package org.bouncycastle.tls.crypto.impl;
import java.io.IOException;
/**
* Interface for block cipher services.
*/
public interface TlsBlockCipherImpl
{
/**
* Set the key to be used by the block cipher implementation supporting this service.
*
* @param key the block cipher key.
*/
void setKey(byte[] key) throws IOException;
/**
* Initialise the parameters for operator.
*
* @param iv the initialization vector.
* @throws IOException if the parameters are inappropriate.
*/
void init(byte[] iv) throws IOException;
/**
* Perform the cipher encryption/decryption returning the output in output.
* <p>
* Note: we have to use doFinal() here as it is the only way to guarantee output from the underlying cipher.
* </p>
* @param input array holding input data to the cipher.
* @param inputOffset offset into input array data starts at.
* @param inputLength length of the input data in the array.
* @param output array to hold the cipher output.
* @param outputOffset offset into output array to start saving output.
* @return the amount of data written to output.
* @throws IOException in case of failure.
*/
int doFinal(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset) throws IOException;
/**
* Return the blocksize (in bytes) of the underlying block cipher.
*
* @return the cipher's blocksize.
*/
int getBlockSize();
}