/*

 * Copyright (c) 2000, 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.

 */

/*

 *

 *  (C) Copyright IBM Corp. 1999 All Rights Reserved.

 *  Copyright 1997 The Open Group Research Institute.  All rights reserved.

 */

package sun.security.krb5;

import sun.security.krb5.internal.*;

import sun.security.util.*;

import java.net.*;

import java.util.Vector;

import java.io.IOException;

import java.math.BigInteger;

import sun.security.krb5.internal.ccache.CCacheOutputStream;

import sun.security.krb5.internal.util.KerberosString;

/**

 * This class encapsulates a Kerberos principal.

 */

public class PrincipalName

    implements Cloneable {

    //name types

    /**

     * Name type not known

     */

    public static final int KRB_NT_UNKNOWN =   0;

    /**

     * Just the name of the principal as in DCE, or for users

     */

    public static final int KRB_NT_PRINCIPAL = 1;

    /**

     * Service and other unique instance (krbtgt)

     */

    public static final int KRB_NT_SRV_INST =  2;

    /**

     * Service with host name as instance (telnet, rcommands)

     */

    public static final int KRB_NT_SRV_HST =   3;

    /**

     * Service with host as remaining components

     */

    public static final int KRB_NT_SRV_XHST =  4;

    /**

     * Unique ID

     */

    public static final int KRB_NT_UID = 5;

    /**

     * TGS Name

     */

    public static final String TGS_DEFAULT_SRV_NAME = "krbtgt";

    public static final int TGS_DEFAULT_NT = KRB_NT_SRV_INST;

    public static final char NAME_COMPONENT_SEPARATOR = '/';

    public static final char NAME_REALM_SEPARATOR = '@';

    public static final char REALM_COMPONENT_SEPARATOR = '.';

    public static final String NAME_COMPONENT_SEPARATOR_STR = "/";

    public static final String NAME_REALM_SEPARATOR_STR = "@";

    public static final String REALM_COMPONENT_SEPARATOR_STR = ".";

    private int nameType;

    private String[] nameStrings;  // Principal names don't mutate often

    private Realm nameRealm;  // optional; a null realm means use default

    // Note: the nameRealm is not included in the default ASN.1 encoding

    // cached salt, might be changed by KDC info, not used in clone

    private String salt = null;

    protected PrincipalName() {

    }

    public PrincipalName(String[] nameParts, int type)

        throws IllegalArgumentException, IOException {

        if (nameParts == null) {

            throw new IllegalArgumentException("Null input not allowed");

        }

        nameStrings = new String[nameParts.length];

        System.arraycopy(nameParts, 0, nameStrings, 0, nameParts.length);

        nameType = type;

        nameRealm = null;

    }

    public PrincipalName(String[] nameParts) throws IOException {

        this(nameParts, KRB_NT_UNKNOWN);

    }

    public Object clone() {

        try {

            PrincipalName pName = (PrincipalName) super.clone();

            // Re-assign mutable fields

            if (nameStrings != null) {

                pName.nameStrings = nameStrings.clone();

            }

            if (nameRealm != null) {

                pName.nameRealm = (Realm)nameRealm.clone();

            }

            return pName;

        } catch (CloneNotSupportedException ex) {

            throw new AssertionError("Should never happen");

        }

    }

    /*

     * Added to workaround a bug where the equals method that takes a

     * PrincipalName is not being called but Object.equals(Object) is

     * being called.

     */

    public boolean equals(Object o) {

        if (o instanceof PrincipalName)

            return equals((PrincipalName)o);

        else

            return false;

    }

    public boolean equals(PrincipalName other) {

        if (!equalsWithoutRealm(other)) {

            return false;

        }

        if ((nameRealm != null && other.nameRealm == null) ||

            (nameRealm == null && other.nameRealm != null)) {

            return false;

        }

        if (nameRealm != null && other.nameRealm != null) {

            if (!nameRealm.equals(other.nameRealm)) {

                return false;

            }

        }

        return true;

    }

    boolean equalsWithoutRealm(PrincipalName other) {

        if ((nameStrings != null && other.nameStrings == null) ||

            (nameStrings == null && other.nameStrings != null))

            return false;

        if (nameStrings != null && other.nameStrings != null) {

            if (nameStrings.length != other.nameStrings.length)

                return false;

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

                if (!nameStrings[i].equals(other.nameStrings[i]))

                    return false;

        }

        return true;

    }

    /**

     * Returns the ASN.1 encoding of the

     * <xmp>

     * PrincipalName    ::= SEQUENCE {

     *          name-type       [0] Int32,

     *          name-string     [1] SEQUENCE OF KerberosString

     * }

     *

     * KerberosString   ::= GeneralString (IA5String)

     * </xmp>

     *

     * <p>

     * This definition reflects the Network Working Group RFC 4120

     * specification available at

     * <a href="http://www.ietf.org/rfc/rfc4120.txt">

     * http://www.ietf.org/rfc/rfc4120.txt</a>.

     *

     * @param encoding a Der-encoded data.

     * @exception Asn1Exception if an error occurs while decoding

     * an ASN1 encoded data.

     * @exception Asn1Exception if there is an ASN1 encoding error

     * @exception IOException if an I/O error occurs

     * @exception IllegalArgumentException if encoding is null

     * reading encoded data.

     *

     */

    public PrincipalName(DerValue encoding)

        throws Asn1Exception, IOException {

        nameRealm = null;

        DerValue der;

        if (encoding == null) {

            throw new IllegalArgumentException("Null input not allowed");

        }

        if (encoding.getTag() != DerValue.tag_Sequence) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        der = encoding.getData().getDerValue();

        if ((der.getTag() & 0x1F) == 0x00) {

            BigInteger bint = der.getData().getBigInteger();

            nameType = bint.intValue();

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        der = encoding.getData().getDerValue();

        if ((der.getTag() & 0x01F) == 0x01) {

            DerValue subDer = der.getData().getDerValue();

            if (subDer.getTag() != DerValue.tag_SequenceOf) {

                throw new Asn1Exception(Krb5.ASN1_BAD_ID);

            }

            Vector<String> v = new Vector<>();

            DerValue subSubDer;

            while(subDer.getData().available() > 0) {

                subSubDer = subDer.getData().getDerValue();

                v.addElement(new KerberosString(subSubDer).toString());

            }

            if (v.size() > 0) {

                nameStrings = new String[v.size()];

                v.copyInto(nameStrings);

            } else {

                nameStrings = new String[] {""};

            }

        } else  {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

    }

    /**

     * Parse (unmarshal) a <code>PrincipalName</code> from a DER

     * input stream.  This form

     * parsing might be used when expanding a value which is part of

     * a constructed sequence and uses explicitly tagged type.

     *

     * @exception Asn1Exception on error.

     * @param data the Der input stream value, which contains one or

     * more marshaled value.

     * @param explicitTag tag number.

     * @param optional indicate if this data field is optional

     * @return an instance of <code>PrincipalName</code>.

     *

     */

    public static PrincipalName parse(DerInputStream data,

                                      byte explicitTag, boolean

                                      optional)

        throws Asn1Exception, IOException {

        if ((optional) && (((byte)data.peekByte() & (byte)0x1F) !=

                           explicitTag))

            return null;

        DerValue der = data.getDerValue();

        if (explicitTag != (der.getTag() & (byte)0x1F))

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        else {

            DerValue subDer = der.getData().getDerValue();

            return new PrincipalName(subDer);

        }

    }

    // This is protected because the definition of a principal

    // string is fixed

    // XXX Error checkin consistent with MIT krb5_parse_name

    // Code repetition, realm parsed again by class Realm

    protected static String[] parseName(String name) {

        Vector<String> tempStrings = new Vector<>();

        String temp = name;

        int i = 0;

        int componentStart = 0;

        String component;

        while (i < temp.length()) {

            if (temp.charAt(i) == NAME_COMPONENT_SEPARATOR) {

                /*

                 * If this separator is escaped then don't treat it

                 * as a separator

                 */

                if (i > 0 && temp.charAt(i - 1) == '\\') {

                    temp = temp.substring(0, i - 1) +

                        temp.substring(i, temp.length());

                    continue;

                }

                else {

                    if (componentStart < i) {

                        component = temp.substring(componentStart, i);

                        tempStrings.addElement(component);

                    }

                    componentStart = i + 1;

                }

            } else

                if (temp.charAt(i) == NAME_REALM_SEPARATOR) {

                    /*

                     * If this separator is escaped then don't treat it

                     * as a separator

                     */

                    if (i > 0 && temp.charAt(i - 1) == '\\') {

                        temp = temp.substring(0, i - 1) +

                            temp.substring(i, temp.length());

                        continue;

                    } else {

                        if (componentStart < i) {

                            component = temp.substring(componentStart, i);

                            tempStrings.addElement(component);

                        }

                        componentStart = i + 1;

                        break;

                    }

                }

            i++;

        }

        if (i == temp.length())

        if (componentStart < i) {

            component = temp.substring(componentStart, i);

            tempStrings.addElement(component);

        }

        String[] result = new String[tempStrings.size()];

        tempStrings.copyInto(result);

        return result;

    }

    public PrincipalName(String name, int type)

        throws RealmException {

        if (name == null) {

            throw new IllegalArgumentException("Null name not allowed");

        }

        String[] nameParts = parseName(name);

        Realm tempRealm = null;

        String realmString = Realm.parseRealmAtSeparator(name);

        if (realmString == null) {

            try {

                Config config = Config.getInstance();

                realmString = config.getDefaultRealm();

            } catch (KrbException e) {

                RealmException re =

                    new RealmException(e.getMessage());

                re.initCause(e);

                throw re;

            }

        }

        if (realmString != null)

            tempRealm = new Realm(realmString);

        switch (type) {

        case KRB_NT_SRV_HST:

            if (nameParts.length >= 2) {

                String hostName = nameParts[1];

                try {

                    // RFC4120 does not recommend canonicalizing a hostname.

                    // However, for compatibility reason, we will try

                    // canonicalize it and see if the output looks better.

                    String canonicalized = (InetAddress.getByName(hostName)).

                            getCanonicalHostName();

                    // Looks if canonicalized is a longer format of hostName,

                    // we accept cases like

                    //     bunny -> bunny.rabbit.hole

                    if (canonicalized.toLowerCase()

                            .startsWith(hostName.toLowerCase()+".")) {

                        hostName = canonicalized;

                    }

                } catch (UnknownHostException e) {

                    // no canonicalization, use old

                }

                nameParts[1] = hostName.toLowerCase();

            }

            nameStrings = nameParts;

            nameType = type;

                // We will try to get realm name from the mapping in

                // the configuration. If it is not specified

                // we will use the default realm. This nametype does

                // not allow a realm to be specified. The name string must of

                // the form service@host and this is internally changed into

                // service/host by Kerberos

            String mapRealm =  mapHostToRealm(nameParts[1]);

            if (mapRealm != null) {

                nameRealm = new Realm(mapRealm);

            } else {

                nameRealm = tempRealm;

            }

            break;

        case KRB_NT_UNKNOWN:

        case KRB_NT_PRINCIPAL:

        case KRB_NT_SRV_INST:

        case KRB_NT_SRV_XHST:

        case KRB_NT_UID:

            nameStrings = nameParts;

            nameType = type;

            nameRealm = tempRealm;

            break;

        default:

            throw new IllegalArgumentException("Illegal name type");

        }

    }

    public PrincipalName(String name) throws RealmException {

        this(name, KRB_NT_UNKNOWN);

    }

    public PrincipalName(String name, String realm) throws RealmException {

        this(name, KRB_NT_UNKNOWN);

        nameRealm = new Realm(realm);

    }

    public String getRealmAsString() {

        return getRealmString();

    }

    public String getPrincipalNameAsString() {

        StringBuffer temp = new StringBuffer(nameStrings[0]);

        for (int i = 1; i < nameStrings.length; i++)

            temp.append(nameStrings[i]);

        return temp.toString();

    }

    public int hashCode() {

        return toString().hashCode();

    }

    public String getName() {

        return toString();

    }

    public int getNameType() {

        return nameType;

    }

    public String[] getNameStrings() {

        return nameStrings;

    }

    public byte[][] toByteArray() {

        byte[][] result = new byte[nameStrings.length][];

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

            result[i] = new byte[nameStrings[i].length()];

            result[i] = nameStrings[i].getBytes();

        }

        return result;

    }

    public String getRealmString() {

        if (nameRealm != null)

            return nameRealm.toString();

        return null;

    }

    public Realm getRealm() {

        return nameRealm;

    }

    public void setRealm(Realm new_nameRealm) throws RealmException {

        nameRealm = new_nameRealm;

    }

    public void setRealm(String realmsString) throws RealmException {

        nameRealm = new Realm(realmsString);

    }

    public String getSalt() {

        if (salt == null) {

            StringBuffer salt = new StringBuffer();

            if (nameRealm != null) {

                salt.append(nameRealm.toString());

            }

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

                salt.append(nameStrings[i]);

            }

            return salt.toString();

        }

        return salt;

    }

    public String toString() {

        StringBuffer str = new StringBuffer();

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

            if (i > 0)

                str.append("/");

            str.append(nameStrings[i]);

        }

        if (nameRealm != null) {

            str.append("@");

            str.append(nameRealm.toString());

        }

        return str.toString();

    }

    public String getNameString() {

        StringBuffer str = new StringBuffer();