/*
* $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpclient/tags/4.0-beta1/module-client/src/examples/org/apache/http/examples/client/ClientPreemptiveDigestAuthentication.java $
* $Revision: 659971 $
* $Date: 2008-05-25 14:01:22 +0200 (Sun, 25 May 2008) $
* ====================================================================
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.http.examples.client;
import java.io.IOException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.auth.AuthScheme;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.AuthState;
import org.apache.http.auth.Credentials;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.impl.auth.DigestScheme;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
/**
* An example of HttpClient can be customized to authenticate
* preemptively using DIGEST scheme.
* <b/>
* Generally, preemptive authentication can be considered less
* secure than a response to an authentication challenge
* and therefore discouraged.
* <b/>
* This code is NOT officially supported! Use at your risk.
*/
public class ClientPreemptiveDigestAuthentication {
public static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
httpclient.getCredentialsProvider().setCredentials(
new AuthScope("localhost", 80),
new UsernamePasswordCredentials("username", "password"));
BasicHttpContext localcontext = new BasicHttpContext();
// Generate DIGEST scheme object, initialize it and stick it to
// the local execution context
DigestScheme digestAuth = new DigestScheme();
// Suppose we already know the realm name
digestAuth.overrideParamter("realm", "some realm");
// Suppose we already know the expected nonce value
digestAuth.overrideParamter("nonce", "whatever");
localcontext.setAttribute("preemptive-auth", digestAuth);
// Add as the first request interceptor
httpclient.addRequestInterceptor(new PreemptiveAuth(), 0);
// Add as the last response interceptor
httpclient.addResponseInterceptor(new PersistentDigest());
HttpHost targetHost = new HttpHost("localhost", 80, "http");
HttpGet httpget = new HttpGet("/");
System.out.println("executing request: " + httpget.getRequestLine());
System.out.println("to target: " + targetHost);
for (int i = 0; i < 3; i++) {
HttpResponse response = httpclient.execute(targetHost, httpget, localcontext);
HttpEntity entity = response.getEntity();
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
System.out.println("Chunked?: " + entity.isChunked());
entity.consumeContent();
}
}
}
static class PreemptiveAuth implements HttpRequestInterceptor {
public void process(
final HttpRequest request,
final HttpContext context) throws HttpException, IOException {
AuthState authState = (AuthState) context.getAttribute(
ClientContext.TARGET_AUTH_STATE);
// If no auth scheme avaialble yet, try to initialize it preemptively
if (authState.getAuthScheme() == null) {
AuthScheme authScheme = (AuthScheme) context.getAttribute(
"preemptive-auth");
CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(
ClientContext.CREDS_PROVIDER);
HttpHost targetHost = (HttpHost) context.getAttribute(
ExecutionContext.HTTP_TARGET_HOST);
if (authScheme != null) {
Credentials creds = credsProvider.getCredentials(
new AuthScope(
targetHost.getHostName(),
targetHost.getPort()));
if (creds == null) {
throw new HttpException("No credentials for preemptive authentication");
}
authState.setAuthScheme(authScheme);
authState.setCredentials(creds);
}
}
}
}
static class PersistentDigest implements HttpResponseInterceptor {
public void process(
final HttpResponse response,
final HttpContext context) throws HttpException, IOException {
AuthState authState = (AuthState) context.getAttribute(
ClientContext.TARGET_AUTH_STATE);
if (authState != null) {
AuthScheme authScheme = authState.getAuthScheme();
// Stick the auth scheme to the local context, so
// we could try to authenticate subsequent requests
// preemptively
if (authScheme instanceof DigestScheme) {
context.setAttribute("preemptive-auth", authScheme);
}
}
}
}
}