<?php

/**
 * Authproc filter to generate a persistent NameID.
 *
 * @package simpleSAMLphp
 */
class sspmod_saml_Auth_Process_SQLPersistentNameID extends sspmod_saml_BaseNameIDGenerator {

	/**
	 * Which attribute contains the unique identifier of the user.
	 *
	 * @var string
	 */
	private $attribute;

	/**
	 * Whether we should create a persistent NameID if not explicitly requested (as saml:PersistentNameID does).
	 *
	 * @var boolean
	 */
	private $allowUnspecified;

	/**
	 * Whether we should create a persistent NameID if a different format is requested.
	 *
	 * @var boolean
	 */
	private $allowDifferent;

	/**
	 * Whether we should ignore allowCreate in the NameID policy
	 *
	 * @var boolean
	 */
	private $alwaysCreate;


	/**
	 * Initialize this filter, parse configuration.
	 *
	 * @param array $config  Configuration information about this filter.
	 * @param mixed $reserved  For future use.
	 */
	public function __construct($config, $reserved) {
		parent::__construct($config, $reserved);
		assert('is_array($config)');

		$this->format = SAML2_Const::NAMEID_PERSISTENT;

		if (!isset($config['attribute'])) {
			throw new SimpleSAML_Error_Exception('PersistentNameID: Missing required option \'attribute\'.');
		}
		$this->attribute = $config['attribute'];

		if (isset($config['allowUnspecified'])) {
			$this->allowUnspecified = (bool)$config['allowUnspecified'];
		} else {
			$this->allowUnspecified = FALSE;
		}

		if (isset($config['allowDifferent'])) {
			$this->allowDifferent = (bool)$config['allowDifferent'];
		} else {
			$this->allowDifferent = FALSE;
		}

		if (isset($config['alwaysCreate'])) {
			$this->alwaysCreate = (bool)$config['alwaysCreate'];
		} else {
			$this->alwaysCreate = FALSE;
		}
	}


	/**
	 * Get the NameID value.
	 *
	 * @return string|NULL  The NameID value.
	 */
	protected function getValue(array &$state) {

		if (!isset($state['saml:NameIDFormat']) && !$this->allowUnspecified) {
			SimpleSAML_Logger::debug('SQLPersistentNameID: Request did not specify persistent NameID format -  not generating persistent NameID.');
			return NULL;
		}

		$validNameIdFormats = @array_filter(array($state['saml:NameIDFormat'], $state['SPMetadata']['NameIDPolicy'], $state['SPMetadata']['NameIDFormat']));
		if (count($validNameIdFormats) && !in_array($this->format, $validNameIdFormats) && !$this->allowDifferent) {
			SimpleSAML_Logger::debug('SQLPersistentNameID: SP expects different NameID format (' . implode(', ', $validNameIdFormats) . ') -  not generating persistent NameID.');
			return NULL;
		}

		if (!isset($state['Destination']['entityid'])) {
			SimpleSAML_Logger::warning('SQLPersistentNameID: No SP entity ID - not generating persistent NameID.');
			return NULL;
		}
		$spEntityId = $state['Destination']['entityid'];

		if (!isset($state['Source']['entityid'])) {
			SimpleSAML_Logger::warning('SQLPersistentNameID: No IdP entity ID - not generating persistent NameID.');
			return NULL;
		}
		$idpEntityId = $state['Source']['entityid'];

		if (!isset($state['Attributes'][$this->attribute]) || count($state['Attributes'][$this->attribute]) === 0) {
			SimpleSAML_Logger::warning('SQLPersistentNameID: Missing attribute ' . var_export($this->attribute, TRUE) . ' on user - not generating persistent NameID.');
			return NULL;
		}
		if (count($state['Attributes'][$this->attribute]) > 1) {
			SimpleSAML_Logger::warning('SQLPersistentNameID: More than one value in attribute ' . var_export($this->attribute, TRUE) . ' on user - not generating persistent NameID.');
			return NULL;
		}
		$uid = array_values($state['Attributes'][$this->attribute]); /* Just in case the first index is no longer 0. */
		$uid = $uid[0];


		$value = sspmod_saml_IdP_SQLNameID::get($idpEntityId, $spEntityId, $uid);
		if ($value !== NULL) {
			SimpleSAML_Logger::debug('SQLPersistentNameID: Found persistent NameID ' . var_export($value, TRUE) . ' for user ' . var_export($uid, TRUE) . '.');
			return $value;
		}

		if ((!isset($state['saml:AllowCreate']) || !$state['saml:AllowCreate']) && !$this->alwaysCreate) {
			SimpleSAML_Logger::warning('SQLPersistentNameID: Did not find persistent NameID for user, and not allowed to create new NameID.');
			throw new sspmod_saml_Error(SAML2_Const::STATUS_RESPONDER, 'urn:oasis:names:tc:SAML:2.0:status:InvalidNameIDPolicy');
		}

		$value = bin2hex(openssl_random_pseudo_bytes(20));
		SimpleSAML_Logger::debug('SQLPersistentNameID: Created persistent NameID ' . var_export($value, TRUE) . ' for user ' . var_export($uid, TRUE) . '.');
		sspmod_saml_IdP_SQLNameID::add($idpEntityId, $spEntityId, $uid, $value);

		return $value;
	}

}