# SessionToken.java

    /*
    ** Module   : SessionToken.java
    ** Abstract : unique object which identifies a security context by subject
    **            and session ID
    **
    ** Copyright (c) 2009-2021, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- -----------------------------------Description-----------------------------------
    ** 001 CA  20091119   @44434 Initial version. Unique session token describing
    **                           a security context.
    ** 002 SBI 20170225          Changed to be a simple DTO, GWT serializable.
    **         20170705          Fixed toString().
    ** 003 CA  20211016          Fixed toString() for negative session IDs.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program 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 Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.security;

    import java.io.Serializable;

    /**
     * Unique object describing a security context, by its session ID and authenticated subject.
     */
    public final class SessionToken
    implements Serializable
    {
       /** Unique session ID - always non-zero for user sessions */
       private int sessionID;

       /** The subject name. */
       private String subject;

       /**
        * Default constructor
        */
       public SessionToken()
       {
          this.subject = "<system>";
       }

       /**
        * Create a session token for the given session ID and subject.
        *
        * @param    sessionID
        *           the session ID
        * @param    subject
        *           the subject name; may be null for {@link SecurityContext#SYSTEM_SESSION sessions}
        */
       public SessionToken(int sessionID, String subject)
       {
          this.sessionID = sessionID;
          this.subject = subject == null ? "<system>" : subject.intern();
       }

       /**
        * Gets session ID.
        *
        * @return   The session ID.
        */
       public int getSessionID()
       {
          return sessionID;
       }

       /**
        * Gets subject name.
        *
        * @return   The subject name.
        */
       public String getSubject()
       {
          return subject;
       }

       /**
        * Sets the unique session ID - always non-zero for user sessions.
        *
        * @param    sessionID
        *           The new unique session ID - always non-zero for user sessions
        */
       public void setSessionID(int sessionID)
       {
          this.sessionID = sessionID;
       }

       /**
        * Sets the subject name.
        *
        * @param    subject
        *           The new subject name
        */
       public void setSubject(String subject)
       {
          this.subject = subject;
       }

       /**
        * Gets the string representation of this token.
        *
        * @return   The description of this token
        */
       public String toString()
       {
          StringBuilder buf = new StringBuilder(subject);
          buf.append(':');
          /** GWT String emulation doesn't support format(String, int) */
          /*buf.append(String.format("%08X", sessionID));*/
          byte hexMask = 0x0f;
          int byteMask = 0xff;
          char[] hex = new char[] {'0','1','2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
          int[] bytes = new int[4];
          int i = sessionID;
          for (int k = 0; k < 4; k++)
          {
             bytes[3 - k] =  i & byteMask;
             i = (i >> 8);
          }
          for (int k = 0; k < 4; k++)
          {
             buf.append(hex[bytes[k] >> 4]).append(hex[bytes[k] & hexMask]);
          }

          return buf.toString();
       }
    }