First Commit

externals/cryptopp/gcm.h

@@ -0,0 +1,139 @@
+// 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 &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 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