Java class that initializes a HttpClient using X.509-certificate-based client authentication.

SslHttpUtil.java

import org.apache.http.client.HttpClient;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.SingleClientConnManager;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;

import javax.net.ssl.KeyManager;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;

import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;

/**
 * Initializes a HttpClient using X.509-certificate-based client authentication.
 * @author Sebastian Kempken
 *
 */
public class SslHttpUtil {
    
    private static final KeyManager[] getKeyManagersFromKeyStore(KeyStore keyStore, char[] password) throws NoSuchAlgorithmException, UnrecoverableKeyException, KeyStoreException
    {
        final KeyManagerFactory kmfactory = KeyManagerFactory.getInstance(
            KeyManagerFactory.getDefaultAlgorithm());
        kmfactory.init(keyStore, password);
        final KeyManager[] kms =  kmfactory.getKeyManagers();
        return kms;
    }

    public static final HttpClient createSslHttpClient(KeyStore keyStore, char[] password)  {
        try
        {
            SSLContext sslcontext = SSLContext.getInstance("TLS");
            final KeyManager[] km = getKeyManagersFromKeyStore(keyStore, password);
            sslcontext.init(km, null, null);
            
            SSLSocketFactory sslSocketFactory = new SSLSocketFactory(sslcontext);
            
            Scheme https = new Scheme("https", sslSocketFactory, 443);
            Scheme http = new Scheme("http", PlainSocketFactory.getSocketFactory(), 80);
            
            SchemeRegistry schemeRegistry = new SchemeRegistry();
            schemeRegistry.register(http);
            schemeRegistry.register(https);
           
            final HttpParams params = new BasicHttpParams();
            ClientConnectionManager cm = new SingleClientConnManager(params, schemeRegistry);
            
            
            return new DefaultHttpClient(cm, params);
        }
        catch(Exception exception)
        {
            throw new RuntimeException("Error initializing HttpClient", exception);
        }
    }
}