org.gss_project.gss.server.domain.Nonce.java Source code

Introduction

Here is the source code for org.gss_project.gss.server.domain.Nonce.java

Source

/*
 * Copyright 2008, 2009 Electronic Business Systems Ltd.
 *
 * This file is part of GSS.
 *
 * GSS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GSS 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GSS.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.gss_project.gss.server.domain;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.SecureRandom;
import java.util.Calendar;
import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;

/**
 * The class that holds an issued nonce for a user.
 *
 * @author past
 */
@Entity
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Nonce {

    /**
     * The logger.
     */
    private static Log logger = LogFactory.getLog(Nonce.class);

    /**
     * The nonce size in bytes.
     */
    private static final int NONCE_SIZE = 20;

    /**
     * The persistence ID of the object.
     */
    @Id
    @GeneratedValue
    private Long id;

    /**
     * The nonce issued for logging in this user.
     */
    private byte[] nonce;

    /**
     * The nonce encoded in Base64.
     */
    private String encodedNonce;

    /**
     * The time that the user's issued nonce
     * will expire.
     */
    @Temporal(TemporalType.TIMESTAMP)
    private Date nonceExpiryDate;

    /**
     * The ID of the user for whom this nonce was issued.
     */
    private Long userId;

    /**
     * Retrieve the id.
     *
     * @return the id
     */
    public Long getId() {
        return id;
    }

    /**
     * Retrieve the nonce. If it is not valid or non-existent,
     * this method returns null. Therefore, call sites must
     * request a regeneration of the authentication token in
     * both cases.
     *
     * @return the nonce
     */
    public byte[] getNonce() {
        if (isNonceValid())
            return nonce;
        return null;
    }

    /**
     * Return true if the nonce is usable, or false
     * if a new one must be regenerated.
     *
     * @return true if the nonce is valid
     */
    private boolean isNonceValid() {
        if (nonce == null)
            return false;
        if (nonceExpiryDate == null)
            return false;
        if (nonceExpiryDate.before(new Date()))
            return false;
        return true;
    }

    /**
     * Creates a new nonce and resets its expiry date.
     *
     * @param userId the ID of the associated user
     * @return a new nonce
     */
    public static Nonce createNonce(Long userId) {
        Nonce n = new Nonce();
        n.userId = userId;
        SecureRandom random = new SecureRandom();
        n.nonce = new byte[NONCE_SIZE];
        random.nextBytes(n.nonce);
        Calendar cal = Calendar.getInstance();
        // Set nonce time-to-live to 5 minutes.
        cal.add(Calendar.MINUTE, 5);
        n.nonceExpiryDate = cal.getTime();
        try {
            n.encodedNonce = URLEncoder.encode(new String(Base64.encodeBase64(n.nonce), "US-ASCII"), "US-ASCII");
        } catch (UnsupportedEncodingException e) {
            logger.error(e);
        }
        return n;
    }

    /**
     * Retrieve the userId.
     *
     * @return the userId
     */
    public Long getUserId() {
        return userId;
    }

    /**
     * Modify the nonce.
     *
     * @param aNonce the nonce to set
     */
    public void setNonce(byte[] aNonce) {
        nonce = aNonce;
    }

    /**
     * Modify the nonceExpiryDate.
     *
     * @param aNonceExpiryDate the nonceExpiryDate to set
     */
    public void setNonceExpiryDate(Date aNonceExpiryDate) {
        nonceExpiryDate = aNonceExpiryDate;
    }

    /**
     * Retrieve the encodedNonce.
     *
     * @return the encodedNonce
     */
    public String getEncodedNonce() {
        return encodedNonce;
    }

    /**
     * Retrieve the nonceExpiryDate.
     *
     * @return the nonceExpiryDate
     */
    public Date getNonceExpiryDate() {
        return nonceExpiryDate;
    }

}