OpenId4Java Login Example

I was trying these days to integrate OpenId into a web application and I’ve noticed that the documentation about this area is pretty poor so, for the ones who want to avoid a lot of headache I will post my example step by step.

I use openid4java library from here

1. Add this to a jsp page:

<!--Open IDs login-->&nbsp;
<div style="margin-left: 50px; margin-top: 40px; height: 60px;"><form action="/servlet/loginServlet?identifier=https://www.google.com/accounts/o8/id" method="post"> <input class="google openid_large_btn" style="background: #fff url(/resources/images/login/openid-logos.png?v=3); background-position: -1px -1px;" type="image" value=" " /></form>
<form action="/servlet/loginServlet?identifier=https://me.yahoo.com" method="post"><input class="google openid_large_btn" style="background: #fff url(/resources/images/login/openid-logos.png?v=3); background-position: -1px -63px;" type="image" value=" " /> </form></div>

Please note I use an image with two logos (google and yahoo) for my example (you can download it from here:  http://sstatic.net/Img/openid/openid-logos.png?v=3 )

2. Build the LoginServlet class which uses Google and Yahoo for authenticating with openid.

public class LoginServlet extends javax.servlet.http.HttpServlet {

	final static String YAHOO_ENDPOINT = "https://me.yahoo.com";
	final static String GOOGLE_ENDPOINT = "https://www.google.com/accounts/o8/id";

	private final Log log = LogFactory.getLog(this.getClass());
	private static final long serialVersionUID = 309579782731258702L;
	private ServletContext context;
	private ConsumerManager manager;

	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		context = config.getServletContext();
		try {
			this.manager = new ConsumerManager();
		} catch (ConsumerException e) {
			throw new ServletException(e);
		}
	}

protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
log.debug("------------------------");
log.debug("context: " + context);
Identifier identifier = this.verifyResponse(req);
log.debug("identifier: " + identifier);
// if openid login succeded redirect to home page using our demo account
//if your site is open to anyone without login you can do the redirect directly
if (identifier != null) {
WebAuthentication pwl = new WebAuthentication();
pwl.login("guest", "guest");**
resp.sendRedirect("/index.jsp");
} else {
System.out.println("login with openid failed");
}
}
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		String identifier = req.getParameter("identifier");
		this.authRequest(identifier, req, resp);
	}

	// --- placing the authentication request ---
	public String authRequest(String userSuppliedString,
			HttpServletRequest httpReq, HttpServletResponse httpResp)
			throws IOException {
		try {
			// configure the return_to URL where your application will receive
			// the authentication responses from the OpenID provider
			String returnToUrl = httpReq.getRequestURL().toString();

			// --- Forward proxy setup (only if needed) ---
			// ProxyProperties proxyProps = new ProxyProperties();
			// proxyProps.setProxyName("proxy.example.com");
			// proxyProps.setProxyPort(8080);
			// HttpClientFactory.setProxyProperties(proxyProps);

			// perform discovery on the user-supplied identifier
			List discoveries = manager.discover(userSuppliedString);

			// attempt to associate with the OpenID provider
			// and retrieve one service endpoint for authentication
			DiscoveryInformation discovered = manager.associate(discoveries);

			// store the discovery information in the user's session
			httpReq.getSession().setAttribute("openid-disc", discovered);

			// obtain a AuthRequest message to be sent to the OpenID provider
			AuthRequest authReq = manager.authenticate(discovered, returnToUrl);

			FetchRequest fetch = FetchRequest.createFetchRequest();
			if (userSuppliedString.startsWith(GOOGLE_ENDPOINT)) {
				fetch.addAttribute("email",
						"http://axschema.org/contact/email", true);
				fetch.addAttribute("firstName",
						"http://axschema.org/namePerson/first", true);
				fetch.addAttribute("lastName",
						"http://axschema.org/namePerson/last", true);
			} else if (userSuppliedString.startsWith(YAHOO_ENDPOINT)) {
				fetch.addAttribute("email",
						"http://axschema.org/contact/email", true);
				fetch.addAttribute("fullname",
						"http://axschema.org/namePerson", true);
			} else { // works for myOpenID
				fetch.addAttribute("fullname",
						"http://schema.openid.net/namePerson", true);
				fetch.addAttribute("email",
						"http://schema.openid.net/contact/email", true);
			}

			// attach the extension to the authentication request
			authReq.addExtension(fetch);

			httpResp.sendRedirect(authReq.getDestinationUrl(true));

		} catch (OpenIDException e) {
			// present error to the user
		}

		return null;
	}

	// --- processing the authentication response ---
	public Identifier verifyResponse(HttpServletRequest httpReq) {
		try {
			// extract the parameters from the authentication response
			// (which comes in as a HTTP request from the OpenID provider)
			ParameterList response = new ParameterList(
					httpReq.getParameterMap());

			// retrieve the previously stored discovery information
			DiscoveryInformation discovered = (DiscoveryInformation) httpReq
					.getSession().getAttribute("openid-disc");

			// extract the receiving URL from the HTTP request
			StringBuffer receivingURL = httpReq.getRequestURL();
			String queryString = httpReq.getQueryString();
			if (queryString != null && queryString.length() > 0)
				receivingURL.append("?").append(httpReq.getQueryString());

			// verify the response; ConsumerManager needs to be the same
			// (static) instance used to place the authentication request
			VerificationResult verification = manager.verify(
					receivingURL.toString(), response, discovered);

			// examine the verification result and extract the verified
			// identifier
			Identifier verified = verification.getVerifiedId();
			if (verified != null) {
				AuthSuccess authSuccess = (AuthSuccess) verification
						.getAuthResponse();

				if (authSuccess.hasExtension(AxMessage.OPENID_NS_AX)) {
					FetchResponse fetchResp = (FetchResponse) authSuccess
							.getExtension(AxMessage.OPENID_NS_AX);

					List emails = fetchResp.getAttributeValues("email");
					String email = (String) emails.get(0);
					log.info("OpenIdlogin done with email: " + email);
				}

				return verified; // success
			}
		} catch (OpenIDException e) {
			// present error to the user
		}

		return null;
	}

}

3. Add the servlet configuration in web.xml

<servlet>
  <servlet-name>loginOpenIdServlet</servlet-name>
  <servlet-class>your.package.LoginServlet</servlet-class>
 </servlet>

Enjoy it;)