001 /* SecureRandomSpi.java --- Secure Random Service Provider Interface
002 Copyright (C) 1999, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package java.security;
039 import java.io.Serializable;
040
041 /**
042 SecureRandomSpi is the Service Provider Interface for SecureRandom
043 providers. It provides an interface for providers to the
044 SecureRandom engine to write their own pseudo-random number
045 generator.
046
047 @since JDK 1.2
048
049 @author Mark Benvenuto (ivymccough@worldnet.att.net)
050 */
051 public abstract class SecureRandomSpi implements Serializable
052 {
053 private static final long serialVersionUID = -2991854161009191830L;
054
055 /**
056 Default Constructor for SecureRandomSpi
057 */
058 public SecureRandomSpi()
059 {
060 }
061
062 /**
063 Updates the seed for SecureRandomSpi but does not reset seed.
064 It does to this so repeated called never decrease randomness.
065 */
066 protected abstract void engineSetSeed(byte[] seed);
067
068 /**
069 Gets a user specified number of bytes depending on the length
070 of the array?
071
072 @param bytes array to fill with random bytes
073 */
074 protected abstract void engineNextBytes(byte[] bytes);
075
076 /**
077 Gets a user specified number of bytes specified by the
078 parameter.
079
080 @param numBytes number of random bytes to generate
081
082 @return an array full of random bytes
083 */
084 protected abstract byte[] engineGenerateSeed(int numBytes);
085 }