eu.europa.esig.dss.spi.x509.tsp.TimestampIdentifierBuilder Maven / Gradle / Ivy
/**
* DSS - Digital Signature Services
* Copyright (C) 2015 European Commission, provided under the CEF programme
*
* This file is part of the "DSS - Digital Signature Services" project.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package eu.europa.esig.dss.spi.x509.tsp;
import eu.europa.esig.dss.model.DSSException;
import eu.europa.esig.dss.model.identifier.IdentifierBuilder;
import eu.europa.esig.dss.utils.Utils;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Objects;
/**
* Builds an {@code eu.europa.esig.dss.spi.x509.tsp.TimestampTokenIdentifier}
* for the provided {@code eu.europa.esig.dss.spi.x509.tsp.TimestampToken}.
* This class provided a format independent implementation.
* Please use inherited classed for format-specific implementations.
*
*/
public class TimestampIdentifierBuilder implements IdentifierBuilder {
private static final long serialVersionUID = 8108224076397826022L;
/** Time-stamp token to build an identifier for */
protected final byte[] timestampTokenBinaries;
/** Name of the document containing the time-stamp token */
private String filename;
/**
* Default constructor to build an implementation independent identifier
*
* @param timestampTokenBinaries byte array representing a DER-encoded time-stamp binary octets
*/
public TimestampIdentifierBuilder(final byte[] timestampTokenBinaries) {
Objects.requireNonNull(timestampTokenBinaries, "Timestamp token binaries cannot be null!");
this.timestampTokenBinaries = timestampTokenBinaries;
}
/**
* Sets a time-stamp document filename
*
* @param filename {@link String}
* @return this {@link TimestampIdentifierBuilder}
*/
public TimestampIdentifierBuilder setFilename(String filename) {
this.filename = filename;
return this;
}
/**
* Builds {@code TimestampTokenIdentifier} for the provided {@code eu.europa.esig.dss.spi.x509.tsp.TimestampToken}
*
* @return {@link TimestampTokenIdentifier}
*/
@Override
public TimestampTokenIdentifier build() {
return new TimestampTokenIdentifier(buildBinaries());
}
/**
* Builds unique binary data describing the time-stamp token
*
* @return a byte array
*/
protected byte[] buildBinaries() {
try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
writeTimestampBinaries(baos);
writeTimestampPosition(baos);
return baos.toByteArray();
} catch (IOException e) {
throw new DSSException(String.format("An error occurred while building an Identifier : %s", e.getMessage()), e);
}
}
/**
* Writes DER-encoded binaries of the current time-stamp token to the given {@code ByteArrayOutputStream}
*
* @param baos {@link ByteArrayOutputStream} to write time-stamp binaries to
* @throws IOException if an exception occurs
*/
protected void writeTimestampBinaries(ByteArrayOutputStream baos) throws IOException {
baos.write(timestampTokenBinaries);
}
/**
* Writes the current time-stamp position within a document
*
* @param baos {@link ByteArrayOutputStream} to add data to
* @throws IOException if an exception occurs
*/
protected void writeTimestampPosition(ByteArrayOutputStream baos) throws IOException {
try (DataOutputStream dos = new DataOutputStream(baos)) {
String positionId = getUniquePositionId();
if (positionId != null) {
dos.writeChars(positionId);
}
dos.flush();
}
}
/**
* Returns Id representing a current signature position in a file,
* considering its pre-siblings, master signatures when present
*
* @return {@link String} position id
*/
protected String getUniquePositionId() {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(getTimestampPosition());
if (filename != null) {
stringBuilder.append(filename);
}
return stringBuilder.toString();
}
/**
* Returns a position of a time-stamp token within a document among other time-stamps
*
* @return time-stamp position identifier
*/
protected Object getTimestampPosition() {
// return empty string by default
return Utils.EMPTY_STRING;
}
}