com.cryptoregistry.tweet.salt.stream.HSalsa20 Maven / Gradle / Ivy
//
// Copyright (c) 2011, Neil Alexander T.
// All rights reserved.
//
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// or without modification, are permitted provided that the following
// conditions are met:
//
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// - Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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package com.cryptoregistry.tweet.salt.stream;
public class HSalsa20 extends Salsa20 {
public static final int ROUNDS = 20;
@Override
public int crypto_core(byte[] outv, byte[] inv, byte[] k, byte[] c) {
int x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
int j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
int i;
j0 = x0 = load_littleendian(c, 0);
j1 = x1 = load_littleendian(k, 0);
j2 = x2 = load_littleendian(k, 4);
j3 = x3 = load_littleendian(k, 8);
j4 = x4 = load_littleendian(k, 12);
j5 = x5 = load_littleendian(c, 4);
if (inv != null) {
j6 = x6 = load_littleendian(inv, 0);
j7 = x7 = load_littleendian(inv, 4);
j8 = x8 = load_littleendian(inv, 8);
j9 = x9 = load_littleendian(inv, 12);
} else {
j6 = x6 = j7 = x7 = j8 = x8 = j9 = x9 = 0;
}
j10 = x10 = load_littleendian(c, 8);
j11 = x11 = load_littleendian(k, 16);
j12 = x12 = load_littleendian(k, 20);
j13 = x13 = load_littleendian(k, 24);
j14 = x14 = load_littleendian(k, 28);
j15 = x15 = load_littleendian(c, 12);
for (i = ROUNDS; i > 0; i -= 2) {
x4 ^= rotate(x0 + x12, 7);
x8 ^= rotate(x4 + x0, 9);
x12 ^= rotate(x8 + x4, 13);
x0 ^= rotate(x12 + x8, 18);
x9 ^= rotate(x5 + x1, 7);
x13 ^= rotate(x9 + x5, 9);
x1 ^= rotate(x13 + x9, 13);
x5 ^= rotate(x1 + x13, 18);
x14 ^= rotate(x10 + x6, 7);
x2 ^= rotate(x14 + x10, 9);
x6 ^= rotate(x2 + x14, 13);
x10 ^= rotate(x6 + x2, 18);
x3 ^= rotate(x15 + x11, 7);
x7 ^= rotate(x3 + x15, 9);
x11 ^= rotate(x7 + x3, 13);
x15 ^= rotate(x11 + x7, 18);
x1 ^= rotate(x0 + x3, 7);
x2 ^= rotate(x1 + x0, 9);
x3 ^= rotate(x2 + x1, 13);
x0 ^= rotate(x3 + x2, 18);
x6 ^= rotate(x5 + x4, 7);
x7 ^= rotate(x6 + x5, 9);
x4 ^= rotate(x7 + x6, 13);
x5 ^= rotate(x4 + x7, 18);
x11 ^= rotate(x10 + x9, 7);
x8 ^= rotate(x11 + x10, 9);
x9 ^= rotate(x8 + x11, 13);
x10 ^= rotate(x9 + x8, 18);
x12 ^= rotate(x15 + x14, 7);
x13 ^= rotate(x12 + x15, 9);
x14 ^= rotate(x13 + x12, 13);
x15 ^= rotate(x14 + x13, 18);
}
x0 += j0;
x1 += j1;
x2 += j2;
x3 += j3;
x4 += j4;
x5 += j5;
x6 += j6;
x7 += j7;
x8 += j8;
x9 += j9;
x10 += j10;
x11 += j11;
x12 += j12;
x13 += j13;
x14 += j14;
x15 += j15;
x0 -= load_littleendian(c, 0);
x5 -= load_littleendian(c, 4);
x10 -= load_littleendian(c, 8);
x15 -= load_littleendian(c, 12);
if (inv != null) {
x6 -= load_littleendian(inv, 0);
x7 -= load_littleendian(inv, 4);
x8 -= load_littleendian(inv, 8);
x9 -= load_littleendian(inv, 12);
}
store_littleendian(outv, 0, x0);
store_littleendian(outv, 4, x5);
store_littleendian(outv, 8, x10);
store_littleendian(outv, 12, x15);
store_littleendian(outv, 16, x6);
store_littleendian(outv, 20, x7);
store_littleendian(outv, 24, x8);
store_littleendian(outv, 28, x9);
return 0;
}
}
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