-
Tim van Dijen authored
ldap_connect() can return false too
Unverified08acde41
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<?php
namespace SimpleSAML\Auth;
use SimpleSAML\Error;
use SimpleSAML\Logger;
/**
* Constants defining possible errors
*/
define('ERR_INTERNAL', 1);
define('ERR_NO_USER', 2);
define('ERR_WRONG_PW', 3);
define('ERR_AS_DATA_INCONSIST', 4);
define('ERR_AS_INTERNAL', 5);
define('ERR_AS_ATTRIBUTE', 6);
// not defined in earlier PHP versions
if (!defined('LDAP_OPT_DIAGNOSTIC_MESSAGE')) {
define('LDAP_OPT_DIAGNOSTIC_MESSAGE', 0x0032);
}
/**
* The LDAP class holds helper functions to access an LDAP database.
*
* @author Andreas Aakre Solberg, UNINETT AS. <andreas.solberg@uninett.no>
* @author Anders Lund, UNINETT AS. <anders.lund@uninett.no>
* @package SimpleSAMLphp
*/
class LDAP
{
/**
* LDAP link identifier.
*
* @var resource|bool
*/
protected $ldap = null;
/**
* LDAP user: authz_id if SASL is in use, binding dn otherwise
*/
protected $authz_id = null;
/**
* Timeout value, in seconds.
*
* @var int
*/
protected $timeout = 0;
/**
* Private constructor restricts instantiation to getInstance().
*
* @param string $hostname
* @param bool $enable_tls
* @param bool $debug
* @param int $timeout
* @param int $port
* @param bool $referrals
*/
public function __construct($hostname, $enable_tls = true, $debug = false, $timeout = 0, $port = 389, $referrals = true)
{
// Debug
Logger::debug('Library - LDAP __construct(): Setup LDAP with '.
'host=\''.$hostname.
'\', tls='.var_export($enable_tls, true).
', debug='.var_export($debug, true).
', timeout='.var_export($timeout, true). ', referrals='.var_export($referrals, true));
/*
* Set debug level before calling connect. Note that this passes
* NULL to ldap_set_option, which is an undocumented feature.
*
* OpenLDAP 2.x.x or Netscape Directory SDK x.x needed for this option.
*/
if ($debug && !ldap_set_option(null, LDAP_OPT_DEBUG_LEVEL, 7)) {
Logger::warning('Library - LDAP __construct(): Unable to set debug level (LDAP_OPT_DEBUG_LEVEL) to 7');
}
/*
* Prepare a connection for to this LDAP server. Note that this function
* doesn't actually connect to the server.
*/
$this->ldap = @ldap_connect($hostname, $port);
if ($this->ldap === false) {
throw $this->makeException('Library - LDAP __construct(): Unable to connect to \''.$hostname.'\'', ERR_INTERNAL);
}
// Enable LDAP protocol version 3
if (!@ldap_set_option($this->ldap, LDAP_OPT_PROTOCOL_VERSION, 3)) {
throw $this->makeException('Library - LDAP __construct(): Failed to set LDAP Protocol version (LDAP_OPT_PROTOCOL_VERSION) to 3', ERR_INTERNAL);
}
// Set referral option
if (!@ldap_set_option($this->ldap, LDAP_OPT_REFERRALS, $referrals)) {
throw $this->makeException('Library - LDAP __construct(): Failed to set LDAP Referrals (LDAP_OPT_REFERRALS) to '.$referrals, ERR_INTERNAL);
}
// Set timeouts, if supported
// (OpenLDAP 2.x.x or Netscape Directory SDK x.x needed)
$this->timeout = $timeout;
if ($timeout > 0) {
if (!@ldap_set_option($this->ldap, LDAP_OPT_NETWORK_TIMEOUT, $timeout)) {
Logger::warning('Library - LDAP __construct(): Unable to set timeouts (LDAP_OPT_NETWORK_TIMEOUT) to '.$timeout);
}
if (!@ldap_set_option($this->ldap, LDAP_OPT_TIMELIMIT, $timeout)) {
Logger::warning('Library - LDAP __construct(): Unable to set timeouts (LDAP_OPT_TIMELIMIT) to '.$timeout);
}
}
// Enable TLS, if needed
if (stripos($hostname, "ldaps:") === false && $enable_tls) {
if (!@ldap_start_tls($this->ldap)) {
throw $this->makeException('Library - LDAP __construct(): Unable to force TLS', ERR_INTERNAL);
}
}
}
/**
* Convenience method to create an LDAPException as well as log the
* description.
*
* @param string $description
* The exception's description
* @return \Exception
*/
private function makeException($description, $type = null)
{
$errNo = 0x00;
// Log LDAP code and description, if possible
if (empty($this->ldap)) {
Logger::error($description);
} else {
$errNo = @ldap_errno($this->ldap);
}
// Decide exception type and return
if ($type) {
if ($errNo !== 0) {
// Only log real LDAP errors; not success
Logger::error($description.'; cause: \''.ldap_error($this->ldap).'\' (0x'.dechex($errNo).')');
} else {
Logger::error($description);
}
switch ($type) {
case ERR_INTERNAL:// 1 - ExInternal
return new Error\Exception($description, $errNo);
case ERR_NO_USER:// 2 - ExUserNotFound
return new Error\UserNotFound($description, $errNo);
case ERR_WRONG_PW:// 3 - ExInvalidCredential
return new Error\InvalidCredential($description, $errNo);
case ERR_AS_DATA_INCONSIST:// 4 - ExAsDataInconsist
return new Error\AuthSource('ldap', $description);
case ERR_AS_INTERNAL:// 5 - ExAsInternal
return new Error\AuthSource('ldap', $description);
}
} else {
if ($errNo !== 0) {
$description .= '; cause: \''.ldap_error($this->ldap).'\' (0x'.dechex($errNo).')';
if (@ldap_get_option($this->ldap, LDAP_OPT_DIAGNOSTIC_MESSAGE, $extendedError) && !empty($extendedError)) {
$description .= '; additional: \''.$extendedError.'\'';
}
}
switch ($errNo) {
case 0x20://LDAP_NO_SUCH_OBJECT
Logger::warning($description);
return new Error\UserNotFound($description, $errNo);
case 0x31://LDAP_INVALID_CREDENTIALS
Logger::info($description);
return new Error\InvalidCredential($description, $errNo);
case -1://NO_SERVER_CONNECTION
Logger::error($description);
return new Error\AuthSource('ldap', $description);
default:
Logger::error($description);
return new Error\AuthSource('ldap', $description);
}
}
}
/**
* Search for DN from a single base.
*
* @param string $base
* Indication of root of subtree to search
* @param string|array $attribute
* The attribute name(s) to search for.
* @param string $value
* The attribute value to search for.
* Additional search filter
* @param string|null $searchFilter
* The scope of the search
* @param string $scope
* @return string
* The DN of the resulting found element.
* @throws Error\Exception if:
* - Attribute parameter is wrong type
* @throws Error\AuthSource if:
* - Not able to connect to LDAP server
* - False search result
* - Count return false
* - Searche found more than one result
* - Failed to get first entry from result * - Failed to get DN for entry
* @throws Error\UserNotFound if:
* - Zero entries were found
*/
private function search($base, $attribute, $value, $searchFilter = null, $scope = "subtree")
{
// Create the search filter
$attribute = self::escape_filter_value($attribute, false);
$value = self::escape_filter_value($value, true);
$filter = '';
foreach ($attribute as $attr) {
$filter .= '('.$attr.'='.$value.')';
}
$filter = '(|'.$filter.')';
// Append LDAP filters if defined
if ($searchFilter != null) {
$filter = "(&".$filter."".$searchFilter.")";
}
// Search using generated filter
Logger::debug('Library - LDAP search(): Searching base ('.$scope.') \''.$base.'\' for \''.$filter.'\'');
if ($scope === 'base') {
$result = @ldap_read($this->ldap, $base, $filter, array(), 0, 0, $this->timeout, LDAP_DEREF_NEVER);
} else if ($scope === 'onelevel') {
$result = @ldap_list($this->ldap, $base, $filter, array(), 0, 0, $this->timeout, LDAP_DEREF_NEVER);
} else {
$result = @ldap_search($this->ldap, $base, $filter, array(), 0, 0, $this->timeout, LDAP_DEREF_NEVER);
}
if ($result === false) {
throw $this->makeException('Library - LDAP search(): Failed search on base \''.$base.'\' for \''.$filter.'\'');
}
// Sanity checks on search results
$count = @ldap_count_entries($this->ldap, $result);
if ($count === false) {
throw $this->makeException('Library - LDAP search(): Failed to get number of entries returned');
} elseif ($count > 1) {
// More than one entry is found. External error
throw $this->makeException('Library - LDAP search(): Found '.$count.' entries searching base \''.$base.'\' for \''.$filter.'\'', ERR_AS_DATA_INCONSIST);
} elseif ($count === 0) {
// No entry is fond => wrong username is given (or not registered in the catalogue). User error
throw $this->makeException('Library - LDAP search(): Found no entries searching base \''.$base.'\' for \''.$filter.'\'', ERR_NO_USER);
}
// Resolve the DN from the search result
$entry = @ldap_first_entry($this->ldap, $result);
if ($entry === false) {
throw $this->makeException('Library - LDAP search(): Unable to retrieve result after searching base \''.$base.'\' for \''.$filter.'\'');
}
$dn = @ldap_get_dn($this->ldap, $entry);
if ($dn === false) {
throw $this->makeException('Library - LDAP search(): Unable to get DN after searching base \''.$base.'\' for \''.$filter.'\'');
}
return $dn;
}
/**
* Search for a DN.
*
* @param string|array $base
* The base, or bases, which to search from.
* @param string|array $attribute
* The attribute name(s) searched for.
* @param string $value
* The attribute value searched for.
* @param bool $allowZeroHits * Determines if the method will throw an exception if no hits are found.
* Defaults to FALSE.
* @param string|null $searchFilter
* Additional searchFilter to be added to the (attribute=value) filter
* @param string $scope
* The scope of the search
* @return string
* The DN of the matching element, if found. If no element was found and
* $allowZeroHits is set to FALSE, an exception will be thrown; otherwise
* NULL will be returned.
* @throws Error\AuthSource if:
* - LDAP search encounter some problems when searching cataloge
* - Not able to connect to LDAP server
* @throws Error\UserNotFound if:
* - $allowZeroHits is FALSE and no result is found
*
*/
public function searchfordn($base, $attribute, $value, $allowZeroHits = false, $searchFilter = null, $scope = 'subtree')
{
// Traverse all search bases, returning DN if found
$bases = \SimpleSAML\Utils\Arrays::arrayize($base);
foreach ($bases as $current) {
try {
// Single base search
$result = $this->search($current, $attribute, $value, $searchFilter, $scope);
// We don't hawe to look any futher if user is found
if (!empty($result)) {
return $result;
}
// If search failed, attempt the other base DNs
} catch (Error\UserNotFound $e) {
// Just continue searching
}
}
// Decide what to do for zero entries
Logger::debug('Library - LDAP searchfordn(): No entries found');
if ($allowZeroHits) {
// Zero hits allowed
return null;
} else {
// Zero hits not allowed
throw $this->makeException('Library - LDAP searchfordn(): LDAP search returned zero entries for filter \'('.
join(' | ', $attribute).' = '.$value.')\' on base(s) \'('.join(' & ', $bases).')\'', 2);
}
}
/**
* This method was created specifically for the ldap:AttributeAddUsersGroups->searchActiveDirectory()
* method, but could be used for other LDAP search needs. It will search LDAP and return all the entries.
*
* @throws \Exception
* @param string|array $bases
* @param string|array $filters Array of 'attribute' => 'values' to be combined into the filter, or a raw filter string
* @param string|array $attributes Array of attributes requested from LDAP
* @param bool $and If multiple filters defined, then either bind them with & or |
* @param bool $escape Weather to escape the filter values or not
* @param string $scope The scope of the search
* @return array
*/
public function searchformultiple($bases, $filters, $attributes = array(), $and = true, $escape = true, $scope = 'subtree')
{
// Escape the filter values, if requested
if ($escape) {
$filters = $this->escape_filter_value($filters, false);
}
// Build search filter
$filter = ''; if (is_array($filters)) {
foreach ($filters as $attribute => $value) {
$filter .= "($attribute=$value)";
}
if (count($filters) > 1) {
$filter = ($and ? '(&' : '(|').$filter.')';
}
} elseif (is_string($filters)) {
$filter = $filters;
}
// Verify filter was created
if ($filter == '' || $filter == '(=)') {
throw $this->makeException('ldap:LdapConnection->search_manual : No search filters defined', ERR_INTERNAL);
}
// Verify at least one base was passed
$bases = (array) $bases;
if (empty($bases)) {
throw $this->makeException('ldap:LdapConnection->search_manual : No base DNs were passed', ERR_INTERNAL);
}
// Search each base until result is found
$result = false;
foreach ($bases as $base) {
if ($scope === 'base') {
$result = @ldap_read($this->ldap, $base, $filter, $attributes, 0, 0, $this->timeout);
} else if ($scope === 'onelevel') {
$result = @ldap_list($this->ldap, $base, $filter, $attributes, 0, 0, $this->timeout);
} else {
$result = @ldap_search($this->ldap, $base, $filter, $attributes, 0, 0, $this->timeout);
}
if ($result !== false && @ldap_count_entries($this->ldap, $result) > 0) {
break;
}
}
// Verify that a result was found in one of the bases
if ($result === false) {
throw $this->makeException(
'ldap:LdapConnection->search_manual : Failed to search LDAP using base(s) ['.
implode('; ', $bases).'] with filter ['.$filter.']. LDAP error ['.
ldap_error($this->ldap).']'
);
} elseif (@ldap_count_entries($this->ldap, $result) < 1) {
throw $this->makeException(
'ldap:LdapConnection->search_manual : No entries found in LDAP using base(s) ['.
implode('; ', $bases).'] with filter ['.$filter.']',
ERR_NO_USER
);
}
// Get all results
$results = ldap_get_entries($this->ldap, $result);
if ($results === false) {
throw $this->makeException(
'ldap:LdapConnection->search_manual : Unable to retrieve entries from search results'
);
}
// parse each entry and process its attributes
for ($i = 0; $i < $results['count']; $i++) {
$entry = $results[$i];
// iterate over the attributes of the entry
for ($j = 0; $j < $entry['count']; $j++) {
$name = $entry[$j];
$attribute = $entry[$name];
// decide whether to base64 encode or not
for ($k = 0; $k < $attribute['count']; $k++) {
// base64 encode binary attributes
if (strtolower($name) === 'jpegphoto' || strtolower($name) === 'objectguid') {
$results[$i][$name][$k] = base64_encode($attribute[$k]);
}
}
}
}
// Remove the count and return
unset($results['count']);
return $results;
}
/**
* Bind to LDAP with a specific DN and password. Simple wrapper around
* ldap_bind() with some additional logging.
*
* @param string $dn
* The DN used.
* @param string $password
* The password used.
* @param array $sasl_args
* Array of SASL options for SASL bind
* @return bool
* Returns TRUE if successful, FALSE if
* LDAP_INVALID_CREDENTIALS, LDAP_X_PROXY_AUTHZ_FAILURE,
* LDAP_INAPPROPRIATE_AUTH, LDAP_INSUFFICIENT_ACCESS
* @throws Error\Exception on other errors
*/
public function bind($dn, $password, array $sasl_args = null)
{
if ($sasl_args != null) {
if (!function_exists('ldap_sasl_bind')) {
$ex_msg = 'Library - missing SASL support';
throw $this->makeException($ex_msg);
}
// SASL Bind, with error handling
$authz_id = $sasl_args['authz_id'];
$error = @ldap_sasl_bind(
$this->ldap,
$dn,
$password,
$sasl_args['mech'],
$sasl_args['realm'],
$sasl_args['authc_id'],
$sasl_args['authz_id'],
$sasl_args['props']
);
} else {
// Simple Bind, with error handling
$authz_id = $dn;
$error = @ldap_bind($this->ldap, $dn, $password);
}
if ($error === true) {
// Good
$this->authz_id = $authz_id;
Logger::debug('Library - LDAP bind(): Bind successful with DN \''.$dn.'\'');
return true;
}
/* Handle errors
* LDAP_INVALID_CREDENTIALS
* LDAP_INSUFFICIENT_ACCESS */
switch (ldap_errno($this->ldap)) {
case 32: // LDAP_NO_SUCH_OBJECT // no break
case 47: // LDAP_X_PROXY_AUTHZ_FAILURE
// no break
case 48: // LDAP_INAPPROPRIATE_AUTH
// no break
case 49: // LDAP_INVALID_CREDENTIALS
// no break
case 50: // LDAP_INSUFFICIENT_ACCESS
return false;
default:
break;
}
// Bad
throw $this->makeException('Library - LDAP bind(): Bind failed with DN \''.$dn.'\'');
}
/**
* Applies an LDAP option to the current connection.
*
* @throws Exception
* @param $option
* @param $value
* @return void
*/
public function setOption($option, $value)
{
// Attempt to set the LDAP option
if (!@ldap_set_option($this->ldap, $option, $value)) {
throw $this->makeException(
'ldap:LdapConnection->setOption : Failed to set LDAP option ['.
$option.'] with the value ['.$value.'] error: '.ldap_error($this->ldap),
ERR_INTERNAL
);
}
// Log debug message
Logger::debug(
'ldap:LdapConnection->setOption : Set the LDAP option ['.
$option.'] with the value ['.$value.']'
);
}
/**
* Search a given DN for attributes, and return the resulting associative
* array.
*
* @param string $dn
* The DN of an element.
* @param string|array $attributes
* The names of the attribute(s) to retrieve. Defaults to NULL; that is,
* all available attributes. Note that this is not very effective.
* @param int $maxsize
* The maximum size of any attribute's value(s). If exceeded, the attribute
* will not be returned.
* @return array
* The array of attributes and their values.
* @see http://no.php.net/manual/en/function.ldap-read.php
*/
public function getAttributes($dn, $attributes = null, $maxsize = null)
{
// Preparations, including a pretty debug message...
$description = 'all attributes';
if (is_array($attributes)) {
$description = '\''.join(',', $attributes).'\'';
} else {
// Get all attributes...
// TODO: Verify that this originally was the intended behaviour. Could $attributes be a string? $attributes = array();
}
Logger::debug('Library - LDAP getAttributes(): Getting '.$description.' from DN \''.$dn.'\'');
// Attempt to get attributes
// TODO: Should aliases be dereferenced?
$result = @ldap_read($this->ldap, $dn, 'objectClass=*', $attributes, 0, 0, $this->timeout);
if ($result === false) {
throw $this->makeException('Library - LDAP getAttributes(): Failed to get attributes from DN \''.$dn.'\'');
}
$entry = @ldap_first_entry($this->ldap, $result);
if ($entry === false) {
throw $this->makeException('Library - LDAP getAttributes(): Could not get first entry from DN \''.$dn.'\'');
}
$attributes = @ldap_get_attributes($this->ldap, $entry); // Recycling $attributes... Possibly bad practice.
if ($attributes === false) {
throw $this->makeException('Library - LDAP getAttributes(): Could not get attributes of first entry from DN \''.$dn.'\'');
}
// Parsing each found attribute into our result set
$result = array(); // Recycling $result... Possibly bad practice.
for ($i = 0; $i < $attributes['count']; $i++) {
// Ignore attributes that exceed the maximum allowed size
$name = $attributes[$i];
$attribute = $attributes[$name];
// Deciding whether to base64 encode
$values = array();
for ($j = 0; $j < $attribute['count']; $j++) {
$value = $attribute[$j];
if (!empty($maxsize) && strlen($value) > $maxsize) {
// Ignoring and warning
Logger::warning('Library - LDAP getAttributes(): Attribute \''.
$name.'\' exceeded maximum allowed size by '.(strlen($value) - $maxsize));
continue;
}
// Base64 encode binary attributes
if (strtolower($name) === 'jpegphoto' || strtolower($name) === 'objectguid' || strtolower($name) === 'ms-ds-consistencyguid') {
$values[] = base64_encode($value);
} else {
$values[] = $value;
}
}
// Adding
$result[$name] = $values;
}
// We're done
Logger::debug('Library - LDAP getAttributes(): Found attributes \'('.join(',', array_keys($result)).')\'');
return $result;
}
/**
* Enter description here...
*
* @param array $config
* @param string $username
* @param string $password
* @return array|bool
*/
public function validate($config, $username, $password = null)
{
/* Escape any characters with a special meaning in LDAP. The following
* characters have a special meaning (according to RFC 2253):
* ',', '+', '"', '\', '<', '>', ';', '*'
* These characters are escaped by prefixing them with '\'. */
$username = addcslashes($username, ',+"\\<>;*');
if (isset($config['priv_user_dn'])) {
$this->bind($config['priv_user_dn'], $config['priv_user_pw']);
}
if (isset($config['dnpattern'])) {
$dn = str_replace('%username%', $username, $config['dnpattern']);
} else {
$dn = $this->searchfordn($config['searchbase'], $config['searchattributes'], $username);
}
if ($password !== null) { // checking users credentials ... assuming below that she may read her own attributes ...
// escape characters with a special meaning, also in the password
$password = addcslashes($password, ',+"\\<>;*');
if (!$this->bind($dn, $password)) {
Logger::info('Library - LDAP validate(): Failed to authenticate \''.$username.'\' using DN \''.$dn.'\'');
return false;
}
}
/*
* Retrieve attributes from LDAP
*/
$attributes = $this->getAttributes($dn, $config['attributes']);
return $attributes;
}
/**
* Borrowed function from PEAR:LDAP.
*
* Escapes the given VALUES according to RFC 2254 so that they can be safely used in LDAP filters.
*
* Any control characters with an ACII code < 32 as well as the characters with special meaning in
* LDAP filters "*", "(", ")", and "\" (the backslash) are converted into the representation of a
* backslash followed by two hex digits representing the hexadecimal value of the character.
*
* @static
* @param string|array $values Array of values to escape
* @return array Array $values, but escaped
*/
public static function escape_filter_value($values = array(), $singleValue = true)
{
// Parameter validation
$values = \SimpleSAML\Utils\Arrays::arrayize($values);
foreach ($values as $key => $val) {
// Escaping of filter meta characters
$val = str_replace('\\', '\5c', $val);
$val = str_replace('*', '\2a', $val);
$val = str_replace('(', '\28', $val);
$val = str_replace(')', '\29', $val);
// ASCII < 32 escaping
$val = self::asc2hex32($val);
if (null === $val) {
$val = '\0'; // apply escaped "null" if string is empty
}
$values[$key] = $val;
}
if ($singleValue) {
return $values[0];
}
return $values;
}
/**
* Borrowed function from PEAR:LDAP.
*
* Converts all ASCII chars < 32 to "\HEX"
*
* @param string $string String to convert
*
* @static
* @return string
*/
public static function asc2hex32($string)
{
for ($i = 0; $i < strlen($string); $i++) {
$char = substr($string, $i, 1);
if (ord($char) < 32) {
$hex = dechex(ord($char));
if (strlen($hex) == 1) {
$hex = '0'.$hex;
}
$string = str_replace($char, '\\'.$hex, $string);
}
}
return $string;
}
/**
* Convert SASL authz_id into a DN
*/
private function authzid_to_dn($searchBase, $searchAttributes, $authz_id)
{
if (preg_match("/^dn:/", $authz_id)) {
return preg_replace("/^dn:/", "", $authz_id);
}
if (preg_match("/^u:/", $authz_id)) {
return $this->searchfordn(
$searchBase,
$searchAttributes,
preg_replace("/^u:/", "", $authz_id)
);
}
return $authz_id;
}
/**
* ldap_exop_whoami accessor, if available. Use requested authz_id
* otherwise.
*
* ldap_exop_whoami() has been provided as a third party patch that
* waited several years to get its way upstream:
* http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/databases/php-ldap/files
*
* When it was integrated into PHP repository, the function prototype
* was changed, The new prototype was used in third party patch for
* PHP 7.0 and 7.1, hence the version test below.
*/
public function whoami($searchBase, $searchAttributes)
{
$authz_id = '';
if (function_exists('ldap_exop_whoami')) {
if (version_compare(phpversion(), '7', '<')) {
if (ldap_exop_whoami($this->ldap, $authz_id) !== true) {
throw $this->makeException('LDAP whoami exop failure');
}
} else {
if (($authz_id = ldap_exop_whoami($this->ldap)) === false) {
throw $this->makeException('LDAP whoami exop failure');
}
}
} else { $authz_id = $this->authz_id;
}
$dn = $this->authzid_to_dn($searchBase, $searchAttributes, $authz_id);
if (!isset($dn) || ($dn == '')) {
throw $this->makeException('Cannot figure userID');
}
return $dn;
}
}