package gnu.crypto.cipher;
// ----------------------------------------------------------------------------
// $Id: IBlockCipher.java,v 1.8 2005/10/06 04:24:14 rsdio Exp $
//
// Copyright (C) 2001, 2002, Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// GNU Crypto is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING. If not, write to the
//
// Free Software Foundation Inc.,
// 51 Franklin Street, Fifth Floor,
// Boston, MA 02110-1301
// USA
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library. Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
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// not derived from or based on this library. If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so. If you do not wish to
// do so, delete this exception statement from your version.
// ----------------------------------------------------------------------------
import java.security.InvalidKeyException;
import java.util.Iterator;
import java.util.Map;
/**
* <p>The basic visible methods of any symmetric key block cipher.</p>
*
* <p>A symmetric key block cipher is a function that maps n-bit plaintext
* blocks to n-bit ciphertext blocks; n being the cipher's <i>block size</i>.
* This encryption function is parameterised by a k-bit key, and is invertible.
* Its inverse is the decryption function.</p>
*
* <p>Possible initialisation values for an instance of this type are:</p>
*
* <ul>
* <li>The block size in which to operate this block cipher instance. This
* value is <b>optional</b>, if unspecified, the block cipher's default
* block size shall be used.</li>
*
* <li>The byte array containing the user supplied key material to use for
* generating the cipher's session key(s). This value is <b>mandatory</b>
* and should be included in the initialisation parameters. If it isn't,
* an {@link IllegalStateException} will be thrown if any method, other than
* <code>reset()</code> is invoked on the instance. Furthermore, the size of
* this key material shall be taken as an indication on the key size in which
* to operate this instance.</li>
* </ul>
*
* <p><b>IMPLEMENTATION NOTE</b>: Although all the concrete classes in this
* package implement the {@link Cloneable} interface, it is important to note
* here that such an operation <b>DOES NOT</b> clone any session key material
* that may have been used in initialising the source cipher (the instance to be
* cloned). Instead a clone of an already initialised cipher is another instance
* that operates with the <b>same block size</b> but without any knowledge of
* neither key material nor key size.</p>
*
* @version $Revision: 1.8 $
*/
public interface IBlockCipher extends Cloneable {
// Constants
// -------------------------------------------------------------------------
/**
* <p>Property name of the block size in which to operate a block cipher.
* The value associated with this property name is taken to be an
* {@link Integer}.</p>
*/
String CIPHER_BLOCK_SIZE = "gnu.crypto.cipher.block.size";
/**
* <p>Property name of the user-supplied key material. The value associated
* to this property name is taken to be a byte array.</p>
*/
String KEY_MATERIAL = "gnu.crypto.cipher.key.material";
// Methods
// -------------------------------------------------------------------------
/**
* <p>Returns the canonical name of this instance.</p>
*
* @return the canonical name of this instance.
*/
String name();
/**
* <p>Returns the default value, in bytes, of the algorithm's block size.</p>
*
* @return the default value, in bytes, of the algorithm's block size.
*/
int defaultBlockSize();
/**
* <p>Returns the default value, in bytes, of the algorithm's key size.</p>
*
* @return the default value, in bytes, of the algorithm's key size.
*/
int defaultKeySize();
/**
* <p>Returns an {@link Iterator} over the supported block sizes. Each
* element returned by this object is an {@link Integer}.</p>
*
* @return an {@link Iterator} over the supported block sizes.
*/
Iterator blockSizes();
/**
* <p>Returns an {@link Iterator} over the supported key sizes. Each element
* returned by this object is an {@link Integer}.</p>
*
* @return an {@link Iterator} over the supported key sizes.
*/
Iterator keySizes();
/**
* <p>Returns a clone of this instance.</p>
*
* @return a clone copy of this instance.
*/
Object clone();
/**
* <p>Initialises the algorithm with designated attributes. Permissible names
* and values are described in the class documentation above.</p>
*
* @param attributes a set of name-value pairs that describes the desired
* future behaviour of this instance.
* @exception InvalidKeyException if the key data is invalid.
* @exception IllegalStateException if the instance is already initialised.
* @see #KEY_MATERIAL
* @see #CIPHER_BLOCK_SIZE
*/
void init(Map attributes)
throws InvalidKeyException, IllegalStateException;
/**
* <p>Returns the currently set block size for this instance.</p>
*
* @return the current block size for this instance.
* @exception IllegalStateException if the instance is not initialised.
*/
int currentBlockSize() throws IllegalStateException;
/**
* <p>Resets the algorithm instance for re-initialisation and use with other
* characteristics. This method always succeeds.</p>
*/
void reset();
/**
* <p>Encrypts exactly one block of plaintext.</p>
*
* @param in the plaintext.
* @param inOffset index of <code>in</code> from which to start considering
* data.
* @param out the ciphertext.
* @param outOffset index of <code>out</code> from which to store result.
* @exception IllegalStateException if the instance is not initialised.
*/
void encryptBlock(byte[] in, int inOffset, byte[] out, int outOffset)
throws IllegalStateException;
/**
* <p>Decrypts exactly one block of ciphertext.</p>
*
* @param in the plaintext.
* @param inOffset index of <code>in</code> from which to start considering
* data.
* @param out the ciphertext.
* @param outOffset index of <code>out</code> from which to store result.
* @exception IllegalStateException if the instance is not initialised.
*/
void decryptBlock(byte[] in, int inOffset, byte[] out, int outOffset)
throws IllegalStateException;
/**
* <p>A <i>correctness</i> test that consists of basic symmetric encryption /
* decryption test(s) for all supported block and key sizes, as well as one
* (1) variable key Known Answer Test (KAT).</p>
*
* @return <code>true</code> if the implementation passes simple
* <i>correctness</i> tests. Returns <code>false</code> otherwise.
*/
boolean selfTest();
}