code: static public void configureWithSslKeystoreTruststore( HttpClient client, 
  							   File keystoreFile,
  							   String keystorePassword,
  							   File truststoreFile,
  							   String truststorePassword ) 
  	throws CertificateException, FileNotFoundException, IOException, 
  	       KeyStoreException, KeyManagementException, NoSuchAlgorithmException, 
  	       UnrecoverableKeyException {
  
          //
          // create a new https scheme with no SSL verification
          //
          Scheme httpsScheme = SchemeFactory.createHttpsScheme( keystoreFile, keystorePassword,
  							      truststoreFile, truststorePassword );
          //
          // register this new scheme on the https client
          //
          client.getConnectionManager().getSchemeRegistry().register(httpsScheme);
      }
docs: Adding support for SSL mutual authentication using specified keystore/truststore.
  Specifying keystore/truststore is optional. If unspecified, a normal SSL scheme
  is created.