package org.bouncycastle.oldcrypto.macs;
/*
* Copyright (c) 2000 - 2004 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.
*
*/
//import org.bouncycastle.crypto.CipherParameters;
import java.security.DigestException;
import java.security.MessageDigest;
import java.util.Arrays;
import net.i2p.util.SimpleByteCache;
import org.bouncycastle.oldcrypto.Mac;
/**
* HMAC implementation based on RFC2104
*
* H(K XOR opad, H(K XOR ipad, text))
*
* modified by jrandom to use the session key byte array directly and to cache
* a frequently used buffer (called on doFinal). changes released into the public
* domain in 2005.
*
* This is renamed from HMac because the constructor HMac(digest, sz) does not exist
* in the standard bouncycastle library, thus it conflicts in JVMs that contain the
* standard library (Android).
*
* As of 0.9.12, refactored to use standard MessageDigest.
*
* Deprecated - Do not use outside of router or Syndie.
* To be moved to router.
*/
public class I2PHMac
implements Mac
{
private final static int BLOCK_LENGTH = 64;
private final static byte IPAD = (byte)0x36;
private final static byte OPAD = (byte)0x5C;
private final MessageDigest digest;
private final int digestSize;
private final byte[] inputPad = new byte[BLOCK_LENGTH];
private final byte[] outputPad = new byte[BLOCK_LENGTH];
/**
* Standard HMAC, size == digest size.
* @deprecated Use javax.crypto.Mac
*/
@Deprecated
public I2PHMac(MessageDigest digest) {
this(digest, digest.getDigestLength());
}
/**
* @param sz override the digest's size, nonstandard if different.
* SEE NOTES in HMACGenerator about why this isn't compatible with standard HmacMD5
*/
public I2PHMac(MessageDigest digest, int sz) {
this.digest = digest;
this.digestSize = sz;
}
public String getAlgorithmName()
{
return digest.getAlgorithm() + "/HMAC";
}
public MessageDigest getUnderlyingDigest()
{
return digest;
}
//public void init(
// CipherParameters params)
//{
public void init(byte key[])
{
digest.reset();
//byte[] key = ((KeyParameter)params).getKey();
if (key.length > BLOCK_LENGTH)
{
digest.update(key, 0, key.length);
try {
digest.digest(inputPad, 0, digestSize);
} catch (DigestException de) {
digest.reset();
throw new IllegalArgumentException(de);
}
for (int i = digestSize; i < inputPad.length; i++)
{
inputPad[i] = 0;
}
}
else
{
System.arraycopy(key, 0, inputPad, 0, key.length);
for (int i = key.length; i < inputPad.length; i++)
{
inputPad[i] = 0;
}
}
// why reallocate? it hasn't changed sizes, and the arraycopy
// below fills it completely...
//outputPad = new byte[inputPad.length];
System.arraycopy(inputPad, 0, outputPad, 0, inputPad.length);
for (int i = 0; i < inputPad.length; i++)
{
inputPad[i] ^= IPAD;
}
for (int i = 0; i < outputPad.length; i++)
{
outputPad[i] ^= OPAD;
}
digest.update(inputPad, 0, inputPad.length);
}
public int getMacSize() {
return digestSize;
}
public void update(byte in) {
digest.update(in);
}
public void update(byte[] in, int inOff, int len) {
digest.update(in, inOff, len);
}
public int doFinal(byte[] out, int outOff) {
byte[] tmp = acquireTmp(digestSize);
//byte[] tmp = new byte[digestSize];
try {
digest.digest(tmp, 0, digestSize);
digest.update(outputPad, 0, outputPad.length);
digest.update(tmp, 0, tmp.length);
return digest.digest(out, outOff, digestSize);
} catch (DigestException de) {
throw new IllegalArgumentException(de);
} finally {
releaseTmp(tmp);
reset();
}
}
private static byte[] acquireTmp(int sz) {
byte[] rv = SimpleByteCache.acquire(sz);
Arrays.fill(rv, (byte)0x0);
return rv;
}
private static void releaseTmp(byte buf[]) {
SimpleByteCache.release(buf);
}
/**
* Reset the mac generator.
*/
public void reset()
{
/*
* reset the underlying digest.
*/
digest.reset();
/*
* reinitialize the digest.
*/
digest.update(inputPad, 0, inputPad.length);
}
}