org.security4java.X509CertificateRetrieverImpl.java Source code

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Here is the source code for org.security4java.X509CertificateRetrieverImpl.java

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/*
 *    Copyright 2012 Michael Furman
 * 
 *    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.
 *  
 */
package org.security4java;

import java.io.ByteArrayInputStream;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Implementation of <b>X509CertificateRetriever</b> that takes a X509Certificate from a HttpServletRequest attribute.
 * 
 * Allows to override the default attribute name.
 * Allows to take the X509Certificate from the attribute of String type or X509Certificate type.
 *     
 */
public class X509CertificateRetrieverImpl implements X509CertificateRetriever {

    private static final String DEFAULT_X509_CERTIFICATE_ATTRIBUTE_NAME = "javax.servlet.request.X509Certificate";

    private final String certAttrName;

    /**
     * Logger for this class
     */
    protected final Log logger = LogFactory.getLog(getClass());

    public X509CertificateRetrieverImpl(String certAttrName) {
        this.certAttrName = certAttrName == null ? DEFAULT_X509_CERTIFICATE_ATTRIBUTE_NAME : certAttrName;
    }

    public X509CertificateRetrieverImpl() {
        this(null);
    }

    public X509Certificate getClientCertificate(HttpServletRequest request) {
        X509Certificate ret = null;
        if (logger.isDebugEnabled()) {
            logger.debug("getClientCertificate(HttpServletRequest) - start");
        }

        Object attribute = request.getAttribute(certAttrName);
        if (attribute instanceof X509Certificate[]) {
            X509Certificate[] certs = (X509Certificate[]) attribute;
            if (certs != null && certs.length > 0) {
                ret = certs[0];
                if (logger.isDebugEnabled()) {
                    logger.debug("Success to get ClientCertificate [" + ret + "].");
                }
            }
        } else if (attribute instanceof String) {
            if (logger.isDebugEnabled()) {
                logger.debug("Received a String. Try to convert the string [" + attribute + "] into certificate.");
            }
            String certificateString = (String) attribute;
            byte[] certificateData = certificateString.getBytes();
            ByteArrayInputStream certificateInputStream = new ByteArrayInputStream(certificateData);
            X509Certificate certificates[] = null;
            try {
                CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
                X509Certificate x509Certificate = (X509Certificate) certificateFactory
                        .generateCertificate(certificateInputStream);
                certificates = new X509Certificate[1];
                certificates[0] = x509Certificate;
                ret = certificates[0];
                if (logger.isDebugEnabled()) {
                    logger.debug("Success to convert string to client certificate [" + ret + "].");
                }
            } catch (CertificateException e) {
                logger.info("Failed to convert the string into certificate [" + attribute + "]. " + e.getMessage());
            }
        } else if (logger.isDebugEnabled()) {
            logger.debug("No client certificate found in the request.");
        }

        return ret;
    }

}