package org.bouncycastle.tls.crypto.impl.jcajce;
import java.security.InvalidKeyException;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.tls.crypto.TlsHMAC;
/**
* Wrapper class for a JCE MAC based on HMAC to provide the necessary operations for TLS.
*/
public class JceTlsHMAC
implements TlsHMAC
{
private static final Map<String, Integer> internalBlockSizes = new HashMap<String, Integer>();
static
{
internalBlockSizes.put("HmacMD5", 64);
internalBlockSizes.put("HmacSHA1", 64);
internalBlockSizes.put("HmacSHA256", 64);
internalBlockSizes.put("HmacSHA384", 128);
internalBlockSizes.put("HmacSHA512", 128);
}
private final Mac hmac;
private final String algorithm;
private final Integer internalBlockSize;
/**
* Base constructor.
*
* @param hmac MAC implementation.
* @param algorithm algorithm name to use for keys and to get the internal block size.
*/
public JceTlsHMAC(Mac hmac, String algorithm)
{
this(hmac, algorithm, getInternalBlockSize(algorithm));
}
private static int getInternalBlockSize(String algorithm)
{
if (!internalBlockSizes.containsKey(algorithm))
{
throw new IllegalArgumentException("HMAC " + algorithm + " unknown");
}
return internalBlockSizes.get(algorithm);
}
/**
* Base constructor specifying the internal block size.
*
* @param hmac MAC implementation.
* @param algorithm algorithm name to use for keys and to get the internal block size.
* @param internalBlockSize internal block size of the message digest underlying the HMAC.
*/
public JceTlsHMAC(Mac hmac, String algorithm, int internalBlockSize)
{
this.hmac = hmac;
this.algorithm = algorithm;
this.internalBlockSize = internalBlockSize;
}
public void setKey(byte[] key)
{
try
{
hmac.init(new SecretKeySpec(key, algorithm));
}
catch (InvalidKeyException e)
{
e.printStackTrace();
}
}
public void update(byte[] input, int inOff, int length)
{
hmac.update(input, inOff, length);
}
public byte[] calculateMAC()
{
return hmac.doFinal();
}
public int getInternalBlockSize()
{
return internalBlockSize;
}
public int getMacLength()
{
return hmac.getMacLength();
}
public void reset()
{
hmac.reset();
}
}