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/**
 * As of "https://github.com/dfish3r/vt-crypt2 "CRYPT" (vt-crypt2) the source
 * code below the package "edu.vt.middleware.crypt" is dual licensed under both
 * the LGPL and Apache 2 license. As REFCODES.ORG source codes are also licensed
 * under the Apache License, v2.0 ("http://www.apache.org/licenses/TEXT-2.0"),
 * the according Apache 2 license principles are to be applied: "... The Apache
 * License is permissive; unlike copyleft licenses, it does not require a
 * derivative work of the software, or modifications to the original, to be
 * distributed using the same license. It still requires application of the same
 * license to all unmodified parts. In every licensed file, original copyright,
 * patent, trademark, and attribution notices must be preserved (excluding
 * notices that do not pertain to any part of the derivative works.) In every
 * licensed file changed, a notification must be added stating that changes have
 * been made to that file..." ("https://en.wikipedia.org/wiki/Apache_License")
 * 
 * "Software can be freely used, modified and distributed in any environment
 * under this license."
 * 
"A copy of the license must be included in the package." (→ see
 * refcodes-licensing dependency)
 * 
"Changes to the source code of the software under the Apache license do
 * not have to be sent back to the licensor."
 * 
"Own software that uses software under the Apache license does not have
 * to be under the Apache license."
 * 
"Your own software may only be called Apache if the Apache Foundation has
 * given written permission."
 * 
 * (freely translated from "https://de.wikipedia.org/wiki/Apache_License")
 */

/*
 * $Id: SHA256.java 2744 2013-06-25 20:20:29Z dfisher $
 * 
 * Copyright (C) 2003-2013 Virginia Tech. All rights reserved.
 * 
 * SEE TEXT FOR MORE INFORMATION
 * 
 * Author: Middleware Services Email: [email protected] Version: $Revision: 2744
 * $ Updated: $Date: 2013-06-25 16:20:29 -0400 (Tue, 25 Jun 2013) $
 */
package edu.vt.middleware.crypt.digest;

import java.security.SecureRandom;

import org.bouncycastle.crypto.digests.SHA256Digest;

/**
 * 
 * SHA256 contains functions for hashing data using the SHA-256
 * algorithm. This algorithm outputs a 256 bit hash.
 * 
 *
 * @author Middleware Services
 * 
 * @version $Revision: 2744 $
 */
public class SHA256 extends DigestAlgorithm {

	/** Creates an uninitialized instance of an SHA256 digest. */
	public SHA256() {
		super( new SHA256Digest() );
	}

	/**
	 * Creates a new SHA256 digest that may optionally be initialized with
	 * random data.
	 *
	 * @param randomize True to randomize initial state of digest, false
	 *        otherwise.
	 */
	public SHA256( final boolean randomize ) {
		super( new SHA256Digest() );
		if ( randomize ) {
			setRandomProvider( new SecureRandom() );
			setSalt( getRandomSalt() );
		}
	}

	/**
	 * Creates a new SHA256 digest and initializes it with the given salt.
	 *
	 * @param salt Salt data used to initialize digest computation.
	 */
	public SHA256( final byte[] salt ) {
		super( new SHA256Digest() );
		setSalt( salt );
	}
}