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// ccm.h - originally written and placed in the public domain by Wei Dai
/// \file ccm.h
/// \brief CCM block cipher mode of operation
/// \since Crypto++ 5.6.0
#ifndef CRYPTOPP_CCM_H
#define CRYPTOPP_CCM_H
#include "authenc.h"
#include "modes.h"
NAMESPACE_BEGIN(CryptoPP)
/// \brief CCM block cipher base implementation
/// \details Base implementation of the AuthenticatedSymmetricCipher interface
/// \since Crypto++ 5.6.0
class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE CCM_Base : public AuthenticatedSymmetricCipherBase
{
public:
CCM_Base()
: m_digestSize(0), m_L(0), m_messageLength(0), m_aadLength(0) {}
// AuthenticatedSymmetricCipher
std::string AlgorithmName() const
{return GetBlockCipher().AlgorithmName() + std::string("/CCM");}
std::string AlgorithmProvider() const
{return GetBlockCipher().AlgorithmProvider();}
size_t MinKeyLength() const
{return GetBlockCipher().MinKeyLength();}
size_t MaxKeyLength() const
{return GetBlockCipher().MaxKeyLength();}
size_t DefaultKeyLength() const
{return GetBlockCipher().DefaultKeyLength();}
size_t GetValidKeyLength(size_t keylength) const
{return GetBlockCipher().GetValidKeyLength(keylength);}
bool IsValidKeyLength(size_t keylength) const
{return GetBlockCipher().IsValidKeyLength(keylength);}
unsigned int OptimalDataAlignment() const
{return GetBlockCipher().OptimalDataAlignment();}
IV_Requirement IVRequirement() const
{return UNIQUE_IV;}
unsigned int IVSize() const
{return 8;}
unsigned int MinIVLength() const
{return 7;}
unsigned int MaxIVLength() const
{return 13;}
unsigned int DigestSize() const
{return m_digestSize;}
lword MaxHeaderLength() const
{return W64LIT(0)-1;}
lword MaxMessageLength() const
{return m_L<8 ? (W64LIT(1)<<(8*m_L))-1 : W64LIT(0)-1;}
bool NeedsPrespecifiedDataLengths() const
{return true;}
void UncheckedSpecifyDataLengths(lword headerLength, lword messageLength, lword footerLength);
protected:
// AuthenticatedSymmetricCipherBase
bool AuthenticationIsOnPlaintext() const
{return true;}
unsigned int AuthenticationBlockSize() const
{return GetBlockCipher().BlockSize();}
void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs ¶ms);
void Resync(const byte *iv, size_t len);
size_t AuthenticateBlocks(const byte *data, size_t len);
void AuthenticateLastHeaderBlock();
void AuthenticateLastConfidentialBlock();
void AuthenticateLastFooterBlock(byte *mac, size_t macSize);
SymmetricCipher & AccessSymmetricCipher() {return m_ctr;}
virtual BlockCipher & AccessBlockCipher() =0;
virtual int DefaultDigestSize() const =0;
const BlockCipher & GetBlockCipher() const {return const_cast<CCM_Base *>(this)->AccessBlockCipher();}
byte *CBC_Buffer() {return m_buffer+REQUIRED_BLOCKSIZE;}
enum {REQUIRED_BLOCKSIZE = 16};
int m_digestSize, m_L;
word64 m_messageLength, m_aadLength;
CTR_Mode_ExternalCipher::Encryption m_ctr;
};
/// \brief CCM block cipher final implementation
/// \tparam T_BlockCipher block cipher
/// \tparam T_DefaultDigestSize default digest size, in bytes
/// \tparam T_IsEncryption direction in which to operate the cipher
/// \since Crypto++ 5.6.0
template <class T_BlockCipher, int T_DefaultDigestSize, bool T_IsEncryption>
class CCM_Final : public CCM_Base
{
public:
static std::string StaticAlgorithmName()
{return T_BlockCipher::StaticAlgorithmName() + std::string("/CCM");}
bool IsForwardTransformation() const
{return T_IsEncryption;}
private:
BlockCipher & AccessBlockCipher() {return m_cipher;}
int DefaultDigestSize() const {return T_DefaultDigestSize;}
typename T_BlockCipher::Encryption m_cipher;
};
/// \brief CCM block cipher mode of operation
/// \tparam T_BlockCipher block cipher
/// \tparam T_DefaultDigestSize default digest size, in bytes
/// \details \p CCM provides the \p Encryption and \p Decryption typedef. See GCM_Base
/// and GCM_Final for the AuthenticatedSymmetricCipher implementation.
/// \sa <a href="http://www.cryptopp.com/wiki/CCM_Mode">CCM Mode</a> and
/// <A HREF="http://www.cryptopp.com/wiki/Modes_of_Operation">Modes of Operation</A>
/// on the Crypto++ wiki.
/// \since Crypto++ 5.6.0
template <class T_BlockCipher, int T_DefaultDigestSize = 16>
struct CCM : public AuthenticatedSymmetricCipherDocumentation
{
typedef CCM_Final<T_BlockCipher, T_DefaultDigestSize, true> Encryption;
typedef CCM_Final<T_BlockCipher, T_DefaultDigestSize, false> Decryption;
};
NAMESPACE_END
#endif
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