/* * BouncyCastle License * Copyright (c) 2000 - 2006 The Legion Of The Bouncy Castle (http://www.bouncycastle.org) * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package org.bouncycastle.crypto.digests; import org.bouncycastle.crypto.ExtendedDigest; /** * base implementation of MD4 family style digest as outlined in * "Handbook of Applied Cryptography", pages 344 - 347. */ public abstract class GeneralDigest implements ExtendedDigest { private static final int BYTE_LENGTH = 64; private byte[] xBuf; private int xBufOff; private long byteCount; /** * Standard constructor */ protected GeneralDigest() { xBuf = new byte[4]; xBufOff = 0; } /** * Copy constructor. We are using copy constructors in place * of the Object.clone() interface as this interface is not * supported by J2ME. */ protected GeneralDigest(GeneralDigest t) { xBuf = new byte[t.xBuf.length]; System.arraycopy(t.xBuf, 0, xBuf, 0, t.xBuf.length); xBufOff = t.xBufOff; byteCount = t.byteCount; } public void update( byte in) { xBuf[xBufOff++] = in; if (xBufOff == xBuf.length) { processWord(xBuf, 0); xBufOff = 0; } byteCount++; } public void update( byte[] in, int inOff, int len) { // // fill the current word // while ((xBufOff != 0) && (len > 0)) { update(in[inOff]); inOff++; len--; } // // process whole words. // while (len > xBuf.length) { processWord(in, inOff); inOff += xBuf.length; len -= xBuf.length; byteCount += xBuf.length; } // // load in the remainder. // while (len > 0) { update(in[inOff]); inOff++; len--; } } public void finish() { long bitLength = (byteCount << 3); // // add the pad bytes. // update((byte)128); while (xBufOff != 0) { update((byte)0); } processLength(bitLength); processBlock(); } public void reset() { byteCount = 0; xBufOff = 0; for (int i = 0; i < xBuf.length; i++) { xBuf[i] = 0; } } public int getByteLength() { return BYTE_LENGTH; } protected abstract void processWord(byte[] in, int inOff); protected abstract void processLength(long bitLength); protected abstract void processBlock(); }