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/*
* Lion
* (C) 1999-2007,2014 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_LION_H_
#define BOTAN_LION_H_
#include <botan/block_cipher.h>
#include <botan/stream_cipher.h>
#include <botan/hash.h>
namespace Botan {
/**
* Lion is a block cipher construction designed by Ross Anderson and
* Eli Biham, described in "Two Practical and Provably Secure Block
* Ciphers: BEAR and LION". It has a variable block size and is
* designed to encrypt very large blocks (up to a megabyte)
* https://www.cl.cam.ac.uk/~rja14/Papers/bear-lion.pdf
*/
class Lion final : public BlockCipher
{
public:
void encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
void decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
size_t block_size() const override { return m_block_size; }
Key_Length_Specification key_spec() const override
{
return Key_Length_Specification(2, 2*m_hash->output_length(), 2);
}
void clear() override;
std::string name() const override;
std::unique_ptr<BlockCipher> new_object() const override;
/**
* @param hash the hash to use internally
* @param cipher the stream cipher to use internally
* @param block_size the size of the block to use
*/
Lion(std::unique_ptr<HashFunction> hash,
std::unique_ptr<StreamCipher> cipher,
size_t block_size);
private:
void key_schedule(const uint8_t[], size_t) override;
size_t left_size() const { return m_hash->output_length(); }
size_t right_size() const { return m_block_size - left_size(); }
const size_t m_block_size;
std::unique_ptr<HashFunction> m_hash;
std::unique_ptr<StreamCipher> m_cipher;
secure_vector<uint8_t> m_key1, m_key2;
};
}
#endif
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