/*
 * Compilation Copyright (c) 1995-2019 by Wei Dai.  All rights reserved.
 *	This copyright applies only to this software distribution package
 *	as a compilation, and does not imply a copyright on any particular
 *	file in the package.
 * 
 *	Boost Software License - Version 1.0 - August 17th, 2003
 *
 *	Permission is hereby granted, free of charge, to any person or organization
 *	obtaining a copy of the software and accompanying documentation covered by
 *	this license (the "Software") to use, reproduce, display, distribute,
 *	execute, and transmit the Software, and to prepare derivative works of the
 *	Software, and to permit third-parties to whom the Software is furnished to
 *	do so, all subject to the following:
 * 
 *	The copyright notices in the Software and this entire statement, including
 *	the above license grant, this restriction and the following disclaimer,
 *	must be included in all copies of the Software, in whole or in part, and
 *	all derivative works of the Software, unless such copies or derivative
 *	works are solely in the form of machine-executable object code generated by
 *	a source language processor.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 *	SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 *	FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 *	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 *	DEALINGS IN THE SOFTWARE.
 */

// 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 &params);
	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
