/*
    * 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 (nameType != KRB_NT_UNKNOWN &&
             other.nameType != KRB_NT_UNKNOWN &&
             nameType != other.nameType)
             return false;
 
         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();
         for (int i = 0; i < nameStrings.length; i++) {
             if (i > 0)
                 str.append("/");
             str.append(nameStrings[i]);
         }
         return str.toString();
     }
 
     /**
      * Encodes a <code>PrincipalName</code> object.
      * @return the byte array of the encoded PrncipalName object.
      * @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.
      * @exception IOException if an I/O error occurs while reading encoded data.
      *
      */
     public byte[] asn1Encode() throws Asn1Exception, IOException {
         DerOutputStream bytes = new DerOutputStream();
         DerOutputStream temp = new DerOutputStream();
         BigInteger bint = BigInteger.valueOf(this.nameType);
         temp.putInteger(bint);
         bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x00), temp);
         temp = new DerOutputStream();
         DerValue der[] = new DerValue[nameStrings.length];
         for (int i = 0; i < nameStrings.length; i++) {
             der[i] = new KerberosString(nameStrings[i]).toDerValue();
         }
         temp.putSequence(der);
         bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x01), temp);
         temp = new DerOutputStream();
         temp.write(DerValue.tag_Sequence, bytes);
         return temp.toByteArray();
     }
 
 
     /**
      * Checks if two <code>PrincipalName</code> objects have identical values in their corresponding data fields.
      *
      * @param pname the other <code>PrincipalName</code> object.
      * @return true if two have identical values, otherwise, return false.
      */
     // It is used in <code>sun.security.krb5.internal.ccache</code> package.
     public boolean match(PrincipalName pname) {
         boolean matched = true;
         //name type is just a hint, no two names can be the same ignoring name type.
         // if (this.nameType != pname.nameType) {
         //      matched = false;
         // }
         if ((this.nameRealm != null) && (pname.nameRealm != null)) {
             if (!(this.nameRealm.toString().equalsIgnoreCase(pname.nameRealm.toString()))) {
                 matched = false;
             }
         }
         if (this.nameStrings.length != pname.nameStrings.length) {
             matched = false;
         } else {
             for (int i = 0; i < this.nameStrings.length; i++) {
                 if (!(this.nameStrings[i].equalsIgnoreCase(pname.nameStrings[i]))) {
                     matched = false;
                 }
             }
         }
         return matched;
     }
 
     /**
      * Writes data field values of <code>PrincipalName</code> in FCC format to an output stream.
      *
      * @param cos a <code>CCacheOutputStream</code> for writing data.
      * @exception IOException if an I/O exception occurs.
      * @see sun.security.krb5.internal.ccache.CCacheOutputStream
      */
     public void writePrincipal(CCacheOutputStream cos) throws IOException {
         cos.write32(nameType);
         cos.write32(nameStrings.length);
         if (nameRealm != null) {
             byte[] realmBytes = null;
             realmBytes = nameRealm.toString().getBytes();
             cos.write32(realmBytes.length);
             cos.write(realmBytes, 0, realmBytes.length);
         }
         byte[] bytes = null;
         for (int i = 0; i < nameStrings.length; i++) {
             bytes = nameStrings[i].getBytes();
             cos.write32(bytes.length);
             cos.write(bytes, 0, bytes.length);
         }
     }
 
     /**
      * Creates a KRB_NT_SRV_INST name from the supplied
      * name components and realm.
      * @param primary the primary component of the name
      * @param instance the instance component of the name
      * @param realm the realm
      * @throws KrbException
      */
     protected PrincipalName(String primary, String instance, String realm,
                             int type)
         throws KrbException {
 
         if (type != KRB_NT_SRV_INST) {
             throw new KrbException(Krb5.KRB_ERR_GENERIC, "Bad name type");
         }
 
         String[] nParts = new String[2];
         nParts[0] = primary;
         nParts[1] = instance;
 
         this.nameStrings = nParts;
         this.nameRealm = new Realm(realm);
         this.nameType = type;
     }
 
     /**
      * Returns the instance component of a name.
      * In a multi-component name such as a KRB_NT_SRV_INST
      * name, the second component is returned.
      * Null is returned if there are not two or more
      * components in the name.
      * @returns instance component of a multi-component name.
      */
     public String getInstanceComponent()
     {
         if (nameStrings != null && nameStrings.length >= 2)
             {
                 return new String(nameStrings[1]);
             }
 
         return null;
     }
 
     static String mapHostToRealm(String name) {
         String result = null;
         try {
             String subname = null;
             Config c = Config.getInstance();
             if ((result = c.getDefault(name, "domain_realm")) != null)
                 return result;
             else {
                 for (int i = 1; i < name.length(); i++) {
                     if ((name.charAt(i) == '.') && (i != name.length() - 1)) { //mapping could be .ibm.com = AUSTIN.IBM.COM
                         subname = name.substring(i);
                         result = c.getDefault(subname, "domain_realm");
                         if (result != null) {
                             break;
                         }
                         else {
                             subname = name.substring(i + 1);      //or mapping could be ibm.com = AUSTIN.IBM.COM
                             result = c.getDefault(subname, "domain_realm");
                             if (result != null) {
                                 break;
                             }
                         }
                     }
                 }
             }
         } catch (KrbException e) {
         }
         return result;
     }
 
 }