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/*
* EAX Mode
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_EAX_H__
#define BOTAN_EAX_H__
#include <botan/basefilt.h>
#include <botan/block_cipher.h>
#include <botan/mac.h>
namespace Botan {
/*
* EAX Base Class
*/
class BOTAN_DLL EAX_Base : public Keyed_Filter
{
public:
void set_key(const SymmetricKey&);
void set_iv(const InitializationVector&);
void set_header(const byte[], u32bit);
std::string name() const;
bool valid_keylength(u32bit) const;
~EAX_Base() { delete cipher; delete mac; }
protected:
EAX_Base(BlockCipher*, u32bit);
void start_msg();
void increment_counter();
const u32bit TAG_SIZE, BLOCK_SIZE;
BlockCipher* cipher;
MessageAuthenticationCode* mac;
SecureVector<byte> nonce_mac, header_mac, state, buffer;
u32bit position;
};
/*
* EAX Encryption
*/
class BOTAN_DLL EAX_Encryption : public EAX_Base
{
public:
EAX_Encryption(BlockCipher* ciph, u32bit tag_size = 0) :
EAX_Base(ciph, tag_size) {}
EAX_Encryption(BlockCipher* ciph, const SymmetricKey& key,
const InitializationVector& iv,
u32bit tag_size) : EAX_Base(ciph, tag_size)
{
set_key(key);
set_iv(iv);
}
private:
void write(const byte[], u32bit);
void end_msg();
};
/*
* EAX Decryption
*/
class BOTAN_DLL EAX_Decryption : public EAX_Base
{
public:
EAX_Decryption(BlockCipher* ciph, u32bit tag_size = 0);
EAX_Decryption(BlockCipher* ciph, const SymmetricKey& key,
const InitializationVector& iv,
u32bit tag_size = 0);
private:
void write(const byte[], u32bit);
void do_write(const byte[], u32bit);
void end_msg();
SecureVector<byte> queue;
u32bit queue_start, queue_end;
};
}
#endif
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