HttpPreemptiveAuthInterceptor.java

/*
 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * Licensed 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.
 *
 * Contributors:
 *     bstefanescu
 */
package org.nuxeo.ecm.automation.client.jaxrs.impl;

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
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.client.CredentialsProvider;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;

public class HttpPreemptiveAuthInterceptor implements HttpRequestInterceptor {

    protected static final Log log = LogFactory.getLog(HttpPreemptiveAuthInterceptor.class);

    protected final AuthScheme authScheme;

    HttpPreemptiveAuthInterceptor(AuthScheme authScheme) {
        this.authScheme = authScheme;
    }

    @Override
    public void process(HttpRequest request, HttpContext context) throws HttpException, IOException {
        AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
        // If not auth scheme has been initialized yet
        if (authState.getAuthScheme() != null) {
            return;
        }

        // fetch credentials
        CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
        HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
        AuthScope authScope = new AuthScope(targetHost.getHostName(), targetHost.getPort());

        // Obtain credentials matching the target host
        Credentials creds = credsProvider.getCredentials(authScope);

        if (creds == null) {
            log.warn("no credentials provided for " + authScope);
            return;
        }

        authState.setAuthScheme(authScheme);
        authState.setCredentials(creds);
    }

}