paddedblockcipher.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:   PaddedBlockCipher.java

package org.bouncycastle.crypto.modes;

import org.bouncycastle.crypto.*;

/**
 * @deprecated Class PaddedBlockCipher is deprecated
 */

public class PaddedBlockCipher extends BufferedBlockCipher
{

	public PaddedBlockCipher(BlockCipher cipher)
	{
		this.cipher = cipher;
		buf = new byte[cipher.getBlockSize()];
		bufOff = 0;
	}

	public int getOutputSize(int len)
	{
		int total = len + bufOff;
		int leftOver = total % buf.length;
		if (leftOver == 0)
		{
			if (forEncryption)
				return total + buf.length;
			else
				return total;
		} else
		{
			return (total - leftOver) + buf.length;
		}
	}

	public int getUpdateOutputSize(int len)
	{
		int total = len + bufOff;
		int leftOver = total % buf.length;
		if (leftOver == 0)
			return total - buf.length;
		else
			return total - leftOver;
	}

	public int processByte(byte in, byte out[], int outOff)
		throws DataLengthException, IllegalStateException
	{
		int resultLen = 0;
		if (bufOff == buf.length)
		{
			resultLen = cipher.processBlock(buf, 0, out, outOff);
			bufOff = 0;
		}
		buf[bufOff++] = in;
		return resultLen;
	}

	public int processBytes(byte in[], int inOff, int len, byte out[], int outOff)
		throws DataLengthException, IllegalStateException
	{
		if (len < 0)
			throw new IllegalArgumentException("Can't have a negative input length!");
		int blockSize = getBlockSize();
		int length = getUpdateOutputSize(len);
		if (length > 0 && outOff + length > out.length)
			throw new DataLengthException("output buffer too short");
		int resultLen = 0;
		int gapLen = buf.length - bufOff;
		if (len > gapLen)
		{
			System.arraycopy(in, inOff, buf, bufOff, gapLen);
			resultLen += cipher.processBlock(buf, 0, out, outOff);
			bufOff = 0;
			len -= gapLen;
			for (inOff += gapLen; len > buf.length; inOff += blockSize)
			{
				resultLen += cipher.processBlock(in, inOff, out, outOff + resultLen);
				len -= blockSize;
			}

		}
		System.arraycopy(in, inOff, buf, bufOff, len);
		bufOff += len;
		return resultLen;
	}

	public int doFinal(byte out[], int outOff)
		throws DataLengthException, IllegalStateException, InvalidCipherTextException
	{
		int blockSize = cipher.getBlockSize();
		int resultLen = 0;
		if (forEncryption)
		{
			if (bufOff == blockSize)
			{
				if (outOff + 2 * blockSize > out.length)
					throw new DataLengthException("output buffer too short");
				resultLen = cipher.processBlock(buf, 0, out, outOff);
				bufOff = 0;
			}
			byte code = (byte)(blockSize - bufOff);
			for (; bufOff < blockSize; bufOff++)
				buf[bufOff] = code;

			resultLen += cipher.processBlock(buf, 0, out, outOff + resultLen);
		} else
		{
			if (bufOff == blockSize)
			{
				resultLen = cipher.processBlock(buf, 0, buf, 0);
				bufOff = 0;
			} else
			{
				throw new DataLengthException("last block incomplete in decryption");
			}
			int count = buf[blockSize - 1] & 0xff;
			if (count < 0 || count > blockSize)
				throw new InvalidCipherTextException("pad block corrupted");
			resultLen -= count;
			System.arraycopy(buf, 0, out, outOff, resultLen);
		}
		reset();
		return resultLen;
	}
}