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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.
*/
class BOTAN_DLL BlockCipher : public SymmetricAlgorithm
{
public:
/**
* BlockCipher constructor
* @param block_size the size of blocks this cipher processes
* @param key_min the minimum key size
* @param key_max the maximum key size
* @param key_mod the modulo restriction on the key size
*/
BlockCipher(size_t key_min,
size_t key_max = 0,
size_t key_mod = 1) :
SymmetricAlgorithm(key_min, key_max, key_mod) {}
virtual ~BlockCipher() {}
/**
* @return block size of this algorithm
*/
virtual size_t block_size() const = 0;
/**
* @return native parallelism of this cipher in blocks
*/
virtual size_t parallelism() const { return 1; }
/**
* @return prefererred parallelism of this cipher in bytes
*/
size_t parallel_bytes() const
{
return parallelism() * block_size() * BOTAN_BLOCK_CIPHER_PAR_MULT;
}
/**
* 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 block the plaintext block to be encrypted
* 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 block the ciphertext block to be decrypted
* 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); }
/**
* Encrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
* @param blocks the number of blocks to process
*/
virtual void encrypt_n(const byte in[], byte out[],
size_t blocks) const = 0;
/**
* Decrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
* @param blocks the number of blocks to process
*/
virtual void decrypt_n(const byte in[], byte out[],
size_t blocks) const = 0;
/**
* Get a new object representing the same algorithm as *this
*/
virtual BlockCipher* clone() const = 0;
/**
* Zeroize internal state
*/
virtual void clear() = 0;
};
/**
* Represents a block cipher with a single fixed block size
*/
template<size_t BS, size_t KMIN, size_t KMAX = 0, size_t KMOD = 1>
class Block_Cipher_Fixed_Params : public BlockCipher
{
public:
Block_Cipher_Fixed_Params() : BlockCipher(KMIN, KMAX, KMOD) {}
enum { BLOCK_SIZE = BS };
size_t block_size() const { return BS; }
};
}
#endif
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