/*

 * 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.timestamp;

import java.io.IOException;

import java.math.BigInteger;

import java.util.Date;

import sun.security.util.DerValue;

import sun.security.util.ObjectIdentifier;

import sun.security.x509.AlgorithmId;

/**

 * This class provides the timestamp token info resulting from a successful

 * timestamp request, as defined in

 * <a href="http://www.ietf.org/rfc/rfc3161.txt">RFC 3161</a>.

 *

 * The timestampTokenInfo ASN.1 type has the following definition:

 * <pre>

 *

 *     TSTInfo ::= SEQUENCE {

 *         version                INTEGER  { v1(1) },

 *         policy                 TSAPolicyId,

 *         messageImprint         MessageImprint,

 *           -- MUST have the same value as the similar field in

 *           -- TimeStampReq

 *         serialNumber           INTEGER,

 *          -- Time-Stamping users MUST be ready to accommodate integers

 *          -- up to 160 bits.

 *         genTime                GeneralizedTime,

 *         accuracy               Accuracy                 OPTIONAL,

 *         ordering               BOOLEAN             DEFAULT FALSE,

 *         nonce                  INTEGER                  OPTIONAL,

 *           -- MUST be present if the similar field was present

 *           -- in TimeStampReq.  In that case it MUST have the same value.

 *         tsa                    [0] GeneralName          OPTIONAL,

 *         extensions             [1] IMPLICIT Extensions  OPTIONAL }

 *

 *     Accuracy ::= SEQUENCE {

 *         seconds        INTEGER           OPTIONAL,

 *         millis     [0] INTEGER  (1..999) OPTIONAL,

 *         micros     [1] INTEGER  (1..999) OPTIONAL  }

 *

 * </pre>

 *

 * @since 1.5

 * @see Timestamper

 * @author Vincent Ryan

 */

public class TimestampToken {

    private int version;

    private ObjectIdentifier policy;

    private BigInteger serialNumber;

    private AlgorithmId hashAlgorithm;

    private byte[] hashedMessage;

    private Date genTime;

    private BigInteger nonce;

    /**

     * Constructs an object to store a timestamp token.

     *

     * @param status A buffer containing the ASN.1 BER encoding of the

     *               TSTInfo element defined in RFC 3161.

     */

    public TimestampToken(byte[] timestampTokenInfo) throws IOException {

        if (timestampTokenInfo == null) {

            throw new IOException("No timestamp token info");

        }

        parse(timestampTokenInfo);

    }

    /**

     * Extract the date and time from the timestamp token.

     *

     * @return The date and time when the timestamp was generated.

     */

    public Date getDate() {

        return genTime;

    }

    public AlgorithmId getHashAlgorithm() {

        return hashAlgorithm;

    }

    // should only be used internally, otherwise return a clone

    public byte[] getHashedMessage() {

        return hashedMessage;

    }

    public BigInteger getNonce() {

        return nonce;

    }

    /*

     * Parses the timestamp token info.

     *

     * @param timestampTokenInfo A buffer containing an ASN.1 BER encoded

     *                           TSTInfo.

     * @throws IOException The exception is thrown if a problem is encountered

     *         while parsing.

     */

    private void parse(byte[] timestampTokenInfo) throws IOException {

        DerValue tstInfo = new DerValue(timestampTokenInfo);

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

            throw new IOException("Bad encoding for timestamp token info");

        }

        // Parse version

        version = tstInfo.data.getInteger();

        // Parse policy

        policy = tstInfo.data.getOID();

        // Parse messageImprint

        DerValue messageImprint = tstInfo.data.getDerValue();

        hashAlgorithm = AlgorithmId.parse(messageImprint.data.getDerValue());

        hashedMessage = messageImprint.data.getOctetString();

        // Parse serialNumber

        serialNumber = tstInfo.data.getBigInteger();

        // Parse genTime

        genTime = tstInfo.data.getGeneralizedTime();

        // Parse optional elements, if present

        while (tstInfo.data.available() > 0) {

            DerValue d = tstInfo.data.getDerValue();

            if (d.tag == DerValue.tag_Integer) {    // must be the nonce

                nonce = d.getBigInteger();

                break;

            }

            // Additional fields:

            // Parse accuracy

            // Parse ordering

            // Parse tsa

            // Parse extensions

        }

    }

}