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externals/cryptopp/gf256.h

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+// gf256.h - originally written and placed in the public domain by Wei Dai
+
+/// \file gf256.h
+/// \brief Classes and functions for schemes over GF(256)
+
+#ifndef CRYPTOPP_GF256_H
+#define CRYPTOPP_GF256_H
+
+#include "cryptlib.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// \brief GF(256) with polynomial basis
+class GF256
+{
+public:
+	typedef byte Element;
+	typedef int RandomizationParameter;
+
+	GF256(byte modulus) : m_modulus(modulus) {}
+
+	Element RandomElement(RandomNumberGenerator &rng, int ignored = 0) const
+		{CRYPTOPP_UNUSED(ignored); return rng.GenerateByte();}
+
+	bool Equal(Element a, Element b) const
+		{return a==b;}
+
+	Element Zero() const
+		{return 0;}
+
+	Element Add(Element a, Element b) const
+		{return a^b;}
+
+	Element& Accumulate(Element &a, Element b) const
+		{return a^=b;}
+
+	Element Inverse(Element a) const
+		{return a;}
+
+	Element Subtract(Element a, Element b) const
+		{return a^b;}
+
+	Element& Reduce(Element &a, Element b) const
+		{return a^=b;}
+
+	Element Double(Element a) const
+		{CRYPTOPP_UNUSED(a); return 0;}
+
+	Element One() const
+		{return 1;}
+
+	Element Multiply(Element a, Element b) const;
+
+	Element Square(Element a) const
+		{return Multiply(a, a);}
+
+	bool IsUnit(Element a) const
+		{return a != 0;}
+
+	Element MultiplicativeInverse(Element a) const;
+
+	Element Divide(Element a, Element b) const
+		{return Multiply(a, MultiplicativeInverse(b));}
+
+private:
+	word m_modulus;
+};
+
+NAMESPACE_END
+
+#endif