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/*************************************************
* Lion Source File *
* (C) 1999-2007 The Botan Project *
*************************************************/
#include <botan/lion.h>
#include <botan/lookup.h>
#include <botan/bit_ops.h>
#include <botan/parsing.h>
namespace Botan {
/*************************************************
* Lion Encryption *
*************************************************/
void Lion::enc(const byte in[], byte out[]) const
{
SecureVector<byte> buffer(LEFT_SIZE);
xor_buf(buffer, in, key1, LEFT_SIZE);
cipher->set_key(buffer, LEFT_SIZE);
cipher->encrypt(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
hash->update(out + LEFT_SIZE, RIGHT_SIZE);
hash->final(buffer);
xor_buf(out, in, buffer, LEFT_SIZE);
xor_buf(buffer, out, key2, LEFT_SIZE);
cipher->set_key(buffer, LEFT_SIZE);
cipher->encrypt(out + LEFT_SIZE, RIGHT_SIZE);
}
/*************************************************
* Lion Decryption *
*************************************************/
void Lion::dec(const byte in[], byte out[]) const
{
SecureVector<byte> buffer(LEFT_SIZE);
xor_buf(buffer, in, key2, LEFT_SIZE);
cipher->set_key(buffer, LEFT_SIZE);
cipher->encrypt(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
hash->update(out + LEFT_SIZE, RIGHT_SIZE);
hash->final(buffer);
xor_buf(out, in, buffer, LEFT_SIZE);
xor_buf(buffer, out, key1, LEFT_SIZE);
cipher->set_key(buffer, LEFT_SIZE);
cipher->encrypt(out + LEFT_SIZE, RIGHT_SIZE);
}
/*************************************************
* Lion Key Schedule *
*************************************************/
void Lion::key(const byte key[], u32bit length)
{
clear();
key1.copy(key, length / 2);
key2.copy(key + length / 2, length / 2);
}
/*************************************************
* Return the name of this type *
*************************************************/
std::string Lion::name() const
{
return "Lion(" + hash->name() + "," +
cipher->name() + "," +
to_string(BLOCK_SIZE) + ")";
}
/*************************************************
* Return a clone of this object *
*************************************************/
BlockCipher* Lion::clone() const
{
return new Lion(hash->name(), cipher->name(), BLOCK_SIZE);
}
/*************************************************
* Clear memory of sensitive data *
*************************************************/
void Lion::clear() throw()
{
hash->clear();
cipher->clear();
key1.clear();
key2.clear();
}
/*************************************************
* Lion Constructor *
*************************************************/
Lion::Lion(const std::string& hash_name, const std::string& sc_name,
u32bit block_len) :
BlockCipher(block_len, 2, 2*output_length_of(hash_name), 2),
LEFT_SIZE(output_length_of(hash_name)), RIGHT_SIZE(BLOCK_SIZE - LEFT_SIZE)
{
hash = get_hash(hash_name);
cipher = get_stream_cipher(sc_name);
if(2*LEFT_SIZE + 1 > BLOCK_SIZE)
throw Invalid_Argument(name() + ": Chosen block size is too small");
if(!cipher->valid_keylength(LEFT_SIZE))
throw Exception(name() + ": This stream/hash combination is invalid");
key1.create(LEFT_SIZE);
key2.create(LEFT_SIZE);
}
}
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