YOURLS-AuthMgrPlus/authmgr/plugin.php

390 lines
12 KiB
PHP
Raw Normal View History

<?php
/*
Plugin Name: Authorization Manager
Plugin URI: https://github.com/nicwaller/yourls-authmgr-plugin
Description: Restrict classes of users to specific functions
Version: 0.9.2
Author: nicwaller
Author URI: https://github.com/nicwaller
*/
// No direct call
if( !defined( 'YOURLS_ABSPATH' ) ) die();
/****************** SET UP CONSTANTS ******************/
/**
* This plugin uses filter chains to evaluate whether specific actions
* should be allowed to proceed. The filter names are defined here.
*/
define( 'AUTHMGR_ALLOW', 'filter_authmgr_allow' );
define( 'AUTHMGR_HASROLE', 'filter_authmgr_hasrole' );
// Define constants used for naming roles (but they don't work in config.php)
class AuthmgrRoles {
const Administrator = 'Administrator';
const Editor = 'Editor';
const Contributor = 'Contributor';
}
// Define constants used for naming capabilities
class AuthmgrCapability {
const ShowAdmin = 'ShowAdmin'; // only display admin panel
const AddURL = 'AddURL';
const DeleteURL = 'DeleteURL';
const EditURL = 'EditURL';
const ManagePlugins = 'ManagePlugins';
const API = 'API';
const ViewStats = 'ViewStats';
}
/********** Add hooks to intercept functionality in CORE ********/
yourls_add_action( 'load_template_infos', 'authmgr_intercept_stats' );
function authmgr_intercept_stats() {
authmgr_require_capability( AuthmgrCapability::ViewStats );
}
yourls_add_action( 'api', 'authmgr_intercept_api' );
function authmgr_intercept_api() {
authmgr_require_capability( AuthmgrCapability::API );
}
yourls_add_action( 'auth_successful', 'authmgr_intercept_admin' );
/**
* YOURLS processes most actions in the admin page. It would be ideal
* to add a unique hook for each action, but unfortunately we need to
* hook the admin page load itself, and try to figure out what action
* is intended.
*
* At this point, reasonably assume that the current request is for
* a rendering of the admin page.
*/
function authmgr_intercept_admin() {
authmgr_require_capability( AuthmgrCapability::ShowAdmin );
// we use this GET param to send up a feedback notice to user
if ( isset( $_GET['access'] ) && $_GET['access']=='denied' ) {
yourls_add_notice('Access Denied');
}
$action_capability_map = array(
'add' => AuthmgrCapability::AddURL,
'delete' => AuthmgrCapability::DeleteURL,
'edit_display' => AuthmgrCapability::EditURL,
'edit_save' => AuthmgrCapability::EditURL,
'activate' => AuthmgrCapability::ManagePlugins,
'deactivate' => AuthmgrCapability::ManagePlugins,
);
// intercept requests for plugin management
if ( isset( $_REQUEST['plugin'] ) ) {
$action_keyword = $_REQUEST['action'];
$cap_needed = $action_capability_map[$action_keyword];
if ( $cap_needed !== NULL && authmgr_have_capability( $cap_needed ) !== true) {
yourls_redirect( yourls_admin_url( '?access=denied' ), 302 );
}
}
// Key actions like Add/Edit/Delete are AJAX requests
if ( yourls_is_Ajax() ) {
$action_keyword = $_REQUEST['action'];
$cap_needed = $action_capability_map[$action_keyword];
if ( authmgr_have_capability( $cap_needed ) !== true) {
$err = array();
$err['status'] = 'fail';
$err['code'] = 'error:authorization';
$err['message'] = 'Access Denied';
$err['errorCode'] = '403';
echo json_encode( $err );
die();
}
}
}
yourls_add_filter( 'logout_link', 'authmgr_html_append_roles' );
/**
* This is a cosmetic filter that makes it possible to see which roles are
* currently available, just by mousing over the username in the logout link.
*/
function authmgr_html_append_roles( $original ) {
$authenticated = yourls_is_valid_user();
if ( $authenticated === true ) {
$listcaps = implode(', ', authmgr_enumerate_current_capabilities());
return '<div title="'.$listcaps.'">'.$original.'</div>';
} else {
return $original;
}
}
/**************** CAPABILITY TEST/ENUMERATION ****************/
/*
* If capability is not permitted in current context, then abort.
* This is the most basic way to intercept unauthorized usage.
*/
function authmgr_require_capability( $capability ) {
if ( !authmgr_have_capability( $capability ) ) {
// If the user can't view admin interface, return a plain error.
if ( !authmgr_have_capability( AuthmgrCapability::ShowAdmin ) ) {
header("HTTP/1.0 403 Forbidden");
die('Require permissions to show admin interface.');
}
// Otherwise, render errors in admin interface
yourls_redirect( yourls_admin_url( '?access=denied' ), 302 );
die();
}
}
/*
* Returns array of capabilities currently available.
*/
function authmgr_enumerate_current_capabilities() {
$current_capabilities = array();
$all_capabilities = authmgr_enumerate_all_capabilities();
foreach ( $all_capabilities as $cap ) {
if ( authmgr_have_capability( $cap ) ) {
$current_capabilities[] = $cap;
}
}
return $current_capabilities;
}
function authmgr_enumerate_all_capabilities() {
return array(
AuthmgrCapability::ShowAdmin,
AuthmgrCapability::AddURL,
AuthmgrCapability::DeleteURL,
AuthmgrCapability::EditURL,
AuthmgrCapability::ManagePlugins,
AuthmgrCapability::API,
AuthmgrCapability::ViewStats,
);
}
/*
* This is where everything comes together.
*
* Use the "allow" filter chain to see if the requested capability
* is permitted in the current context. Any function in the filter
* chain can change the response, but well-behaved functions will
* only change 'false' to 'true', never the other way around.
*/
function authmgr_have_capability( $capability ) {
return yourls_apply_filter( AUTHMGR_ALLOW, false, $capability);
}
/******************* FILTERS THAT GRANT CAPABILITIES *****************************/
/* Whether an action is permitted is decided by running a filter chain. */
/*********************************************************************************/
/*
* What capabilities are always available, including anonymous users?
*/
yourls_add_filter( AUTHMGR_ALLOW, 'authmgr_check_anon_capability', 5 );
function authmgr_check_anon_capability( $original, $capability ) {
global $authmgr_anon_capabilities;
// Shortcut - trust approval given by earlier filters
if ( $original === true ) return true;
// Make sure the anon rights list has been setup
authmgr_environment_check();
// Check list of capabilities that don't require authentication
return in_array( $capability, $authmgr_anon_capabilities );
}
/*
* What capabilities are available through role assignments to the active user?
*/
yourls_add_filter( AUTHMGR_ALLOW, 'authmgr_check_user_capability', 10 );
function authmgr_check_user_capability( $original, $capability ) {
global $authmgr_role_capabilities;
// Shortcut - trust approval given by earlier filters
if ( $original === true ) return true;
// ensure $authmgr_role_capabilities has been set up
authmgr_environment_check();
// If the user is not authenticated, then give up because only users have roles.
$authenticated = yourls_is_valid_user();
if ( $authenticated !== true )
return false;
// Enumerate the capabilities available to this user through roles
$user_caps = array();
foreach ( $authmgr_role_capabilities as $rolename => $rolecaps ) {
if ( authmgr_user_has_role( YOURLS_USER, $rolename ) ) {
$user_caps = array_merge( $user_caps, $rolecaps );
}
}
$user_caps = array_unique( $user_caps );
// Is the desired capability in the enumerated list of capabilities?
return in_array( $capability, $user_caps );
}
/*
* If the user is connecting from an IP address designated for admins,
* then all capabilities are automatically granted.
*
* By default, only 127.0.0.0/8 (localhost) is an admin range.
*/
yourls_add_filter( AUTHMGR_ALLOW, 'authmgr_check_admin_ipranges', 15 );
function authmgr_check_admin_ipranges( $original, $capability ) {
global $authmgr_admin_ipranges;
// Shortcut - trust approval given by earlier filters
if ( $original === true ) return true;
// ensure $authmgr_admin_ipranges is setup
authmgr_environment_check();
foreach ($authmgr_admin_ipranges as $range) {
if ( authmgr_cidr_match( $_SERVER['REMOTE_ADDR'], $range ) )
return true;
}
return $original; // effectively returns false
}
/*
* What capabilities are available when making API requests without a username?
*/
yourls_add_filter( AUTHMGR_ALLOW, 'authmgr_check_apiuser_capability', 15 );
function authmgr_check_apiuser_capability( $original, $capability ) {
// Shortcut - trust approval given by earlier filters
if ( $original === true ) return true;
// In API mode and not using user/path authn? Let it go.
if ( yourls_is_API() && !isset($_REQUEST['username']) )
return true;
return $original;
}
/******************** ROLE TEST AND ENUMERATION ***********************/
/*
* Determine whether a specific user has a role.
*/
function authmgr_user_has_role( $username, $rolename ) {
return yourls_apply_filter( AUTHMGR_HASROLE, false, $username, $rolename );
}
// ******************* FILTERS THAT GRANT ROLE MEMBERSHIP *********************
// By filtering AUTHMGR_HASROLE, you can connect internal roles to something else.
// Any filter handlers should execute as quickly as possible.
/*
* What role memberships are defined for the user in user/config.php?
*/
yourls_add_filter( AUTHMGR_HASROLE, 'authmgr_user_has_role_in_config');
function authmgr_user_has_role_in_config( $original, $username, $rolename ) {
global $authmgr_role_assignment;
// if no role assignments are created, grant everything
// so the site still works even if stuff is configured wrong
if ( empty( $authmgr_role_assignment ) )
return true;
// do this the case-insensitive way
// the entire array was made lowercase in environment check
$username = strtolower($username);
$rolename = strtolower($rolename);
// if the role doesn't exist, give up now.
if ( !in_array( $rolename, array_keys( $authmgr_role_assignment ) ) )
return false;
$users_in_role = $authmgr_role_assignment[$rolename];
return in_array( $username, $users_in_role );
}
/********************* VALIDATE CONFIGURATION ************************/
function authmgr_environment_check() {
global $authmgr_anon_capabilities;
global $authmgr_role_capabilities;
global $authmgr_role_assignment;
if ( !isset( $authmgr_anon_capabilities) ) {
$authmgr_anon_capabilities = array(
AuthmgrCapability::API,
);
}
if ( !isset( $authmgr_role_capabilities) ) {
$authmgr_role_capabilities = array(
AuthmgrRoles::Administrator => array(
AuthmgrCapability::ShowAdmin,
AuthmgrCapability::AddURL,
AuthmgrCapability::DeleteURL,
AuthmgrCapability::EditURL,
AuthmgrCapability::ManagePlugins,
AuthmgrCapability::API,
AuthmgrCapability::ViewStats,
),
AuthmgrRoles::Editor => array(
AuthmgrCapability::ShowAdmin,
AuthmgrCapability::AddURL,
AuthmgrCapability::EditURL,
AuthmgrCapability::DeleteURL,
AuthmgrCapability::ViewStats,
),
AuthmgrRoles::Contributor => array(
AuthmgrCapability::ShowAdmin,
AuthmgrCapability::AddURL,
AuthmgrCapability::ViewStats,
),
);
}
if ( !isset( $authmgr_role_assignment ) ) {
$authmgr_role_assignment = array();
}
if ( !isset( $authmgr_iprange_roles ) ) {
$authmgr_admin_ipranges = array(
'127.0.0.0/8',
);
}
// convert role assignment table to lower case if it hasn't been done already
// this makes searches much easier!
$authmgr_role_assignment_lower = array();
foreach ( $authmgr_role_assignment as $key => $value ) {
$t_key = strtolower( $key );
$t_value = array_map('strtolower', $value);
$authmgr_role_assignment_lower[$t_key] = $t_value;
}
$authmgr_role_assignment = $authmgr_role_assignment_lower;
unset($authmgr_role_assignment_lower);
return true;
}
// ***************** GENERAL UTILITY FUNCTIONS ********************
/*
* Borrowed from:
* http://stackoverflow.com/questions/594112/matching-an-ip-to-a-cidr-mask-in-php5
*/
function authmgr_cidr_match($ip, $range)
{
list ($subnet, $bits) = split('/', $range);
$ip = ip2long($ip);
$subnet = ip2long($subnet);
$mask = -1 << (32 - $bits);
$subnet &= $mask; # nb: in case the supplied subnet wasn't correctly aligned
return ($ip & $mask) == $subnet;
}