Back to index...

	/*
	* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 in the LICENSE file that
	* accompanied this code).
	*
	* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.security.provider;

	import static sun.security.provider.ByteArrayAccess.*;
	import java.nio.*;
	import java.util.*;
	import java.security.*;

	/**
	* This class implements the Secure Hash Algorithm SHA-3 developed by
	* the National Institute of Standards and Technology along with the
	* National Security Agency as defined in FIPS PUB 202.
	*
	* <p>It implements java.security.MessageDigestSpi, and can be used
	* through Java Cryptography Architecture (JCA), as a pluggable
	* MessageDigest implementation.
	*
	* @since 9
	* @author Valerie Peng
	*/
	abstract class SHA3 extends DigestBase {

	private static final int WIDTH = 200; // in bytes, e.g. 1600 bits
	private static final int DM = 5; // dimension of lanes

	private static final int NR = 24; // number of rounds

	// precomputed round constants needed by the step mapping Iota
	private static final long[] RC_CONSTANTS = {
	0x01L, 0x8082L, 0x800000000000808aL,
	0x8000000080008000L, 0x808bL, 0x80000001L,
	0x8000000080008081L, 0x8000000000008009L, 0x8aL,
	0x88L, 0x80008009L, 0x8000000aL,
	0x8000808bL, 0x800000000000008bL, 0x8000000000008089L,
	0x8000000000008003L, 0x8000000000008002L, 0x8000000000000080L,
	0x800aL, 0x800000008000000aL, 0x8000000080008081L,
	0x8000000000008080L, 0x80000001L, 0x8000000080008008L,
	};

	private byte[] state = new byte[WIDTH];
	private final long[] lanes = new long[DM*DM];

	/**
	* Creates a new SHA-3 object.
	*/
	SHA3(String name, int digestLength) {
	super(name, digestLength, (WIDTH - (2 * digestLength)));
	}

	/**
	* Core compression function. Processes blockSize bytes at a time
	* and updates the state of this object.
	*/
	void implCompress(byte[] b, int ofs) {
	for (int i = 0; i < buffer.length; i++) {
	state[i] ^= b[ofs++];
	}
	keccak();
	}

	/**
	* Return the digest. Subclasses do not need to reset() themselves,
	* DigestBase calls implReset() when necessary.
	*/
	void implDigest(byte[] out, int ofs) {
	int numOfPadding =
	setPaddingBytes(buffer, (int)(bytesProcessed % buffer.length));
	if (numOfPadding < 1) {
	throw new ProviderException("Incorrect pad size: " + numOfPadding);
	}
	for (int i = 0; i < buffer.length; i++) {
	state[i] ^= buffer[i];
	}
	keccak();
	System.arraycopy(state, 0, out, ofs, engineGetDigestLength());
	}

	/**
	* Resets the internal state to start a new hash.
	*/
	void implReset() {
	Arrays.fill(state, (byte)0);
	Arrays.fill(lanes, 0L);
	}

	/**
	* Utility function for padding the specified data based on the
	* pad10*1 algorithm (section 5.1) and the 2-bit suffix "01" required
	* for SHA-3 hash (section 6.1).
	*/
	private static int setPaddingBytes(byte[] in, int len) {
	if (len != in.length) {
	// erase leftover values
	Arrays.fill(in, len, in.length, (byte)0);
	// directly store the padding bytes into the input
	// as the specified buffer is allocated w/ size = rateR
	in[len] \|= (byte) 0x06;
	in[in.length - 1] \|= (byte) 0x80;
	}
	return (in.length - len);
	}

	/**
	* Utility function for transforming the specified byte array 's'
	* into array of lanes 'm' as defined in section 3.1.2.
	*/
	private static void bytes2Lanes(byte[] s, long[] m) {
	int sOfs = 0;
	// Conversion traverses along x-axis before y-axis
	for (int y = 0; y < DM; y++, sOfs += 40) {
	b2lLittle(s, sOfs, m, DM*y, 40);
	}
	}

	/**
	* Utility function for transforming the specified array of
	* lanes 'm' into a byte array 's' as defined in section 3.1.3.
	*/
	private static void lanes2Bytes(long[] m, byte[] s) {
	int sOfs = 0;
	// Conversion traverses along x-axis before y-axis
	for (int y = 0; y < DM; y++, sOfs += 40) {
	l2bLittle(m, DM*y, s, sOfs, 40);
	}
	}

	/**
	* Step mapping Theta as defined in section 3.2.1 .
	*/
	private static long[] smTheta(long[] a) {
	long c0 = a[0]^a[5]^a[10]^a[15]^a[20];
	long c1 = a[1]^a[6]^a[11]^a[16]^a[21];
	long c2 = a[2]^a[7]^a[12]^a[17]^a[22];
	long c3 = a[3]^a[8]^a[13]^a[18]^a[23];
	long c4 = a[4]^a[9]^a[14]^a[19]^a[24];
	long d0 = c4 ^ Long.rotateLeft(c1, 1);
	long d1 = c0 ^ Long.rotateLeft(c2, 1);
	long d2 = c1 ^ Long.rotateLeft(c3, 1);
	long d3 = c2 ^ Long.rotateLeft(c4, 1);
	long d4 = c3 ^ Long.rotateLeft(c0, 1);
	for (int y = 0; y < a.length; y += DM) {
	a[y] ^= d0;
	a[y+1] ^= d1;
	a[y+2] ^= d2;
	a[y+3] ^= d3;
	a[y+4] ^= d4;
	}
	return a;
	}

	/**
	* Merged Step mapping Rho (section 3.2.2) and Pi (section 3.2.3).
	* for performance. Optimization is achieved by precalculating
	* shift constants for the following loop
	* int xNext, yNext;
	* for (int t = 0, x = 1, y = 0; t <= 23; t++, x = xNext, y = yNext) {
	* int numberOfShift = ((t + 1)*(t + 2)/2) % 64;
	* a[y][x] = Long.rotateLeft(a[y][x], numberOfShift);
	* xNext = y;
	* yNext = (2 * x + 3 * y) % DM;
	* }
	* and with inplace permutation.
	*/
	private static long[] smPiRho(long[] a) {
	long tmp = Long.rotateLeft(a[10], 3);
	a[10] = Long.rotateLeft(a[1], 1);
	a[1] = Long.rotateLeft(a[6], 44);
	a[6] = Long.rotateLeft(a[9], 20);
	a[9] = Long.rotateLeft(a[22], 61);
	a[22] = Long.rotateLeft(a[14], 39);
	a[14] = Long.rotateLeft(a[20], 18);
	a[20] = Long.rotateLeft(a[2], 62);
	a[2] = Long.rotateLeft(a[12], 43);
	a[12] = Long.rotateLeft(a[13], 25);
	a[13] = Long.rotateLeft(a[19], 8);
	a[19] = Long.rotateLeft(a[23], 56);
	a[23] = Long.rotateLeft(a[15], 41);
	a[15] = Long.rotateLeft(a[4], 27);
	a[4] = Long.rotateLeft(a[24], 14);
	a[24] = Long.rotateLeft(a[21], 2);
	a[21] = Long.rotateLeft(a[8], 55);
	a[8] = Long.rotateLeft(a[16], 45);
	a[16] = Long.rotateLeft(a[5], 36);
	a[5] = Long.rotateLeft(a[3], 28);
	a[3] = Long.rotateLeft(a[18], 21);
	a[18] = Long.rotateLeft(a[17], 15);
	a[17] = Long.rotateLeft(a[11], 10);
	a[11] = Long.rotateLeft(a[7], 6);
	a[7] = tmp;
	return a;
	}

	/**
	* Step mapping Chi as defined in section 3.2.4.
	*/
	private static long[] smChi(long[] a) {
	for (int y = 0; y < a.length; y+=DM) {
	long ay0 = a[y];
	long ay1 = a[y+1];
	long ay2 = a[y+2];
	long ay3 = a[y+3];
	long ay4 = a[y+4];
	a[y] = ay0 ^ ((~ay1) & ay2);
	a[y+1] = ay1 ^ ((~ay2) & ay3);
	a[y+2] = ay2 ^ ((~ay3) & ay4);
	a[y+3] = ay3 ^ ((~ay4) & ay0);
	a[y+4] = ay4 ^ ((~ay0) & ay1);
	}
	return a;
	}

	/**
	* Step mapping Iota as defined in section 3.2.5.
	*/
	private static long[] smIota(long[] a, int rndIndex) {
	a[0] ^= RC_CONSTANTS[rndIndex];
	return a;
	}

	/**
	* The function Keccak as defined in section 5.2 with
	* rate r = 1600 and capacity c = (digest length x 2).
	*/
	private void keccak() {
	// convert the 200-byte state into 25 lanes
	bytes2Lanes(state, lanes);
	// process the lanes through step mappings
	for (int ir = 0; ir < NR; ir++) {
	smIota(smChi(smPiRho(smTheta(lanes))), ir);
	}
	// convert the resulting 25 lanes back into 200-byte state
	lanes2Bytes(lanes, state);
	}

	public Object clone() throws CloneNotSupportedException {
	SHA3 copy = (SHA3) super.clone();
	copy.state = copy.state.clone();
	return copy;
	}

	/**
	* SHA3-224 implementation class.
	*/
	public static final class SHA224 extends SHA3 {
	public SHA224() {
	super("SHA3-224", 28);
	}
	}

	/**
	* SHA3-256 implementation class.
	*/
	public static final class SHA256 extends SHA3 {
	public SHA256() {
	super("SHA3-256", 32);
	}
	}

	/**
	* SHAs-384 implementation class.
	*/
	public static final class SHA384 extends SHA3 {
	public SHA384() {
	super("SHA3-384", 48);
	}
	}

	/**
	* SHA3-512 implementation class.
	*/
	public static final class SHA512 extends SHA3 {
	public SHA512() {
	super("SHA3-512", 64);
	}
	}
	}

Back to index...