OpenID for Node.js v0.2.0 released

I am pleased to announce the release of OpenID for Node.js v0.2.0. It deserves a blog post since the new version is a bump of the minor version number. What does this mean to the users of the library?

API changes

The API of the entire thing has changed. All callbacks exposed and used by the library are now on the form callback(error, args). This convention is familiar to Node.js developers, and gives us the advantage of simpler integration with other libraries, as well as a slight increase in the fidelity of error messages.

What has changed?

  • authenticate now expects a callback which will be called with (error, authUrl). Existing code which expects (authUrl) will not get an authUrl (but possibly an error instead), and so authentication won’t work after upgrade until you change your code.
  • verifyAssertion also expects a callback of the same form, which will be called with (error, result). Again, existing code depends on receiving a (result) call, and will break.
  • loadAssociation and saveAssociation must now accept a callback on the form (error, result) as an additional parameter. Previously, these functions were synchronous, so existing implementations will have to adapt so they call the callback rather than return.

What is new?

As usual, we have fixed several bugs. The library is gaining a community, and there have been several contributions along the 0.1 release path leading up to 0.2.0. Thank you all for your participation!

Apart from the changes above, 0.2.0 also introduces a discovery cache for caching discovered information. This cache is used to avoid additional HTTP requests when verifying assertions from the OpenID providers. The default cache is an in-memory cache, but you can implement your own by overloading two functions:

  • loadDiscoveredInformation(claimedIdentifier, callback) is expected to look for and load a cached provider for the given claimedIdentifier. It is expected to call callback(error, provider) when finished, with either an error or a provider (duh).
  • saveDiscoveredInformation(provider, callback) is expected to cache the given provider. The key for this object is provider.claimedIdentifier, which loadDiscoveredInformation uses for lookup. After saving, the function is expected to call callback(error) with an error if something failed, or nothing if all went well.

I have been very reluctant to make these significant API changes, but the recent development, reported issues, and feature requests have convinced me that a unified API, and a more familiar API for Node.js developers, is the right way. Also, adapting to the new API is a pretty easy process. I hope you agree with me that the introduction of these changes is best in the long run.

Diffie-Hellman support in Node.js

Yay! My patch implementing support for Diffie-Hellman key exchange in Node.js has finally been merged into the Node.js master branch. This will simplify the OpenID for Node.js codebase a lot. It will also make the OpenID association phase run a lot faster, since the current code does Diffie-Hellman in Javascript while the Node.js crypto version does it all in native code using OpenSSL.

A brief API overview:

  • crypto.createDiffieHellman(prime_length)
    • Creates a Diffie-Hellman key exchange object and generates a prime of the given bit length. The generator used is 2.
  • crypto.createDiffieHellman(prime, encoding='binary')
    • Creates a Diffie-Hellman key exchange object using the supplied prime. The generator used is 2. Encoding can be 'binary', 'hex', or 'base64'.
  • diffieHellman.generateKeys(encoding='binary')
    • Generates private and public Diffie-Hellman key values, and returns the public key in the specified encoding. This key should be transferred to the other party. Encoding can be 'binary', 'hex', or 'base64'.
  • diffieHellman.computeSecret(other_public_key, input_encoding='binary', output_encoding=input_encoding)
    • Computes the shared secret using other_public_key as the other party’s public key and returns the computed shared secret. Supplied key is interpreted using specified input_encoding, and secret is encoded using specified output_encoding. Encodings can be 'binary', 'hex', or 'base64'. If no output encoding is given, the input encoding is used as output encoding.
  • diffieHellman.getPrime(encoding='binary')
    • Returns the Diffie-Hellman prime in the specified encoding, which can be 'binary', 'hex', or 'base64'.
  • diffieHellman.getGenerator(encoding='binary')
    • Returns the Diffie-Hellman prime in the specified encoding, which can be 'binary', 'hex', or 'base64'.
  • diffieHellman.getPublicKey(encoding='binary')
    • Returns the Diffie-Hellman public key in the specified encoding, which can be 'binary', 'hex', or 'base64'.
  • diffieHellman.getPrivateKey(encoding='binary')
    • Returns the Diffie-Hellman private key in the specified encoding, which can be 'binary', 'hex', or 'base64'.
  • diffieHellman.setPublicKey(public_key, encoding='binary')
    • Sets the Diffie-Hellman public key. Key encoding can be 'binary', 'hex', or 'base64'.
  • diffieHellman.setPrivateKey(public_key, encoding='binary')
    • Sets the Diffie-Hellman private key. Key encoding can be 'binary', 'hex', or 'base64'.

NOTE: The API is still subject to change.

I would appreciate getting a note if you actually do something useful with it. :) Play around with it and let me know what you think!

OpenID for node.js

I am happy to announce the immediate availability of my implementation of OpenID for node.js. I’ve spent a few nights working on this, which is my first node.js library, and I finally got to the point where the library was complete enough for a first public release.

Installation

Installing is very simple using npm:

npm install openid 

If you don’t use npm, you can of course just download and require. Remember dependencies from the lib folder, and remember adding paths to require.paths if necessary.

Usage

One of the main design goals for the library has been simplicity. Using OpenID for node.js is pretty simple, here’s a minimal sample server:

var openid = require('openid');
var url = require('url');
var server = require('http').createServer(
    function(req, res)
    {
        var parsedUrl = url.parse(req.url, true);
        if(parsedUrl.pathname == '/verify')
        {
            // Verify identity assertion
            var result = openid.verifyAssertion(req); // or req.url
            res.writeHead(200);
            res.end(result.authenticated ? 'Success :) ' : 'Failure :( ');
        }
        else if(parsedUrl.pathname == '/authenticate')
        {
            // Resolve identifier, associate, build authentication URL
            openid.authenticate(
                parsedUrl.query.openid_identifier, // user supplied identifier
                'http://example.com/verify', // our callback URL
                null, // realm (optional)
                false, // attempt immediate authentication first?
                function(authUrl)
                {
                    res.writeHead(302, { Location: authUrl });
                    res.end();
                });
        }
        else
        {
            // Deliver an OpenID form on all other URLs
            res.writeHead(200);
            res.end('<!DOCTYPE html><html><body>'
                + '<form method="get" action="/authenticate">'
                + '<p>Login using OpenID</p>'
                + '<input name="openid_identifier" />'
                + '<input type="submit" value="Login" />'
                + '</form></body></html>');
        }
    });
server.listen(80);

Source

I use GitHub for source control, so you can follow me and the node-openid repository there.

Licensing

OpenID for node.js is licensed under the MIT license. Details can be found in the LICENSE file on GitHub. The library includes third-party code released under the MIT and BSD licenses, see README for details.

Wishes for node.js

I’ve come across a couple of missing features which I’d love to see in node.js in the near future:

  • The crypto module should support Diffie-Hellman key exchange (OpenSSL supports it, so please provide bindings)
  • A big integer library should be available alongside the crypto module, and preferably seamlessly integrated with the crypto module – perhaps bindings to the GMP library could suffice?
  • More seamless unit testing libraries would be good

In addition, I would love to see a tailored IDE for node.js applications.

Problems running .NET 4.0 tests using NUnit 2.5 with (or without) Continuous Testing?

NUnit 2.5 up to and including 2.5.4 fails to properly detect certain revisions of .NET 4.0, causing it to crash. The issue is documented in this bug report on LaunchPad. The bug has been fixed in 2.5.5 and later, so go grab the latest version of NUnit 2.5 and run your tests smoothly again, preferably on each build using Continuous Testing, of course. :)

Mocking HtmlHelper in ASP.NET MVC 2 and 3 using Moq

Still having trouble mocking HtmlHelper? This is an update to my previous post on mocking HtmlHelper way back when ASP.NET MVC RC1 was released. Eric notified me through a comment on the post and a question on StackOverflow that the code for ASP.NET MVC RC1 did not work with ASP.NET MVC 2. The code in this post should work with ASP.NET MVC 2 and ASP.NET MVC 3 Preview 1.


public static HtmlHelper CreateHtmlHelper(ViewDataDictionary vd)
{
    Mock<ViewContext> mockViewContext = new Mock<ViewContext>(
        new ControllerContext(
            new Mock<HttpContextBase>().Object,
            new RouteData(),
            new Mock<ControllerBase>().Object),
        new Mock<IView>().Object,
        vd,
        new TempDataDictionary(),
        new Mock<TextWriter>().Object);
    var mockViewDataContainer = new Mock<IViewDataContainer>();
    mockViewDataContainer.Setup(v => v.ViewData)
        .Returns(vd);
    return new HtmlHelper(mockViewContext.Object,
                            mockViewDataContainer.Object);
}