Web Access Control implementation for Node.js

A stand-alone or express/connect Web Access Control implementation designed for Node.js with configurable graph callback.

See also:

• Wiki article
• Ontology

Usage

Example code:

var fileCallbackOptions = {'baseUrl':'http://example.com','filename':'access.ttl'};

var accessControl = require('wac')({'graphCallback':wac.fileGraphCallback(fileCallbackOptions)});

accessControl.hasAccess('http://example.com/resource', 'GET', 'http://example.com/agent#me', null, callback);

This code creates an access control object using the rules defined in the turtle file 'access.ttl' with the base URL 'http://example.com'. The last line tests access for the resource 'http://example.com/resource' using HTTP method 'GET' for agent 'http://example.com/agent#me'.

Express middleware example code:

app.use(accessControl.middleware({}));

Uses express/connect middleware functionality of the previously created accessControl object.

wac options

cors (default: false)

Enables or disables cross-origin requests. If the application parameter is not null a cross-origin request is detected.

graph

A graph which contains the access control rules as RDF Interfaces: Graph. This option or the graphCallback option is required!

graphCallback

A callback function to fetch the graph which contains the access control rules as RDF Interfaces: Graph.

The function must accept two parameters:

• resource The resource permission is requested
• callback The callback function which is called with the graph as single parameter

This option or the graph option is required!

wac.fileGraphCallback(options)

A graphCallback function for single file access control rules.

The following options are required:

• baseUrl The base URL for the Turtle file
• filename The filename of the Turtle file

wac.directoryFileGraphCallback(options)

A graphCallbackfunction for per directory file access control rules.

The following options are required if there is no default:

• basePath The path to look at relative to the base URL (default: '')
• baseUrl The URL for the parser relative to the base path
• filename The filename of the access control rule files (default: '.acl.ttl')

hasAccess(resource, method, agent, application, callback)

Stand-alone function to check whether a agent/application has access to a resource with the given method/mode.

The following parameters must be provided:

• resource URL of the resource to check
• method HTTP method or WAC mode
• agent URL of the agent
• application CORS host
• callback The callback function with a single boolean parameter

middleware(options)

Function to create a express/connect middleware.

The following options are available:

• forbidden A function to send the 403 forbidden response (default: send only 403 status code)

The req.absoluteUrl() function is required provided by the express-utils middleware.