/*
* $Id: OCSPVerifier.java 5502 2012-10-30 14:16:05Z achingarev $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2012 1T3XT BVBA
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
* 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
*
* This program 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 Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General Public License.
*
* In accordance with Section 7(b) of the GNU Affero General Public License,
* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the iText software without
* disclosing the source code of your own applications.
* These activities include: offering paid services to customers as an ASP,
* serving PDFs on the fly in a web application, shipping iText with a closed
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*
* For more information, please contact iText Software Corp. at this
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*/
package com.itextpdf.text.pdf.security;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Date;
import java.util.Enumeration;
import java.util.List;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
import org.bouncycastle.cert.ocsp.BasicOCSPResp;
import org.bouncycastle.cert.ocsp.CertificateStatus;
import org.bouncycastle.cert.ocsp.OCSPException;
import org.bouncycastle.cert.ocsp.SingleResp;
import org.bouncycastle.operator.ContentVerifierProvider;
import org.bouncycastle.operator.OperatorCreationException;
import org.bouncycastle.operator.bc.BcDigestCalculatorProvider;
import org.bouncycastle.operator.jcajce.JcaContentVerifierProviderBuilder;
import com.itextpdf.text.log.Logger;
import com.itextpdf.text.log.LoggerFactory;
/**
* Class that allows you to verify a certificate against
* one or more OCSP responses.
*/
public class OCSPVerifier extends RootStoreVerifier {
/** The Logger instance */
protected final static Logger LOGGER = LoggerFactory.getLogger(OCSPVerifier.class);
/** The list of OCSP responses. */
protected List<BasicOCSPResp> ocsps;
/**
* Creates an OCSPVerifier instance.
* @param verifier the next verifier in the chain
* @param ocsps a list of OCSP responses
*/
public OCSPVerifier(CertificateVerifier verifier, List<BasicOCSPResp> ocsps) {
super(verifier);
this.ocsps = ocsps;
}
/**
* Verifies if a a valid OCSP response is found for the certificate.
* If this method returns false, it doesn't mean the certificate isn't valid.
* It means we couldn't verify it against any OCSP response that was available.
* @param signCert the certificate that needs to be checked
* @param issuerCert its issuer
* @return a list of <code>VerificationOK</code> objects.
* The list will be empty if the certificate couldn't be verified.
* @see com.itextpdf.text.pdf.security.RootStoreVerifier#verify(java.security.cert.X509Certificate, java.security.cert.X509Certificate, java.util.Date)
*/
public List<VerificationOK> verify(X509Certificate signCert,
X509Certificate issuerCert, Date signDate)
throws GeneralSecurityException, IOException {
List<VerificationOK> result = new ArrayList<VerificationOK>();
int validOCSPsFound = 0;
// first check in the list of OCSP responses that was provided
if (ocsps != null) {
for (BasicOCSPResp ocspResp : ocsps) {
if (verify(ocspResp, signCert, issuerCert, signDate))
validOCSPsFound++;
}
}
// then check online if allowed
boolean online = false;
if (onlineCheckingAllowed && validOCSPsFound == 0) {
if (verify(getOcspResponse(signCert, issuerCert), signCert, issuerCert, signDate)) {
validOCSPsFound++;
online = true;
}
}
// show how many valid OCSP responses were found
LOGGER.info("Valid OCSPs found: " + validOCSPsFound);
if (validOCSPsFound > 0)
result.add(new VerificationOK(signCert, this.getClass(), "Valid OCSPs Found: " + validOCSPsFound + (online ? " (online)" : "")));
if (verifier != null)
result.addAll(verifier.verify(signCert, issuerCert, signDate));
// verify using the previous verifier in the chain (if any)
return result;
}
/**
* Verifies a certificate against a single OCSP response
* @param ocspResp the OCSP response
* @param serialNumber the serial number of the certificate that needs to be checked
* @param issuerCert
* @param signDate
* @return
* @throws GeneralSecurityException
* @throws IOException
*/
public boolean verify(BasicOCSPResp ocspResp, X509Certificate signCert, X509Certificate issuerCert, Date signDate) throws GeneralSecurityException, IOException {
if (ocspResp == null)
return false;
// Getting the responses
SingleResp[] resp = ocspResp.getResponses();
for (int i = 0; i < resp.length; i++) {
// check if the serial number corresponds
if (!signCert.getSerialNumber().equals(resp[i].getCertID().getSerialNumber())) {
continue;
}
// check if the issuer matches
try {
if (!resp[i].getCertID().matchesIssuer(new X509CertificateHolder(issuerCert.getEncoded()), new BcDigestCalculatorProvider())) {
LOGGER.info("OCSP: Issuers doesn't match.");
continue;
}
} catch (OCSPException e) {
continue;
}
// check if the OCSP response was valid at the time of signing
if (signDate.after(resp[i].getNextUpdate())) {
LOGGER.info(String.format("OCSP no longer valid: %s after %s", signDate, resp[i].getNextUpdate()));
continue;
}
// check the status of the certificate
Object status = resp[i].getCertStatus();
if (status == CertificateStatus.GOOD) {
// check if the OCSP response was genuine
isValidResponse(ocspResp, issuerCert);
return true;
}
}
return false;
}
/**
* Verifies if an OCSP response is genuine
* @param ocspResp the OCSP response
* @param issuerCert the issuer certificate
* @throws GeneralSecurityException
* @throws IOException
*/
public void isValidResponse(BasicOCSPResp ocspResp, X509Certificate issuerCert) throws GeneralSecurityException, IOException {
// by default the OCSP responder certificate is the issuer certificate
X509Certificate responderCert = issuerCert;
// check if there's a responder certificate
X509CertificateHolder[] certHolders = ocspResp.getCerts();
if (certHolders.length > 0) {
responderCert = new JcaX509CertificateConverter().setProvider( "BC" ).getCertificate(certHolders[0]);
try {
responderCert.verify(issuerCert.getPublicKey());
}
catch(GeneralSecurityException e) {
if (super.verify(responderCert, issuerCert, null).size() == 0)
throw new VerificationException(responderCert, "Responder certificate couldn't be verified");
}
}
// verify if the signature of the response is valid
if (!verifyResponse(ocspResp, responderCert))
throw new VerificationException(responderCert, "OCSP response could not be verified");
}
/**
* Verifies if the signature of the response is valid.
* If it doesn't verify against the responder certificate, it may verify
* using a trusted anchor.
* @param ocspResp the response object
* @param responderCert the certificate that may be used to sign the response
* @return true if the response can be trusted
*/
public boolean verifyResponse(BasicOCSPResp ocspResp, X509Certificate responderCert) {
// testing using the responder certificate
if (isSignatureValid(ocspResp, responderCert))
return true;
// testing using trusted anchors
if (rootStore == null)
return false;
try {
// loop over the certificates in the root store
for (Enumeration<String> aliases = rootStore.aliases(); aliases.hasMoreElements();) {
String alias = aliases.nextElement();
try {
if (!rootStore.isCertificateEntry(alias))
continue;
X509Certificate anchor = (X509Certificate)rootStore.getCertificate(alias);
if (isSignatureValid(ocspResp, anchor))
return true;
} catch (GeneralSecurityException e) {
continue;
}
}
}
catch (GeneralSecurityException e) {
return false;
}
return false;
}
/**
* Checks if an OCSP response is genuine
* @param ocspResp the OCSP response
* @param responderCert the responder certificate
* @return true if the OCSP response verifies against the responder certificate
*/
public boolean isSignatureValid(BasicOCSPResp ocspResp, Certificate responderCert) {
try {
ContentVerifierProvider verifierProvider = new JcaContentVerifierProviderBuilder().setProvider("BC").build(responderCert.getPublicKey());
return ocspResp.isSignatureValid(verifierProvider);
} catch (OperatorCreationException e) {
return false;
} catch (OCSPException e) {
return false;
}
}
/**
* Gets an OCSP response online and returns it if the status is GOOD
* (without further checking).
* @param signCert the signing certificate
* @param issuerCert the issuer certificate
* @return an OCSP response
*/
public BasicOCSPResp getOcspResponse(X509Certificate signCert, X509Certificate issuerCert) {
if (signCert == null && issuerCert == null) {
return null;
}
OcspClientBouncyCastle ocsp = new OcspClientBouncyCastle();
BasicOCSPResp ocspResp = ocsp.getBasicOCSPResp(signCert, issuerCert, null);
if (ocspResp == null) {
return null;
}
SingleResp[] resp = ocspResp.getResponses();
for (int i = 0; i < resp.length; i++) {
Object status = resp[i].getCertStatus();
if (status == CertificateStatus.GOOD) {
return ocspResp;
}
}
return null;
}
}