/*

 * Copyright (c) 2002, 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 java.util.Objects;

import jdk.internal.HotSpotIntrinsicCandidate;

import static sun.security.provider.ByteArrayAccess.*;

/**

 * This class implements the Secure Hash Algorithm SHA-384 and SHA-512

 * developed by the National Institute of Standards and Technology along

 * with the National Security Agency.

 *

 * The two algorithms are almost identical. This file contains a base

 * class SHA5 and two nested static subclasses as the classes to be used

 * by the JCA framework.

 *

 * <p>It implements java.security.MessageDigestSpi, and can be used

 * through Java Cryptography Architecture (JCA), as a pluggable

 * MessageDigest implementation.

 *

 * @since       1.4.2

 * @author      Valerie Peng

 * @author      Andreas Sterbenz

 */

abstract class SHA5 extends DigestBase {

    private static final int ITERATION = 80;

    // Constants for each round/iteration

    private static final long[] ROUND_CONSTS = {

        0x428A2F98D728AE22L, 0x7137449123EF65CDL, 0xB5C0FBCFEC4D3B2FL,

        0xE9B5DBA58189DBBCL, 0x3956C25BF348B538L, 0x59F111F1B605D019L,

        0x923F82A4AF194F9BL, 0xAB1C5ED5DA6D8118L, 0xD807AA98A3030242L,

        0x12835B0145706FBEL, 0x243185BE4EE4B28CL, 0x550C7DC3D5FFB4E2L,

        0x72BE5D74F27B896FL, 0x80DEB1FE3B1696B1L, 0x9BDC06A725C71235L,

        0xC19BF174CF692694L, 0xE49B69C19EF14AD2L, 0xEFBE4786384F25E3L,

        0x0FC19DC68B8CD5B5L, 0x240CA1CC77AC9C65L, 0x2DE92C6F592B0275L,

        0x4A7484AA6EA6E483L, 0x5CB0A9DCBD41FBD4L, 0x76F988DA831153B5L,

        0x983E5152EE66DFABL, 0xA831C66D2DB43210L, 0xB00327C898FB213FL,

        0xBF597FC7BEEF0EE4L, 0xC6E00BF33DA88FC2L, 0xD5A79147930AA725L,

        0x06CA6351E003826FL, 0x142929670A0E6E70L, 0x27B70A8546D22FFCL,

        0x2E1B21385C26C926L, 0x4D2C6DFC5AC42AEDL, 0x53380D139D95B3DFL,

        0x650A73548BAF63DEL, 0x766A0ABB3C77B2A8L, 0x81C2C92E47EDAEE6L,

        0x92722C851482353BL, 0xA2BFE8A14CF10364L, 0xA81A664BBC423001L,

        0xC24B8B70D0F89791L, 0xC76C51A30654BE30L, 0xD192E819D6EF5218L,

        0xD69906245565A910L, 0xF40E35855771202AL, 0x106AA07032BBD1B8L,

        0x19A4C116B8D2D0C8L, 0x1E376C085141AB53L, 0x2748774CDF8EEB99L,

        0x34B0BCB5E19B48A8L, 0x391C0CB3C5C95A63L, 0x4ED8AA4AE3418ACBL,

        0x5B9CCA4F7763E373L, 0x682E6FF3D6B2B8A3L, 0x748F82EE5DEFB2FCL,

        0x78A5636F43172F60L, 0x84C87814A1F0AB72L, 0x8CC702081A6439ECL,

        0x90BEFFFA23631E28L, 0xA4506CEBDE82BDE9L, 0xBEF9A3F7B2C67915L,

        0xC67178F2E372532BL, 0xCA273ECEEA26619CL, 0xD186B8C721C0C207L,

        0xEADA7DD6CDE0EB1EL, 0xF57D4F7FEE6ED178L, 0x06F067AA72176FBAL,

        0x0A637DC5A2C898A6L, 0x113F9804BEF90DAEL, 0x1B710B35131C471BL,

        0x28DB77F523047D84L, 0x32CAAB7B40C72493L, 0x3C9EBE0A15C9BEBCL,

        0x431D67C49C100D4CL, 0x4CC5D4BECB3E42B6L, 0x597F299CFC657E2AL,

        0x5FCB6FAB3AD6FAECL, 0x6C44198C4A475817L

    };

    // buffer used by implCompress()

    private long[] W;

    // state of this object

    private long[] state;

    // initial state value. different between SHA-384 and SHA-512

    private final long[] initialHashes;

    /**

     * Creates a new SHA object.

     */

    SHA5(String name, int digestLength, long[] initialHashes) {

        super(name, digestLength, 128);

        this.initialHashes = initialHashes;

        state = new long[8];

        W = new long[80];

        implReset();

    }

    final void implReset() {

        System.arraycopy(initialHashes, 0, state, 0, state.length);

    }

    final void implDigest(byte[] out, int ofs) {

        long bitsProcessed = bytesProcessed << 3;

        int index = (int)bytesProcessed & 0x7f;

        int padLen = (index < 112) ? (112 - index) : (240 - index);

        engineUpdate(padding, 0, padLen + 8);

        i2bBig4((int)(bitsProcessed >>> 32), buffer, 120);

        i2bBig4((int)bitsProcessed, buffer, 124);

        implCompress(buffer, 0);

        int len = engineGetDigestLength();

        if (len == 28) {

            // Special case for SHA-512/224

            l2bBig(state, 0, out, ofs, 24);

            i2bBig4((int)(state[3] >> 32), out, ofs + 24);

        } else {

            l2bBig(state, 0, out, ofs, len);

        }

    }

    /**

     * logical function ch(x,y,z) as defined in spec:

     * @return (x and y) xor ((complement x) and z)

     * @param x long

     * @param y long

     * @param z long

     */

    private static long lf_ch(long x, long y, long z) {

        return (x & y) ^ ((~x) & z);

    }

    /**

     * logical function maj(x,y,z) as defined in spec:

     * @return (x and y) xor (x and z) xor (y and z)

     * @param x long

     * @param y long

     * @param z long

     */

    private static long lf_maj(long x, long y, long z) {

        return (x & y) ^ (x & z) ^ (y & z);

    }

    /**

     * logical function R(x,s) - right shift

     * @return x right shift for s times

     * @param x long

     * @param s int

     */

    private static long lf_R(long x, int s) {

        return (x >>> s);

    }

    /**

     * logical function S(x,s) - right rotation

     * @return x circular right shift for s times

     * @param x long

     * @param s int

     */

    private static long lf_S(long x, int s) {

        return (x >>> s) | (x << (64 - s));

    }

    /**

     * logical function sigma0(x) - xor of results of right rotations

     * @return S(x,28) xor S(x,34) xor S(x,39)

     * @param x long

     */

    private static long lf_sigma0(long x) {

        return lf_S(x, 28) ^ lf_S(x, 34) ^ lf_S(x, 39);

    }

    /**

     * logical function sigma1(x) - xor of results of right rotations

     * @return S(x,14) xor S(x,18) xor S(x,41)

     * @param x long

     */

    private static long lf_sigma1(long x) {

        return lf_S(x, 14) ^ lf_S(x, 18) ^ lf_S(x, 41);

    }

    /**

     * logical function delta0(x) - xor of results of right shifts/rotations

     * @return long

     * @param x long

     */

    private static long lf_delta0(long x) {

        return lf_S(x, 1) ^ lf_S(x, 8) ^ lf_R(x, 7);

    }

    /**

     * logical function delta1(x) - xor of results of right shifts/rotations

     * @return long

     * @param x long

     */

    private static long lf_delta1(long x) {

        return lf_S(x, 19) ^ lf_S(x, 61) ^ lf_R(x, 6);

    }

    /**

     * Compute the hash for the current block.

     *

     * This is in the same vein as Peter Gutmann's algorithm listed in

     * the back of Applied Cryptography, Compact implementation of

     * "old" NIST Secure Hash Algorithm.

     */

    final void implCompress(byte[] buf, int ofs) {

        implCompressCheck(buf, ofs);

        implCompress0(buf, ofs);

    }

    private void implCompressCheck(byte[] buf, int ofs) {

        Objects.requireNonNull(buf);

        // The checks performed by the method 'b2iBig128'

        // are sufficient for the case when the method

        // 'implCompressImpl' is replaced with a compiler

        // intrinsic.

        b2lBig128(buf, ofs, W);

    }

    // The method 'implCompressImpl' seems not to use its parameters.

    // The method can, however, be replaced with a compiler intrinsic

    // that operates directly on the array 'buf' (starting from

    // offset 'ofs') and not on array 'W', therefore 'buf' and 'ofs'

    // must be passed as parameter to the method.

    @HotSpotIntrinsicCandidate

    private final void implCompress0(byte[] buf, int ofs) {

        // The first 16 longs are from the byte stream, compute the rest of

        // the W[]'s

        for (int t = 16; t < ITERATION; t++) {

            W[t] = lf_delta1(W[t-2]) + W[t-7] + lf_delta0(W[t-15])

                   + W[t-16];

        }

        long a = state[0];

        long b = state[1];

        long c = state[2];

        long d = state[3];

        long e = state[4];

        long f = state[5];

        long g = state[6];

        long h = state[7];

        for (int i = 0; i < ITERATION; i++) {

            long T1 = h + lf_sigma1(e) + lf_ch(e,f,g) + ROUND_CONSTS[i] + W[i];

            long T2 = lf_sigma0(a) + lf_maj(a,b,c);

            h = g;

            g = f;

            f = e;

            e = d + T1;

            d = c;

            c = b;

            b = a;

            a = T1 + T2;

        }

        state[0] += a;

        state[1] += b;

        state[2] += c;

        state[3] += d;

        state[4] += e;

        state[5] += f;

        state[6] += g;

        state[7] += h;

    }

    public Object clone() throws CloneNotSupportedException {

        SHA5 copy = (SHA5) super.clone();

        copy.state = copy.state.clone();

        copy.W = new long[80];

        return copy;

    }

    /**

     * SHA-512 implementation class.

     */

    public static final class SHA512 extends SHA5 {

        private static final long[] INITIAL_HASHES = {

            0x6a09e667f3bcc908L, 0xbb67ae8584caa73bL,

            0x3c6ef372fe94f82bL, 0xa54ff53a5f1d36f1L,

            0x510e527fade682d1L, 0x9b05688c2b3e6c1fL,

            0x1f83d9abfb41bd6bL, 0x5be0cd19137e2179L

        };

        public SHA512() {

            super("SHA-512", 64, INITIAL_HASHES);

        }

    }

    /**

     * SHA-384 implementation class.

     */

    public static final class SHA384 extends SHA5 {

        private static final long[] INITIAL_HASHES = {

            0xcbbb9d5dc1059ed8L, 0x629a292a367cd507L,

            0x9159015a3070dd17L, 0x152fecd8f70e5939L,

            0x67332667ffc00b31L, 0x8eb44a8768581511L,

            0xdb0c2e0d64f98fa7L, 0x47b5481dbefa4fa4L

        };

        public SHA384() {

            super("SHA-384", 48, INITIAL_HASHES);

        }

    }

    public static final class SHA512_224 extends SHA5 {

        private static final long[] INITIAL_HASHES = {

                0x8C3D37C819544DA2L, 0x73E1996689DCD4D6L,

                0x1DFAB7AE32FF9C82L, 0x679DD514582F9FCFL,

                0x0F6D2B697BD44DA8L, 0x77E36F7304C48942L,

                0x3F9D85A86A1D36C8L, 0x1112E6AD91D692A1L

        };

        public SHA512_224() {

            super("SHA-512/224", 28, INITIAL_HASHES);

        }

    }

    public static final class SHA512_256 extends SHA5 {

        private static final long[] INITIAL_HASHES = {

                0x22312194FC2BF72CL, 0x9F555FA3C84C64C2L,

                0x2393B86B6F53B151L, 0x963877195940EABDL,

                0x96283EE2A88EFFE3L, 0xBE5E1E2553863992L,

                0x2B0199FC2C85B8AAL, 0x0EB72DDC81C52CA2L

        };

        public SHA512_256() {

            super("SHA-512/256", 32, INITIAL_HASHES);

        }

    }

}