/*
* $Id: CertificateVerification.java 5467 2012-10-07 14:30:13Z blowagie $
*
* 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
* source product.
*
* For more information, please contact iText Software Corp. at this
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*/
package com.itextpdf.text.pdf.security;
import java.security.KeyStore;
import java.security.cert.CRL;
import java.security.cert.Certificate;
import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Enumeration;
import java.util.GregorianCalendar;
import java.util.List;
import org.bouncycastle.cert.ocsp.BasicOCSPResp;
import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoVerifierBuilder;
import org.bouncycastle.operator.jcajce.JcaContentVerifierProviderBuilder;
import org.bouncycastle.tsp.TimeStampToken;
/**
* This class consists of some methods that allow you to verify certificates.
*/
public class CertificateVerification {
/**
* Verifies a single certificate.
* @param cert the certificate to verify
* @param crls the certificate revocation list or <CODE>null</CODE>
* @param calendar the date or <CODE>null</CODE> for the current date
* @return a <CODE>String</CODE> with the error description or <CODE>null</CODE>
* if no error
*/
public static String verifyCertificate(X509Certificate cert, Collection<CRL> crls, Calendar calendar) {
if (calendar == null)
calendar = new GregorianCalendar();
if (cert.hasUnsupportedCriticalExtension()) {
for (String oid : cert.getCriticalExtensionOIDs()) {
// KEY USAGE and DIGITAL SIGNING is ALLOWED
if ("2.5.29.15".equals(oid) && cert.getKeyUsage()[0]) {
continue;
}
try {
// EXTENDED KEY USAGE and TIMESTAMPING is ALLOWED
if ("2.5.29.37".equals(oid) && cert.getExtendedKeyUsage().contains("1.3.6.1.5.5.7.3.8")) {
continue;
}
} catch (CertificateParsingException e) {
// DO NOTHING;
}
return "Has unsupported critical extension";
}
}
try {
cert.checkValidity(calendar.getTime());
}
catch (Exception e) {
return e.getMessage();
}
if (crls != null) {
for (CRL crl : crls) {
if (crl.isRevoked(cert))
return "Certificate revoked";
}
}
return null;
}
/**
* Verifies a certificate chain against a KeyStore.
* @param certs the certificate chain
* @param keystore the <CODE>KeyStore</CODE>
* @param crls the certificate revocation list or <CODE>null</CODE>
* @param calendar the date or <CODE>null</CODE> for the current date
* @return <CODE>null</CODE> if the certificate chain could be validated or a
* <CODE>Object[]{cert,error}</CODE> where <CODE>cert</CODE> is the
* failed certificate and <CODE>error</CODE> is the error message
*/
public static List<VerificationException> verifyCertificates(Certificate certs[], KeyStore keystore, Collection<CRL> crls, Calendar calendar) {
List<VerificationException> result = new ArrayList<VerificationException>();
if (calendar == null)
calendar = new GregorianCalendar();
for (int k = 0; k < certs.length; ++k) {
X509Certificate cert = (X509Certificate)certs[k];
String err = verifyCertificate(cert, crls, calendar);
if (err != null)
result.add(new VerificationException(cert, err));
try {
for (Enumeration<String> aliases = keystore.aliases(); aliases.hasMoreElements();) {
try {
String alias = aliases.nextElement();
if (!keystore.isCertificateEntry(alias))
continue;
X509Certificate certStoreX509 = (X509Certificate)keystore.getCertificate(alias);
if (verifyCertificate(certStoreX509, crls, calendar) != null)
continue;
try {
cert.verify(certStoreX509.getPublicKey());
return result;
}
catch (Exception e) {
continue;
}
}
catch (Exception ex) {
}
}
}
catch (Exception e) {
}
int j;
for (j = 0; j < certs.length; ++j) {
if (j == k)
continue;
X509Certificate certNext = (X509Certificate)certs[j];
try {
cert.verify(certNext.getPublicKey());
break;
}
catch (Exception e) {
}
}
if (j == certs.length) {
result.add(new VerificationException(cert, "Cannot be verified against the KeyStore or the certificate chain"));
}
}
if (result.size() == 0)
result.add(new VerificationException(null, "Invalid state. Possible circular certificate chain"));
return result;
}
/**
* Verifies a certificate chain against a KeyStore.
* @param certs the certificate chain
* @param keystore the <CODE>KeyStore</CODE>
* @param calendar the date or <CODE>null</CODE> for the current date
* @return <CODE>null</CODE> if the certificate chain could be validated or a
* <CODE>Object[]{cert,error}</CODE> where <CODE>cert</CODE> is the
* failed certificate and <CODE>error</CODE> is the error message
*/
public static List<VerificationException> verifyCertificates(Certificate certs[], KeyStore keystore, Calendar calendar) {
return verifyCertificates(certs, keystore, null, calendar);
}
/**
* Verifies an OCSP response against a KeyStore.
* @param ocsp the OCSP response
* @param keystore the <CODE>KeyStore</CODE>
* @param provider the provider or <CODE>null</CODE> to use the BouncyCastle provider
* @return <CODE>true</CODE> is a certificate was found
*/
public static boolean verifyOcspCertificates(BasicOCSPResp ocsp, KeyStore keystore, String provider) {
if (provider == null)
provider = "BC";
try {
for (Enumeration<String> aliases = keystore.aliases(); aliases.hasMoreElements();) {
try {
String alias = aliases.nextElement();
if (!keystore.isCertificateEntry(alias))
continue;
X509Certificate certStoreX509 = (X509Certificate)keystore.getCertificate(alias);
if (ocsp.isSignatureValid(new JcaContentVerifierProviderBuilder().setProvider(provider).build(certStoreX509.getPublicKey())))
return true;
}
catch (Exception ex) {
}
}
}
catch (Exception e) {
}
return false;
}
/**
* Verifies a time stamp against a KeyStore.
* @param ts the time stamp
* @param keystore the <CODE>KeyStore</CODE>
* @param provider the provider or <CODE>null</CODE> to use the BouncyCastle provider
* @return <CODE>true</CODE> is a certificate was found
*/
public static boolean verifyTimestampCertificates(TimeStampToken ts, KeyStore keystore, String provider) {
if (provider == null)
provider = "BC";
try {
for (Enumeration<String> aliases = keystore.aliases(); aliases.hasMoreElements();) {
try {
String alias = aliases.nextElement();
if (!keystore.isCertificateEntry(alias))
continue;
X509Certificate certStoreX509 = (X509Certificate)keystore.getCertificate(alias);
ts.isSignatureValid(new JcaSimpleSignerInfoVerifierBuilder().setProvider(provider).build(certStoreX509));
return true;
}
catch (Exception ex) {
}
}
}
catch (Exception e) {
}
return false;
}
}