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Diffstat (limited to 'lib/cryptopp/gcm.h')
| -rw-r--r-- | lib/cryptopp/gcm.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/cryptopp/gcm.h b/lib/cryptopp/gcm.h new file mode 100644 index 000000000..272a51c9c --- /dev/null +++ b/lib/cryptopp/gcm.h @@ -0,0 +1,106 @@ +#ifndef CRYPTOPP_GCM_H +#define CRYPTOPP_GCM_H + +#include "authenc.h" +#include "modes.h" + +NAMESPACE_BEGIN(CryptoPP) + +//! . +enum GCM_TablesOption {GCM_2K_Tables, GCM_64K_Tables}; + +//! . +class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE GCM_Base : public AuthenticatedSymmetricCipherBase +{ +public: + // AuthenticatedSymmetricCipher + std::string AlgorithmName() const + {return GetBlockCipher().AlgorithmName() + std::string("/GCM");} + 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}; +}; + +//! . +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; +}; + +//! <a href="http://www.cryptolounge.org/wiki/GCM">GCM</a> +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 |