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/**
* Block Cipher Base Class
* (C) 1999-2009 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_BLOCK_CIPHER_H__
#define BOTAN_BLOCK_CIPHER_H__
#include <botan/sym_algo.h>
namespace Botan {
/**
* This class represents a block cipher object.
*
* It would be very useful to extend this interface to support the
* encryption of multiple blocks at a time. This could help
* performance, wrt cache effects in the software implementations, and
* could be a big deal when supporting block ciphers implemented as
* hardware devices. It could be used by implementations of ECB, and
* more importantly counter mode (which most designs are moving to, due
* to the parallelism possible in counter mode which is not the case
* with feedback-based modes like CBC).
*
* Probable future API here:
* virtual void encrypt_n(const byte in[], byte out[],
* u32bit blocks) const = 0;
* virtual void decrypt_n(const byte in[], byte out[],
* u32bit blocks) const = 0;
*/
class BOTAN_DLL BlockCipher : public SymmetricAlgorithm
{
public:
/**
* The block size of this algorithm.
*/
const u32bit BLOCK_SIZE;
/**
* Encrypt a block.
* @param in The plaintext block to be encrypted as a byte array.
* Must be of length BLOCK_SIZE.
* @param out The byte array designated to hold the encrypted block.
* Must be of length BLOCK_SIZE.
*/
void encrypt(const byte in[], byte out[]) const
{ encrypt_n(in, out, 1); }
/**
* Decrypt a block.
* @param in The ciphertext block to be decypted as a byte array.
* Must be of length BLOCK_SIZE.
* @param out The byte array designated to hold the decrypted block.
* Must be of length BLOCK_SIZE.
*/
void decrypt(const byte in[], byte out[]) const
{ decrypt_n(in, out, 1); }
/**
* Encrypt a block.
* @param in The plaintext block to be encrypted as a byte array.
* Must be of length BLOCK_SIZE. Will hold the result when the function
* has finished.
*/
void encrypt(byte block[]) const { encrypt_n(block, block, 1); }
/**
* Decrypt a block.
* @param in The ciphertext block to be decrypted as a byte array.
* Must be of length BLOCK_SIZE. Will hold the result when the function
* has finished.
*/
void decrypt(byte block[]) const { decrypt_n(block, block, 1); }
virtual void encrypt_n(const byte in[], byte out[],
u32bit blocks) const = 0;
virtual void decrypt_n(const byte in[], byte out[],
u32bit blocks) const = 0;
/**
* Get a new object representing the same algorithm as *this
*/
virtual BlockCipher* clone() const = 0;
/**
* Zeroize internal state
*/
virtual void clear() throw() = 0;
BlockCipher(u32bit block_size,
u32bit key_min,
u32bit key_max = 0,
u32bit key_mod = 1) :
SymmetricAlgorithm(key_min, key_max, key_mod),
BLOCK_SIZE(block_size) {}
virtual ~BlockCipher() {}
};
}
#endif
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