Modified source engine (2017) developed by valve and leaked in 2020. Not for commercial purporses
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// eax.h - written and placed in the public domain by Wei Dai
//! \file
//! \headerfile eax.h
//! \brief EAX block cipher mode of operation
#ifndef CRYPTOPP_EAX_H
#define CRYPTOPP_EAX_H
#include "authenc.h"
#include "modes.h"
#include "cmac.h"
NAMESPACE_BEGIN(CryptoPP)
//! \class EAX_Base
//! \brief EAX block cipher mode of operation
//! \details Implementations and overrides in \p EAX_Base apply to both \p ENCRYPTION and \p DECRYPTION directions
class CRYPTOPP_NO_VTABLE EAX_Base : public AuthenticatedSymmetricCipherBase
{
public:
// AuthenticatedSymmetricCipher
std::string AlgorithmName() const
{return GetMAC().GetCipher().AlgorithmName() + std::string("/EAX");}
size_t MinKeyLength() const
{return GetMAC().MinKeyLength();}
size_t MaxKeyLength() const
{return GetMAC().MaxKeyLength();}
size_t DefaultKeyLength() const
{return GetMAC().DefaultKeyLength();}
size_t GetValidKeyLength(size_t n) const
{return GetMAC().GetValidKeyLength(n);}
bool IsValidKeyLength(size_t n) const
{return GetMAC().IsValidKeyLength(n);}
unsigned int OptimalDataAlignment() const
{return GetMAC().OptimalDataAlignment();}
IV_Requirement IVRequirement() const
{return UNIQUE_IV;}
unsigned int IVSize() const
{return GetMAC().TagSize();}
unsigned int MinIVLength() const
{return 0;}
unsigned int MaxIVLength() const
{return UINT_MAX;}
unsigned int DigestSize() const
{return GetMAC().TagSize();}
lword MaxHeaderLength() const
{return LWORD_MAX;}
lword MaxMessageLength() const
{return LWORD_MAX;}
protected:
// AuthenticatedSymmetricCipherBase
bool AuthenticationIsOnPlaintext() const
{return false;}
unsigned int AuthenticationBlockSize() const
{return 1;}
void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs &params);
void Resync(const byte *iv, size_t len);
size_t AuthenticateBlocks(const byte *data, size_t len);
void AuthenticateLastHeaderBlock();
void AuthenticateLastFooterBlock(byte *mac, size_t macSize);
SymmetricCipher & AccessSymmetricCipher() {return m_ctr;}
const CMAC_Base & GetMAC() const {return const_cast<EAX_Base *>(this)->AccessMAC();}
virtual CMAC_Base & AccessMAC() =0;
CTR_Mode_ExternalCipher::Encryption m_ctr;
};
//! \class EAX_Final
//! \brief Class specific methods used to operate the cipher.
//! \tparam T_BlockCipher block cipher
//! \tparam T_IsEncryption direction in which to operate the cipher
//! \details Implementations and overrides in \p GCM_Final apply to either
//! \p ENCRYPTION or \p DECRYPTION, depending on the template parameter \p T_IsEncryption.
//! \details \p EAX_Final does not use inner classes \p Enc and \p Dec.
template <class T_BlockCipher, bool T_IsEncryption>
class EAX_Final : public EAX_Base
{
public:
static std::string StaticAlgorithmName()
{return T_BlockCipher::StaticAlgorithmName() + std::string("/EAX");}
bool IsForwardTransformation() const
{return T_IsEncryption;}
private:
CMAC_Base & AccessMAC() {return m_cmac;}
CMAC<T_BlockCipher> m_cmac;
};
#ifdef EAX // EAX is defined to 11 on GCC 3.4.3, OpenSolaris 8.11
#undef EAX
#endif
//! \class EAX
//! \brief The EAX block cipher mode of operation
//! \details EAX is an Authenticated Encryption with Associated Data (AEAD) block
//! cipher mode of operation designed to simultaneously provide both authentication
//! and privacy of the message.
//! \tparam T_BlockCipher block cipher
//! \details \p EAX provides the \p Encryption and \p Decryption typedef.
//! \sa <a href="http://www.cryptolounge.org/wiki/EAX">EAX</a> at the Crypto Lounge
template <class T_BlockCipher>
struct EAX : public AuthenticatedSymmetricCipherDocumentation
{
typedef EAX_Final<T_BlockCipher, true> Encryption;
typedef EAX_Final<T_BlockCipher, false> Decryption;
};
NAMESPACE_END
#endif