/*
*
*
* Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.midp.crypto;
/**
* Implements an abstract class that generalizes random number
* generators.
*/
public abstract class SecureRandom {
/** Identifies a utility pseudo random number generation algorithm. */
public static final byte ALG_PSEUDO_RANDOM = 1;
/**
* Identifies a cryptographically secure random number generation
* algorithm.
*/
public static final byte ALG_SECURE_RANDOM = 2;
/**
* Protected constructor for subclassing.
*/
protected SecureRandom() {
}
/**
* Creates a RandomData instance of the selected algorithm. <BR />
* <P />
* <B>WARNING:</B> Requests for a secure random number generator
* are currently redirected to a class that implements a weakly
* unpredictable source of random data. Licensees of this reference
* implementation are strongly urged to link requests for
* ALG_SECURE_RANDOM to better generators that may be available
* on their specific platforms.
*
* @param alg the desired random number generation algorithm, e.g.
* ALG_PSEUDO_RANDOM
*
* @return a RandomData instance implementing the selected algorithm.
*
* @exception NoSuchAlgorithmException if an unsupported algorithm is
* requested.
*/
public static SecureRandom getInstance(byte alg)
throws NoSuchAlgorithmException {
switch (alg) {
case ALG_SECURE_RANDOM:
// return (new SRand());
case ALG_PSEUDO_RANDOM:
return (new PRand());
default:
throw new NoSuchAlgorithmException();
}
}
/**
* Generates the next bytes of random data. <BR />
* @param buf output buffer in which the random data is to be placed
* @param off starting offset within buf for the random data
* @param len number of bytes of random data to be placed in buf
*/
public abstract void nextBytes(byte[] buf, int off, int len);
/**
* Seeds the random number generator. <BR />
* @param buf input buffer containing the seed
* @param off offset within buf where the seed starts
* @param len number of bytes of seed data in buf
*/
public abstract void setSeed(byte[] buf, int off, int len);
}