httpclient/src/examples/org/apache/hc/client5/http/examples/ClientPreemptiveDigestAuthentication.java

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 * 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
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 * Unless required by applicable law or agreed to in writing,
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 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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 *
 * This software consists of voluntary contributions made by many
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package org.apache.hc.client5.http.examples;

import org.apache.hc.client5.http.auth.AuthCache;
import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
import org.apache.hc.client5.http.impl.auth.BasicAuthCache;
import org.apache.hc.client5.http.impl.auth.DigestScheme;
import org.apache.hc.client5.http.impl.sync.CloseableHttpClient;
import org.apache.hc.client5.http.impl.sync.HttpClients;
import org.apache.hc.client5.http.methods.CloseableHttpResponse;
import org.apache.hc.client5.http.methods.HttpGet;
import org.apache.hc.client5.http.protocol.HttpClientContext;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.entity.EntityUtils;

/**
 * An example of HttpClient can be customized to authenticate
 * preemptively using DIGEST scheme.
 * <p>
 * Generally, preemptive authentication can be considered less
 * secure than a response to an authentication challenge
 * and therefore discouraged.
 * </p>
 */
public class ClientPreemptiveDigestAuthentication {

    public static void main(String[] args) throws Exception {
        try (CloseableHttpClient httpclient = HttpClients.createDefault()) {

            // Create AuthCache instance
            AuthCache authCache = new BasicAuthCache();
            // Generate DIGEST scheme object, initialize it and add it to the local auth cache
            DigestScheme digestAuth = new DigestScheme();
            // Suppose we already know the realm name and the expected nonce value
            digestAuth.initPreemptive(new UsernamePasswordCredentials("user", "passwd".toCharArray()), "whatever", "realm");

            HttpHost target = new HttpHost("httpbin.org", 80, "http");
            authCache.put(target, digestAuth);

            // Add AuthCache to the execution context
            HttpClientContext localContext = HttpClientContext.create();
            localContext.setAuthCache(authCache);

            HttpGet httpget = new HttpGet("http://httpbin.org/digest-auth/auth/user/passwd");

            System.out.println("Executing request " + httpget.getRequestLine() + " to target " + target);
            for (int i = 0; i < 3; i++) {
                try (CloseableHttpResponse response = httpclient.execute(target, httpget, localContext)) {
                    System.out.println("----------------------------------------");
                    System.out.println(response.getStatusLine());
                    EntityUtils.consume(response.getEntity());
                }
            }
        }
    }

}