sha256digest.java

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// Decompiled by Jad v1.5.8e2. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://kpdus.tripod.com/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi space 
// Source File Name:   SHA256Digest.java

package org.bouncycastle.crypto.digests;


// Referenced classes of package org.bouncycastle.crypto.digests:
//			GeneralDigest

public class SHA256Digest extends GeneralDigest
{

	private static final int DIGEST_LENGTH = 32;
	private int H1;
	private int H2;
	private int H3;
	private int H4;
	private int H5;
	private int H6;
	private int H7;
	private int H8;
	private int X[];
	private int xOff;
	static final int K[] = {
		0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 
		0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0xfc19dc6, 0x240ca1cc, 
		0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 
		0x6ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 
		0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 
		0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 
		0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
	};

	public SHA256Digest()
	{
		X = new int[64];
		reset();
	}

	public SHA256Digest(SHA256Digest t)
	{
		super(t);
		X = new int[64];
		H1 = t.H1;
		H2 = t.H2;
		H3 = t.H3;
		H4 = t.H4;
		H5 = t.H5;
		H6 = t.H6;
		H7 = t.H7;
		H8 = t.H8;
		System.arraycopy(t.X, 0, X, 0, t.X.length);
		xOff = t.xOff;
	}

	public String getAlgorithmName()
	{
		return "SHA-256";
	}

	public int getDigestSize()
	{
		return 32;
	}

	protected void processWord(byte in[], int inOff)
	{
		X[xOff++] = (in[inOff] & 0xff) << 24 | (in[inOff + 1] & 0xff) << 16 | (in[inOff + 2] & 0xff) << 8 | in[inOff + 3] & 0xff;
		if (xOff == 16)
			processBlock();
	}

	private void unpackWord(int word, byte out[], int outOff)
	{
		out[outOff] = (byte)(word >>> 24);
		out[outOff + 1] = (byte)(word >>> 16);
		out[outOff + 2] = (byte)(word >>> 8);
		out[outOff + 3] = (byte)word;
	}

	protected void processLength(long bitLength)
	{
		if (xOff > 14)
			processBlock();
		X[14] = (int)(bitLength >>> 32);
		X[15] = (int)(bitLength & -1L);
	}

	public int doFinal(byte out[], int outOff)
	{
		finish();
		unpackWord(H1, out, outOff);
		unpackWord(H2, out, outOff + 4);
		unpackWord(H3, out, outOff + 8);
		unpackWord(H4, out, outOff + 12);
		unpackWord(H5, out, outOff + 16);
		unpackWord(H6, out, outOff + 20);
		unpackWord(H7, out, outOff + 24);
		unpackWord(H8, out, outOff + 28);
		reset();
		return 32;
	}

	public void reset()
	{
		super.reset();
		H1 = 0x6a09e667;
		H2 = 0xbb67ae85;
		H3 = 0x3c6ef372;
		H4 = 0xa54ff53a;
		H5 = 0x510e527f;
		H6 = 0x9b05688c;
		H7 = 0x1f83d9ab;
		H8 = 0x5be0cd19;
		xOff = 0;
		for (int i = 0; i != X.length; i++)
			X[i] = 0;

	}

	protected void processBlock()
	{
		for (int t = 16; t <= 63; t++)
			X[t] = Theta1(X[t - 2]) + X[t - 7] + Theta0(X[t - 15]) + X[t - 16];

		int a = H1;
		int b = H2;
		int c = H3;
		int d = H4;
		int e = H5;
		int f = H6;
		int g = H7;
		int h = H8;
		for (int t = 0; t <= 63; t++)
		{
			int T1 = h + Sum1(e) + Ch(e, f, g) + K[t] + X[t];
			int T2 = Sum0(a) + Maj(a, b, c);
			h = g;
			g = f;
			f = e;
			e = d + T1;
			d = c;
			c = b;
			b = a;
			a = T1 + T2;
		}

		H1 += a;
		H2 += b;
		H3 += c;
		H4 += d;
		H5 += e;
		H6 += f;
		H7 += g;
		H8 += h;
		xOff = 0;
		for (int i = 0; i != X.length; i++)
			X[i] = 0;

	}

	private int rotateRight(int x, int n)
	{
		return x >>> n | x << 32 - n;
	}

	private int Ch(int x, int y, int z)
	{
		return x & y ^ ~x & z;
	}

	private int Maj(int x, int y, int z)
	{
		return x & y ^ x & z ^ y & z;
	}

	private int Sum0(int x)
	{
		return rotateRight(x, 2) ^ rotateRight(x, 13) ^ rotateRight(x, 22);
	}

	private int Sum1(int x)
	{
		return rotateRight(x, 6) ^ rotateRight(x, 11) ^ rotateRight(x, 25);
	}

	private int Theta0(int x)
	{
		return rotateRight(x, 7) ^ rotateRight(x, 18) ^ x >>> 3;
	}

	private int Theta1(int x)
	{
		return rotateRight(x, 17) ^ rotateRight(x, 19) ^ x >>> 10;
	}

}