/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package sun.security.x509;

import java.io.IOException;

import java.io.OutputStream;

import java.security.cert.*;

import java.util.Date;

import java.util.Enumeration;

import sun.security.util.*;

/**

 * This class defines the interval for which the certificate is valid.

 *

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 * @see CertAttrSet

 */

public class CertificateValidity implements CertAttrSet<String> {

    /**

     * Identifier for this attribute, to be used with the

     * get, set, delete methods of Certificate, x509 type.

     */

    public static final String IDENT = "x509.info.validity";

    /**

     * Sub attributes name for this CertAttrSet.

     */

    public static final String NAME = "validity";

    public static final String NOT_BEFORE = "notBefore";

    public static final String NOT_AFTER = "notAfter";

    private static final long YR_2050 = 2524636800000L;

    // Private data members

    private Date        notBefore;

    private Date        notAfter;

    // Returns the first time the certificate is valid.

    private Date getNotBefore() {

        return (new Date(notBefore.getTime()));

    }

    // Returns the last time the certificate is valid.

    private Date getNotAfter() {

       return (new Date(notAfter.getTime()));

    }

    // Construct the class from the DerValue

    private void construct(DerValue derVal) throws IOException {

        if (derVal.tag != DerValue.tag_Sequence) {

            throw new IOException("Invalid encoded CertificateValidity, " +

                                  "starting sequence tag missing.");

        }

        // check if UTCTime encoded or GeneralizedTime

        if (derVal.data.available() == 0)

            throw new IOException("No data encoded for CertificateValidity");

        DerInputStream derIn = new DerInputStream(derVal.toByteArray());

        DerValue[] seq = derIn.getSequence(2);

        if (seq.length != 2)

            throw new IOException("Invalid encoding for CertificateValidity");

        if (seq[0].tag == DerValue.tag_UtcTime) {

            notBefore = derVal.data.getUTCTime();

        } else if (seq[0].tag == DerValue.tag_GeneralizedTime) {

            notBefore = derVal.data.getGeneralizedTime();

        } else {

            throw new IOException("Invalid encoding for CertificateValidity");

        }

        if (seq[1].tag == DerValue.tag_UtcTime) {

            notAfter = derVal.data.getUTCTime();

        } else if (seq[1].tag == DerValue.tag_GeneralizedTime) {

            notAfter = derVal.data.getGeneralizedTime();

        } else {

            throw new IOException("Invalid encoding for CertificateValidity");

        }

    }

    /**

     * Default constructor for the class.

     */

    public CertificateValidity() { }

    /**

     * The default constructor for this class for the specified interval.

     *

     * @param notBefore the date and time before which the certificate

     *                   is not valid.

     * @param notAfter the date and time after which the certificate is

     *                  not valid.

     */

    public CertificateValidity(Date notBefore, Date notAfter) {

        this.notBefore = notBefore;

        this.notAfter = notAfter;

    }

    /**

     * Create the object, decoding the values from the passed DER stream.

     *

     * @param in the DerInputStream to read the CertificateValidity from.

     * @exception IOException on decoding errors.

     */

    public CertificateValidity(DerInputStream in) throws IOException {

        DerValue derVal = in.getDerValue();

        construct(derVal);

    }

    /**

     * Return the validity period as user readable string.

     */

    public String toString() {

        if (notBefore == null || notAfter == null)

            return "";

        return ("Validity: [From: " + notBefore.toString() +

             ",\n               To: " + notAfter.toString() + "]");

    }

    /**

     * Encode the CertificateValidity period in DER form to the stream.

     *

     * @param out the OutputStream to marshal the contents to.

     * @exception IOException on errors.

     */

    public void encode(OutputStream out) throws IOException {

        // in cases where default constructor is used check for

        // null values

        if (notBefore == null || notAfter == null) {

            throw new IOException("CertAttrSet:CertificateValidity:" +

                                  " null values to encode.\n");

        }

        DerOutputStream pair = new DerOutputStream();

        if (notBefore.getTime() < YR_2050) {

            pair.putUTCTime(notBefore);

        } else

            pair.putGeneralizedTime(notBefore);

        if (notAfter.getTime() < YR_2050) {

            pair.putUTCTime(notAfter);

        } else {

            pair.putGeneralizedTime(notAfter);

        }

        DerOutputStream seq = new DerOutputStream();

        seq.write(DerValue.tag_Sequence, pair);

        out.write(seq.toByteArray());

    }

    /**

     * Set the attribute value.

     */

    public void set(String name, Object obj) throws IOException {

        if (!(obj instanceof Date)) {

            throw new IOException("Attribute must be of type Date.");

        }

        if (name.equalsIgnoreCase(NOT_BEFORE)) {

            notBefore = (Date)obj;

        } else if (name.equalsIgnoreCase(NOT_AFTER)) {

            notAfter = (Date)obj;

        } else {

            throw new IOException("Attribute name not recognized by " +

                            "CertAttrSet: CertificateValidity.");

        }

    }

    /**

     * Get the attribute value.

     */

    public Object get(String name) throws IOException {

        if (name.equalsIgnoreCase(NOT_BEFORE)) {

            return (getNotBefore());

        } else if (name.equalsIgnoreCase(NOT_AFTER)) {

            return (getNotAfter());

        } else {

            throw new IOException("Attribute name not recognized by " +

                            "CertAttrSet: CertificateValidity.");

        }

    }

    /**

     * Delete the attribute value.

     */

    public void delete(String name) throws IOException {

        if (name.equalsIgnoreCase(NOT_BEFORE)) {

            notBefore = null;

        } else if (name.equalsIgnoreCase(NOT_AFTER)) {

            notAfter = null;

        } else {

            throw new IOException("Attribute name not recognized by " +

                            "CertAttrSet: CertificateValidity.");

        }

    }

    /**

     * Return an enumeration of names of attributes existing within this

     * attribute.

     */

    public Enumeration<String> getElements() {

        AttributeNameEnumeration elements = new AttributeNameEnumeration();

        elements.addElement(NOT_BEFORE);

        elements.addElement(NOT_AFTER);

        return (elements.elements());

    }

    /**

     * Return the name of this attribute.

     */

    public String getName() {

        return (NAME);

    }

    /**

     * Verify that the current time is within the validity period.

     *

     * @exception CertificateExpiredException if the certificate has expired.

     * @exception CertificateNotYetValidException if the certificate is not

     * yet valid.

     */

    public void valid()

    throws CertificateNotYetValidException, CertificateExpiredException {

        Date now = new Date();

        valid(now);

    }

    /**

     * Verify that the passed time is within the validity period.

     * @param now the Date against which to compare the validity

     * period.

     *

     * @exception CertificateExpiredException if the certificate has expired

     * with respect to the <code>Date</code> supplied.

     * @exception CertificateNotYetValidException if the certificate is not

     * yet valid with respect to the <code>Date</code> supplied.

     *

     */

    public void valid(Date now)

    throws CertificateNotYetValidException, CertificateExpiredException {

        /*

         * we use the internal Dates rather than the passed in Date

         * because someone could override the Date methods after()

         * and before() to do something entirely different.

         */

        if (notBefore.after(now)) {

            throw new CertificateNotYetValidException("NotBefore: " +

                                                      notBefore.toString());

        }

        if (notAfter.before(now)) {

            throw new CertificateExpiredException("NotAfter: " +

                                                  notAfter.toString());

        }

    }

}