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// authenc.h - written and placed in the public domain by Wei Dai
//! \file
//! \headerfile authenc.h
//! \brief Base classes for working with authenticated encryption modes of encryption
//! \since Crypto++ 5.6.0
#ifndef CRYPTOPP_AUTHENC_H
#define CRYPTOPP_AUTHENC_H
#include "cryptlib.h"
#include "secblock.h"
NAMESPACE_BEGIN(CryptoPP)
//! \class AuthenticatedSymmetricCipherBase
//! \brief Base implementation for one direction (encryption or decryption) of a stream cipher or block cipher mode with authentication
//! \since Crypto++ 5.6.0
class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE AuthenticatedSymmetricCipherBase : public AuthenticatedSymmetricCipher
{
public:
AuthenticatedSymmetricCipherBase() : m_state(State_Start), m_bufferedDataLength(0),
m_totalHeaderLength(0), m_totalMessageLength(0), m_totalFooterLength(0) {}
bool IsRandomAccess() const {return false;}
bool IsSelfInverting() const {return true;}
//! \brief Sets the key for this object without performing parameter validation
//! \param key a byte buffer used to key the cipher
//! \param length the length of the byte buffer
//! \param params additional parameters passed as NameValuePairs
//! \details key must be at least DEFAULT_KEYLENGTH in length.
void UncheckedSetKey(const byte * key, unsigned int length,const CryptoPP::NameValuePairs ¶ms)
{CRYPTOPP_UNUSED(key), CRYPTOPP_UNUSED(length), CRYPTOPP_UNUSED(params); CRYPTOPP_ASSERT(false);}
void SetKey(const byte *userKey, size_t keylength, const NameValuePairs ¶ms);
void Restart() {if (m_state > State_KeySet) m_state = State_KeySet;}
void Resynchronize(const byte *iv, int length=-1);
void Update(const byte *input, size_t length);
void ProcessData(byte *outString, const byte *inString, size_t length);
void TruncatedFinal(byte *mac, size_t macSize);
protected:
void AuthenticateData(const byte *data, size_t len);
const SymmetricCipher & GetSymmetricCipher() const {return const_cast<AuthenticatedSymmetricCipherBase *>(this)->AccessSymmetricCipher();};
virtual SymmetricCipher & AccessSymmetricCipher() =0;
virtual bool AuthenticationIsOnPlaintext() const =0;
virtual unsigned int AuthenticationBlockSize() const =0;
virtual void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs ¶ms) =0;
virtual void Resync(const byte *iv, size_t len) =0;
virtual size_t AuthenticateBlocks(const byte *data, size_t len) =0;
virtual void AuthenticateLastHeaderBlock() =0;
virtual void AuthenticateLastConfidentialBlock() {}
virtual void AuthenticateLastFooterBlock(byte *mac, size_t macSize) =0;
enum State {State_Start, State_KeySet, State_IVSet, State_AuthUntransformed, State_AuthTransformed, State_AuthFooter};
State m_state;
unsigned int m_bufferedDataLength;
lword m_totalHeaderLength, m_totalMessageLength, m_totalFooterLength;
AlignedSecByteBlock m_buffer;
};
NAMESPACE_END
#endif
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