libjava/java/security/SecureRandomSpi.java

   1 /* SecureRandomSpi.java --- Secure Random Service Provider Interface
   2    Copyright (C) 1999, 2005  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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 package java.security;
  39 import java.io.Serializable;
  40
  41 /**
  42    SecureRandomSpi is the Service Provider Interface for SecureRandom
  43    providers. It provides an interface for providers to the
  44    SecureRandom engine to write their own pseudo-random number
  45    generator.
  46
  47    @since JDK 1.2
  48
  49    @author Mark Benvenuto (ivymccough@worldnet.att.net)
  50  */
  51 public abstract class SecureRandomSpi implements Serializable
  52 {
  53   private static final long serialVersionUID = -2991854161009191830L;
  54
  55   /**
  56      Default Constructor for SecureRandomSpi
  57    */
  58   public SecureRandomSpi()
  59   {
  60   }
  61
  62   /**
  63      Updates the seed for SecureRandomSpi but does not reset seed.
  64      It does to this so repeated called never decrease randomness.
  65    */
  66   protected abstract void engineSetSeed(byte[] seed);
  67
  68   /**
  69      Gets a user specified number of bytes depending on the length
  70      of the array?
  71
  72      @param bytes array to fill with random bytes
  73    */
  74   protected abstract void engineNextBytes(byte[] bytes);
  75
  76   /**
  77      Gets a user specified number of bytes specified by the
  78      parameter.
  79
  80      @param numBytes number of random bytes to generate
  81
  82      @return an array full of random bytes
  83    */
  84   protected abstract byte[] engineGenerateSeed(int numBytes);
  85 }