* @copyright 2009 Benedikt Hallinger
* @license http://www.gnu.org/licenses/lgpl-3.0.txt LGPLv3
* @version SVN: $Id: Filter.php 289978 2009-10-27 09:56:41Z beni $
* @link http://pear.php.net/package/Net_LDAP2/
*/
/**
* Includes
*/
require_once 'PEAR.php';
require_once 'Util.php';
/**
* Object representation of a part of a LDAP filter.
*
* This Class is not completely compatible to the PERL interface!
*
* The purpose of this class is, that users can easily build LDAP filters
* without having to worry about right escaping etc.
* A Filter is built using several independent filter objects
* which are combined afterwards. This object works in two
* modes, depending how the object is created.
* If the object is created using the {@link create()} method, then this is a leaf-object.
* If the object is created using the {@link combine()} method, then this is a container object.
*
* LDAP filters are defined in RFC-2254 and can be found under
* {@link http://www.ietf.org/rfc/rfc2254.txt}
*
* Here a quick copy&paste example:
*
* $filter0 = Net_LDAP2_Filter::create('stars', 'equals', '***');
* $filter_not0 = Net_LDAP2_Filter::combine('not', $filter0);
*
* $filter1 = Net_LDAP2_Filter::create('gn', 'begins', 'bar');
* $filter2 = Net_LDAP2_Filter::create('gn', 'ends', 'baz');
* $filter_comp = Net_LDAP2_Filter::combine('or',array($filter_not0, $filter1, $filter2));
*
* echo $filter_comp->asString();
* // This will output: (|(!(stars=\0x5c0x2a\0x5c0x2a\0x5c0x2a))(gn=bar*)(gn=*baz))
* // The stars in $filter0 are treaten as real stars unless you disable escaping.
*
*
* @category Net
* @package Net_LDAP2
* @author Benedikt Hallinger
* @license http://www.gnu.org/copyleft/lesser.html LGPL
* @link http://pear.php.net/package/Net_LDAP2/
*/
class Net_LDAP2_Filter extends PEAR
{
/**
* Storage for combination of filters
*
* This variable holds a array of filter objects
* that should be combined by this filter object.
*
* @access protected
* @var array
*/
protected $_subfilters = array();
/**
* Match of this filter
*
* If this is a leaf filter, then a matching rule is stored,
* if it is a container, then it is a logical operator
*
* @access protected
* @var string
*/
protected $_match;
/**
* Single filter
*
* If we operate in leaf filter mode,
* then the constructing method stores
* the filter representation here
*
* @acces private
* @var string
*/
protected $_filter;
/**
* Create a new Net_LDAP2_Filter object and parse $filter.
*
* This is for PERL Net::LDAP interface.
* Construction of Net_LDAP2_Filter objects should happen through either
* {@link create()} or {@link combine()} which give you more control.
* However, you may use the perl iterface if you already have generated filters.
*
* @param string $filter LDAP filter string
*
* @see parse()
*/
public function __construct($filter = false)
{
// The optional parameter must remain here, because otherwise create() crashes
if (false !== $filter) {
$filter_o = self::parse($filter);
if (PEAR::isError($filter_o)) {
$this->_filter = $filter_o; // assign error, so asString() can report it
} else {
$this->_filter = $filter_o->asString();
}
}
}
/**
* Constructor of a new part of a LDAP filter.
*
* The following matching rules exists:
* - equals: One of the attributes values is exactly $value
* Please note that case sensitiviness is depends on the
* attributes syntax configured in the server.
* - begins: One of the attributes values must begin with $value
* - ends: One of the attributes values must end with $value
* - contains: One of the attributes values must contain $value
* - present | any: The attribute can contain any value but must be existent
* - greater: The attributes value is greater than $value
* - less: The attributes value is less than $value
* - greaterOrEqual: The attributes value is greater or equal than $value
* - lessOrEqual: The attributes value is less or equal than $value
* - approx: One of the attributes values is similar to $value
*
* If $escape is set to true (default) then $value will be escaped
* properly. If it is set to false then $value will be treaten as raw filter value string.
* You should escape yourself using {@link Net_LDAP2_Util::escape_filter_value()}!
*
* Examples:
*
* // This will find entries that contain an attribute "sn" that ends with "foobar":
* $filter = new Net_LDAP2_Filter('sn', 'ends', 'foobar');
*
* // This will find entries that contain an attribute "sn" that has any value set:
* $filter = new Net_LDAP2_Filter('sn', 'any');
*
*
* @param string $attr_name Name of the attribute the filter should apply to
* @param string $match Matching rule (equals, begins, ends, contains, greater, less, greaterOrEqual, lessOrEqual, approx, any)
* @param string $value (optional) if given, then this is used as a filter
* @param boolean $escape Should $value be escaped? (default: yes, see {@link Net_LDAP2_Util::escape_filter_value()} for detailed information)
*
* @return Net_LDAP2_Filter|Net_LDAP2_Error
*/
public static function &create($attr_name, $match, $value = '', $escape = true)
{
$leaf_filter = new Net_LDAP2_Filter();
if ($escape) {
$array = Net_LDAP2_Util::escape_filter_value(array($value));
$value = $array[0];
}
switch (strtolower($match)) {
case 'equals':
$leaf_filter->_filter = '(' . $attr_name . '=' . $value . ')';
break;
case 'begins':
$leaf_filter->_filter = '(' . $attr_name . '=' . $value . '*)';
break;
case 'ends':
$leaf_filter->_filter = '(' . $attr_name . '=*' . $value . ')';
break;
case 'contains':
$leaf_filter->_filter = '(' . $attr_name . '=*' . $value . '*)';
break;
case 'greater':
$leaf_filter->_filter = '(' . $attr_name . '>' . $value . ')';
break;
case 'less':
$leaf_filter->_filter = '(' . $attr_name . '<' . $value . ')';
break;
case 'greaterorequal':
case '>=':
$leaf_filter->_filter = '(' . $attr_name . '>=' . $value . ')';
break;
case 'lessorequal':
case '<=':
$leaf_filter->_filter = '(' . $attr_name . '<=' . $value . ')';
break;
case 'approx':
case '~=':
$leaf_filter->_filter = '(' . $attr_name . '~=' . $value . ')';
break;
case 'any':
case 'present': // alias that may improve user code readability
$leaf_filter->_filter = '(' . $attr_name . '=*)';
break;
default:
return PEAR::raiseError('Net_LDAP2_Filter create error: matching rule "' . $match . '" not known!');
}
return $leaf_filter;
}
/**
* Combine two or more filter objects using a logical operator
*
* This static method combines two or more filter objects and returns one single
* filter object that contains all the others.
* Call this method statically: $filter = Net_LDAP2_Filter('or', array($filter1, $filter2))
* If the array contains filter strings instead of filter objects, we will try to parse them.
*
* @param string $log_op The locicall operator. May be "and", "or", "not" or the subsequent logical equivalents "&", "|", "!"
* @param array|Net_LDAP2_Filter $filters array with Net_LDAP2_Filter objects
*
* @return Net_LDAP2_Filter|Net_LDAP2_Error
* @static
*/
public static function &combine($log_op, $filters)
{
if (PEAR::isError($filters)) {
return $filters;
}
// substitude named operators to logical operators
if ($log_op == 'and') $log_op = '&';
if ($log_op == 'or') $log_op = '|';
if ($log_op == 'not') $log_op = '!';
// tests for sane operation
if ($log_op == '!') {
// Not-combination, here we only accept one filter object or filter string
if ($filters instanceof Net_LDAP2_Filter) {
$filters = array($filters); // force array
} elseif (is_string($filters)) {
$filter_o = self::parse($filters);
if (PEAR::isError($filter_o)) {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: '.$filter_o->getMessage());
return $err;
} else {
$filters = array($filter_o);
}
} elseif (is_array($filters)) {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: operator is "not" but $filter is an array!');
return $err;
} else {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: operator is "not" but $filter is not a valid Net_LDAP2_Filter nor a filter string!');
return $err;
}
} elseif ($log_op == '&' || $log_op == '|') {
if (!is_array($filters) || count($filters) < 2) {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: parameter $filters is not an array or contains less than two Net_LDAP2_Filter objects!');
return $err;
}
} else {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: logical operator is not known!');
return $err;
}
$combined_filter = new Net_LDAP2_Filter();
foreach ($filters as $key => $testfilter) { // check for errors
if (PEAR::isError($testfilter)) {
return $testfilter;
} elseif (is_string($testfilter)) {
// string found, try to parse into an filter object
$filter_o = self::parse($testfilter);
if (PEAR::isError($filter_o)) {
return $filter_o;
} else {
$filters[$key] = $filter_o;
}
} elseif (!$testfilter instanceof Net_LDAP2_Filter) {
$err = PEAR::raiseError('Net_LDAP2_Filter combine error: invalid object passed in array $filters!');
return $err;
}
}
$combined_filter->_subfilters = $filters;
$combined_filter->_match = $log_op;
return $combined_filter;
}
/**
* Parse FILTER into a Net_LDAP2_Filter object
*
* This parses an filter string into Net_LDAP2_Filter objects.
*
* @param string $FILTER The filter string
*
* @access static
* @return Net_LDAP2_Filter|Net_LDAP2_Error
* @todo Leaf-mode: Do we need to escape at all? what about *-chars?check for the need of encoding values, tackle problems (see code comments)
*/
public static function parse($FILTER)
{
if (preg_match('/^\((.+?)\)$/', $FILTER, $matches)) {
if (in_array(substr($matches[1], 0, 1), array('!', '|', '&'))) {
// Subfilter processing: pass subfilters to parse() and combine
// the objects using the logical operator detected
// we have now something like "&(...)(...)(...)" but at least one part ("!(...)").
// Each subfilter could be an arbitary complex subfilter.
// extract logical operator and filter arguments
$log_op = substr($matches[1], 0, 1);
$remaining_component = substr($matches[1], 1);
// split $remaining_component into individual subfilters
// we cannot use split() for this, because we do not know the
// complexiness of the subfilter. Thus, we look trough the filter
// string and just recognize ending filters at the first level.
// We record the index number of the char and use that information
// later to split the string.
$sub_index_pos = array();
$prev_char = ''; // previous character looked at
$level = 0; // denotes the current bracket level we are,
// >1 is too deep, 1 is ok, 0 is outside any
// subcomponent
for ($curpos = 0; $curpos < strlen($remaining_component); $curpos++) {
$cur_char = substr($remaining_component, $curpos, 1);
// rise/lower bracket level
if ($cur_char == '(' && $prev_char != '\\') {
$level++;
} elseif ($cur_char == ')' && $prev_char != '\\') {
$level--;
}
if ($cur_char == '(' && $prev_char == ')' && $level == 1) {
array_push($sub_index_pos, $curpos); // mark the position for splitting
}
$prev_char = $cur_char;
}
// now perform the splits. To get also the last part, we
// need to add the "END" index to the split array
array_push($sub_index_pos, strlen($remaining_component));
$subfilters = array();
$oldpos = 0;
foreach ($sub_index_pos as $s_pos) {
$str_part = substr($remaining_component, $oldpos, $s_pos - $oldpos);
array_push($subfilters, $str_part);
$oldpos = $s_pos;
}
// some error checking...
if (count($subfilters) == 1) {
// only one subfilter found
} elseif (count($subfilters) > 1) {
// several subfilters found
if ($log_op == "!") {
return PEAR::raiseError("Filter parsing error: invalid filter syntax - NOT operator detected but several arguments given!");
}
} else {
// this should not happen unless the user specified a wrong filter
return PEAR::raiseError("Filter parsing error: invalid filter syntax - got operator '$log_op' but no argument!");
}
// Now parse the subfilters into objects and combine them using the operator
$subfilters_o = array();
foreach ($subfilters as $s_s) {
$o = self::parse($s_s);
if (PEAR::isError($o)) {
return $o;
} else {
array_push($subfilters_o, self::parse($s_s));
}
}
$filter_o = self::combine($log_op, $subfilters_o);
return $filter_o;
} else {
// This is one leaf filter component, do some syntax checks, then escape and build filter_o
// $matches[1] should be now something like "foo=bar"
// detect multiple leaf components
// [TODO] Maybe this will make problems with filters containing brackets inside the value
if (stristr($matches[1], ')(')) {
return PEAR::raiseError("Filter parsing error: invalid filter syntax - multiple leaf components detected!");
} else {
$filter_parts = preg_split('/(?|<|>=|<=)/', $matches[1], 2, PREG_SPLIT_DELIM_CAPTURE);
if (count($filter_parts) != 3) {
return PEAR::raiseError("Filter parsing error: invalid filter syntax - unknown matching rule used");
} else {
$filter_o = new Net_LDAP2_Filter();
// [TODO]: Do we need to escape at all? what about *-chars user provide and that should remain special?
// I think, those prevent escaping! We need to check against PERL Net::LDAP!
// $value_arr = Net_LDAP2_Util::escape_filter_value(array($filter_parts[2]));
// $value = $value_arr[0];
$value = $filter_parts[2];
$filter_o->_filter = '('.$filter_parts[0].$filter_parts[1].$value.')';
return $filter_o;
}
}
}
} else {
// ERROR: Filter components must be enclosed in round brackets
return PEAR::raiseError("Filter parsing error: invalid filter syntax - filter components must be enclosed in round brackets");
}
}
/**
* Get the string representation of this filter
*
* This method runs through all filter objects and creates
* the string representation of the filter. If this
* filter object is a leaf filter, then it will return
* the string representation of this filter.
*
* @return string|Net_LDAP2_Error
*/
public function asString()
{
if ($this->isLeaf()) {
$return = $this->_filter;
} else {
$return = '';
foreach ($this->_subfilters as $filter) {
$return = $return.$filter->asString();
}
$return = '(' . $this->_match . $return . ')';
}
return $return;
}
/**
* Alias for perl interface as_string()
*
* @see asString()
* @return string|Net_LDAP2_Error
*/
public function as_string()
{
return $this->asString();
}
/**
* Print the text representation of the filter to FH, or the currently selected output handle if FH is not given
*
* This method is only for compatibility to the perl interface.
* However, the original method was called "print" but due to PHP language restrictions,
* we can't have a print() method.
*
* @param resource $FH (optional) A filehandle resource
*
* @return true|Net_LDAP2_Error
*/
public function printMe($FH = false)
{
if (!is_resource($FH)) {
if (PEAR::isError($FH)) {
return $FH;
}
$filter_str = $this->asString();
if (PEAR::isError($filter_str)) {
return $filter_str;
} else {
print($filter_str);
}
} else {
$filter_str = $this->asString();
if (PEAR::isError($filter_str)) {
return $filter_str;
} else {
$res = @fwrite($FH, $this->asString());
if ($res == false) {
return PEAR::raiseError("Unable to write filter string to filehandle \$FH!");
}
}
}
return true;
}
/**
* This can be used to escape a string to provide a valid LDAP-Filter.
*
* LDAP will only recognise certain characters as the
* character istself if they are properly escaped. This is
* what this method does.
* The method can be called statically, so you can use it outside
* for your own purposes (eg for escaping only parts of strings)
*
* In fact, this is just a shorthand to {@link Net_LDAP2_Util::escape_filter_value()}.
* For upward compatibiliy reasons you are strongly encouraged to use the escape
* methods provided by the Net_LDAP2_Util class.
*
* @param string $value Any string who should be escaped
*
* @static
* @return string The string $string, but escaped
* @deprecated Do not use this method anymore, instead use Net_LDAP2_Util::escape_filter_value() directly
*/
public static function escape($value)
{
$return = Net_LDAP2_Util::escape_filter_value(array($value));
return $return[0];
}
/**
* Is this a container or a leaf filter object?
*
* @access protected
* @return boolean
*/
protected function isLeaf()
{
if (count($this->_subfilters) > 0) {
return false; // Container!
} else {
return true; // Leaf!
}
}
}
?>