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/**
* Stream Cipher
* (C) 1999-2007 Jack Lloyd
*/
#ifndef BOTAN_STREAM_CIPHER_H__
#define BOTAN_STREAM_CIPHER_H__
#include <botan/exceptn.h>
#include <botan/symkey.h>
#include <botan/sym_algo.h>
namespace Botan {
/*************************************************
* Stream Cipher *
*************************************************/
class BOTAN_DLL StreamCipher : public SymmetricAlgorithm
{
public:
const u32bit IV_LENGTH;
/**
* Encrypt a message.
* @param i the plaintext
* @param o the byte array to hold the output, i.e. the ciphertext
* @param len the length of both i and o
*/
void encrypt(const byte i[], byte o[], u32bit len) { cipher(i, o, len); }
/**
* Decrypt a message.
* @param i the ciphertext to decrypt
* @param o the byte array to hold the output, i.e. the plaintext
* @param len the length of both i and o
*/
void decrypt(const byte i[], byte o[], u32bit len) { cipher(i, o, len); }
/**
* Encrypt a message.
* @param in the plaintext as input, after the function has
* returned it will hold the ciphertext
* @param len the length of in
*/
void encrypt(byte in[], u32bit len) { cipher(in, in, len); }
/**
* Decrypt a message.
* @param in the ciphertext as input, after the function has
* returned it will hold the plaintext
* @param len the length of in
*/
void decrypt(byte in[], u32bit len) { cipher(in, in, len); }
/**
* Resync the cipher using the IV
* @param iv the initialization vector
* @param iv_len the length of the IV in bytes
*/
virtual void resync(const byte iv[], u32bit iv_len);
/**
* Seek ahead in the stream.
* @param len the length to seek ahead.
*/
virtual void seek(u32bit len);
/**
* Get a new object representing the same algorithm as *this
*/
virtual StreamCipher* clone() const = 0;
/**
* Zeroize internal state
*/
virtual void clear() throw() = 0;
StreamCipher(u32bit key_min, u32bit key_max = 0,
u32bit key_mod = 1,
u32bit iv_len = 0) :
SymmetricAlgorithm(key_min, key_max, key_mod),
IV_LENGTH(iv_len) {}
virtual ~StreamCipher() {}
private:
virtual void cipher(const byte[], byte[], u32bit) = 0;
};
}
#endif
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