lion.cpp

Go to the documentation of this file.

/*
* Lion
* (C) 1999-2007,2014 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/internal/lion.h>
#include <botan/internal/fmt.h>
#include <botan/exceptn.h>
 
namespace Botan {
 
/*
* Lion Encryption
*/
void Lion::encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const
   {
   assert_key_material_set();
 
   const size_t LEFT_SIZE = left_size();
   const size_t RIGHT_SIZE = right_size();
 
   secure_vector<uint8_t> buffer_vec(LEFT_SIZE);
   uint8_t* buffer = buffer_vec.data();
 
   for(size_t i = 0; i != blocks; ++i)
      {
      xor_buf(buffer, in, m_key1.data(), LEFT_SIZE);
      m_cipher->set_key(buffer, LEFT_SIZE);
      m_cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
 
      m_hash->update(out + LEFT_SIZE, RIGHT_SIZE);
      m_hash->final(buffer);
      xor_buf(out, in, buffer, LEFT_SIZE);
 
      xor_buf(buffer, out, m_key2.data(), LEFT_SIZE);
      m_cipher->set_key(buffer, LEFT_SIZE);
      m_cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
 
      in += m_block_size;
      out += m_block_size;
      }
   }
 
/*
* Lion Decryption
*/
void Lion::decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const
   {
   assert_key_material_set();
 
   const size_t LEFT_SIZE = left_size();
   const size_t RIGHT_SIZE = right_size();
 
   secure_vector<uint8_t> buffer_vec(LEFT_SIZE);
   uint8_t* buffer = buffer_vec.data();
 
   for(size_t i = 0; i != blocks; ++i)
      {
      xor_buf(buffer, in, m_key2.data(), LEFT_SIZE);
      m_cipher->set_key(buffer, LEFT_SIZE);
      m_cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
 
      m_hash->update(out + LEFT_SIZE, RIGHT_SIZE);
      m_hash->final(buffer);
      xor_buf(out, in, buffer, LEFT_SIZE);
 
      xor_buf(buffer, out, m_key1.data(), LEFT_SIZE);
      m_cipher->set_key(buffer, LEFT_SIZE);
      m_cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
 
      in += m_block_size;
      out += m_block_size;
      }
   }
 
bool Lion::has_keying_material() const
   {
   return !m_key1.empty() && !m_key2.empty();
   }
 
/*
* Lion Key Schedule
*/
void Lion::key_schedule(const uint8_t key[], size_t length)
   {
   clear();
 
   const size_t half = length / 2;
 
   m_key1.resize(left_size());
   m_key2.resize(left_size());
   clear_mem(m_key1.data(), m_key1.size());
   clear_mem(m_key2.data(), m_key2.size());
   copy_mem(m_key1.data(), key, half);
   copy_mem(m_key2.data(), key + half, half);
   }
 
/*
* Return the name of this type
*/
std::string Lion::name() const
   {
   return fmt("Lion({},{},{})", m_hash->name(), m_cipher->name(), block_size());
   }
 
std::unique_ptr<BlockCipher> Lion::new_object() const
   {
   return std::make_unique<Lion>(m_hash->new_object(), m_cipher->new_object(), block_size());
   }
 
/*
* Clear memory of sensitive data
*/
void Lion::clear()
   {
   zap(m_key1);
   zap(m_key2);
   m_hash->clear();
   m_cipher->clear();
   }
 
/*
* Lion Constructor
*/
Lion::Lion(std::unique_ptr<HashFunction> hash,
           std::unique_ptr<StreamCipher> cipher,
           size_t bs) :
   m_block_size(std::max<size_t>(2*hash->output_length() + 1, bs)),
   m_hash(std::move(hash)),
   m_cipher(std::move(cipher))
   {
   if(2*left_size() + 1 > m_block_size)
      {
      throw Invalid_Argument(fmt("Block size {} is too small for {}", m_block_size, name()));
      }
 
   if(!m_cipher->valid_keylength(left_size()))
      {
      throw Invalid_Argument(fmt("Lion does not support combining {} and {}",
                                 m_cipher->name(), m_hash->name()));
      }
   }
 
}