/*
 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.security.provider.certpath;

import java.io.IOException;
import java.util.Date;

import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.security.cert.X509CertSelector;
import java.security.cert.CertificateException;

import sun.security.util.DerOutputStream;
import sun.security.x509.SerialNumber;
import sun.security.x509.KeyIdentifier;
import sun.security.x509.AuthorityKeyIdentifierExtension;

An adaptable X509 certificate selector for forward certification path
building.
Since:
1.7/**
 * An adaptable X509 certificate selector for forward certification path
 * building.
 *
 * @since 1.7
 */
class AdaptableX509CertSelector extends X509CertSelector {
    // The start date of a validity period.
    private Date startDate = null;

    // The end date of a validity period.
    private Date endDate = null;

    AdaptableX509CertSelector() {
        super();
    }

    
Sets the criterion of the X509Certificate validity period.
Normally, we may not have to check that a certificate validity period
must fall within its issuer's certificate validity period. However,
when we face root CA key updates for version 1 certificates, according
to scheme of RFC 4210 or 2510, the validity periods should be checked
to determine the right issuer's certificate.
Conservatively, we will only check the validity periods for version
1 and version 2 certificates. For version 3 certificates, we can
determine the right issuer by authority and subject key identifier
extensions.
Params:
startDate – the start date of a validity period that must fall
       within the certificate validity period for the X509Certificate
endDate – the end date of a validity period that must fall
       within the certificate validity period for the X509Certificate/**
     * Sets the criterion of the X509Certificate validity period.
     *
     * Normally, we may not have to check that a certificate validity period
     * must fall within its issuer's certificate validity period. However,
     * when we face root CA key updates for version 1 certificates, according
     * to scheme of RFC 4210 or 2510, the validity periods should be checked
     * to determine the right issuer's certificate.
     *
     * Conservatively, we will only check the validity periods for version
     * 1 and version 2 certificates. For version 3 certificates, we can
     * determine the right issuer by authority and subject key identifier
     * extensions.
     *
     * @param startDate the start date of a validity period that must fall
     *        within the certificate validity period for the X509Certificate
     * @param endDate the end date of a validity period that must fall
     *        within the certificate validity period for the X509Certificate
     */
    void setValidityPeriod(Date startDate, Date endDate) {
        this.startDate = startDate;
        this.endDate = endDate;
    }

    
Parse the authority key identifier extension.
If the keyIdentifier field of the extension is non-null, set the
subjectKeyIdentifier criterion. If the authorityCertSerialNumber
field is non-null, set the serialNumber criterion.
Note that we will not set the subject criterion according to the
authorityCertIssuer field of the extension. The caller MUST set
the subject criterion before call match().
Params:
akidext – the authorityKeyIdentifier extension/**
     * Parse the authority key identifier extension.
     *
     * If the keyIdentifier field of the extension is non-null, set the
     * subjectKeyIdentifier criterion. If the authorityCertSerialNumber
     * field is non-null, set the serialNumber criterion.
     *
     * Note that we will not set the subject criterion according to the
     * authorityCertIssuer field of the extension. The caller MUST set
     * the subject criterion before call match().
     *
     * @param akidext the authorityKeyIdentifier extension
     */
    void parseAuthorityKeyIdentifierExtension(
            AuthorityKeyIdentifierExtension akidext) throws IOException {
        if (akidext != null) {
            KeyIdentifier akid = (KeyIdentifier)akidext.get(akidext.KEY_ID);
            if (akid != null) {
                DerOutputStream derout = new DerOutputStream();
                derout.putOctetString(akid.getIdentifier());
                super.setSubjectKeyIdentifier(derout.toByteArray());
            }

            SerialNumber asn =
                (SerialNumber)akidext.get(akidext.SERIAL_NUMBER);
            if (asn != null) {
                super.setSerialNumber(asn.getNumber());
            }

            // the subject criterion should be set by the caller.
        }
    }

    
Decides whether a Certificate should be selected.
For the purpose of compatibility, when a certificate is of
version 1 and version 2, or the certificate does not include
a subject key identifier extension, the selection criterion
of subjectKeyIdentifier will be disabled.
/**
     * Decides whether a <code>Certificate</code> should be selected.
     *
     * For the purpose of compatibility, when a certificate is of
     * version 1 and version 2, or the certificate does not include
     * a subject key identifier extension, the selection criterion
     * of subjectKeyIdentifier will be disabled.
     */
    @Override
    public boolean match(Certificate cert) {
        if (!(cert instanceof X509Certificate)) {
            return false;
        }

        X509Certificate xcert = (X509Certificate)cert;
        int version = xcert.getVersion();

        // Check the validity period for version 1 and 2 certificate.
        if (version < 3) {
            if (startDate != null) {
                try {
                    xcert.checkValidity(startDate);
                } catch (CertificateException ce) {
                    return false;
                }
            }

            if (endDate != null) {
                try {
                    xcert.checkValidity(endDate);
                } catch (CertificateException ce) {
                    return false;
                }
            }
        }

        if (version < 3 || xcert.getExtensionValue("2.5.29.14") == null) {
            // If no SubjectKeyIdentifier extension, don't bother to check it.
            setSubjectKeyIdentifier(null);
        }

        return super.match(cert);
    }

    @Override
    public Object clone() {
        AdaptableX509CertSelector copy =
                        (AdaptableX509CertSelector)super.clone();
        if (startDate != null) {
            copy.startDate = (Date)startDate.clone();
        }

        if (endDate != null) {
            copy.endDate = (Date)endDate.clone();
        }

        return copy;
    }
}