Source for javax.security.auth.callback.PasswordCallback

   1: /* PasswordCallback.java -- callback for passwords.
   2:    Copyright (C) 2003, Free Software Foundation, Inc.
   3: 
   4: This file is 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, or (at your option)
   9: 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; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 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 javax.security.auth.callback;
  40: 
  41: import java.io.Serializable;
  42: 
  43: /**
  44:  * Underlying security services instantiate and pass a <code>PasswordCallback</code>
  45:  * to the <code>handle()</code> method of a {@link CallbackHandler} to retrieve
  46:  * password information.
  47:  *
  48:  * @see CallbackHandler,
  49:  */
  50: public class PasswordCallback implements Callback, Serializable
  51: {
  52: 
  53:   // Constants and variables
  54:   // -------------------------------------------------------------------------
  55: 
  56:   /**
  57:    * @serial
  58:    * @since 1.4
  59:    */
  60:   private String prompt;
  61: 
  62:   /**
  63:    * @serial
  64:    * @since 1.4
  65:    */
  66:   private boolean echoOn;
  67: 
  68:   /**
  69:    * @serial
  70:    * @since 1.4
  71:    */
  72:   private char[] inputPassword;
  73: 
  74:   // Constructor(s)
  75:   // -------------------------------------------------------------------------
  76: 
  77:   /**
  78:    * Construct a <code>PasswordCallback</code> with a prompt and a boolean
  79:    * specifying whether the password should be displayed as it is being typed.
  80:    *
  81:    * @param prompt the prompt used to request the password.
  82:    * @param echoOn <code>true</code> if the password should be displayed as it
  83:    * is being typed.
  84:    * @throws IllegalArgumentException if <code>prompt</code> is <code>null</code>
  85:    * or if <code>prompt</code> has a length of <code>0</code>.
  86:    */
  87:   public PasswordCallback(String prompt, boolean echoOn)
  88:   {
  89:     super();
  90: 
  91:     setPrompt(prompt);
  92:     this.echoOn = echoOn;
  93:   }
  94: 
  95:   // Class methods
  96:   // -------------------------------------------------------------------------
  97: 
  98:   // Instance methods
  99:   // -------------------------------------------------------------------------
 100: 
 101:   /**
 102:    * Get the prompt.
 103:    *
 104:    * @return the prompt.
 105:    */
 106:   public String getPrompt()
 107:   {
 108:     return prompt;
 109:   }
 110: 
 111:   /**
 112:    * Return whether the password should be displayed as it is being typed.
 113:    *
 114:    * @return the whether the password should be displayed as it is being typed.
 115:    */
 116:   public boolean isEchoOn()
 117:   {
 118:     return echoOn;
 119:   }
 120: 
 121:   /**
 122:    * <p>Set the retrieved password.</p>
 123:    *
 124:    * <p>This method makes a copy of the input password before storing it.</p>
 125:    *
 126:    * @param password the retrieved password, which may be <code>null</code>.
 127:    * @see #getPassword()
 128:    */
 129:   public void setPassword(char[] password)
 130:   {
 131:     inputPassword = (password == null ? null : (char[]) password.clone());
 132:   }
 133: 
 134:   /**
 135:    * <p>Get the retrieved password.</p>
 136:    *
 137:    * <p>This method returns a copy of the retrieved password.</p>
 138:    *
 139:    * @return the retrieved password, which may be <code>null</code>.
 140:    * @see #setPassword(char[])
 141:    */
 142:   public char[] getPassword()
 143:   {
 144:     return (inputPassword == null ? null : (char[]) inputPassword.clone());
 145:   }
 146: 
 147:   /** Clear the retrieved password. */
 148:   public void clearPassword()
 149:   {
 150:     if (inputPassword != null)
 151:       {
 152:     for (int i = 0; i < inputPassword.length; i++)
 153:       {
 154:         inputPassword[i] = '\0';
 155:       }
 156:     inputPassword = null;
 157:       }
 158:   }
 159: 
 160:   private void setPrompt(String prompt) throws IllegalArgumentException
 161:   {
 162:     if ((prompt == null) || (prompt.length() == 0))
 163:       {
 164:     throw new IllegalArgumentException("invalid prompt");
 165:       }
 166:     this.prompt = prompt;
 167:   }
 168: }