Source for gnu.javax.security.auth.Password

   1: /* Password.java -- opaque wrapper around a password.
   2:    Copyright (C) 2004, 2006 Free Software Foundation, Inc.
   3: 
   4: This file is a part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2 of the License, or (at
   9: your option) any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; if not, write to the Free Software
  18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19: USA
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version.  */
  37: 
  38: 
  39: package gnu.javax.security.auth;
  40: 
  41: import gnu.java.security.util.ExpirableObject;
  42: 
  43: import javax.security.auth.DestroyFailedException;
  44: 
  45: /**
  46:  * Immutible, though destroyable, password class.
  47:  *
  48:  * <p>Extends {@link ExpirableObject}, implementing {@link doDestroy()}
  49:  * in which encapsulated {@link char[]}, and {@link byte[]} password fields
  50:  * are cleared (elements set to zero) in order to thwart memory heap
  51:  * snooping.
  52:  */
  53: public final class Password extends ExpirableObject
  54: {
  55: 
  56:   // Constants and variables
  57:   // -------------------------------------------------------------------------
  58: 
  59:   /**
  60:    * Password stored in {@link char[]} format.
  61:    */
  62:   private final char[] password;
  63: 
  64:   /**
  65:    * Password stored in {@link byte[]} format.
  66:    */
  67:   private final byte[] bPassword;
  68: 
  69:   /**
  70:    * Indicates whether this Password object's {@link doDestroy()} method has
  71:    * been called.  See also, {@link ExpirableObject#Destroy()}.
  72:    */
  73:   private boolean mIsDestroyed = false;
  74: 
  75:   // Constructor(s)
  76:   // -------------------------------------------------------------------------
  77: 
  78:   /**
  79:    * Create a new expirable Password object that will expire after the
  80:    * default timeout {@link ExpirableObject#DEFAULT_TIMEOUT}.
  81:    *
  82:    * @param password The character array password to associate with this
  83:    * Password object.
  84:    */
  85:   public Password (char[] password)
  86:   {
  87:     this (password, 0, password.length, DEFAULT_TIMEOUT);
  88:   }
  89: 
  90:   /**
  91:    * Create a new expirable Password object that will expire after the
  92:    * timeout denoted by constructor parameter, <i>delay</i>.
  93:    *
  94:    * @param password The character array password to associate with this
  95:    * Password object.
  96:    * @param delay The number of miliseconds before this Password object
  97:    * will be automatically destroyed.
  98:    */
  99:   public Password (char[] password, long delay)
 100:   {
 101:     this (password, 0, password.length, delay);
 102:   }
 103: 
 104:   /**
 105:    * Create a new expirable Password object that will expire after the
 106:    * default timeout {@link ExpirableObject#DEFAULT_TIMEOUT}.
 107:    *
 108:    * @param password The character array password to associate with this
 109:    * Password object.
 110:    * @param offset The <i>password</i> character array parameter element
 111:    * marking the beginning of the contained password string.
 112:    * @param length The number of characters, beginning at <i>offset</i>,
 113:    * to be copied into this object's {@link password} field.
 114:    */
 115:   public Password (char[] password, int offset, int length)
 116:   {
 117:     this (password, offset, length, DEFAULT_TIMEOUT);
 118:   }
 119: 
 120:   /**
 121:    * Create a new expirable Password object that will expire after the
 122:    * timeout denoted by constructor parameter, <i>delay</i>.
 123:    *
 124:    * @param password The character array password to associate with this
 125:    * Password object.
 126:    * @param offset The <i>password</i> character array parameter element
 127:    * marking the beginning of the contained password string.
 128:    * @param length The number of characters, beginning at <i>offset</i>,
 129:    * to be copied into this object's {@link password} field.
 130:    * @param delay The number of miliseconds before this Password object
 131:    * will be automatically destroyed.
 132:    */
 133:   public Password (char[] password, int offset, int length, long delay)
 134:   {
 135:     super (delay);
 136: 
 137:     if (offset < 0 || length < 0 || offset + length > password.length)
 138:       throw new ArrayIndexOutOfBoundsException ("off=" + offset + " length=" +
 139:                                                 length + " array.length=" +
 140:                                                 password.length);
 141: 
 142:     int i, j;
 143:     this.password = new char[length];
 144:     bPassword = new byte[length];
 145: 
 146:     for(i = 0, j = offset; i < length; i++, j++)
 147:       {
 148:         this.password[i] = (char) password[j];
 149:         // XXX this should use character encodings, other than ASCII.
 150:         bPassword[i] = (byte) (password[j] & 0x7F);
 151:       }
 152:   }
 153: 
 154:   /**
 155:    * Create a new expirable Password object that will expire after the
 156:    * default timeout {@link ExpirableObject#DEFAULT_TIMEOUT}.
 157:    *
 158:    * @param password The byte array password to associate with this
 159:    * Password object.
 160:    */
 161:   public Password (byte[] password)
 162:   {
 163:     this (password, 0, password.length, DEFAULT_TIMEOUT);
 164:   }
 165: 
 166:   /**
 167:    * Create a new expirable Password object that will expire after the
 168:    * timeout denoted by constructor parameter, <i>delay</i>.
 169:    *
 170:    * @param password The byte array password to associate with this
 171:    * Password object.
 172:    * @param delay The number of miliseconds before this Password object
 173:    * will be automatically destroyed.
 174:    */
 175:   public Password (byte[] password, long delay)
 176:   {
 177:     this (password, 0, password.length, delay);
 178:   }
 179: 
 180:   /**
 181:    * Create a new expirable Password object that will expire after the
 182:    * default timeout {@link ExpirableObject#DEFAULT_TIMEOUT}.
 183:    *
 184:    * @param password The byte array password to associate with this
 185:    * Password object.
 186:    * @param offset The <i>password</i> byte array parameter element
 187:    * marking the beginning of the contained password string.
 188:    * @param length The number of bytes, beginning at <i>offset</i>,
 189:    * to be copied into this object's {@link password} field.
 190:    */
 191:   public Password (byte[] password, int offset, int length)
 192:   {
 193:     this (password, offset, length, DEFAULT_TIMEOUT);
 194:   }
 195: 
 196:   /**
 197:    * Create a new expirable Password object that will expire after the
 198:    * timeout denoted by constructor parameter, <i>delay</i>.
 199:    *
 200:    * @param password The byte array password to associate with this
 201:    * Password object.
 202:    * @param offset The <i>password</i> byte array parameter element
 203:    * marking the beginning of the contained password string.
 204:    * @param length The number of bytes, beginning at <i>offset</i>,
 205:    * to be copied into this object's {@link bPassword} field.
 206:    * @param delay The number of miliseconds before this Password object
 207:    * will be automatically destroyed.
 208:    */
 209:   public Password (byte[] password, int offset, int length, long delay)
 210:   {
 211:     super (delay);
 212: 
 213:     if (offset < 0 || length < 0 || offset + length > password.length)
 214:       throw new ArrayIndexOutOfBoundsException ("off=" + offset + " length=" +
 215:                                                 length + " array.length=" +
 216:                                                 password.length);
 217: 
 218:     int i, j;
 219:     this.password = new char[length];
 220:     bPassword = new byte[length];
 221: 
 222:     for (i = 0, j = offset; i < length; i++, j++)
 223:       {
 224:         this.password[i] = (char) password[j];
 225:         bPassword[i] = password[j];
 226:       }
 227:   }
 228: 
 229:   // Instance methods
 230:   // -------------------------------------------------------------------------
 231: 
 232:   /**
 233:    * Returns a reference to the {@link char[]} password storage field,
 234:    * {@link password}.
 235:    */
 236:   public synchronized char[] getPassword()
 237:   {
 238:     if (mIsDestroyed)
 239:       throw new IllegalStateException ("Attempted destroyed password access.");
 240: 
 241:     return password;
 242:   }
 243: 
 244:   /**
 245:    * Returns a reference to the {@link byte[]} password storage field,
 246:    * {@link bPassword}.
 247:    */
 248:   public synchronized byte[] getBytes()
 249:   {
 250:     if (mIsDestroyed)
 251:       throw new IllegalStateException ("Attempted destroyed password access.");
 252: 
 253:     return bPassword;
 254:   }
 255: 
 256:   /**
 257:    * Sets password field char[], and byte[] array elements to zero.
 258:    * This method implements base class {@link ExpirableObject} abstract
 259:    * method, {@link ExpirableObject#doDestroy()}.  See also,
 260:    * {@link ExpirableObject#destroy()}.
 261:    */
 262:   protected synchronized void doDestroy()
 263:   {
 264:     if (isDestroyed())
 265:       return;
 266:     else
 267:       {
 268:         for (int i = 0; i < password.length; i++)
 269:           password[i] = 0;
 270:         for (int i = 0; i < bPassword.length; i++)
 271:           bPassword[i] = 0;
 272:         mIsDestroyed = true;
 273:       }
 274:   }
 275: 
 276:   /**
 277:    * Returns true, or false relative to whether, or not this object's
 278:    * {@link doDestroy()} method has been called.  See also,
 279:    * {@ExpirableObject#destroy()}.
 280:    */
 281:   public synchronized boolean isDestroyed()
 282:   {
 283:     return (mIsDestroyed);
 284:   }
 285: }