Subversion Repositories SmartDukaan

<?php
/**
 * PHP configuration based AclInterface implementation
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.Controller.Component.Acl
 * @since         CakePHP(tm) v 2.1
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */

/**
 * PhpAcl implements an access control system using a plain PHP configuration file.
 * An example file can be found in app/Config/acl.php
 *
 * @package Cake.Controller.Component.Acl
 */
class PhpAcl extends Object implements AclInterface {

/**
 * Constant for deny
 *
 * @var bool
 */
        const DENY = false;

/**
 * Constant for allow
 *
 * @var bool
 */
        const ALLOW = true;

/**
 * Options:
 *  - policy: determines behavior of the check method. Deny policy needs explicit allow rules, allow policy needs explicit deny rules
 *  - config: absolute path to config file that contains the acl rules (@see app/Config/acl.php)
 *
 * @var array
 */
        public $options = array();

/**
 * Aro Object
 *
 * @var PhpAro
 */
        public $Aro = null;

/**
 * Aco Object
 *
 * @var PhpAco
 */
        public $Aco = null;

/**
 * Constructor
 *
 * Sets a few default settings up.
 */
        public function __construct() {
                $this->options = array(
                        'policy' => static::DENY,
                        'config' => APP . 'Config' . DS . 'acl.php',
                );
        }

/**
 * Initialize method
 *
 * @param AclComponent $Component Component instance
 * @return void
 */
        public function initialize(Component $Component) {
                if (!empty($Component->settings['adapter'])) {
                        $this->options = $Component->settings['adapter'] + $this->options;
                }

                App::uses('PhpReader', 'Configure');
                $Reader = new PhpReader(dirname($this->options['config']) . DS);
                $config = $Reader->read(basename($this->options['config']));
                $this->build($config);
                $Component->Aco = $this->Aco;
                $Component->Aro = $this->Aro;
        }

/**
 * build and setup internal ACL representation
 *
 * @param array $config configuration array, see docs
 * @return void
 * @throws AclException When required keys are missing.
 */
        public function build(array $config) {
                if (empty($config['roles'])) {
                        throw new AclException(__d('cake_dev', '"roles" section not found in configuration.'));
                }

                if (empty($config['rules']['allow']) && empty($config['rules']['deny'])) {
                        throw new AclException(__d('cake_dev', 'Neither "allow" nor "deny" rules were provided in configuration.'));
                }

                $rules['allow'] = !empty($config['rules']['allow']) ? $config['rules']['allow'] : array();
                $rules['deny'] = !empty($config['rules']['deny']) ? $config['rules']['deny'] : array();
                $roles = !empty($config['roles']) ? $config['roles'] : array();
                $map = !empty($config['map']) ? $config['map'] : array();
                $alias = !empty($config['alias']) ? $config['alias'] : array();

                $this->Aro = new PhpAro($roles, $map, $alias);
                $this->Aco = new PhpAco($rules);
        }

/**
 * No op method, allow cannot be done with PhpAcl
 *
 * @param string $aro ARO The requesting object identifier.
 * @param string $aco ACO The controlled object identifier.
 * @param string $action Action (defaults to *)
 * @return bool Success
 */
        public function allow($aro, $aco, $action = "*") {
                return $this->Aco->access($this->Aro->resolve($aro), $aco, $action, 'allow');
        }

/**
 * deny ARO access to ACO
 *
 * @param string $aro ARO The requesting object identifier.
 * @param string $aco ACO The controlled object identifier.
 * @param string $action Action (defaults to *)
 * @return bool Success
 */
        public function deny($aro, $aco, $action = "*") {
                return $this->Aco->access($this->Aro->resolve($aro), $aco, $action, 'deny');
        }

/**
 * No op method
 *
 * @param string $aro ARO The requesting object identifier.
 * @param string $aco ACO The controlled object identifier.
 * @param string $action Action (defaults to *)
 * @return bool Success
 */
        public function inherit($aro, $aco, $action = "*") {
                return false;
        }

/**
 * Main ACL check function. Checks to see if the ARO (access request object) has access to the
 * ACO (access control object).
 *
 * @param string $aro ARO
 * @param string $aco ACO
 * @param string $action Action
 * @return bool true if access is granted, false otherwise
 */
        public function check($aro, $aco, $action = "*") {
                $allow = $this->options['policy'];
                $prioritizedAros = $this->Aro->roles($aro);

                if ($action && $action !== "*") {
                        $aco .= '/' . $action;
                }

                $path = $this->Aco->path($aco);

                if (empty($path)) {
                        return $allow;
                }

                foreach ($path as $node) {
                        foreach ($prioritizedAros as $aros) {
                                if (!empty($node['allow'])) {
                                        $allow = $allow || count(array_intersect($node['allow'], $aros));
                                }

                                if (!empty($node['deny'])) {
                                        $allow = $allow && !count(array_intersect($node['deny'], $aros));
                                }
                        }
                }

                return $allow;
        }

}

/**
 * Access Control Object
 *
 */
class PhpAco {

/**
 * holds internal ACO representation
 *
 * @var array
 */
        protected $_tree = array();

/**
 * map modifiers for ACO paths to their respective PCRE pattern
 *
 * @var array
 */
        public static $modifiers = array(
                '*' => '.*',
        );

/**
 * Constructor
 *
 * @param array $rules Rules array
 */
        public function __construct(array $rules = array()) {
                foreach (array('allow', 'deny') as $type) {
                        if (empty($rules[$type])) {
                                $rules[$type] = array();
                        }
                }

                $this->build($rules['allow'], $rules['deny']);
        }

/**
 * return path to the requested ACO with allow and deny rules attached on each level
 *
 * @param string $aco ACO string
 * @return array
 */
        public function path($aco) {
                $aco = $this->resolve($aco);
                $path = array();
                $level = 0;
                $root = $this->_tree;
                $stack = array(array($root, 0));

                while (!empty($stack)) {
                        list($root, $level) = array_pop($stack);

                        if (empty($path[$level])) {
                                $path[$level] = array();
                        }

                        foreach ($root as $node => $elements) {
                                $pattern = '/^' . str_replace(array_keys(static::$modifiers), array_values(static::$modifiers), $node) . '$/';

                                if ($node == $aco[$level] || preg_match($pattern, $aco[$level])) {
                                        // merge allow/denies with $path of current level
                                        foreach (array('allow', 'deny') as $policy) {
                                                if (!empty($elements[$policy])) {
                                                        if (empty($path[$level][$policy])) {
                                                                $path[$level][$policy] = array();
                                                        }
                                                        $path[$level][$policy] = array_merge($path[$level][$policy], $elements[$policy]);
                                                }
                                        }

                                        // traverse
                                        if (!empty($elements['children']) && isset($aco[$level + 1])) {
                                                array_push($stack, array($elements['children'], $level + 1));
                                        }
                                }
                        }
                }

                return $path;
        }

/**
 * allow/deny ARO access to ARO
 *
 * @param string $aro ARO string
 * @param string $aco ACO string
 * @param string $action Action string
 * @param string $type access type
 * @return void
 */
        public function access($aro, $aco, $action, $type = 'deny') {
                $aco = $this->resolve($aco);
                $depth = count($aco);
                $root = $this->_tree;
                $tree = &$root;

                foreach ($aco as $i => $node) {
                        if (!isset($tree[$node])) {
                                $tree[$node] = array(
                                        'children' => array(),
                                );
                        }

                        if ($i < $depth - 1) {
                                $tree = &$tree[$node]['children'];
                        } else {
                                if (empty($tree[$node][$type])) {
                                        $tree[$node][$type] = array();
                                }

                                $tree[$node][$type] = array_merge(is_array($aro) ? $aro : array($aro), $tree[$node][$type]);
                        }
                }

                $this->_tree = &$root;
        }

/**
 * resolve given ACO string to a path
 *
 * @param string $aco ACO string
 * @return array path
 */
        public function resolve($aco) {
                if (is_array($aco)) {
                        return array_map('strtolower', $aco);
                }

                // strip multiple occurrences of '/'
                $aco = preg_replace('#/+#', '/', $aco);
                // make case insensitive
                $aco = ltrim(strtolower($aco), '/');
                return array_filter(array_map('trim', explode('/', $aco)));
        }

/**
 * build a tree representation from the given allow/deny informations for ACO paths
 *
 * @param array $allow ACO allow rules
 * @param array $deny ACO deny rules
 * @return void
 */
        public function build(array $allow, array $deny = array()) {
                $this->_tree = array();

                foreach ($allow as $dotPath => $aros) {
                        if (is_string($aros)) {
                                $aros = array_map('trim', explode(',', $aros));
                        }

                        $this->access($aros, $dotPath, null, 'allow');
                }

                foreach ($deny as $dotPath => $aros) {
                        if (is_string($aros)) {
                                $aros = array_map('trim', explode(',', $aros));
                        }

                        $this->access($aros, $dotPath, null, 'deny');
                }
        }

}

/**
 * Access Request Object
 *
 */
class PhpAro {

/**
 * role to resolve to when a provided ARO is not listed in
 * the internal tree
 *
 * @var string
 */
        const DEFAULT_ROLE = 'Role/default';

/**
 * map external identifiers. E.g. if
 *
 * array('User' => array('username' => 'jeff', 'role' => 'editor'))
 *
 * is passed as an ARO to one of the methods of AclComponent, PhpAcl
 * will check if it can be resolved to an User or a Role defined in the
 * configuration file.
 *
 * @var array
 * @see app/Config/acl.php
 */
        public $map = array(
                'User' => 'User/username',
                'Role' => 'User/role',
        );

/**
 * aliases to map
 *
 * @var array
 */
        public $aliases = array();

/**
 * internal ARO representation
 *
 * @var array
 */
        protected $_tree = array();

/**
 * Constructor
 *
 * @param array $aro The aro data
 * @param array $map The identifier mappings
 * @param array $aliases The aliases to map.
 */
        public function __construct(array $aro = array(), array $map = array(), array $aliases = array()) {
                if (!empty($map)) {
                        $this->map = $map;
                }

                $this->aliases = $aliases;
                $this->build($aro);
        }

/**
 * From the perspective of the given ARO, walk down the tree and
 * collect all inherited AROs levelwise such that AROs from different
 * branches with equal distance to the requested ARO will be collected at the same
 * index. The resulting array will contain a prioritized list of (list of) roles ordered from
 * the most distant AROs to the requested one itself.
 *
 * @param string|array $aro An ARO identifier
 * @return array prioritized AROs
 */
        public function roles($aro) {
                $aros = array();
                $aro = $this->resolve($aro);
                $stack = array(array($aro, 0));

                while (!empty($stack)) {
                        list($element, $depth) = array_pop($stack);
                        $aros[$depth][] = $element;

                        foreach ($this->_tree as $node => $children) {
                                if (in_array($element, $children)) {
                                        array_push($stack, array($node, $depth + 1));
                                }
                        }
                }

                return array_reverse($aros);
        }

/**
 * resolve an ARO identifier to an internal ARO string using
 * the internal mapping information.
 *
 * @param string|array $aro ARO identifier (User.jeff, array('User' => ...), etc)
 * @return string internal aro string (e.g. User/jeff, Role/default)
 */
        public function resolve($aro) {
                foreach ($this->map as $aroGroup => $map) {
                        list ($model, $field) = explode('/', $map, 2);
                        $mapped = '';

                        if (is_array($aro)) {
                                if (isset($aro['model']) && isset($aro['foreign_key']) && $aro['model'] === $aroGroup) {
                                        $mapped = $aroGroup . '/' . $aro['foreign_key'];
                                } elseif (isset($aro[$model][$field])) {
                                        $mapped = $aroGroup . '/' . $aro[$model][$field];
                                } elseif (isset($aro[$field])) {
                                        $mapped = $aroGroup . '/' . $aro[$field];
                                }
                        } elseif (is_string($aro)) {
                                $aro = ltrim($aro, '/');

                                if (strpos($aro, '/') === false) {
                                        $mapped = $aroGroup . '/' . $aro;
                                } else {
                                        list($aroModel, $aroValue) = explode('/', $aro, 2);

                                        $aroModel = Inflector::camelize($aroModel);

                                        if ($aroModel === $model || $aroModel === $aroGroup) {
                                                $mapped = $aroGroup . '/' . $aroValue;
                                        }
                                }
                        }

                        if (isset($this->_tree[$mapped])) {
                                return $mapped;
                        }

                        // is there a matching alias defined (e.g. Role/1 => Role/admin)?
                        if (!empty($this->aliases[$mapped])) {
                                return $this->aliases[$mapped];
                        }
                }
                return static::DEFAULT_ROLE;
        }

/**
 * adds a new ARO to the tree
 *
 * @param array $aro one or more ARO records
 * @return void
 */
        public function addRole(array $aro) {
                foreach ($aro as $role => $inheritedRoles) {
                        if (!isset($this->_tree[$role])) {
                                $this->_tree[$role] = array();
                        }

                        if (!empty($inheritedRoles)) {
                                if (is_string($inheritedRoles)) {
                                        $inheritedRoles = array_map('trim', explode(',', $inheritedRoles));
                                }

                                foreach ($inheritedRoles as $dependency) {
                                        // detect cycles
                                        $roles = $this->roles($dependency);

                                        if (in_array($role, Hash::flatten($roles))) {
                                                $path = '';

                                                foreach ($roles as $roleDependencies) {
                                                        $path .= implode('|', (array)$roleDependencies) . ' -> ';
                                                }

                                                trigger_error(__d('cake_dev', 'cycle detected when inheriting %s from %s. Path: %s', $role, $dependency, $path . $role));
                                                continue;
                                        }

                                        if (!isset($this->_tree[$dependency])) {
                                                $this->_tree[$dependency] = array();
                                        }

                                        $this->_tree[$dependency][] = $role;
                                }
                        }
                }
        }

/**
 * adds one or more aliases to the internal map. Overwrites existing entries.
 *
 * @param array $alias alias from => to (e.g. Role/13 -> Role/editor)
 * @return void
 */
        public function addAlias(array $alias) {
                $this->aliases = $alias + $this->aliases;
        }

/**
 * build an ARO tree structure for internal processing
 *
 * @param array $aros array of AROs as key and their inherited AROs as values
 * @return void
 */
        public function build(array $aros) {
                $this->_tree = array();
                $this->addRole($aros);
        }

}