You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
140 lines
5.0 KiB
140 lines
5.0 KiB
![]()
4 years ago
|
// gcm.h - originally written and placed in the public domain by Wei Dai
|
||
|
|
||
|
/// \file gcm.h
|
||
|
/// \brief GCM block cipher mode of operation
|
||
|
/// \since Crypto++ 5.6.0
|
||
|
|
||
|
#ifndef CRYPTOPP_GCM_H
|
||
|
#define CRYPTOPP_GCM_H
|
||
|
|
||
|
#include "authenc.h"
|
||
|
#include "modes.h"
|
||
|
|
||
|
// Clang 3.3 integrated assembler crash on Linux. Clang 3.4 due to compiler
|
||
|
// error with .intel_syntax, http://llvm.org/bugs/show_bug.cgi?id=24232
|
||
|
#if CRYPTOPP_BOOL_X32 || defined(CRYPTOPP_DISABLE_MIXED_ASM)
|
||
|
# define CRYPTOPP_DISABLE_GCM_ASM 1
|
||
|
#endif
|
||
|
|
||
|
NAMESPACE_BEGIN(CryptoPP)
|
||
|
|
||
|
/// \enum GCM_TablesOption
|
||
|
/// \brief GCM table size options
|
||
|
enum GCM_TablesOption {
|
||
|
/// \brief Use a table with 2K entries
|
||
|
GCM_2K_Tables,
|
||
|
/// \brief Use a table with 64K entries
|
||
|
GCM_64K_Tables};
|
||
|
|
||
|
/// \brief GCM block cipher base implementation
|
||
|
/// \details Base implementation of the AuthenticatedSymmetricCipher interface
|
||
|
/// \since Crypto++ 5.6.0
|
||
|
class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE GCM_Base : public AuthenticatedSymmetricCipherBase
|
||
|
{
|
||
|
public:
|
||
|
// AuthenticatedSymmetricCipher
|
||
|
std::string AlgorithmName() const
|
||
|
{return GetBlockCipher().AlgorithmName() + std::string("/GCM");}
|
||
|
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 n) const
|
||
|
{return GetBlockCipher().GetValidKeyLength(n);}
|
||
|
bool IsValidKeyLength(size_t n) const
|
||
|
{return GetBlockCipher().IsValidKeyLength(n);}
|
||
|
unsigned int OptimalDataAlignment() const;
|
||
|
IV_Requirement IVRequirement() const
|
||
|
{return UNIQUE_IV;}
|
||
|
unsigned int IVSize() const
|
||
|
{return 12;}
|
||
|
unsigned int MinIVLength() const
|
||
|
{return 1;}
|
||
|
unsigned int MaxIVLength() const
|
||
|
{return UINT_MAX;} // (W64LIT(1)<<61)-1 in the standard
|
||
|
unsigned int DigestSize() const
|
||
|
{return 16;}
|
||
|
lword MaxHeaderLength() const
|
||
|
{return (W64LIT(1)<<61)-1;}
|
||
|
lword MaxMessageLength() const
|
||
|
{return ((W64LIT(1)<<39)-256)/8;}
|
||
|
|
||
|
protected:
|
||
|
// AuthenticatedSymmetricCipherBase
|
||
|
bool AuthenticationIsOnPlaintext() const
|
||
|
{return false;}
|
||
|
unsigned int AuthenticationBlockSize() const
|
||
|
{return HASH_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 GCM_TablesOption GetTablesOption() const =0;
|
||
|
|
||
|
const BlockCipher & GetBlockCipher() const {return const_cast<GCM_Base *>(this)->AccessBlockCipher();}
|
||
|
byte *HashBuffer() {return m_buffer+REQUIRED_BLOCKSIZE;}
|
||
|
byte *HashKey() {return m_buffer+2*REQUIRED_BLOCKSIZE;}
|
||
|
byte *MulTable() {return m_buffer+3*REQUIRED_BLOCKSIZE;}
|
||
|
inline void ReverseHashBufferIfNeeded();
|
||
|
|
||
|
class CRYPTOPP_DLL GCTR : public CTR_Mode_ExternalCipher::Encryption
|
||
|
{
|
||
|
protected:
|
||
|
void IncrementCounterBy256();
|
||
|
};
|
||
|
|
||
|
GCTR m_ctr;
|
||
|
static word16 s_reductionTable[256];
|
||
|
static volatile bool s_reductionTableInitialized;
|
||
|
enum {REQUIRED_BLOCKSIZE = 16, HASH_BLOCKSIZE = 16};
|
||
|
};
|
||
|
|
||
|
/// \brief GCM block cipher final implementation
|
||
|
/// \tparam T_BlockCipher block cipher
|
||
|
/// \tparam T_TablesOption table size, either \p GCM_2K_Tables or \p GCM_64K_Tables
|
||
|
/// \tparam T_IsEncryption direction in which to operate the cipher
|
||
|
/// \since Crypto++ 5.6.0
|
||
|
template <class T_BlockCipher, GCM_TablesOption T_TablesOption, bool T_IsEncryption>
|
||
|
class GCM_Final : public GCM_Base
|
||
|
{
|
||
|
public:
|
||
|
static std::string StaticAlgorithmName()
|
||
|
{return T_BlockCipher::StaticAlgorithmName() + std::string("/GCM");}
|
||
|
bool IsForwardTransformation() const
|
||
|
{return T_IsEncryption;}
|
||
|
|
||
|
private:
|
||
|
GCM_TablesOption GetTablesOption() const {return T_TablesOption;}
|
||
|
BlockCipher & AccessBlockCipher() {return m_cipher;}
|
||
|
typename T_BlockCipher::Encryption m_cipher;
|
||
|
};
|
||
|
|
||
|
/// \brief GCM block cipher mode of operation
|
||
|
/// \tparam T_BlockCipher block cipher
|
||
|
/// \tparam T_TablesOption table size, either \p GCM_2K_Tables or \p GCM_64K_Tables
|
||
|
/// \details \p GCM 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/GCM_Mode">GCM 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, GCM_TablesOption T_TablesOption=GCM_2K_Tables>
|
||
|
struct GCM : public AuthenticatedSymmetricCipherDocumentation
|
||
|
{
|
||
|
typedef GCM_Final<T_BlockCipher, T_TablesOption, true> Encryption;
|
||
|
typedef GCM_Final<T_BlockCipher, T_TablesOption, false> Decryption;
|
||
|
};
|
||
|
|
||
|
NAMESPACE_END
|
||
|
|
||
|
#endif
|