package org.bouncycastle.x509;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.security.GeneralSecurityException;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.cert.CRLException;
import java.security.cert.CertPathValidatorException;
import java.security.cert.CertStore;
import java.security.cert.CertStoreException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.PKIXParameters;
import java.security.cert.PolicyQualifierInfo;
import java.security.cert.X509CRL;
import java.security.cert.X509CRLEntry;
import java.security.cert.X509Certificate;
import java.security.interfaces.DSAParams;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.DSAPublicKeySpec;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.security.auth.x500.X500Principal;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Enumerated;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1OutputStream;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.CRLReason;
import org.bouncycastle.asn1.x509.Extension;
import org.bouncycastle.asn1.x509.IssuingDistributionPoint;
import org.bouncycastle.asn1.x509.PolicyInformation;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.asn1.x509.X509Extension;
import org.bouncycastle.jcajce.PKIXCertStoreSelector;
import org.bouncycastle.jce.exception.ExtCertPathValidatorException;
import org.bouncycastle.jce.provider.AnnotatedException;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.jce.provider.PKIXPolicyNode;
import org.bouncycastle.util.Encodable;
import org.bouncycastle.util.Selector;
import org.bouncycastle.util.Store;
import org.bouncycastle.util.StoreException;

class CertPathValidatorUtilities
{
    protected static final PKIXCRLUtil CRL_UTIL = new PKIXCRLUtil();

    protected static final String CERTIFICATE_POLICIES = Extension.certificatePolicies.getId();
    protected static final String BASIC_CONSTRAINTS = Extension.basicConstraints.getId();
    protected static final String POLICY_MAPPINGS = Extension.policyMappings.getId();
    protected static final String SUBJECT_ALTERNATIVE_NAME = Extension.subjectAlternativeName.getId();
    protected static final String NAME_CONSTRAINTS = Extension.nameConstraints.getId();
    protected static final String KEY_USAGE = Extension.keyUsage.getId();
    protected static final String INHIBIT_ANY_POLICY = Extension.inhibitAnyPolicy.getId();
    protected static final String ISSUING_DISTRIBUTION_POINT = Extension.issuingDistributionPoint.getId();
    protected static final String DELTA_CRL_INDICATOR = Extension.deltaCRLIndicator.getId();
    protected static final String POLICY_CONSTRAINTS = Extension.policyConstraints.getId();
    protected static final String FRESHEST_CRL = Extension.freshestCRL.getId();
    protected static final String CRL_DISTRIBUTION_POINTS = Extension.cRLDistributionPoints.getId();
    protected static final String AUTHORITY_KEY_IDENTIFIER = Extension.authorityKeyIdentifier.getId();

    protected static final String ANY_POLICY = "2.5.29.32.0";

    protected static final String CRL_NUMBER = Extension.cRLNumber.getId();

    /*
    * key usage bits
    */
    protected static final int KEY_CERT_SIGN = 5;
    protected static final int CRL_SIGN = 6;

    protected static final String[] crlReasons = new String[]{
        "unspecified",
        "keyCompromise",
        "cACompromise",
        "affiliationChanged",
        "superseded",
        "cessationOfOperation",
        "certificateHold",
        "unknown",
        "removeFromCRL",
        "privilegeWithdrawn",
        "aACompromise"};




    
Returns the issuer of an attribute certificate or certificate.
Params:
cert – The attribute certificate or certificate.
Returns:
The issuer as X500Principal./**
     * Returns the issuer of an attribute certificate or certificate.
     *
     * @param cert The attribute certificate or certificate.
     * @return The issuer as <code>X500Principal</code>.
     */
    protected static X500Principal getEncodedIssuerPrincipal(
        Object cert)
    {
        if (cert instanceof X509Certificate)
        {
            return ((X509Certificate)cert).getIssuerX500Principal();
        }
        else
        {
            return (X500Principal)((X509AttributeCertificate)cert).getIssuer().getPrincipals()[0];
        }
    }

    protected static Date getValidDate(PKIXParameters paramsPKIX)
    {
        Date validDate = paramsPKIX.getDate();

        if (validDate == null)
        {
            validDate = new Date();
        }

        return validDate;
    }

    protected static X500Principal getSubjectPrincipal(X509Certificate cert)
    {
        return cert.getSubjectX500Principal();
    }

    protected static boolean isSelfIssued(X509Certificate cert)
    {
        return cert.getSubjectDN().equals(cert.getIssuerDN());
    }


    
Extract the value of the given extension, if it exists.
Params:
ext – The extension object.
oid – The object identifier to obtain.
Throws:
AnnotatedException – if the extension cannot be read./**
     * Extract the value of the given extension, if it exists.
     *
     * @param ext The extension object.
     * @param oid The object identifier to obtain.
     * @throws AnnotatedException if the extension cannot be read.
     */
    protected static ASN1Primitive getExtensionValue(
        java.security.cert.X509Extension ext,
        String oid)
        throws AnnotatedException
    {
        byte[] bytes = ext.getExtensionValue(oid);
        if (bytes == null)
        {
            return null;
        }

        return getObject(oid, bytes);
    }

    private static ASN1Primitive getObject(
        String oid,
        byte[] ext)
        throws AnnotatedException
    {
        try
        {
            ASN1InputStream aIn = new ASN1InputStream(ext);
            ASN1OctetString octs = (ASN1OctetString)aIn.readObject();

            aIn = new ASN1InputStream(octs.getOctets());
            return aIn.readObject();
        }
        catch (Exception e)
        {
            throw new AnnotatedException("exception processing extension " + oid, e);
        }
    }

    protected static X500Principal getIssuerPrincipal(X509CRL crl)
    {
        return crl.getIssuerX500Principal();
    }

    protected static AlgorithmIdentifier getAlgorithmIdentifier(
        PublicKey key)
        throws CertPathValidatorException
    {
        try
        {
            ASN1InputStream aIn = new ASN1InputStream(key.getEncoded());

            SubjectPublicKeyInfo info = SubjectPublicKeyInfo.getInstance(aIn.readObject());

            return info.getAlgorithmId();
        }
        catch (Exception e)
        {
            throw new ExtCertPathValidatorException("Subject public key cannot be decoded.", e);
        }
    }

    // crl checking


    //
    // policy checking
    //

    protected static final Set getQualifierSet(ASN1Sequence qualifiers)
        throws CertPathValidatorException
    {
        Set pq = new HashSet();

        if (qualifiers == null)
        {
            return pq;
        }

        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        ASN1OutputStream aOut = new ASN1OutputStream(bOut);

        Enumeration e = qualifiers.getObjects();

        while (e.hasMoreElements())
        {
            try
            {
                aOut.writeObject((ASN1Encodable)e.nextElement());

                pq.add(new PolicyQualifierInfo(bOut.toByteArray()));
            }
            catch (IOException ex)
            {
                throw new ExtCertPathValidatorException("Policy qualifier info cannot be decoded.", ex);
            }

            bOut.reset();
        }

        return pq;
    }

    protected static PKIXPolicyNode removePolicyNode(
        PKIXPolicyNode validPolicyTree,
        List[] policyNodes,
        PKIXPolicyNode _node)
    {
        PKIXPolicyNode _parent = (PKIXPolicyNode)_node.getParent();

        if (validPolicyTree == null)
        {
            return null;
        }

        if (_parent == null)
        {
            for (int j = 0; j < policyNodes.length; j++)
            {
                policyNodes[j] = new ArrayList();
            }

            return null;
        }
        else
        {
            _parent.removeChild(_node);
            removePolicyNodeRecurse(policyNodes, _node);

            return validPolicyTree;
        }
    }

    private static void removePolicyNodeRecurse(
        List[] policyNodes,
        PKIXPolicyNode _node)
    {
        policyNodes[_node.getDepth()].remove(_node);

        if (_node.hasChildren())
        {
            Iterator _iter = _node.getChildren();
            while (_iter.hasNext())
            {
                PKIXPolicyNode _child = (PKIXPolicyNode)_iter.next();
                removePolicyNodeRecurse(policyNodes, _child);
            }
        }
    }


    protected static boolean processCertD1i(
        int index,
        List[] policyNodes,
        ASN1ObjectIdentifier pOid,
        Set pq)
    {
        List policyNodeVec = policyNodes[index - 1];

        for (int j = 0; j < policyNodeVec.size(); j++)
        {
            PKIXPolicyNode node = (PKIXPolicyNode)policyNodeVec.get(j);
            Set expectedPolicies = node.getExpectedPolicies();

            if (expectedPolicies.contains(pOid.getId()))
            {
                Set childExpectedPolicies = new HashSet();
                childExpectedPolicies.add(pOid.getId());

                PKIXPolicyNode child = new PKIXPolicyNode(new ArrayList(),
                    index,
                    childExpectedPolicies,
                    node,
                    pq,
                    pOid.getId(),
                    false);
                node.addChild(child);
                policyNodes[index].add(child);

                return true;
            }
        }

        return false;
    }

    protected static void processCertD1ii(
        int index,
        List[] policyNodes,
        ASN1ObjectIdentifier _poid,
        Set _pq)
    {
        List policyNodeVec = policyNodes[index - 1];

        for (int j = 0; j < policyNodeVec.size(); j++)
        {
            PKIXPolicyNode _node = (PKIXPolicyNode)policyNodeVec.get(j);

            if (ANY_POLICY.equals(_node.getValidPolicy()))
            {
                Set _childExpectedPolicies = new HashSet();
                _childExpectedPolicies.add(_poid.getId());

                PKIXPolicyNode _child = new PKIXPolicyNode(new ArrayList(),
                    index,
                    _childExpectedPolicies,
                    _node,
                    _pq,
                    _poid.getId(),
                    false);
                _node.addChild(_child);
                policyNodes[index].add(_child);
                return;
            }
        }
    }

    protected static void prepareNextCertB1(
        int i,
        List[] policyNodes,
        String id_p,
        Map m_idp,
        X509Certificate cert
    )
        throws AnnotatedException, CertPathValidatorException
    {
        boolean idp_found = false;
        Iterator nodes_i = policyNodes[i].iterator();
        while (nodes_i.hasNext())
        {
            PKIXPolicyNode node = (PKIXPolicyNode)nodes_i.next();
            if (node.getValidPolicy().equals(id_p))
            {
                idp_found = true;
                node.setExpectedPolicies((Set)m_idp.get(id_p));
                break;
            }
        }

        if (!idp_found)
        {
            nodes_i = policyNodes[i].iterator();
            while (nodes_i.hasNext())
            {
                PKIXPolicyNode node = (PKIXPolicyNode)nodes_i.next();
                if (ANY_POLICY.equals(node.getValidPolicy()))
                {
                    Set pq = null;
                    ASN1Sequence policies = null;
                    try
                    {
                        policies = DERSequence.getInstance(getExtensionValue(cert, CERTIFICATE_POLICIES));
                    }
                    catch (Exception e)
                    {
                        throw new AnnotatedException("Certificate policies cannot be decoded.", e);
                    }
                    Enumeration e = policies.getObjects();
                    while (e.hasMoreElements())
                    {
                        PolicyInformation pinfo = null;

                        try
                        {
                            pinfo = PolicyInformation.getInstance(e.nextElement());
                        }
                        catch (Exception ex)
                        {
                            throw new AnnotatedException("Policy information cannot be decoded.", ex);
                        }
                        if (ANY_POLICY.equals(pinfo.getPolicyIdentifier().getId()))
                        {
                            try
                            {
                                pq = getQualifierSet(pinfo.getPolicyQualifiers());
                            }
                            catch (CertPathValidatorException ex)
                            {
                                throw new ExtCertPathValidatorException(
                                    "Policy qualifier info set could not be built.", ex);
                            }
                            break;
                        }
                    }
                    boolean ci = false;
                    if (cert.getCriticalExtensionOIDs() != null)
                    {
                        ci = cert.getCriticalExtensionOIDs().contains(CERTIFICATE_POLICIES);
                    }

                    PKIXPolicyNode p_node = (PKIXPolicyNode)node.getParent();
                    if (ANY_POLICY.equals(p_node.getValidPolicy()))
                    {
                        PKIXPolicyNode c_node = new PKIXPolicyNode(
                            new ArrayList(), i,
                            (Set)m_idp.get(id_p),
                            p_node, pq, id_p, ci);
                        p_node.addChild(c_node);
                        policyNodes[i].add(c_node);
                    }
                    break;
                }
            }
        }
    }

    protected static PKIXPolicyNode prepareNextCertB2(
        int i,
        List[] policyNodes,
        String id_p,
        PKIXPolicyNode validPolicyTree)
    {
        Iterator nodes_i = policyNodes[i].iterator();
        while (nodes_i.hasNext())
        {
            PKIXPolicyNode node = (PKIXPolicyNode)nodes_i.next();
            if (node.getValidPolicy().equals(id_p))
            {
                PKIXPolicyNode p_node = (PKIXPolicyNode)node.getParent();
                p_node.removeChild(node);
                nodes_i.remove();
                for (int k = (i - 1); k >= 0; k--)
                {
                    List nodes = policyNodes[k];
                    for (int l = 0; l < nodes.size(); l++)
                    {
                        PKIXPolicyNode node2 = (PKIXPolicyNode)nodes.get(l);
                        if (!node2.hasChildren())
                        {
                            validPolicyTree = removePolicyNode(validPolicyTree, policyNodes, node2);
                            if (validPolicyTree == null)
                            {
                                break;
                            }
                        }
                    }
                }
            }
        }
        return validPolicyTree;
    }

    protected static boolean isAnyPolicy(
        Set policySet)
    {
        return policySet == null || policySet.contains(ANY_POLICY) || policySet.isEmpty();
    }

    
Return a Collection of all certificates or attribute certificates found
in the X509Store's that are matching the certSelect criteriums.
Params:
certSelect – a Selector object that will be used to select the certificates
certStores – a List containing only X509Store objects. These are used to search for certificates.
Returns:
a Collection of all found X509Certificate or X509AttributeCertificate objects. May be empty but never null./**
     * Return a Collection of all certificates or attribute certificates found
     * in the X509Store's that are matching the certSelect criteriums.
     *
     * @param certSelect a {@link Selector} object that will be used to select
     *                   the certificates
     * @param certStores a List containing only {@link X509Store} objects. These
     *                   are used to search for certificates.
     * @return a Collection of all found {@link X509Certificate} or
     *         {@link org.bouncycastle.x509.X509AttributeCertificate} objects.
     *         May be empty but never <code>null</code>.
     */
    protected static Collection findCertificates(X509CertStoreSelector certSelect,
                                                 List certStores)
        throws AnnotatedException
    {
        Set certs = new HashSet();
        Iterator iter = certStores.iterator();
        org.bouncycastle.jcajce.provider.asymmetric.x509.CertificateFactory certFact = new org.bouncycastle.jcajce.provider.asymmetric.x509.CertificateFactory();

        while (iter.hasNext())
        {
            Object obj = iter.next();

            if (obj instanceof Store)
            {
                Store certStore = (Store)obj;
                try
                {
                    for (Iterator it = certStore.getMatches(certSelect).iterator(); it.hasNext();)
                    {
                        Object cert = it.next();

                        if (cert instanceof Encodable)
                        {
                            certs.add(certFact.engineGenerateCertificate(new ByteArrayInputStream(((Encodable)cert).getEncoded())));
                        }
                        else if (cert instanceof Certificate)
                        {
                             certs.add(cert);
                        }
                        else
                        {
                            throw new AnnotatedException(
                                    "Unknown object found in certificate store.");
                        }
                    }
                }
                catch (StoreException e)
                {
                    throw new AnnotatedException(
                            "Problem while picking certificates from X.509 store.", e);
                }
                catch (IOException e)
                {
                    throw new AnnotatedException(
                            "Problem while extracting certificates from X.509 store.", e);
                }
                catch (CertificateException e)
                {
                    throw new AnnotatedException(
                            "Problem while extracting certificates from X.509 store.", e);
                }
            }
            else
            {
                CertStore certStore = (CertStore)obj;

                try
                {
                    certs.addAll(certStore.getCertificates(certSelect));
                }
                catch (CertStoreException e)
                {
                    throw new AnnotatedException(
                        "Problem while picking certificates from certificate store.",
                        e);
                }
            }
        }
        return certs;
    }

    protected static Collection findCertificates(PKIXCertStoreSelector certSelect,
                                                 List certStores)
        throws AnnotatedException
    {
        Set certs = new HashSet();
        Iterator iter = certStores.iterator();

        while (iter.hasNext())
        {
            Object obj = iter.next();

            if (obj instanceof Store)
            {
                Store certStore = (Store)obj;
                try
                {
                    certs.addAll(certStore.getMatches(certSelect));
                }
                catch (StoreException e)
                {
                    throw new AnnotatedException(
                            "Problem while picking certificates from X.509 store.", e);
                }
            }
            else
            {
                CertStore certStore = (CertStore)obj;

                try
                {
                    certs.addAll(PKIXCertStoreSelector.getCertificates(certSelect, certStore));
                }
                catch (CertStoreException e)
                {
                    throw new AnnotatedException(
                        "Problem while picking certificates from certificate store.",
                        e);
                }
            }
        }
        return certs;
    }

    protected static Collection findCertificates(X509AttributeCertStoreSelector certSelect,
                                                 List certStores)
        throws AnnotatedException
    {
        Set certs = new HashSet();
        Iterator iter = certStores.iterator();

        while (iter.hasNext())
        {
            Object obj = iter.next();

            if (obj instanceof X509Store)
            {
                X509Store certStore = (X509Store)obj;
                try
                {
                    certs.addAll(certStore.getMatches(certSelect));
                }
                catch (StoreException e)
                {
                    throw new AnnotatedException(
                            "Problem while picking certificates from X.509 store.", e);
                }
            }
        }
        return certs;
    }

    private static BigInteger getSerialNumber(
        Object cert)
    {
        if (cert instanceof X509Certificate)
        {
            return ((X509Certificate)cert).getSerialNumber();
        }
        else
        {
            return ((X509AttributeCertificate)cert).getSerialNumber();
        }
    }

    protected static void getCertStatus(
        Date validDate,
        X509CRL crl,
        Object cert,
        CertStatus certStatus)
        throws AnnotatedException
    {
        X509CRLEntry crl_entry = null;

        boolean isIndirect;
        try
        {
            isIndirect = isIndirectCRL(crl);
        }
        catch (CRLException exception)
        {
            throw new AnnotatedException("Failed check for indirect CRL.", exception);
        }

        if (isIndirect)
        {
            crl_entry = crl.getRevokedCertificate(getSerialNumber(cert));

            if (crl_entry == null)
            {
                return;
            }

            X500Principal certIssuer = crl_entry.getCertificateIssuer();

            if (certIssuer == null)
            {
                certIssuer = getIssuerPrincipal(crl);
            }

            if (!getEncodedIssuerPrincipal(cert).equals(certIssuer))
            {
                return;
            }
        }
        else if (!getEncodedIssuerPrincipal(cert).equals(getIssuerPrincipal(crl)))
        {
            return;  // not for our issuer, ignore
        }
        else
        {
            crl_entry = crl.getRevokedCertificate(getSerialNumber(cert));

            if (crl_entry == null)
            {
                return;
            }
        }

        ASN1Enumerated reasonCode = null;
        if (crl_entry.hasExtensions())
        {
            try
            {
                reasonCode = ASN1Enumerated
                    .getInstance(CertPathValidatorUtilities
                        .getExtensionValue(crl_entry,
                            X509Extension.reasonCode.getId()));
            }
            catch (Exception e)
            {
                throw new AnnotatedException(
                    "Reason code CRL entry extension could not be decoded.",
                    e);
            }
        }

        // for reason keyCompromise, caCompromise, aACompromise or
        // unspecified
        if (!(validDate.getTime() < crl_entry.getRevocationDate().getTime())
            || reasonCode == null
            || reasonCode.getValue().intValue() == 0
            || reasonCode.getValue().intValue() == 1
            || reasonCode.getValue().intValue() == 2
            || reasonCode.getValue().intValue() == 8)
        {

            // (i) or (j) (1)
            if (reasonCode != null)
            {
                certStatus.setCertStatus(reasonCode.getValue().intValue());
            }
            // (i) or (j) (2)
            else
            {
                certStatus.setCertStatus(CRLReason.unspecified);
            }
            certStatus.setRevocationDate(crl_entry.getRevocationDate());
        }
    }

    
Return the next working key inheriting DSA parameters if necessary.

This methods inherits DSA parameters from the indexed certificate or
previous certificates in the certificate chain to the returned
PublicKey. The list is searched upwards, meaning the end
certificate is at position 0 and previous certificates are following.


If the indexed certificate does not contain a DSA key this method simply
returns the public key. If the DSA key already contains DSA parameters
the key is also only returned.

Params:
certs – The certification path.
index – The index of the certificate which contains the public key
             which should be extended with DSA parameters.
Throws:
CertPathValidatorException – if DSA parameters cannot be inherited.
Returns:
The public key of the certificate in list position
        index extended with DSA parameters if applicable./**
     * Return the next working key inheriting DSA parameters if necessary.
     * <p>
     * This methods inherits DSA parameters from the indexed certificate or
     * previous certificates in the certificate chain to the returned
     * <code>PublicKey</code>. The list is searched upwards, meaning the end
     * certificate is at position 0 and previous certificates are following.
     * </p>
     * <p>
     * If the indexed certificate does not contain a DSA key this method simply
     * returns the public key. If the DSA key already contains DSA parameters
     * the key is also only returned.
     * </p>
     *
     * @param certs The certification path.
     * @param index The index of the certificate which contains the public key
     *              which should be extended with DSA parameters.
     * @return The public key of the certificate in list position
     *         <code>index</code> extended with DSA parameters if applicable.
     * @throws CertPathValidatorException if DSA parameters cannot be inherited.
     */
    protected static PublicKey getNextWorkingKey(List certs, int index)
        throws CertPathValidatorException
    {
        Certificate cert = (Certificate)certs.get(index);
        PublicKey pubKey = cert.getPublicKey();
        if (!(pubKey instanceof DSAPublicKey))
        {
            return pubKey;
        }
        DSAPublicKey dsaPubKey = (DSAPublicKey)pubKey;
        if (dsaPubKey.getParams() != null)
        {
            return dsaPubKey;
        }
        for (int i = index + 1; i < certs.size(); i++)
        {
            X509Certificate parentCert = (X509Certificate)certs.get(i);
            pubKey = parentCert.getPublicKey();
            if (!(pubKey instanceof DSAPublicKey))
            {
                throw new CertPathValidatorException(
                    "DSA parameters cannot be inherited from previous certificate.");
            }
            DSAPublicKey prevDSAPubKey = (DSAPublicKey)pubKey;
            if (prevDSAPubKey.getParams() == null)
            {
                continue;
            }
            DSAParams dsaParams = prevDSAPubKey.getParams();
            DSAPublicKeySpec dsaPubKeySpec = new DSAPublicKeySpec(
                dsaPubKey.getY(), dsaParams.getP(), dsaParams.getQ(), dsaParams.getG());
            try
            {
                KeyFactory keyFactory = KeyFactory.getInstance("DSA", BouncyCastleProvider.PROVIDER_NAME);
                return keyFactory.generatePublic(dsaPubKeySpec);
            }
            catch (Exception exception)
            {
                throw new RuntimeException(exception.getMessage());
            }
        }
        throw new CertPathValidatorException("DSA parameters cannot be inherited from previous certificate.");
    }

    protected static void verifyX509Certificate(X509Certificate cert, PublicKey publicKey,
                                                String sigProvider)
        throws GeneralSecurityException
    {
        if (sigProvider == null)
        {
            cert.verify(publicKey);
        }
        else
        {
            cert.verify(publicKey, sigProvider);
        }
    }

    static boolean isIndirectCRL(X509CRL crl)
        throws CRLException
    {
        try
        {
            byte[] idp = crl.getExtensionValue(Extension.issuingDistributionPoint.getId());
            return idp != null
                && IssuingDistributionPoint.getInstance(ASN1OctetString.getInstance(idp).getOctets()).isIndirectCRL();
        }
        catch (Exception e)
        {
            throw new CRLException(
                    "Exception reading IssuingDistributionPoint: " + e);
        }
    }
}