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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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).

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 *

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package sun.security.x509;

import java.io.IOException;

import java.io.OutputStream;

import java.util.*;

import java.util.Collections;

import sun.security.util.DerOutputStream;

import sun.security.util.DerValue;

import sun.security.util.ObjectIdentifier;

/**

 * Represent the CRL Distribution Points Extension (OID = 2.5.29.31).

 * <p>

 * The CRL distribution points extension identifies how CRL information

 * is obtained.  The extension SHOULD be non-critical, but the PKIX profile

 * recommends support for this extension by CAs and applications.

 * <p>

 * For PKIX, if the cRLDistributionPoints extension contains a

 * DistributionPointName of type URI, the following semantics MUST be

 * assumed: the URI is a pointer to the current CRL for the associated

 * reasons and will be issued by the associated cRLIssuer.  The

 * expected values for the URI conform to the following rules.  The

 * name MUST be a non-relative URL, and MUST follow the URL syntax and

 * encoding rules specified in [RFC 1738].  The name must include both

 * a scheme (e.g., "http" or "ftp") and a scheme-specific-part.  The

 * scheme- specific-part must include a fully qualified domain name or

 * IP address as the host.  As specified in [RFC 1738], the scheme

 * name is not case-sensitive (e.g., "http" is equivalent to "HTTP").

 * The host part is also not case-sensitive, but other components of

 * the scheme-specific-part may be case-sensitive. When comparing

 * URIs, conforming implementations MUST compare the scheme and host

 * without regard to case, but assume the remainder of the

 * scheme-specific-part is case sensitive.  Processing rules for other

 * values are not defined by this specification.  If the

 * distributionPoint omits reasons, the CRL MUST include revocations

 * for all reasons. If the distributionPoint omits cRLIssuer, the CRL

 * MUST be issued by the CA that issued the certificate.

 * <p>

 * The ASN.1 definition for this is:

 * <pre>

 * id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::=  { id-ce 31 }

 *

 * cRLDistributionPoints ::= {

 *      CRLDistPointsSyntax }

 *

 * CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint

 * </pre>

 *

 * @author Anne Anderson

 * @author Andreas Sterbenz

 * @since 1.4.2

 * @see DistributionPoint

 * @see Extension

 * @see CertAttrSet

 */

public class CRLDistributionPointsExtension extends Extension

        implements CertAttrSet<String> {

    /**

     * Identifier for this attribute, to be used with the

     * get, set, delete methods of Certificate, x509 type.

     */

    public static final String IDENT =

                                "x509.info.extensions.CRLDistributionPoints";

    /**

     * Attribute name.

     */

    public static final String NAME = "CRLDistributionPoints";

    public static final String POINTS = "points";

    /**

     * The List of DistributionPoint objects.

     */

    private List<DistributionPoint> distributionPoints;

    private String extensionName;

    /**

     * Create a CRLDistributionPointsExtension from a List of

     * DistributionPoint; the criticality is set to false.

     *

     * @param distributionPoints the list of distribution points

     * @throws IOException on error

     */

    public CRLDistributionPointsExtension(

        List<DistributionPoint> distributionPoints) throws IOException {

        this(false, distributionPoints);

    }

    /**

     * Create a CRLDistributionPointsExtension from a List of

     * DistributionPoint.

     *

     * @param isCritical the criticality setting.

     * @param distributionPoints the list of distribution points

     * @throws IOException on error

     */

    public CRLDistributionPointsExtension(boolean isCritical,

        List<DistributionPoint> distributionPoints) throws IOException {

        this(PKIXExtensions.CRLDistributionPoints_Id, isCritical,

            distributionPoints, NAME);

    }

    /**

     * Creates the extension (also called by the subclass).

     */

    protected CRLDistributionPointsExtension(ObjectIdentifier extensionId,

        boolean isCritical, List<DistributionPoint> distributionPoints,

            String extensionName) throws IOException {

        this.extensionId = extensionId;

        this.critical = isCritical;

        this.distributionPoints = distributionPoints;

        encodeThis();

        this.extensionName = extensionName;

    }

    /**

     * Create the extension from the passed DER encoded value of the same.

     *

     * @param critical true if the extension is to be treated as critical.

     * @param value Array of DER encoded bytes of the actual value.

     * @exception IOException on error.

     */

    public CRLDistributionPointsExtension(Boolean critical, Object value)

            throws IOException {

        this(PKIXExtensions.CRLDistributionPoints_Id, critical, value, NAME);

    }

    /**

     * Creates the extension (also called by the subclass).

     */

    protected CRLDistributionPointsExtension(ObjectIdentifier extensionId,

        Boolean critical, Object value, String extensionName)

            throws IOException {

        this.extensionId = extensionId;

        this.critical = critical.booleanValue();

        if (!(value instanceof byte[])) {

            throw new IOException("Illegal argument type");

        }

        extensionValue = (byte[])value;

        DerValue val = new DerValue(extensionValue);

        if (val.tag != DerValue.tag_Sequence) {

            throw new IOException("Invalid encoding for " + extensionName +

                                  " extension.");

        }

        distributionPoints = new ArrayList<DistributionPoint>();

        while (val.data.available() != 0) {

            DerValue seq = val.data.getDerValue();

            DistributionPoint point = new DistributionPoint(seq);

            distributionPoints.add(point);

        }

        this.extensionName = extensionName;

    }

    /**

     * Return the name of this attribute.

     */

    public String getName() {

        return extensionName;

    }

    /**

     * Write the extension to the DerOutputStream.

     *

     * @param out the DerOutputStream to write the extension to.

     * @exception IOException on encoding errors.

     */

    public void encode(OutputStream out) throws IOException {

        encode(out, PKIXExtensions.CRLDistributionPoints_Id, false);

    }

    /**

     * Write the extension to the DerOutputStream.

     * (Also called by the subclass)

     */

    protected void encode(OutputStream out, ObjectIdentifier extensionId,

        boolean isCritical) throws IOException {

        DerOutputStream tmp = new DerOutputStream();

        if (this.extensionValue == null) {

            this.extensionId = extensionId;

            this.critical = isCritical;

            encodeThis();

        }

        super.encode(tmp);

        out.write(tmp.toByteArray());

    }

    /**

     * Set the attribute value.

     */

    @SuppressWarnings("unchecked") // Checked with instanceof

    public void set(String name, Object obj) throws IOException {

        if (name.equalsIgnoreCase(POINTS)) {

            if (!(obj instanceof List)) {

                throw new IOException("Attribute value should be of type List.");

            }

            distributionPoints = (List<DistributionPoint>)obj;

        } else {

            throw new IOException("Attribute name [" + name +

                                  "] not recognized by " +

                                  "CertAttrSet:" + extensionName + '.');

        }

        encodeThis();

    }

    /**

     * Get the attribute value.

     */

    public List<DistributionPoint> get(String name) throws IOException {

        if (name.equalsIgnoreCase(POINTS)) {

            return distributionPoints;

        } else {

            throw new IOException("Attribute name [" + name +

                                  "] not recognized by " +

                                  "CertAttrSet:" + extensionName + '.');

        }

    }

    /**

     * Delete the attribute value.

     */

    public void delete(String name) throws IOException {

        if (name.equalsIgnoreCase(POINTS)) {

            distributionPoints =

                    Collections.<DistributionPoint>emptyList();

        } else {

            throw new IOException("Attribute name [" + name +

                                  "] not recognized by " +

                                  "CertAttrSet:" + extensionName + '.');

        }

        encodeThis();

    }

    /**

     * Return an enumeration of names of attributes existing within this

     * attribute.

     */

    public Enumeration<String> getElements() {

        AttributeNameEnumeration elements = new AttributeNameEnumeration();

        elements.addElement(POINTS);

        return elements.elements();

    }

     // Encode this extension value

    private void encodeThis() throws IOException {

        if (distributionPoints.isEmpty()) {

            this.extensionValue = null;

        } else {

            DerOutputStream pnts = new DerOutputStream();

            for (DistributionPoint point : distributionPoints) {

                point.encode(pnts);

            }

            DerOutputStream seq = new DerOutputStream();

            seq.write(DerValue.tag_Sequence, pnts);

            this.extensionValue = seq.toByteArray();

        }

    }

    /**

     * Return the extension as user readable string.

     */

    public String toString() {

        return super.toString() + extensionName + " [\n  "

               + distributionPoints + "]\n";

    }

}