/*

 * Copyright (c) 1997, 2015, 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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package sun.security.x509;

import java.io.IOException;

import java.io.OutputStream;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.security.cert.CertificateException;

import java.util.*;

import sun.security.util.HexDumpEncoder;

import sun.security.util.*;

/**

 * This class defines the Extensions attribute for the Certificate.

 *

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 * @see CertAttrSet

 */

public class CertificateExtensions implements CertAttrSet<Extension> {

    /**

     * 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";

    /**

     * name

     */

    public static final String NAME = "extensions";

    private static final Debug debug = Debug.getInstance("x509");

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

            new TreeMap<String,Extension>());

    private boolean unsupportedCritExt = false;

    private Map<String,Extension> unparseableExtensions;

    /**

     * Default constructor.

     */

    public CertificateExtensions() { }

    /**

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

     *

     * @param in the DerInputStream to read the Extension from.

     * @exception IOException on decoding errors.

     */

    public CertificateExtensions(DerInputStream in) throws IOException {

        init(in);

    }

    // helper routine

    private void init(DerInputStream in) throws IOException {

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

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

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

            parseExtension(ext);

        }

    }

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

    // Parse the encoded extension

    private void parseExtension(Extension ext) throws IOException {

        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) {

                    return;

                } else {

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

                }

            }

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

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

                    ext.getExtensionValue()};

                    CertAttrSet<?> certExt = (CertAttrSet<?>)

                            cons.newInstance(passed);

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

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

                    }

        } catch (InvocationTargetException invk) {

            Throwable e = invk.getTargetException();

            if (ext.isCritical() == false) {

                // ignore errors parsing non-critical extensions

                if (unparseableExtensions == null) {

                    unparseableExtensions = new TreeMap<String,Extension>();

                }

                unparseableExtensions.put(ext.getExtensionId().toString(),

                        new UnparseableExtension(ext, e));

                if (debug != null) {

                    debug.println("Debug info only." +

                       " Error parsing extension: " + ext);

                    e.printStackTrace();

                    HexDumpEncoder h = new HexDumpEncoder();

                    System.err.println(h.encodeBuffer(ext.getExtensionValue()));

                }

                return;

            }

            if (e instanceof IOException) {

                throw (IOException)e;

            } else {

                throw new IOException(e);

            }

        } catch (IOException e) {

            throw e;

        } catch (Exception e) {

            throw new IOException(e);

        }

    }

    /**

     * Encode the extensions in DER form to the stream, setting

     * the context specific tag as needed in the X.509 v3 certificate.

     *

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

     * @exception CertificateException on encoding errors.

     * @exception IOException on errors.

     */

    public void encode(OutputStream out)

    throws CertificateException, IOException {

        encode(out, false);

    }

    /**

     * Encode the extensions in DER form to the stream.

     *

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

     * @param isCertReq if true then no context specific tag is added.

     * @exception CertificateException on encoding errors.

     * @exception IOException on errors.

     */

    public void encode(OutputStream out, boolean isCertReq)

    throws CertificateException, IOException {

        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 CertificateException("Illegal extension object");

        }

        DerOutputStream seq = new DerOutputStream();

        seq.write(DerValue.tag_Sequence, extOut);

        DerOutputStream tmp;

        if (!isCertReq) { // certificate

            tmp = new DerOutputStream();

            tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)3),

                    seq);

        } else

            tmp = seq; // pkcs#10 certificateRequest

        out.write(tmp.toByteArray());

    }

    /**

     * Set the attribute value.

     * @param name the extension name used in the cache.

     * @param obj the object to set.

     * @exception IOException if the object could not be cached.

     */

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

        if (obj instanceof Extension) {

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

        } else {

            throw new IOException("Unknown extension type.");

        }

    }

    /**

     * Get the attribute value.

     * @param name the extension name used in the lookup.

     * @exception IOException if named extension is not found.

     */

    public Extension get(String name) throws IOException {

        Extension obj = map.get(name);

        if (obj == null) {

            throw new IOException("No extension found with name " + name);

        }

        return (obj);

    }

    // Similar to get(String), but throw no exception, might return null.

    // Used in X509CertImpl::getExtension(OID).

    Extension getExtension(String name) {

        return map.get(name);

    }

    /**

     * Delete the attribute value.

     * @param name the extension name used in the lookup.

     * @exception IOException if named extension is not found.

     */

    public void delete(String name) throws IOException {

        Object obj = map.get(name);

        if (obj == null) {

            throw new IOException("No extension found with name " + name);

        }

        map.remove(name);

    }

    public String getNameByOid(ObjectIdentifier oid) throws IOException {

        for (String name: map.keySet()) {

            if (map.get(name).getExtensionId().equals(oid)) {

                return name;

            }

        }

        return null;

    }

    /**

     * Return an enumeration of names of attributes existing within this

     * attribute.

     */

    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 Certificate.

     */

    public Collection<Extension> getAllExtensions() {

        return map.values();

    }

    public Map<String,Extension> getUnparseableExtensions() {

        if (unparseableExtensions == null) {

            return Collections.emptyMap();

        } else {

            return unparseableExtensions;

        }

    }

    /**

     * Return the name of this attribute.

     */

    public String getName() {

        return NAME;

    }

    /**

     * Return true if a critical extension is found that is

     * not supported, otherwise return false.

     */

    public boolean hasUnsupportedCriticalExtension() {

        return unsupportedCritExt;

    }

    /**

     * Compares this CertificateExtensions for equality with the specified

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

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

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

     *

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

     * CertificateExtensions.

     * @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 CertificateExtensions))

            return false;

        Collection<Extension> otherC =

                ((CertificateExtensions)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 this.getUnparseableExtensions().equals(

                ((CertificateExtensions)other).getUnparseableExtensions());

    }

    /**

     * Returns a hashcode value for this CertificateExtensions.

     *

     * @return the hashcode value.

     */

    public int hashCode() {

        return map.hashCode() + getUnparseableExtensions().hashCode();

    }

    /**

     * Returns a string representation of this {@code CertificateExtensions}

     * 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 CertificateExtensions.

     */

    public String toString() {

        return map.toString();

    }

}

class UnparseableExtension extends Extension {

    private String name;

    private Throwable why;

    public UnparseableExtension(Extension ext, Throwable why) {

        super(ext);

        name = "";

        try {

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

            if (extClass != null) {

                Field field = extClass.getDeclaredField("NAME");

                name = (String)(field.get(null)) + " ";

            }

        } catch (Exception e) {

            // If we cannot find the name, just ignore it

        }

        this.why = why;

    }

    @Override public String toString() {

        return super.toString() +

                "Unparseable " + name + "extension due to\n" + why + "\n\n" +

                new HexDumpEncoder().encodeBuffer(getExtensionValue());

    }

}