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| author | FluorescentCIAAfricanAmerican <[email protected]> | 2020-04-22 12:56:21 -0400 |
|---|---|---|
| committer | FluorescentCIAAfricanAmerican <[email protected]> | 2020-04-22 12:56:21 -0400 |
| commit | 3bf9df6b2785fa6d951086978a3e66f49427166a (patch) | |
| tree | 2c0f1f0c63c4832882bc93814ebd2c2b1c6224e5 /external/crypto++-5.6.3/gcm.h | |
| download | archived-source-engine-2018-hl2-src-master.tar.xz archived-source-engine-2018-hl2-src-master.zip | |
Diffstat (limited to 'external/crypto++-5.6.3/gcm.h')
| -rw-r--r-- | external/crypto++-5.6.3/gcm.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/external/crypto++-5.6.3/gcm.h b/external/crypto++-5.6.3/gcm.h new file mode 100644 index 0000000..2dd91c4 --- /dev/null +++ b/external/crypto++-5.6.3/gcm.h @@ -0,0 +1,127 @@ +// gcm.h - written and placed in the public domain by Wei Dai + +//! \file +//! \headerfile gcm.h +//! \brief GCM block cipher mode of operation + +#ifndef CRYPTOPP_GCM_H +#define CRYPTOPP_GCM_H + +#include "authenc.h" +#include "modes.h" + +NAMESPACE_BEGIN(CryptoPP) + +//! \enum GCM_TablesOption +//! \brief Use either 2K or 64K size tables. +enum GCM_TablesOption {GCM_2K_Tables, GCM_64K_Tables}; + +//! \class GCM_Base +//! \brief CCM block cipher mode of operation. +//! \details Implementations and overrides in \p GCM_Base apply to both \p ENCRYPTION and \p DECRYPTION directions +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}; +}; + +//! \class GCM_Final +//! \brief Class specific methods used to operate the cipher. +//! \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 +//! \details Implementations and overrides in \p GCM_Final apply to either +//! \p ENCRYPTION or \p DECRYPTION, depending on the template parameter \p T_IsEncryption. +//! \details \p GCM_Final does not use inner classes \p Enc and \p Dec. +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; +}; + +//! \class GCM +//! \brief The GCM 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. +//! \sa <a href="http://www.cryptolounge.org/wiki/GCM">GCM</a> at the Crypto Lounge +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 |