be.fedict.commons.eid.jca.BeIDSecureRandom.java Source code

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Here is the source code for be.fedict.commons.eid.jca.BeIDSecureRandom.java

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/*
 * Commons eID Project.
 * Copyright (C) 2008-2013 FedICT.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, see 
 * http://www.gnu.org/licenses/.
 */

package be.fedict.commons.eid.jca;

import java.security.SecureRandomSpi;

import javax.smartcardio.CardException;

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

import be.fedict.commons.eid.client.BeIDCard;
import be.fedict.commons.eid.client.BeIDCards;
import be.fedict.commons.eid.client.CancelledException;

/**
 * eID based implementation of a secure random generator. Can be used to seed
 * for example a mutual SSL handshake. This secure random generator does not
 * feature eID auto recovery.
 * <p/>
 * Usage:
 * 
 * <pre>
 * SecureRandom secureRandom = SecureRandom.getInstance(&quot;BeID&quot;);
 * </pre>
 * 
 * @author Frank Cornelis
 * 
 */
public class BeIDSecureRandom extends SecureRandomSpi {

    private static final long serialVersionUID = 1L;

    private static final Log LOG = LogFactory.getLog(BeIDSecureRandom.class);

    private BeIDCard beIDCard;

    @Override
    protected void engineSetSeed(final byte[] seed) {
        LOG.debug("engineSetSeed");
    }

    @Override
    protected void engineNextBytes(final byte[] bytes) {
        LOG.debug("engineNextBytes: " + bytes.length + " bytes");
        BeIDCard beIDCard = getBeIDCard();
        byte[] randomData;
        try {
            try {
                randomData = beIDCard.getChallenge(bytes.length);
            } catch (Exception e) {
                beIDCard = getBeIDCard(true);
                randomData = beIDCard.getChallenge(bytes.length);
            }
        } catch (final CardException e) {
            throw new RuntimeException(e);
        }
        System.arraycopy(randomData, 0, bytes, 0, bytes.length);
    }

    @Override
    protected byte[] engineGenerateSeed(final int numBytes) {
        LOG.debug("engineGenerateSeed: " + numBytes + " bytes");
        final BeIDCard beIDCard = getBeIDCard();
        byte[] randomData;
        try {
            randomData = beIDCard.getChallenge(numBytes);
        } catch (final CardException e) {
            throw new RuntimeException(e);
        }
        return randomData;
    }

    private BeIDCard getBeIDCard(boolean autoRecover) {
        if (autoRecover) {
            this.beIDCard = null;
        }
        return getBeIDCard();
    }

    private BeIDCard getBeIDCard() {
        if (null != this.beIDCard) {
            return this.beIDCard;
        }
        final BeIDCards beIDCards = new BeIDCards();
        try {
            this.beIDCard = beIDCards.getOneBeIDCard();
        } catch (final CancelledException e) {
            throw new RuntimeException(e);
        }
        return this.beIDCard;
    }
}