/*

 * Copyright (c) 1997, 2013, 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

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 * questions.

 */

package sun.security.x509;

import java.io.IOException;

import java.io.OutputStream;

import java.lang.reflect.Constructor;

import java.lang.reflect.InvocationTargetException;

import java.security.cert.CRLException;

import java.security.cert.CertificateException;

import java.util.Collection;

import java.util.Collections;

import java.util.Enumeration;

import java.util.Map;

import java.util.TreeMap;

import sun.security.util.*;

/**

 * This class defines the CRL Extensions.

 * It is used for both CRL Extensions and CRL Entry Extensions,

 * which are defined are follows:

 * <pre>

 * TBSCertList  ::=  SEQUENCE  {

 *    version              Version OPTIONAL,   -- if present, must be v2

 *    signature            AlgorithmIdentifier,

 *    issuer               Name,

 *    thisUpdate           Time,

 *    nextUpdate           Time  OPTIONAL,

 *    revokedCertificates  SEQUENCE OF SEQUENCE  {

 *        userCertificate         CertificateSerialNumber,

 *        revocationDate          Time,

 *        crlEntryExtensions      Extensions OPTIONAL  -- if present, must be v2

 *    }  OPTIONAL,

 *    crlExtensions        [0] EXPLICIT Extensions OPTIONAL  -- if present, must be v2

 * }

 * </pre>

 *

 * @author Hemma Prafullchandra

 */

public class CRLExtensions {

    private Map<String,Extension> map = Collections.synchronizedMap(

            new TreeMap<String,Extension>());

    private boolean unsupportedCritExt = false;

    /**

     * Default constructor.

     */

    public CRLExtensions() { }

    /**

     * Create the object, decoding the values from the passed DER stream.

     *

     * @param in the DerInputStream to read the Extension from, i.e. the

     *        sequence of extensions.

     * @exception CRLException on decoding errors.

     */

    public CRLExtensions(DerInputStream in) throws CRLException {

        init(in);

    }

    // helper routine

    private void init(DerInputStream derStrm) throws CRLException {

        try {

            DerInputStream str = derStrm;

            byte nextByte = (byte)derStrm.peekByte();

            // check for context specific byte 0; skip it

            if (((nextByte & 0x0c0) == 0x080) &&

                ((nextByte & 0x01f) == 0x000)) {

                DerValue val = str.getDerValue();

                str = val.data;

            }

            DerValue[] exts = str.getSequence(5);

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

                Extension ext = new Extension(exts[i]);

                parseExtension(ext);

            }

        } catch (IOException e) {

            throw new CRLException("Parsing error: " + e.toString());

        }

    }

    private static final Class<?>[] PARAMS = {Boolean.class, Object.class};

    // Parse the encoded extension

    private void parseExtension(Extension ext) throws CRLException {

        try {

            Class<?> extClass = OIDMap.getClass(ext.getExtensionId());

            if (extClass == null) {   // Unsupported extension

                if (ext.isCritical())

                    unsupportedCritExt = true;

                if (map.put(ext.getExtensionId().toString(), ext) != null)

                    throw new CRLException("Duplicate extensions not allowed");

                return;

            }

            Constructor<?> cons = extClass.getConstructor(PARAMS);

            Object[] passed = new Object[] {Boolean.valueOf(ext.isCritical()),

                                            ext.getExtensionValue()};

            CertAttrSet<?> crlExt = (CertAttrSet<?>)cons.newInstance(passed);

            if (map.put(crlExt.getName(), (Extension)crlExt) != null) {

                throw new CRLException("Duplicate extensions not allowed");

            }

        } catch (InvocationTargetException invk) {

            throw new CRLException(invk.getTargetException().getMessage());

        } catch (Exception e) {

            throw new CRLException(e.toString());

        }

    }

    /**

     * Encode the extensions in DER form to the stream.

     *

     * @param out the DerOutputStream to marshal the contents to.

     * @param isExplicit the tag indicating whether this is an entry

     * extension (false) or a CRL extension (true).

     * @exception CRLException on encoding errors.

     */

    public void encode(OutputStream out, boolean isExplicit)

    throws CRLException {

        try {

            DerOutputStream extOut = new DerOutputStream();

            Collection<Extension> allExts = map.values();

            Object[] objs = allExts.toArray();

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

                if (objs[i] instanceof CertAttrSet)

                    ((CertAttrSet)objs[i]).encode(extOut);

                else if (objs[i] instanceof Extension)

                    ((Extension)objs[i]).encode(extOut);

                else

                    throw new CRLException("Illegal extension object");

            }

            DerOutputStream seq = new DerOutputStream();

            seq.write(DerValue.tag_Sequence, extOut);

            DerOutputStream tmp = new DerOutputStream();

            if (isExplicit)

                tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                                             true, (byte)0), seq);

            else

                tmp = seq;

            out.write(tmp.toByteArray());

        } catch (IOException e) {

            throw new CRLException("Encoding error: " + e.toString());

        } catch (CertificateException e) {

            throw new CRLException("Encoding error: " + e.toString());

        }

    }

    /**

     * Get the extension with this alias.

     *

     * @param alias the identifier string for the extension to retrieve.

     */

    public Extension get(String alias) {

        X509AttributeName attr = new X509AttributeName(alias);

        String name;

        String id = attr.getPrefix();

        if (id.equalsIgnoreCase(X509CertImpl.NAME)) { // fully qualified

            int index = alias.lastIndexOf('.');

            name = alias.substring(index + 1);

        } else

            name = alias;

        return map.get(name);

    }

    /**

     * Set the extension value with this alias.

     *

     * @param alias the identifier string for the extension to set.

     * @param obj the Object to set the extension identified by the

     *        alias.

     */

    public void set(String alias, Object obj) {

        map.put(alias, (Extension)obj);

    }

    /**

     * Delete the extension value with this alias.

     *

     * @param alias the identifier string for the extension to delete.

     */

    public void delete(String alias) {

        map.remove(alias);

    }

    /**

     * Return an enumeration of the extensions.

     * @return an enumeration of the extensions in this CRL.

     */

    public Enumeration<Extension> getElements() {

        return Collections.enumeration(map.values());

    }

    /**

     * Return a collection view of the extensions.

     * @return a collection view of the extensions in this CRL.

     */

    public Collection<Extension> getAllExtensions() {

        return map.values();

    }

    /**

     * Return true if a critical extension is found that is

     * not supported, otherwise return false.

     */

    public boolean hasUnsupportedCriticalExtension() {

        return unsupportedCritExt;

    }

    /**

     * Compares this CRLExtensions for equality with the specified

     * object. If the {@code other} object is an

     * {@code instanceof} {@code CRLExtensions}, then

     * all the entries are compared with the entries from this.

     *

     * @param other the object to test for equality with this CRLExtensions.

     * @return true iff all the entries match that of the Other,

     * false otherwise.

     */

    public boolean equals(Object other) {

        if (this == other)

            return true;

        if (!(other instanceof CRLExtensions))

            return false;

        Collection<Extension> otherC =

                        ((CRLExtensions)other).getAllExtensions();

        Object[] objs = otherC.toArray();

        int len = objs.length;

        if (len != map.size())

            return false;

        Extension otherExt, thisExt;

        String key = null;

        for (int i = 0; i < len; i++) {

            if (objs[i] instanceof CertAttrSet)

                key = ((CertAttrSet)objs[i]).getName();

            otherExt = (Extension)objs[i];

            if (key == null)

                key = otherExt.getExtensionId().toString();

            thisExt = map.get(key);

            if (thisExt == null)

                return false;

            if (! thisExt.equals(otherExt))

                return false;

        }

        return true;

    }

    /**

     * Returns a hashcode value for this CRLExtensions.

     *

     * @return the hashcode value.

     */

    public int hashCode() {

        return map.hashCode();

    }

    /**

     * Returns a string representation of this {@code CRLExtensions} object

     * in the form of a set of entries, enclosed in braces and separated

     * by the ASCII characters "<code>,&nbsp;</code>" (comma and space).

     * <p>Overrides to {@code toString} method of {@code Object}.

     *

     * @return  a string representation of this CRLExtensions.

     */

    public String toString() {

        return map.toString();

    }

}