/* SecureRandomSpi.java --- Secure Random Service Provider Interface
   Copyright (C) 1999, 2005  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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any later version.

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General Public License for more details.

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02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
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package java.security;
import java.io.Serializable;

/**
   SecureRandomSpi is the Service Provider Interface for SecureRandom
   providers. It provides an interface for providers to the 
   SecureRandom engine to write their own pseudo-random number
   generator.

   @since JDK 1.2       

   @author Mark Benvenuto (ivymccough@worldnet.att.net)
 */
public abstract class SecureRandomSpi implements Serializable
{
  private static final long serialVersionUID = -2991854161009191830L;

  /**
     Default Constructor for SecureRandomSpi
   */
  public SecureRandomSpi()
  {
  }

  /**
     Updates the seed for SecureRandomSpi but does not reset seed. 
     It does to this so repeated called never decrease randomness.
   */
  protected abstract void engineSetSeed(byte[] seed);

  /**
     Gets a user specified number of bytes depending on the length
     of the array?

     @param bytes array to fill with random bytes
   */
  protected abstract void engineNextBytes(byte[] bytes);

  /**
     Gets a user specified number of bytes specified by the 
     parameter.

     @param numBytes number of random bytes to generate

     @return an array full of random bytes
   */
  protected abstract byte[] engineGenerateSeed(int numBytes);
}