package org.bouncycastle.crypto.tls;
import java.io.ByteArrayOutputStream;
import org.bouncycastle.crypto.Digest;
/**
* Buffers input until the hash algorithm is determined.
*/
class DeferredHash
implements TlsHandshakeHash
{
protected TlsContext context;
private ByteArrayOutputStream buf = new ByteArrayOutputStream();
private int prfAlgorithm = -1;
private Digest hash = null;
DeferredHash()
{
this.buf = new ByteArrayOutputStream();
this.hash = null;
}
private DeferredHash(Digest hash)
{
this.buf = null;
this.hash = hash;
}
public void init(TlsContext context)
{
this.context = context;
}
public TlsHandshakeHash commit()
{
int prfAlgorithm = context.getSecurityParameters().getPrfAlgorithm();
Digest prfHash = TlsUtils.createPRFHash(prfAlgorithm);
byte[] data = buf.toByteArray();
prfHash.update(data, 0, data.length);
if (prfHash instanceof TlsHandshakeHash)
{
TlsHandshakeHash tlsPRFHash = (TlsHandshakeHash)prfHash;
tlsPRFHash.init(context);
return tlsPRFHash.commit();
}
this.prfAlgorithm = prfAlgorithm;
this.hash = prfHash;
this.buf = null;
return this;
}
public TlsHandshakeHash fork()
{
checkHash();
return new DeferredHash(TlsUtils.clonePRFHash(prfAlgorithm, hash));
}
public String getAlgorithmName()
{
checkHash();
return hash.getAlgorithmName();
}
public int getDigestSize()
{
checkHash();
return hash.getDigestSize();
}
public void update(byte input)
{
if (hash == null)
{
buf.write(input);
}
else
{
hash.update(input);
}
}
public void update(byte[] input, int inOff, int len)
{
if (hash == null)
{
buf.write(input, inOff, len);
}
else
{
hash.update(input, inOff, len);
}
}
public int doFinal(byte[] output, int outOff)
{
checkHash();
return hash.doFinal(output, outOff);
}
public void reset()
{
if (hash == null)
{
buf.reset();
}
else
{
hash.reset();
}
}
protected void checkHash()
{
if (hash == null)
{
throw new IllegalStateException("No hash algorithm has been set");
}
}
}