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/*
* CTR-BE Mode
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_CTR_BE_H__
#define BOTAN_CTR_BE_H__
#include <botan/block_cipher.h>
#include <botan/stream_cipher.h>
namespace Botan {
/**
* CTR-BE (Counter mode, big-endian)
*/
class BOTAN_DLL CTR_BE : public StreamCipher
{
public:
void cipher(const byte in[], byte out[], size_t length);
void set_iv(const byte iv[], size_t iv_len);
bool valid_iv_length(size_t iv_len) const
{ return (iv_len <= permutation->block_size()); }
Key_Length_Specification key_spec() const
{
return permutation->key_spec();
}
std::string name() const;
CTR_BE* clone() const
{ return new CTR_BE(permutation->clone()); }
void clear();
/**
* @param cipher the underlying block cipher to use
*/
CTR_BE(BlockCipher* cipher);
~CTR_BE();
private:
void key_schedule(const byte key[], size_t key_len);
void increment_counter();
BlockCipher* permutation;
secure_vector<byte> counter, buffer;
size_t position;
};
}
#endif
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