eu.europa.esig.dss.spi.policy.BasicASN1SignaturePolicyValidator 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.policy;
import eu.europa.esig.dss.enumerations.DigestAlgorithm;
import eu.europa.esig.dss.model.DSSDocument;
import eu.europa.esig.dss.model.Digest;
import eu.europa.esig.dss.model.signature.SignaturePolicyValidationResult;
import eu.europa.esig.dss.spi.DSSASN1Utils;
import eu.europa.esig.dss.spi.DSSUtils;
import eu.europa.esig.dss.utils.Utils;
import eu.europa.esig.dss.model.signature.SignaturePolicy;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Arrays;
/**
* Default implementation, checks only the hash of the policy
*
* Note : this implementation is not registered as a service to allow overriding
*
* @author davyd.santos
*
*/
public class BasicASN1SignaturePolicyValidator extends AbstractSignaturePolicyValidator {
private static final Logger LOG = LoggerFactory.getLogger(BasicASN1SignaturePolicyValidator.class);
/**
* Default constructor
*/
public BasicASN1SignaturePolicyValidator() {
// empty
}
@Override
public boolean canValidate(SignaturePolicy signaturePolicy) {
if (signaturePolicy.getPolicyContent() != null) {
byte firstByte = DSSUtils.readFirstByte(signaturePolicy.getPolicyContent());
return DSSASN1Utils.isASN1SequenceTag(firstByte);
}
return false;
}
@Override
public SignaturePolicyValidationResult validate(SignaturePolicy signaturePolicy) {
SignaturePolicyValidationResult validationResult = new SignaturePolicyValidationResult();
final DSSDocument policyContent = signaturePolicy.getPolicyContent();
if (policyContent == null) {
validationResult.addError(GENERAL_ERROR_KEY, "The signature policy content is not obtained.");
return validationResult;
}
validationResult.setIdentified(true);
final Digest digest = signaturePolicy.getDigest();
if (digest == null) {
validationResult.addError(GENERAL_ERROR_KEY, "The policy digest value is not defined.");
return validationResult;
}
// valid if no errors occur
validationResult.setDigestValid(true);
try {
final byte[] policyBytes = DSSUtils.toByteArray(policyContent);
ASN1Sequence asn1Sequence = DSSASN1Utils.toASN1Primitive(policyBytes);
if (asn1Sequence != null) {
validationResult.setAsn1Processable(true);
/*
* a) If the resulting document is based on TR 102 272 [i.2] (ESI: ASN.1 format for signature policies),
* use the digest value present in the SignPolicyDigest element from the resulting document.
* Check that the digest algorithm indicated in the SignPolicyDigestAlg from the resulting
* document is equal to the digest algorithm indicated in the property.
*/
/*
* b) If the resulting document is based on TR 102 038 [i.3] ((ESI) XML format for signature policies),
* use the digest value present in signPolicyHash element from the resulting document.
* Check that the digest algorithm indicated in the signPolicyHashAlg from the resulting
* document is equal to the digest algorithm indicated in the attribute.
*/
final ASN1Sequence signPolicyHashAlgObject = (ASN1Sequence) asn1Sequence.getObjectAt(0);
final AlgorithmIdentifier signPolicyHashAlgIdentifier = AlgorithmIdentifier.getInstance(signPolicyHashAlgObject);
DigestAlgorithm signPolicyHashAlgFromPolicy = DigestAlgorithm.forOID(signPolicyHashAlgIdentifier.getAlgorithm().getId());
if (signPolicyHashAlgFromPolicy.equals(digest.getAlgorithm())) {
validationResult.setDigestAlgorithmsEqual(true);
Digest recalculatedDigest = getComputedDigest(policyContent, signPolicyHashAlgFromPolicy);
validationResult.setDigest(recalculatedDigest);
boolean equal = digest.equals(recalculatedDigest);
validationResult.setDigestValid(equal);
if (!equal) {
validationResult.addError(GENERAL_ERROR_KEY,
"The policy digest value (" + Utils.toBase64(digest.getValue()) + ") does not match the re-calculated digest value ("
+ Utils.toBase64(recalculatedDigest.getValue()) + ").");
}
final ASN1OctetString signPolicyHash = (ASN1OctetString) asn1Sequence.getObjectAt(2);
final byte[] policyDigestValueFromPolicy = signPolicyHash.getOctets();
equal = Arrays.equals(digest.getValue(), policyDigestValueFromPolicy);
validationResult.setDigestValid(equal);
if (!equal) {
validationResult.addError(GENERAL_ERROR_KEY, "The policy digest value (" + Utils.toBase64(digest.getValue())
+ ") does not match the digest value from the policy file ("
+ Utils.toBase64(policyDigestValueFromPolicy) + ").");
}
} else {
validationResult.addError(GENERAL_ERROR_KEY, "The digest algorithm indicated in the SignPolicyHashAlg from the resulting document (" + signPolicyHashAlgFromPolicy
+ ") is not equal to the digest " + "algorithm (" + digest.getAlgorithm() + ").");
validationResult.setDigestAlgorithmsEqual(false);
validationResult.setDigestValid(false);
}
}
} catch (Exception e) {
// When any error (communication) we just set the status to false
validationResult.setDigestValid(false);
validationResult.addError(GENERAL_ERROR_KEY, e.getMessage());
// Do nothing
LOG.warn(e.getMessage(), e);
}
return validationResult;
}
@Override
public Digest getComputedDigest(DSSDocument policyDocument, DigestAlgorithm digestAlgorithm) {
byte[] asn1SignaturePolicyDigest = DSSASN1Utils.getAsn1SignaturePolicyDigest(
digestAlgorithm, DSSUtils.toByteArray(policyDocument));
return new Digest(digestAlgorithm, asn1SignaturePolicyDigest);
}
}