*
* @param number $page Page number to list (starting at 1)
* @param number $size Number of entries to display on one page
*/
public function set_vlv_page($page, $size = 10)
{
$this->list_page = $page;
$this->page_size = $size;
}
/**
* Establish a connection to the LDAP server
*/
public function connect($host = null)
{
if (!function_exists('ldap_connect')) {
rcube::raise_error(array('code' => 100, 'type' => 'ldap',
'file' => __FILE__, 'line' => __LINE__,
'message' => "No ldap support in this installation of PHP"),
true);
return false;
}
if (is_resource($this->conn) & & $this->config['host'] == $host)
return true;
if (empty($this->config['ldap_version']))
$this->config['ldap_version'] = 3;
// iterate over hosts if none specified
if (!$host) {
if (!is_array($this->config['hosts']))
$this->config['hosts'] = array($this->config['hosts']);
foreach ($this->config['hosts'] as $host) {
if ($this->connect($host)) {
return true;
}
}
return false;
}
// open connection to the given $host
$host = rcube_utils::idn_to_ascii(rcube_utils::parse_host($host));
$hostname = $host . ($this->config['port'] ? ':'.$this->config['port'] : '');
$this->_debug("C: Connect to $hostname [{$this->config['name']}]");
if ($lc = @ldap_connect($host, $this->config['port'])) {
if ($this->config['use_tls'] === true)
if (!ldap_start_tls($lc))
continue;
$this->_debug("S: OK");
ldap_set_option($lc, LDAP_OPT_PROTOCOL_VERSION, $this->config['ldap_version']);
$this->config['host'] = $host;
$this->conn = $lc;
if (!empty($this->config['network_timeout']))
ldap_set_option($lc, LDAP_OPT_NETWORK_TIMEOUT, $this->config['network_timeout']);
if (isset($this->config['referrals']))
ldap_set_option($lc, LDAP_OPT_REFERRALS, $this->config['referrals']);
}
else {
$this->_debug("S: NOT OK");
}
if (!is_resource($this->conn)) {
rcube::raise_error(array('code' => 100, 'type' => 'ldap',
'file' => __FILE__, 'line' => __LINE__,
'message' => "Could not connect to any LDAP server, last tried $hostname"),
true);
return false;
}
return true;
}
/**
* Bind connection with (SASL-) user and password
*
* @param string $authc Authentication user
* @param string $pass Bind password
* @param string $authz Autorization user
*
* @return boolean True on success, False on error
*/
public function sasl_bind($authc, $pass, $authz=null)
{
if (!$this->conn) {
return false;
}
if (!function_exists('ldap_sasl_bind')) {
rcube::raise_error(array('code' => 100, 'type' => 'ldap',
'file' => __FILE__, 'line' => __LINE__,
'message' => "Unable to bind: ldap_sasl_bind() not exists"),
true);
return false;
}
if (!empty($authz)) {
$authz = 'u:' . $authz;
}
if (!empty($this->config['auth_method'])) {
$method = $this->config['auth_method'];
}
else {
$method = 'DIGEST-MD5';
}
$this->_debug("C: SASL Bind [mech: $method, authc: $authc, authz: $authz, pass: $pass]");
if (ldap_sasl_bind($this->conn, NULL, $pass, $method, NULL, $authc, $authz)) {
$this->_debug("S: OK");
return true;
}
$this->_debug("S: ".ldap_error($this->conn));
rcube::raise_error(array(
'code' => ldap_errno($this->conn), 'type' => 'ldap',
'file' => __FILE__, 'line' => __LINE__,
'message' => "SASL Bind failed for authcid=$authc ".ldap_error($this->conn)),
true);
return false;
}
/**
* Bind connection with DN and password
*
* @param string $dn Bind DN
* @param string $pass Bind password
*
* @return boolean True on success, False on error
*/
public function bind($dn, $pass)
{
if (!$this->conn) {
return false;
}
$this->_debug("C: Bind $dn [pass: $pass]");
if (@ldap_bind($this->conn, $dn, $pass)) {
$this->_debug("S: OK");
return true;
}
$this->_debug("S: ".ldap_error($this->conn));
rcube::raise_error(array(
'code' => ldap_errno($this->conn), 'type' => 'ldap',
'file' => __FILE__, 'line' => __LINE__,
'message' => "Bind failed for dn=$dn: ".ldap_error($this->conn)),
true);
return false;
}
/**
* Close connection to LDAP server
*/
public function close()
{
if ($this->conn) {
$this->_debug("C: Close");
ldap_unbind($this->conn);
$this->conn = null;
}
}
/**
* Return the last result set
*
* @return object rcube_ldap_result Result object
*/
function get_result()
{
return $this->result;
}
/**
* Get a specific LDAP entry, identified by its DN
*
* @param string $dn Record identifier
* @return array Hash array
*/
function get_entry($dn)
{
$rec = null;
if ($this->conn & & $dn) {
$this->_debug("C: Read $dn [(objectclass=*)]");
if ($ldap_result = @ldap_read($this->conn, $dn, '(objectclass=*)', $this->attributes)) {
$this->_debug("S: OK");
if ($entry = ldap_first_entry($this->conn, $ldap_result)) {
$rec = ldap_get_attributes($this->conn, $entry);
}
}
else {
$this->_debug("S: ".ldap_error($this->conn));
}
if (!empty($rec)) {
$rec['dn'] = $dn; // Add in the dn for the entry.
}
}
return $rec;
}
/**
* Execute the LDAP search based on the stored credentials
*
* @param string $base_dn The base DN to query
* @param string $filter The LDAP filter for search
* @param string $scope The LDAP scope (list|sub|base)
* @param array $attrs List of entry attributes to read
* @param array $prop Hash array with query configuration properties:
* - sort: array of sort attributes (has to be in sync with the VLV index)
* - search: search string used for VLV controls
* @param boolean $count_only Set to true if only entry count is requested
*
* @return mixed rcube_ldap_result object or number of entries (if count_only=true) or false on error
*/
public function search($base_dn, $filter = '', $scope = 'sub', $attrs = array('dn'), $prop = array(), $count_only = false)
{
if (!$this->conn) {
return false;
}
if (empty($filter)) {
$filter = '(objectclass=*)';
}
$this->_debug("C: Search $base_dn for $filter");
$function = self::scope2func($scope, $ns_function);
// find available VLV index for this query
if (!$count_only & & ($vlv_sort = $this->_find_vlv($base_dn, $filter, $scope, $prop['sort']))) {
// when using VLV, we get the total count by...
// ...either reading numSubOrdinates attribute
if (($sub_filter = $this->config['numsub_filter']) & &
($result_count = @$ns_function($this->conn, $base_dn, $sub_filter, array('numSubOrdinates'), 0, 0, 0))
) {
$counts = ldap_get_entries($this->conn, $result_count);
for ($vlv_count = $j = 0; $j < $counts['count']; $j++)
$vlv_count += $counts[$j]['numsubordinates'][0];
$this->_debug("D: total numsubordinates = " . $vlv_count);
}
// ...or by fetching all records dn and count them
else if (!function_exists('ldap_parse_virtuallist_control')) {
$vlv_count = $this->search($base_dn, $filter, $scope, array('dn'), $prop, true);
}
$this->vlv_active = $this->_vlv_set_controls($vlv_sort, $this->list_page, $this->page_size, $prop['search']);
}
else {
$this->vlv_active = false;
}
// only fetch dn for count (should keep the payload low)
if ($ldap_result = @$function($this->conn, $base_dn, $filter,
$attrs, 0, (int)$this->config['sizelimit'], (int)$this->config['timelimit'])
) {
// when running on a patched PHP we can use the extended functions
// to retrieve the total count from the LDAP search result
if ($this->vlv_active & & function_exists('ldap_parse_virtuallist_control')) {
if (ldap_parse_result($this->conn, $ldap_result, $errcode, $matcheddn, $errmsg, $referrals, $serverctrls)) {
ldap_parse_virtuallist_control($this->conn, $serverctrls, $last_offset, $vlv_count, $vresult);
$this->_debug("S: VLV result: last_offset=$last_offset; content_count=$vlv_count");
}
else {
$this->_debug("S: ".($errmsg ? $errmsg : ldap_error($this->conn)));
}
}
else if ($this->debug) {
$this->_debug("S: ".ldap_count_entries($this->conn, $ldap_result)." record(s) found");
}
$this->result = new rcube_ldap_result($this->conn, $ldap_result, $base_dn, $filter, $vlv_count);
return $count_only ? $this->result->count() : $this->result;
}
else {
$this->_debug("S: ".ldap_error($this->conn));
}
return false;
}
/**
* Modify an LDAP entry on the server
*
* @param string $dn Entry DN
* @param array $params Hash array of entry attributes
* @param int $mode Update mode (UPDATE_MOD_ADD | UPDATE_MOD_DELETE | UPDATE_MOD_REPLACE)
*/
public function modify($dn, $parms, $mode = 255)
{
// TODO: implement this
return false;
}
/**
* Wrapper for ldap_add()
*
* @see ldap_add()
*/
public function add($dn, $entry)
{
$this->_debug("C: Add $dn: ".print_r($entry, true));
$res = ldap_add($this->conn, $dn, $entry);
if ($res === false) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_delete()
*
* @see ldap_delete()
*/
public function delete($dn)
{
$this->_debug("C: Delete $dn");
$res = ldap_delete($this->conn, $dn);
if ($res === false) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_mod_replace()
*
* @see ldap_mod_replace()
*/
public function mod_replace($dn, $entry)
{
$this->_debug("C: Replace $dn: ".print_r($entry, true));
if (!ldap_mod_replace($this->conn, $dn, $entry)) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_mod_add()
*
* @see ldap_mod_add()
*/
public function mod_add($dn, $entry)
{
$this->_debug("C: Add $dn: ".print_r($entry, true));
if (!ldap_mod_add($this->conn, $dn, $entry)) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_mod_del()
*
* @see ldap_mod_del()
*/
public function mod_del($dn, $entry)
{
$this->_debug("C: Delete $dn: ".print_r($entry, true));
if (!ldap_mod_del($this->conn, $dn, $entry)) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_rename()
*
* @see ldap_rename()
*/
public function rename($dn, $newrdn, $newparent = null, $deleteoldrdn = true)
{
$this->_debug("C: Rename $dn to $newrdn");
if (!ldap_rename($this->conn, $dn, $newrdn, $newparent, $deleteoldrdn)) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return true;
}
/**
* Wrapper for ldap_list() + ldap_get_entries()
*
* @see ldap_list()
* @see ldap_get_entries()
*/
public function list_entries($dn, $filter, $attributes = array('dn'))
{
$list = array();
$this->_debug("C: List $dn [{$filter}]");
if ($result = ldap_list($this->conn, $dn, $filter, $attributes)) {
$list = ldap_get_entries($this->conn, $result);
if ($list === false) {
$this->_debug("S: ".ldap_error($this->conn));
return array();
}
$count = $list['count'];
unset($list['count']);
$this->_debug("S: $count record(s)");
}
else {
$this->_debug("S: ".ldap_error($this->conn));
}
return $list;
}
/**
* Wrapper for ldap_read() + ldap_get_entries()
*
* @see ldap_read()
* @see ldap_get_entries()
*/
public function read_entries($dn, $filter, $attributes = null)
{
$this->_debug("C: Read $dn [{$filter}]");
if ($this->conn & & $dn) {
if (!$attributes)
$attributes = $this->attributes;
$result = @ldap_read($this->conn, $dn, $filter, $attributes, 0, (int)$this->config['sizelimit'], (int)$this->config['timelimit']);
if ($result === false) {
$this->_debug("S: ".ldap_error($this->conn));
return false;
}
$this->_debug("S: OK");
return ldap_get_entries($this->conn, $result);
}
return false;
}
/**
* Choose the right PHP function according to scope property
*
* @param string $scope The LDAP scope (sub|base|list)
* @param string $ns_function Function to be used for numSubOrdinates queries
* @return string PHP function to be used to query directory
*/
public static function scope2func($scope, & $ns_function = null)
{
switch ($scope) {
case 'sub':
$function = $ns_function = 'ldap_search';
break;
case 'base':
$function = $ns_function = 'ldap_read';
break;
default:
$function = 'ldap_list';
$ns_function = 'ldap_read';
break;
}
return $function;
}
/**
* Convert the given scope integer value to a string representation
*/
public static function scopeint2str($scope)
{
switch ($scope) {
case 2: return 'sub';
case 1: return 'one';
case 0: return 'base';
default: $this->_debug("Scope $scope is not a valid scope integer");
}
return '';
}
/**
* Escapes the given value according to RFC 2254 so that it can be safely used in LDAP filters.
*
* @param string $val Value to quote
* @return string The escaped value
*/
public static function escape_value($val)
{
return strtr($str, array('*'=>'\2a', '('=>'\28', ')'=>'\29',
'\\'=>'\5c', '/'=>'\2f'));
}
/**
* Escapes a DN value according to RFC 2253
*
* @param string $dn DN value o quote
* @return string The escaped value
*/
public static function escape_dn($dn)
{
return strtr($str, array(','=>'\2c', '='=>'\3d', '+'=>'\2b',
'< '=>'\3c', '>'=>'\3e', ';'=>'\3b', '\\'=>'\5c',
'"'=>'\22', '#'=>'\23'));
}
/**
* Normalize a LDAP result by converting entry attributes arrays into single values
*
* @param array $result LDAP result set fetched with ldap_get_entries()
* @return array Hash array with normalized entries, indexed by their DNs
*/
public static function normalize_result($result)
{
if (!is_array($result)) {
return array();
}
$entries = array();
for ($i = 0; $i < $result['count']; $i++) {
$key = $result[$i]['dn'] ? $result[$i]['dn'] : $i;
$entries[$key] = self::normalize_entry($result[$i]);
}
return $entries;
}
/**
* Turn an LDAP entry into a regular PHP array with attributes as keys.
*
* @param array $entry Attributes array as retrieved from ldap_get_attributes() or ldap_get_entries()
*
* @return array Hash array with attributes as keys
*/
public static function normalize_entry($entry)
{
if (!isset($entry['count'])) {
return $entry;
}
$rec = array();
for ($i=0; $i < $entry['count']; $i++) {
$attr = $entry[$i];
if ($entry[$attr]['count'] == 1) {
switch ($attr) {
case 'objectclass':
$rec[$attr] = array(strtolower($entry[$attr][0]));
break;
default:
$rec[$attr] = $entry[$attr][0];
break;
}
}
else {
for ($j=0; $j < $entry[$attr]['count']; $j++) {
$rec[$attr][$j] = $entry[$attr][$j];
}
}
}
return $rec;
}
/**
* Set server controls for Virtual List View (paginated listing)
*/
private function _vlv_set_controls($sort, $list_page, $page_size, $search = null)
{
$sort_ctrl = array('oid' => "1.2.840.113556.1.4.473", 'value' => self::_sort_ber_encode((array)$sort));
$vlv_ctrl = array('oid' => "2.16.840.1.113730.3.4.9", 'value' => self::_vlv_ber_encode(($offset = ($list_page-1) * $page_size + 1), $page_size, $search), 'iscritical' => true);
$this->_debug("C: Set controls sort=" . join(' ', unpack('H'.(strlen($sort_ctrl['value'])*2), $sort_ctrl['value'])) . " ($sort[0]);"
. " vlv=" . join(' ', (unpack('H'.(strlen($vlv_ctrl['value'])*2), $vlv_ctrl['value']))) . " ($offset/$page_size; $search)");
if (!ldap_set_option($this->conn, LDAP_OPT_SERVER_CONTROLS, array($sort_ctrl, $vlv_ctrl))) {
$this->_debug("S: ".ldap_error($this->conn));
$this->set_error(self::ERROR_SEARCH, 'vlvnotsupported');
return false;
}
return true;
}
/**
* Returns unified attribute name (resolving aliases)
*/
private static function _attr_name($namev)
{
// list of known attribute aliases
static $aliases = array(
'gn' => 'givenname',
'rfc822mailbox' => 'email',
'userid' => 'uid',
'emailaddress' => 'email',
'pkcs9email' => 'email',
);
list($name, $limit) = explode(':', $namev, 2);
$suffix = $limit ? ':'.$limit : '';
return (isset($aliases[$name]) ? $aliases[$name] : $name) . $suffix;
}
/**
* Quotes attribute value string
*
* @param string $str Attribute value
* @param bool $dn True if the attribute is a DN
*
* @return string Quoted string
*/
public static function quote_string($str, $dn=false)
{
// take firt entry if array given
if (is_array($str))
$str = reset($str);
if ($dn)
$replace = array(','=>'\2c', '='=>'\3d', '+'=>'\2b', '< '=>'\3c',
'>'=>'\3e', ';'=>'\3b', '\\'=>'\5c', '"'=>'\22', '#'=>'\23');
else
$replace = array('*'=>'\2a', '('=>'\28', ')'=>'\29', '\\'=>'\5c',
'/'=>'\2f');
return strtr($str, $replace);
}
/**
* Prints debug info to the log
*/
private function _debug($str)
{
if ($this->debug & & class_exists('rcube')) {
rcube::write_log('ldap', $str);
}
}
/***************** Virtual List View (VLV) related utility functions **************** */
/**
* Return the search string value to be used in VLV controls
*/
private function _vlv_search($sort, $search)
{
foreach ($search as $attr => $value) {
if (!in_array(strtolower($attr), $sort)) {
$this->_debug("d: Cannot use VLV search using attribute not indexed: $attr (not in " . var_export($sort, true) . ")");
return null;
} else {
return $value;
}
}
}
/**
* Find a VLV index matching the given query attributes
*
* @return string Sort attribute or False if no match
*/
private function _find_vlv($base_dn, $filter, $scope, $sort_attrs = null)
{
if (!$this->config['vlv'] || $scope == 'base') {
return false;
}
// get vlv config
$vlv_config = $this->_read_vlv_config();
if ($vlv = $vlv_config[$base_dn]) {
$this->_debug("D: Found a VLV for $base_dn");
if ($vlv['filter'] == strtolower($filter) || stripos($filter, '(& '.$vlv['filter'].'(') === 0) {
$this->_debug("D: Filter matches");
if ($vlv['scope'] == $scope) {
// Not passing any sort attributes means you don't care
if (empty($sort_attrs) || in_array($sort_attrs, $vlv['sort'])) {
return $vlv['sort'][0];
}
}
else {
$this->_debug("D: Scope does not match");
}
}
else {
$this->_debug("D: Filter does not match");
}
}
else {
$this->_debug("D: No VLV for $base_dn");
}
return false;
}
/**
* Return VLV indexes and searches including necessary configuration
* details.
*/
private function _read_vlv_config()
{
if (empty($this->config['vlv']) || empty($this->config['config_root_dn'])) {
return array();
}
// return hard-coded VLV config
else if (is_array($this->config['vlv'])) {
return $this->config['vlv'];
}
// return cached result
if (is_array($this->vlv_config)) {
return $this->vlv_config;
}
if ($this->cache & & ($cached_config = $this->cache->get('vlvconfig'))) {
$this->vlv_config = $cached_config;
return $this->vlv_config;
}
$this->vlv_config = array();
$ldap_result = ldap_search($this->conn, $this->config['config_root_dn'], '(objectclass=vlvsearch)', array('*'), 0, 0, 0);
$vlv_searches = new rcube_ldap_result($this->conn, $ldap_result, $this->config['config_root_dn'], '(objectclass=vlvsearch)');
if ($vlv_searches->count() < 1 ) {
$this->_debug("D: Empty result from search for '(objectclass=vlvsearch)' on '$config_root_dn'");
return array();
}
foreach ($vlv_searches->entries(true) as $vlv_search_dn => $vlv_search_attrs) {
// Multiple indexes may exist
$ldap_result = ldap_search($this->conn, $vlv_search_dn, '(objectclass=vlvindex)', array('*'), 0, 0, 0);
$vlv_indexes = new rcube_ldap_result($this->conn, $ldap_result, $vlv_search_dn, '(objectclass=vlvindex)');
// Reset this one for each VLV search.
$_vlv_sort = array();
foreach ($vlv_indexes->entries(true) as $vlv_index_dn => $vlv_index_attrs) {
$_vlv_sort[] = explode(' ', $vlv_index_attrs['vlvsort']);
}
$this->vlv_config[$vlv_search_attrs['vlvbase']] = array(
'scope' => self::scopeint2str($vlv_search_attrs['vlvscope']),
'filter' => strtolower($vlv_search_attrs['vlvfilter']),
'sort' => $_vlv_sort,
);
}
// cache this
if ($this->cache)
$this->cache->set('vlvconfig', $this->vlv_config);
$this->_debug("D: Refreshed VLV config: " . var_export($this->vlv_config, true));
return $this->vlv_config;
}
/**
* Generate BER encoded string for Virtual List View option
*
* @param integer List offset (first record)
* @param integer Records per page
*
* @return string BER encoded option value
*/
private static function _vlv_ber_encode($offset, $rpp, $search = '')
{
/*
this string is ber-encoded, php will prefix this value with:
04 (octet string) and 10 (length of 16 bytes)
the code behind this string is broken down as follows:
30 = ber sequence with a length of 0e (14) bytes following
02 = type integer (in two's complement form) with 2 bytes following (beforeCount): 01 00 (ie 0)
02 = type integer (in two's complement form) with 2 bytes following (afterCount): 01 18 (ie 25-1=24)
a0 = type context-specific/constructed with a length of 06 (6) bytes following
02 = type integer with 2 bytes following (offset): 01 01 (ie 1)
02 = type integer with 2 bytes following (contentCount): 01 00
with a search string present:
81 = type context-specific/constructed with a length of 04 (4) bytes following (the length will change here)
81 indicates a user string is present where as a a0 indicates just a offset search
81 = type context-specific/constructed with a length of 06 (6) bytes following
The following info was taken from the ISO/IEC 8825-1:2003 x.690 standard re: the
encoding of integer values (note: these values are in
two-complement form so since offset will never be negative bit 8 of the
leftmost octet should never by set to 1):
8.3.2: If the contents octets of an integer value encoding consist
of more than one octet, then the bits of the first octet (rightmost)
and bit 8 of the second (to the left of first octet) octet:
a) shall not all be ones; and
b) shall not all be zero
*/
if ($search) {
$search = preg_replace('/[^-[:alpha:] ,.()0-9]+/', '', $search);
$ber_val = self::_string2hex($search);
$str = self::_ber_addseq($ber_val, '81');
}
else {
// construct the string from right to left
$str = "020100"; # contentCount
$ber_val = self::_ber_encode_int($offset); // returns encoded integer value in hex format
// calculate octet length of $ber_val
$str = self::_ber_addseq($ber_val, '02') . $str;
// now compute length over $str
$str = self::_ber_addseq($str, 'a0');
}
// now tack on records per page
$str = "020100" . self::_ber_addseq(self::_ber_encode_int($rpp-1), '02') . $str;
// now tack on sequence identifier and length
$str = self::_ber_addseq($str, '30');
return pack('H'.strlen($str), $str);
}
/**
* create ber encoding for sort control
*
* @param array List of cols to sort by
* @return string BER encoded option value
*/
private static function _sort_ber_encode($sortcols)
{
$str = '';
foreach (array_reverse((array)$sortcols) as $col) {
$ber_val = self::_string2hex($col);
// 30 = ber sequence with a length of octet value
// 04 = octet string with a length of the ascii value
$oct = self::_ber_addseq($ber_val, '04');
$str = self::_ber_addseq($oct, '30') . $str;
}
// now tack on sequence identifier and length
$str = self::_ber_addseq($str, '30');
return pack('H'.strlen($str), $str);
}
/**
* Add BER sequence with correct length and the given identifier
*/
private static function _ber_addseq($str, $identifier)
{
$len = dechex(strlen($str)/2);
if (strlen($len) % 2 != 0)
$len = '0'.$len;
return $identifier . $len . $str;
}
/**
* Returns BER encoded integer value in hex format
*/
private static function _ber_encode_int($offset)
{
$val = dechex($offset);
$prefix = '';
// check if bit 8 of high byte is 1
if (preg_match('/^[89abcdef]/', $val))
$prefix = '00';
if (strlen($val)%2 != 0)
$prefix .= '0';
return $prefix . $val;
}
/**
* Returns ascii string encoded in hex
*/
private static function _string2hex($str)
{
$hex = '';
for ($i=0; $i < strlen ( $ str ) ; $ i + + ) {
$hex .= dechex(ord($str[$i]));
}
return $hex;
}
}
