/*

 * Copyright 2002-2006 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.security.x509;

import java.io.IOException;

import java.util.*;

import sun.security.util.BitArray;

import sun.security.util.DerOutputStream;

import sun.security.util.DerValue;

/**

 * Represent the DistributionPoint sequence used in the CRL

 * Distribution Points Extension (OID = 2.5.29.31).

 * <p>

 * The ASN.1 definition for this is:

 * <pre>

 * DistributionPoint ::= SEQUENCE {

 *      distributionPoint       [0]     DistributionPointName OPTIONAL,

 *      reasons                 [1]     ReasonFlags OPTIONAL,

 *      cRLIssuer               [2]     GeneralNames OPTIONAL }

 *

 * DistributionPointName ::= CHOICE {

 *      fullName                [0]     GeneralNames,

 *      nameRelativeToCRLIssuer [1]     RelativeDistinguishedName }

 *

 * ReasonFlags ::= BIT STRING {

 *      unused                  (0),

 *      keyCompromise           (1),

 *      cACompromise            (2),

 *      affiliationChanged      (3),

 *      superseded              (4),

 *      cessationOfOperation    (5),

 *      certificateHold         (6),

 *      privilegeWithdrawn      (7),

 *      aACompromise            (8) }

 *

 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName

 *

 * GeneralName ::= CHOICE {

 *         otherName                   [0] INSTANCE OF OTHER-NAME,

 *         rfc822Name                  [1] IA5String,

 *         dNSName                     [2] IA5String,

 *         x400Address                 [3] ORAddress,

 *         directoryName               [4] Name,

 *         ediPartyName                [5] EDIPartyName,

 *         uniformResourceIdentifier   [6] IA5String,

 *         iPAddress                   [7] OCTET STRING,

 *         registeredID                [8] OBJECT IDENTIFIER }

 *

 * RelativeDistinguishedName ::=

 *   SET OF AttributeTypeAndValue

 *

 * AttributeTypeAndValue ::= SEQUENCE {

 *   type     AttributeType,

 *   value    AttributeValue }

 *

 * AttributeType ::= OBJECT IDENTIFIER

 *

 * AttributeValue ::= ANY DEFINED BY AttributeType

 * </pre>

 * <p>

 * Instances of this class are designed to be immutable. However, since this

 * is an internal API we do not use defensive cloning for values for

 * performance reasons. It is the responsibility of the consumer to ensure

 * that no mutable elements are modified.

 *

 * @author Anne Anderson

 * @author Andreas Sterbenz

 * @since 1.4.2

 * @see CRLDistributionPointsExtension

 */

public class DistributionPoint {

    // reason flag bits

    // NOTE that these are NOT quite the same as the CRL reason code extension

    public final static int KEY_COMPROMISE         = 1;

    public final static int CA_COMPROMISE          = 2;

    public final static int AFFILIATION_CHANGED    = 3;

    public final static int SUPERSEDED             = 4;

    public final static int CESSATION_OF_OPERATION = 5;

    public final static int CERTIFICATE_HOLD       = 6;

    public final static int PRIVILEGE_WITHDRAWN    = 7;

    public final static int AA_COMPROMISE          = 8;

    private static final String[] REASON_STRINGS = {

        null,

        "key compromise",

        "CA compromise",

        "affiliation changed",

        "superseded",

        "cessation of operation",

        "certificate hold",

        "privilege withdrawn",

        "AA compromise",

    };

    // context specific tag values

    private static final byte TAG_DIST_PT = 0;

    private static final byte TAG_REASONS = 1;

    private static final byte TAG_ISSUER = 2;

    private static final byte TAG_FULL_NAME = 0;

    private static final byte TAG_REL_NAME = 1;

    // only one of fullName and relativeName can be set

    private GeneralNames fullName;

    private RDN relativeName;

    // reasonFlags or null

    private boolean[] reasonFlags;

    // crlIssuer or null

    private GeneralNames crlIssuer;

    // cached hashCode value

    private volatile int hashCode;

    /**

     * Constructor for the class using GeneralNames for DistributionPointName

     *

     * @param fullName the GeneralNames of the distribution point; may be null

     * @param reasons the CRL reasons included in the CRL at this distribution

     *        point; may be null

     * @param issuer the name(s) of the CRL issuer for the CRL at this

     *        distribution point; may be null

     */

    public DistributionPoint(GeneralNames fullName, boolean[] reasonFlags,

            GeneralNames crlIssuer) {

        if ((fullName == null) && (crlIssuer == null)) {

            throw new IllegalArgumentException

                        ("fullName and crlIssuer may not both be null");

        }

        this.fullName = fullName;

        this.reasonFlags = reasonFlags;

        this.crlIssuer = crlIssuer;

    }

    /**

     * Constructor for the class using RelativeDistinguishedName for

     * DistributionPointName

     *

     * @param relativeName the RelativeDistinguishedName of the distribution

     *        point; may not be null

     * @param reasons the CRL reasons included in the CRL at this distribution

     *        point; may be null

     * @param issuer the name(s) of the CRL issuer for the CRL at this

     *        distribution point; may not be null or empty.

     */

    public DistributionPoint(RDN relativeName, boolean[] reasonFlags,

            GeneralNames crlIssuer) {

        if ((relativeName == null) && (crlIssuer == null)) {

            throw new IllegalArgumentException

                        ("relativeName and crlIssuer may not both be null");

        }

        this.relativeName = relativeName;

        this.reasonFlags = reasonFlags;

        this.crlIssuer = crlIssuer;

    }

    /**

     * Create the object from the passed DER encoded form.

     *

     * @param val the DER encoded form of the DistributionPoint

     * @throws IOException on error

     */

    public DistributionPoint(DerValue val) throws IOException {

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

            throw new IOException("Invalid encoding of DistributionPoint.");

        }

        // Note that all the fields in DistributionPoint are defined as

        // being OPTIONAL, i.e., there could be an empty SEQUENCE, resulting

        // in val.data being null.

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

            DerValue opt = val.data.getDerValue();

            if (opt.isContextSpecific(TAG_DIST_PT) && opt.isConstructed()) {

                if ((fullName != null) || (relativeName != null)) {

                    throw new IOException("Duplicate DistributionPointName in "

                                          + "DistributionPoint.");

                }

                DerValue distPnt = opt.data.getDerValue();

                if (distPnt.isContextSpecific(TAG_FULL_NAME)

                        && distPnt.isConstructed()) {

                    distPnt.resetTag(DerValue.tag_Sequence);

                    fullName = new GeneralNames(distPnt);

                } else if (distPnt.isContextSpecific(TAG_REL_NAME)

                        && distPnt.isConstructed()) {

                    distPnt.resetTag(DerValue.tag_Set);

                    relativeName = new RDN(distPnt);

                } else {

                    throw new IOException("Invalid DistributionPointName in "

                                          + "DistributionPoint");

                }

            } else if (opt.isContextSpecific(TAG_REASONS)

                                                && !opt.isConstructed()) {

                if (reasonFlags != null) {

                    throw new IOException("Duplicate Reasons in " +

                                          "DistributionPoint.");

                }

                opt.resetTag(DerValue.tag_BitString);

                reasonFlags = (opt.getUnalignedBitString()).toBooleanArray();

            } else if (opt.isContextSpecific(TAG_ISSUER)

                                                && opt.isConstructed()) {

                if (crlIssuer != null) {

                    throw new IOException("Duplicate CRLIssuer in " +

                                          "DistributionPoint.");

                }

                opt.resetTag(DerValue.tag_Sequence);

                crlIssuer = new GeneralNames(opt);

            } else {

                throw new IOException("Invalid encoding of " +

                                      "DistributionPoint.");

            }

        }

        if ((crlIssuer == null) && (fullName == null) && (relativeName == null)) {

            throw new IOException("One of fullName, relativeName, "

                + " and crlIssuer has to be set");

        }

    }

    /**

     * Return the full distribution point name or null if not set.

     */

    public GeneralNames getFullName() {

        return fullName;

    }

    /**

     * Return the relative distribution point name or null if not set.

     */

    public RDN getRelativeName() {

        return relativeName;

    }

    /**

     * Return the reason flags or null if not set.

     */

    public boolean[] getReasonFlags() {

        return reasonFlags;

    }

    /**

     * Return the CRL issuer name or null if not set.

     */

    public GeneralNames getCRLIssuer() {

        return crlIssuer;

    }

    /**

     * Write the DistributionPoint value to the DerOutputStream.

     *

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

     * @exception IOException on error.

     */

    public void encode(DerOutputStream out) throws IOException {

        DerOutputStream tagged = new DerOutputStream();

        // NOTE: only one of pointNames and pointRDN can be set

        if ((fullName != null) || (relativeName != null)) {

            DerOutputStream distributionPoint = new DerOutputStream();

            if (fullName != null) {

                DerOutputStream derOut = new DerOutputStream();

                fullName.encode(derOut);

                distributionPoint.writeImplicit(

                    DerValue.createTag(DerValue.TAG_CONTEXT, true, TAG_FULL_NAME),

                    derOut);

            } else if (relativeName != null) {

                DerOutputStream derOut = new DerOutputStream();

                relativeName.encode(derOut);

                distributionPoint.writeImplicit(

                    DerValue.createTag(DerValue.TAG_CONTEXT, true, TAG_REL_NAME),

                    derOut);

            }

            tagged.write(

                DerValue.createTag(DerValue.TAG_CONTEXT, true, TAG_DIST_PT),

                distributionPoint);

        }

        if (reasonFlags != null) {

            DerOutputStream reasons = new DerOutputStream();

            BitArray rf = new BitArray(reasonFlags);

            reasons.putTruncatedUnalignedBitString(rf);

            tagged.writeImplicit(

                DerValue.createTag(DerValue.TAG_CONTEXT, false, TAG_REASONS),

                reasons);

        }

        if (crlIssuer != null) {

            DerOutputStream issuer = new DerOutputStream();

            crlIssuer.encode(issuer);

            tagged.writeImplicit(

                DerValue.createTag(DerValue.TAG_CONTEXT, true, TAG_ISSUER),

                issuer);

        }

        out.write(DerValue.tag_Sequence, tagged);

    }

    /**

     * Utility function for a.equals(b) where both a and b may be null.

     */

    private static boolean equals(Object a, Object b) {

        return (a == null) ? (b == null) : a.equals(b);

    }

    /**

     * Compare an object to this DistributionPoint for equality.

     *

     * @param obj Object to be compared to this

     * @return true if objects match; false otherwise

     */

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj instanceof DistributionPoint == false) {

            return false;

        }

        DistributionPoint other = (DistributionPoint)obj;

        boolean equal = equals(this.fullName, other.fullName)

                     && equals(this.relativeName, other.relativeName)

                     && equals(this.crlIssuer, other.crlIssuer)

                     && Arrays.equals(this.reasonFlags, other.reasonFlags);

        return equal;

    }

    public int hashCode() {

        int hash = hashCode;

        if (hash == 0) {

            hash = 1;

            if (fullName != null) {

                hash += fullName.hashCode();

            }

            if (relativeName != null) {

                hash += relativeName.hashCode();

            }

            if (crlIssuer != null) {

                hash += crlIssuer.hashCode();

            }

            if (reasonFlags != null) {

                for (int i = 0; i < reasonFlags.length; i++) {

                    if (reasonFlags[i]) {

                        hash += i;

                    }

                }

            }

            hashCode = hash;

        }

        return hash;

    }

    /**

     * Return a string representation for reasonFlag bit 'reason'.

     */

    private static String reasonToString(int reason) {

        if ((reason > 0) && (reason < REASON_STRINGS.length)) {

            return REASON_STRINGS[reason];

        }

        return "Unknown reason " + reason;

    }

    /**

     * Return a printable string of the Distribution Point.

     */

    public String toString() {

        StringBuilder sb = new StringBuilder();

        if (fullName != null) {

            sb.append("DistributionPoint:\n     " + fullName + "\n");

        }

        if (relativeName != null) {

            sb.append("DistributionPoint:\n     " + relativeName + "\n");

        }

        if (reasonFlags != null) {

            sb.append("   ReasonFlags:\n");

            for (int i = 0; i < reasonFlags.length; i++) {

                if (reasonFlags[i]) {

                    sb.append("    " + reasonToString(i) + "\n");

                }

            }

        }

        if (crlIssuer != null) {

            sb.append("   CRLIssuer:" + crlIssuer + "\n");

        }

        return sb.toString();

    }

}