package org.bouncycastle.crypto.modes;

import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.InvalidCipherTextException;

A block cipher mode that includes authenticated encryption with a streaming mode and optional associated data.
 Implementations of this interface may operate in a packet mode (where all input data is buffered and processed dugin the call to doFinal(byte[], int)), or in a streaming mode (where output data is incrementally produced with each call to processByte(byte, byte[], int) or processBytes(byte[], int, int, byte[], int). 
 This is important to consider during decryption: in a streaming mode, unauthenticated plaintext data may be output prior to the call to doFinal(byte[], int) that results in an authentication failure. The higher level protocol utilising this cipher must ensure the plaintext data is handled appropriately until the end of data is reached and the entire ciphertext is authenticated. 
See Also:
AEADParameters/**
 * A block cipher mode that includes authenticated encryption with a streaming mode and optional associated data.
 * <p>
 * Implementations of this interface may operate in a packet mode (where all input data is buffered and 
 * processed dugin the call to {@link #doFinal(byte[], int)}), or in a streaming mode (where output data is
 * incrementally produced with each call to {@link #processByte(byte, byte[], int)} or 
 * {@link #processBytes(byte[], int, int, byte[], int)}.
 * </p>
 * This is important to consider during decryption: in a streaming mode, unauthenticated plaintext data
 * may be output prior to the call to {@link #doFinal(byte[], int)} that results in an authentication
 * failure. The higher level protocol utilising this cipher must ensure the plaintext data is handled 
 * appropriately until the end of data is reached and the entire ciphertext is authenticated.
 * @see org.bouncycastle.crypto.params.AEADParameters
 */
public interface AEADBlockCipher
{
    
initialise the underlying cipher. Parameter can either be an AEADParameters or a ParametersWithIV object.
Params:
forEncryption – true if we are setting up for encryption, false otherwise.
params – the necessary parameters for the underlying cipher to be initialised.
Throws:
IllegalArgumentException – if the params argument is inappropriate./**
     * initialise the underlying cipher. Parameter can either be an AEADParameters or a ParametersWithIV object.
     *
     * @param forEncryption true if we are setting up for encryption, false otherwise.
     * @param params the necessary parameters for the underlying cipher to be initialised.
     * @exception IllegalArgumentException if the params argument is inappropriate.
     */
    public void init(boolean forEncryption, CipherParameters params)
        throws IllegalArgumentException;

    
Return the name of the algorithm.
Returns:
the algorithm name./**
     * Return the name of the algorithm.
     * 
     * @return the algorithm name.
     */
    public String getAlgorithmName();

    
return the cipher this object wraps.
Returns:
the cipher this object wraps./**
     * return the cipher this object wraps.
     *
     * @return the cipher this object wraps.
     */
    public BlockCipher getUnderlyingCipher();

    
Add a single byte to the associated data check.

If the implementation supports it, this will be an online operation and will not retain the associated data.
Params:
in – the byte to be processed./**
     * Add a single byte to the associated data check.
     * <br>If the implementation supports it, this will be an online operation and will not retain the associated data.
     *
     * @param in the byte to be processed.
     */
    public void processAADByte(byte in);

    
Add a sequence of bytes to the associated data check.

If the implementation supports it, this will be an online operation and will not retain the associated data.
Params:
in – the input byte array.
inOff – the offset into the in array where the data to be processed starts.
len – the number of bytes to be processed./**
     * Add a sequence of bytes to the associated data check.
     * <br>If the implementation supports it, this will be an online operation and will not retain the associated data.
     *
     * @param in the input byte array.
     * @param inOff the offset into the in array where the data to be processed starts.
     * @param len the number of bytes to be processed.
     */
    public void processAADBytes(byte[] in, int inOff, int len);

    
encrypt/decrypt a single byte.
Params:
in – the byte to be processed.
out – the output buffer the processed byte goes into.
outOff – the offset into the output byte array the processed data starts at.
Throws:
DataLengthException – if the output buffer is too small.
Returns:
the number of bytes written to out./**
     * encrypt/decrypt a single byte.
     *
     * @param in the byte to be processed.
     * @param out the output buffer the processed byte goes into.
     * @param outOff the offset into the output byte array the processed data starts at.
     * @return the number of bytes written to out.
     * @exception DataLengthException if the output buffer is too small.
     */
    public int processByte(byte in, byte[] out, int outOff)
        throws DataLengthException;

    
process a block of bytes from in putting the result into out.
Params:
in – the input byte array.
inOff – the offset into the in array where the data to be processed starts.
len – the number of bytes to be processed.
out – the output buffer the processed bytes go into.
outOff – the offset into the output byte array the processed data starts at.
Throws:
DataLengthException – if the output buffer is too small.
Returns:
the number of bytes written to out./**
     * process a block of bytes from in putting the result into out.
     *
     * @param in the input byte array.
     * @param inOff the offset into the in array where the data to be processed starts.
     * @param len the number of bytes to be processed.
     * @param out the output buffer the processed bytes go into.
     * @param outOff the offset into the output byte array the processed data starts at.
     * @return the number of bytes written to out.
     * @exception DataLengthException if the output buffer is too small.
     */
    public int processBytes(byte[] in, int inOff, int len, byte[] out, int outOff)
        throws DataLengthException;

    
Finish the operation either appending or verifying the MAC at the end of the data.
Params:
out – space for any resulting output data.
outOff – offset into out to start copying the data at.
Throws:
IllegalStateException – if the cipher is in an inappropriate state.
InvalidCipherTextException – if the MAC fails to match.
Returns:
number of bytes written into out./**
     * Finish the operation either appending or verifying the MAC at the end of the data.
     *
     * @param out space for any resulting output data.
     * @param outOff offset into out to start copying the data at.
     * @return number of bytes written into out.
     * @throws IllegalStateException if the cipher is in an inappropriate state.
     * @throws org.bouncycastle.crypto.InvalidCipherTextException if the MAC fails to match.
     */
    public int doFinal(byte[] out, int outOff)
        throws IllegalStateException, InvalidCipherTextException;

    
Return the value of the MAC associated with the last stream processed.
Returns:
MAC for plaintext data./**
     * Return the value of the MAC associated with the last stream processed.
     *
     * @return MAC for plaintext data.
     */
    public byte[] getMac();

    
return the size of the output buffer required for a processBytes
an input of len bytes.

The returned size may be dependent on the initialisation of this cipher
and may not be accurate once subsequent input data is processed - this method
should be invoked immediately prior to input data being processed.

Params:
len – the length of the input.
Returns:
the space required to accommodate a call to processBytes
with len bytes of input./**
     * return the size of the output buffer required for a processBytes
     * an input of len bytes.
     * <p>
     * The returned size may be dependent on the initialisation of this cipher
     * and may not be accurate once subsequent input data is processed - this method
     * should be invoked immediately prior to input data being processed.
     * </p>
     *
     * @param len the length of the input.
     * @return the space required to accommodate a call to processBytes
     * with len bytes of input.
     */
    public int getUpdateOutputSize(int len);

    
return the size of the output buffer required for a processBytes plus a
doFinal with an input of len bytes.
 The returned size may be dependent on the initialisation of this cipher and may not be accurate once subsequent input data is processed - this method should be invoked immediately prior to a call to final processing of input data and a call to doFinal(byte[], int). 
Params:
len – the length of the input.
Returns:
the space required to accommodate a call to processBytes and doFinal
with len bytes of input./**
     * return the size of the output buffer required for a processBytes plus a
     * doFinal with an input of len bytes.
     * <p>
     * The returned size may be dependent on the initialisation of this cipher
     * and may not be accurate once subsequent input data is processed - this method
     * should be invoked immediately prior to a call to final processing of input data
     * and a call to {@link #doFinal(byte[], int)}.
     * </p>
     * @param len the length of the input.
     * @return the space required to accommodate a call to processBytes and doFinal
     * with len bytes of input.
     */
    public int getOutputSize(int len);

    
Reset the cipher. After resetting the cipher is in the same state
as it was after the last init (if there was one).
/**
     * Reset the cipher. After resetting the cipher is in the same state
     * as it was after the last init (if there was one).
     */
    public void reset();
}