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/*
* OFB Mode
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_OUTPUT_FEEDBACK_MODE_H__
#define BOTAN_OUTPUT_FEEDBACK_MODE_H__
#include <botan/stream_cipher.h>
#include <botan/block_cipher.h>
namespace Botan {
/**
* Output Feedback Mode
*/
class BOTAN_DLL OFB : public StreamCipher
{
public:
void cipher(const byte in[], byte out[], u32bit length);
void set_iv(const byte iv[], u32bit iv_len);
bool valid_iv_length(u32bit iv_len) const
{ return (iv_len <= permutation->BLOCK_SIZE); }
std::string name() const;
OFB* clone() const
{ return new OFB(permutation->clone()); }
void clear();
/**
* @param cipher the underlying block cipher to use
*/
OFB(BlockCipher* cipher);
~OFB();
private:
void key_schedule(const byte key[], u32bit key_len);
BlockCipher* permutation;
SecureVector<byte> buffer;
u32bit position;
};
}
#endif
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