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/*
* ANSI X9.19 MAC
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/x919_mac.h>
#include <botan/internal/xor_buf.h>
#include <algorithm>
namespace Botan {
/*
* Update an ANSI X9.19 MAC Calculation
*/
void ANSI_X919_MAC::add_data(const byte input[], size_t length)
{
size_t xored = std::min(8 - position, length);
xor_buf(&state[position], input, xored);
position += xored;
if(position < 8) return;
e->encrypt(state);
input += xored;
length -= xored;
while(length >= 8)
{
xor_buf(state, input, 8);
e->encrypt(state);
input += 8;
length -= 8;
}
xor_buf(state, input, length);
position = length;
}
/*
* Finalize an ANSI X9.19 MAC Calculation
*/
void ANSI_X919_MAC::final_result(byte mac[])
{
if(position)
e->encrypt(state);
d->decrypt(state, mac);
e->encrypt(mac);
zeroise(state);
position = 0;
}
/*
* ANSI X9.19 MAC Key Schedule
*/
void ANSI_X919_MAC::key_schedule(const byte key[], u32bit length)
{
e->set_key(key, 8);
if(length == 8) d->set_key(key, 8);
else d->set_key(key + 8, 8);
}
/*
* Clear memory of sensitive data
*/
void ANSI_X919_MAC::clear()
{
e->clear();
d->clear();
zeroise(state);
position = 0;
}
std::string ANSI_X919_MAC::name() const
{
return "X9.19-MAC";
}
MessageAuthenticationCode* ANSI_X919_MAC::clone() const
{
return new ANSI_X919_MAC(e->clone());
}
/*
* ANSI X9.19 MAC Constructor
*/
ANSI_X919_MAC::ANSI_X919_MAC(BlockCipher* e_in) :
MessageAuthenticationCode(e_in->BLOCK_SIZE,
e_in->MINIMUM_KEYLENGTH,
2*e_in->MAXIMUM_KEYLENGTH,
2*e_in->KEYLENGTH_MULTIPLE),
e(e_in), d(e->clone()), state(e->BLOCK_SIZE), position(0)
{
if(e->name() != "DES")
throw Invalid_Argument("ANSI X9.19 MAC only supports DES");
}
/*
* ANSI X9.19 MAC Destructor
le*/
ANSI_X919_MAC::~ANSI_X919_MAC()
{
delete e;
delete d;
}
}
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