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139 lines
5.0 KiB
139 lines
5.0 KiB
// gcm.h - originally written and placed in the public domain by Wei Dai |
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/// \file gcm.h |
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/// \brief GCM block cipher mode of operation |
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/// \since Crypto++ 5.6.0 |
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#ifndef CRYPTOPP_GCM_H |
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#define CRYPTOPP_GCM_H |
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#include "authenc.h" |
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#include "modes.h" |
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// Clang 3.3 integrated assembler crash on Linux. Clang 3.4 due to compiler |
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// error with .intel_syntax, http://llvm.org/bugs/show_bug.cgi?id=24232 |
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#if CRYPTOPP_BOOL_X32 || defined(CRYPTOPP_DISABLE_MIXED_ASM) |
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# define CRYPTOPP_DISABLE_GCM_ASM 1 |
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#endif |
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NAMESPACE_BEGIN(CryptoPP) |
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/// \enum GCM_TablesOption |
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/// \brief GCM table size options |
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enum GCM_TablesOption { |
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/// \brief Use a table with 2K entries |
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GCM_2K_Tables, |
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/// \brief Use a table with 64K entries |
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GCM_64K_Tables}; |
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/// \brief GCM block cipher base implementation |
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/// \details Base implementation of the AuthenticatedSymmetricCipher interface |
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/// \since Crypto++ 5.6.0 |
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class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE GCM_Base : public AuthenticatedSymmetricCipherBase |
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{ |
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public: |
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// AuthenticatedSymmetricCipher |
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std::string AlgorithmName() const |
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{return GetBlockCipher().AlgorithmName() + std::string("/GCM");} |
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std::string AlgorithmProvider() const |
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{return GetBlockCipher().AlgorithmProvider();} |
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size_t MinKeyLength() const |
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{return GetBlockCipher().MinKeyLength();} |
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size_t MaxKeyLength() const |
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{return GetBlockCipher().MaxKeyLength();} |
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size_t DefaultKeyLength() const |
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{return GetBlockCipher().DefaultKeyLength();} |
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size_t GetValidKeyLength(size_t n) const |
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{return GetBlockCipher().GetValidKeyLength(n);} |
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bool IsValidKeyLength(size_t n) const |
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{return GetBlockCipher().IsValidKeyLength(n);} |
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unsigned int OptimalDataAlignment() const; |
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IV_Requirement IVRequirement() const |
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{return UNIQUE_IV;} |
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unsigned int IVSize() const |
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{return 12;} |
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unsigned int MinIVLength() const |
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{return 1;} |
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unsigned int MaxIVLength() const |
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{return UINT_MAX;} // (W64LIT(1)<<61)-1 in the standard |
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unsigned int DigestSize() const |
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{return 16;} |
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lword MaxHeaderLength() const |
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{return (W64LIT(1)<<61)-1;} |
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lword MaxMessageLength() const |
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{return ((W64LIT(1)<<39)-256)/8;} |
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protected: |
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// AuthenticatedSymmetricCipherBase |
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bool AuthenticationIsOnPlaintext() const |
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{return false;} |
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unsigned int AuthenticationBlockSize() const |
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{return HASH_BLOCKSIZE;} |
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void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs ¶ms); |
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void Resync(const byte *iv, size_t len); |
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size_t AuthenticateBlocks(const byte *data, size_t len); |
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void AuthenticateLastHeaderBlock(); |
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void AuthenticateLastConfidentialBlock(); |
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void AuthenticateLastFooterBlock(byte *mac, size_t macSize); |
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SymmetricCipher & AccessSymmetricCipher() {return m_ctr;} |
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virtual BlockCipher & AccessBlockCipher() =0; |
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virtual GCM_TablesOption GetTablesOption() const =0; |
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const BlockCipher & GetBlockCipher() const {return const_cast<GCM_Base *>(this)->AccessBlockCipher();} |
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byte *HashBuffer() {return m_buffer+REQUIRED_BLOCKSIZE;} |
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byte *HashKey() {return m_buffer+2*REQUIRED_BLOCKSIZE;} |
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byte *MulTable() {return m_buffer+3*REQUIRED_BLOCKSIZE;} |
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inline void ReverseHashBufferIfNeeded(); |
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class CRYPTOPP_DLL GCTR : public CTR_Mode_ExternalCipher::Encryption |
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{ |
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protected: |
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void IncrementCounterBy256(); |
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}; |
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GCTR m_ctr; |
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static word16 s_reductionTable[256]; |
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static volatile bool s_reductionTableInitialized; |
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enum {REQUIRED_BLOCKSIZE = 16, HASH_BLOCKSIZE = 16}; |
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}; |
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/// \brief GCM block cipher final implementation |
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/// \tparam T_BlockCipher block cipher |
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/// \tparam T_TablesOption table size, either \p GCM_2K_Tables or \p GCM_64K_Tables |
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/// \tparam T_IsEncryption direction in which to operate the cipher |
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/// \since Crypto++ 5.6.0 |
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template <class T_BlockCipher, GCM_TablesOption T_TablesOption, bool T_IsEncryption> |
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class GCM_Final : public GCM_Base |
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{ |
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public: |
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static std::string StaticAlgorithmName() |
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{return T_BlockCipher::StaticAlgorithmName() + std::string("/GCM");} |
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bool IsForwardTransformation() const |
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{return T_IsEncryption;} |
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private: |
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GCM_TablesOption GetTablesOption() const {return T_TablesOption;} |
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BlockCipher & AccessBlockCipher() {return m_cipher;} |
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typename T_BlockCipher::Encryption m_cipher; |
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}; |
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/// \brief GCM block cipher mode of operation |
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/// \tparam T_BlockCipher block cipher |
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/// \tparam T_TablesOption table size, either \p GCM_2K_Tables or \p GCM_64K_Tables |
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/// \details \p GCM provides the \p Encryption and \p Decryption typedef. See GCM_Base |
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/// and GCM_Final for the AuthenticatedSymmetricCipher implementation. |
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/// \sa <a href="http://www.cryptopp.com/wiki/GCM_Mode">GCM Mode</a> and |
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/// <A HREF="http://www.cryptopp.com/wiki/Modes_of_Operation">Modes of Operation</A> |
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/// on the Crypto++ wiki. |
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/// \since Crypto++ 5.6.0 |
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template <class T_BlockCipher, GCM_TablesOption T_TablesOption=GCM_2K_Tables> |
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struct GCM : public AuthenticatedSymmetricCipherDocumentation |
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{ |
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typedef GCM_Final<T_BlockCipher, T_TablesOption, true> Encryption; |
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typedef GCM_Final<T_BlockCipher, T_TablesOption, false> Decryption; |
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}; |
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NAMESPACE_END |
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#endif
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