net.jsign.timestamp.Timestamper Maven / Gradle / Ivy
/**
* Copyright 2014 Emmanuel Bourg
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.jsign.timestamp;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.cms.AttributeTable;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.SignerInformation;
import org.bouncycastle.cms.SignerInformationStore;
import org.bouncycastle.util.CollectionStore;
import org.bouncycastle.util.Store;
import net.jsign.DigestAlgorithm;
import net.jsign.asn1.authenticode.AuthenticodeSignedDataGenerator;
/**
* Interface for a timestamping service.
*
* @author Emmanuel Bourg
* @since 1.3
*/
public abstract class Timestamper {
/** The URL of the current timestamping service */
protected URL tsaurl;
/** The URLs of the timestamping services */
protected List tsaurls;
/** The number of retries */
protected int retries = 3;
/** Seconds to wait between retries */
protected int retryWait = 10;
public void setURL(String tsaurl) {
setURLs(tsaurl);
}
/**
* @since 2.0
*/
public void setURLs(String... tsaurls) {
List urls = new ArrayList<>();
for (String tsaurl : tsaurls) {
try {
urls.add(new URL(tsaurl));
} catch (MalformedURLException e) {
throw new IllegalArgumentException("Invalid timestamping URL: " + tsaurl, e);
}
}
this.tsaurls = urls;
}
/**
* Set the number of retries.
*/
public void setRetries(int retries) {
this.retries = retries;
}
/**
* Set the number of seconds to wait between retries.
*/
public void setRetryWait(int retryWait) {
this.retryWait = retryWait;
}
/**
* Timestamp the specified signature.
*
* @param algo the digest algorithm used for the timestamp
* @param sigData the signed data to be timestamped
* @return the signed data with the timestamp added
*/
public CMSSignedData timestamp(DigestAlgorithm algo, CMSSignedData sigData) throws IOException, CMSException {
CMSSignedData token = null;
// Retry the timestamping and failover other services if a TSA is unavailable for a short period of time
int attempts = Math.max(retries, tsaurls.size());
TimestampingException exception = new TimestampingException("Unable to complete the timestamping after " + attempts + " attempt" + (attempts > 1 ? "s" : ""));
int count = 0;
while (token == null && count < Math.max(retries, tsaurls.size())) {
try {
tsaurl = tsaurls.get(count % tsaurls.size());
token = timestamp(algo, getEncryptedDigest(sigData));
break;
} catch (TimestampingException | IOException e) {
exception.addSuppressed(e);
}
// pause before the next attempt
try {
Thread.sleep(retryWait * 1000);
count++;
} catch (InterruptedException ie) {
}
}
if (token == null) {
throw exception;
}
return modifySignedData(sigData, getUnsignedAttributes(token), getExtraCertificates(token));
}
/**
* Return the encrypted digest of the specified signature.
*/
private byte[] getEncryptedDigest(CMSSignedData sigData) {
SignerInformation signerInformation = sigData.getSignerInfos().getSigners().iterator().next();
return signerInformation.toASN1Structure().getEncryptedDigest().getOctets();
}
/**
* Return the certificate chain of the timestamping authority if it isn't included
* with the counter signature in the unsigned attributes.
*/
protected Collection getExtraCertificates(CMSSignedData token) {
return null;
}
/**
* Return the counter signature to be added as an unsigned attribute.
*/
protected abstract AttributeTable getUnsignedAttributes(CMSSignedData token);
protected CMSSignedData modifySignedData(CMSSignedData sigData, AttributeTable unsignedAttributes, Collection extraCertificates) throws IOException, CMSException {
SignerInformation signerInformation = sigData.getSignerInfos().getSigners().iterator().next();
signerInformation = SignerInformation.replaceUnsignedAttributes(signerInformation, unsignedAttributes);
Collection certificates = new ArrayList<>();
certificates.addAll(sigData.getCertificates().getMatches(null));
if (extraCertificates != null) {
certificates.addAll(extraCertificates);
}
Store certificateStore = new CollectionStore<>(certificates);
AuthenticodeSignedDataGenerator generator = new AuthenticodeSignedDataGenerator();
generator.addCertificates(certificateStore);
generator.addSigners(new SignerInformationStore(signerInformation));
ASN1ObjectIdentifier contentType = new ASN1ObjectIdentifier(sigData.getSignedContentTypeOID());
ASN1Encodable content = ASN1Sequence.getInstance(sigData.getSignedContent().getContent());
return generator.generate(contentType, content);
}
protected abstract CMSSignedData timestamp(DigestAlgorithm algo, byte[] encryptedDigest) throws IOException, CMSException, TimestampingException;
/**
* Returns the timestamper for the specified mode.
*/
public static Timestamper create(TimestampingMode mode) {
switch (mode) {
case AUTHENTICODE:
return new AuthenticodeTimestamper();
case RFC3161:
return new RFC3161Timestamper();
default:
throw new IllegalArgumentException("Unsupported timestamping mode: " + mode);
}
}
}