Authenticating to sharepoint with kerberos from a java HttpClient

Question

I have a linux\java6 client that will authenticate to sharepoint2010 with NTLM and then send HTTP REST web services using Apache Commons HttpClient.

I can do this with NTLM , but I want to use the same REST API to access sharepoint 2010 that uses kerberos auth.

Any examples how to authenticate and send REST over HTTP with a kerberos sharepoint? (preferably using HttpClient)

p.s. I dont have access to sharepoint code, but i do have access to sharepoint admin configurations. This is roughly how I authenticate with NTLM:

HttpClient httpClient = new HttpClient(new SimpleHttpConnectionManager(true));
AuthPolicy.registerAuthScheme(AuthPolicy.NTLM, JCIFS_NTLMScheme.class);
String  localHostName = Inet4Address.getLocalHost().getHostName();
authscope = new AuthScope(uri.getHost(), AuthScope.ANY_PORT);
httpClient.getState().setCredentials(authscope,new NTCredentials(
             getUsername(),getPassword(),localHostName,getDomain()));

// after the initial ntlm auth I can call my REST service with "httpClient.executeMethod" 

int status = httpClient.executeMethod(new GetMethod(accessURI + "/sitecollection/info"));

Answer 1

Please confirm that your environment is correctly setup for Kerberos, this can be achieved by running kinit. If this fails you will need to ensure that your krb5.ini (windows) or krb5.conf (linux) are setup to point to your domain controller correctly.

Once you have confirmed that Kerberos is functional you can use the example code from HttpClient as pasted below.

Please note that there are many issues that can cause Kerberos to fail, such as time synchronisation, supported encryption types, trust relationships across domain forests and it's also worth ensuring that your client is on a seperate box to the server.

Here is the example code which is available in the HttpClient download, you will need to ensure your JAAS configuration and krb5.conf or ini are correct!

public class ClientKerberosAuthentication {

    public static void main(String[] args) throws Exception {

        System.setProperty("java.security.auth.login.config", "login.conf");
        System.setProperty("java.security.krb5.conf", "krb5.conf");
        System.setProperty("sun.security.krb5.debug", "true");
        System.setProperty("javax.security.auth.useSubjectCredsOnly","false");

        DefaultHttpClient httpclient = new DefaultHttpClient();
        try {
            httpclient.getAuthSchemes().register(AuthPolicy.SPNEGO, new SPNegoSchemeFactory());

            Credentials use_jaas_creds = new Credentials() {

                public String getPassword() {
                    return null;
                }

                public Principal getUserPrincipal() {
                    return null;
                }

            };

            httpclient.getCredentialsProvider().setCredentials(
                    new AuthScope(null, -1, null),
                    use_jaas_creds);

            HttpUriRequest request = new HttpGet("http://kerberoshost/");
            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();

            System.out.println("----------------------------------------");
            System.out.println(response.getStatusLine());
            System.out.println("----------------------------------------");
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
            System.out.println("----------------------------------------");

            // This ensures the connection gets released back to the manager
            EntityUtils.consume(entity);

        } finally {
            // When HttpClient instance is no longer needed,
            // shut down the connection manager to ensure
            // immediate deallocation of all system resources
            httpclient.getConnectionManager().shutdown();
        }
    }

}