opensslpbeparametersgenerator.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:   OpenSSLPBEParametersGenerator.java

package org.bouncycastle.crypto.generators;

import org.bouncycastle.crypto.*;
import org.bouncycastle.crypto.digests.MD5Digest;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;

public class OpenSSLPBEParametersGenerator extends PBEParametersGenerator
{

	private Digest digest;

	public OpenSSLPBEParametersGenerator()
	{
		digest = new MD5Digest();
	}

	public void init(byte password[], byte salt[])
	{
		super.init(password, salt, 1);
	}

	private byte[] generateDerivedKey(int bytesNeeded)
	{
		byte buf[] = new byte[digest.getDigestSize()];
		byte key[] = new byte[bytesNeeded];
		int offset = 0;
		do
		{
			digest.update(password, 0, password.length);
			digest.update(salt, 0, salt.length);
			digest.doFinal(buf, 0);
			int len = bytesNeeded <= buf.length ? bytesNeeded : buf.length;
			System.arraycopy(buf, 0, key, offset, len);
			offset += len;
			bytesNeeded -= len;
			if (bytesNeeded != 0)
			{
				digest.reset();
				digest.update(buf, 0, buf.length);
			} else
			{
				return key;
			}
		} while (true);
	}

	public CipherParameters generateDerivedParameters(int keySize)
	{
		keySize /= 8;
		byte dKey[] = generateDerivedKey(keySize);
		return new KeyParameter(dKey, 0, keySize);
	}

	public CipherParameters generateDerivedParameters(int keySize, int ivSize)
	{
		keySize /= 8;
		ivSize /= 8;
		byte dKey[] = generateDerivedKey(keySize + ivSize);
		return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize);
	}

	public CipherParameters generateDerivedMacParameters(int keySize)
	{
		return generateDerivedParameters(keySize);
	}
}