1 files changed, 126 insertions, 0 deletions

diff --git a/CryptoPP/ecp.h b/CryptoPP/ecp.h
new file mode 100644
index 000000000..d946be63a
--- /dev/null
+++ b/CryptoPP/ecp.h
@@ -0,0 +1,126 @@
+#ifndef CRYPTOPP_ECP_H
+#define CRYPTOPP_ECP_H
+
+#include "modarith.h"
+#include "eprecomp.h"
+#include "smartptr.h"
+#include "pubkey.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+//! Elliptical Curve Point
+struct CRYPTOPP_DLL ECPPoint
+{
+	ECPPoint() : identity(true) {}
+	ECPPoint(const Integer &x, const Integer &y)
+		: identity(false), x(x), y(y) {}
+
+	bool operator==(const ECPPoint &t) const
+		{return (identity && t.identity) || (!identity && !t.identity && x==t.x && y==t.y);}
+	bool operator< (const ECPPoint &t) const
+		{return identity ? !t.identity : (!t.identity && (x<t.x || (x==t.x && y<t.y)));}
+
+	bool identity;
+	Integer x, y;
+};
+
+CRYPTOPP_DLL_TEMPLATE_CLASS AbstractGroup<ECPPoint>;
+
+//! Elliptic Curve over GF(p), where p is prime
+class CRYPTOPP_DLL ECP : public AbstractGroup<ECPPoint>
+{
+public:
+	typedef ModularArithmetic Field;
+	typedef Integer FieldElement;
+	typedef ECPPoint Point;
+
+	ECP() {}
+	ECP(const ECP &ecp, bool convertToMontgomeryRepresentation = false);
+	ECP(const Integer &modulus, const FieldElement &a, const FieldElement &b)
+		: m_fieldPtr(new Field(modulus)), m_a(a.IsNegative() ? modulus+a : a), m_b(b) {}
+	// construct from BER encoded parameters
+	// this constructor will decode and extract the the fields fieldID and curve of the sequence ECParameters
+	ECP(BufferedTransformation &bt);
+
+	// encode the fields fieldID and curve of the sequence ECParameters
+	void DEREncode(BufferedTransformation &bt) const;
+
+	bool Equal(const Point &P, const Point &Q) const;
+	const Point& Identity() const;
+	const Point& Inverse(const Point &P) const;
+	bool InversionIsFast() const {return true;}
+	const Point& Add(const Point &P, const Point &Q) const;
+	const Point& Double(const Point &P) const;
+	Point ScalarMultiply(const Point &P, const Integer &k) const;
+	Point CascadeScalarMultiply(const Point &P, const Integer &k1, const Point &Q, const Integer &k2) const;
+	void SimultaneousMultiply(Point *results, const Point &base, const Integer *exponents, unsigned int exponentsCount) const;
+
+	Point Multiply(const Integer &k, const Point &P) const
+		{return ScalarMultiply(P, k);}
+	Point CascadeMultiply(const Integer &k1, const Point &P, const Integer &k2, const Point &Q) const
+		{return CascadeScalarMultiply(P, k1, Q, k2);}
+
+	bool ValidateParameters(RandomNumberGenerator &rng, unsigned int level=3) const;
+	bool VerifyPoint(const Point &P) const;
+
+	unsigned int EncodedPointSize(bool compressed = false) const
+		{return 1 + (compressed?1:2)*GetField().MaxElementByteLength();}
+	// returns false if point is compressed and not valid (doesn't check if uncompressed)
+	bool DecodePoint(Point &P, BufferedTransformation &bt, size_t len) const;
+	bool DecodePoint(Point &P, const byte *encodedPoint, size_t len) const;
+	void EncodePoint(byte *encodedPoint, const Point &P, bool compressed) const;
+	void EncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const;
+
+	Point BERDecodePoint(BufferedTransformation &bt) const;
+	void DEREncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const;
+
+	Integer FieldSize() const {return GetField().GetModulus();}
+	const Field & GetField() const {return *m_fieldPtr;}
+	const FieldElement & GetA() const {return m_a;}
+	const FieldElement & GetB() const {return m_b;}
+
+	bool operator==(const ECP &rhs) const
+		{return GetField() == rhs.GetField() && m_a == rhs.m_a && m_b == rhs.m_b;}
+
+private:
+	clonable_ptr<Field> m_fieldPtr;
+	FieldElement m_a, m_b;
+	mutable Point m_R;
+};
+
+CRYPTOPP_DLL_TEMPLATE_CLASS DL_FixedBasePrecomputationImpl<ECP::Point>;
+CRYPTOPP_DLL_TEMPLATE_CLASS DL_GroupPrecomputation<ECP::Point>;
+
+template <class T> class EcPrecomputation;
+
+//! ECP precomputation
+template<> class EcPrecomputation<ECP> : public DL_GroupPrecomputation<ECP::Point>
+{
+public:
+	typedef ECP EllipticCurve;
+	
+	// DL_GroupPrecomputation
+	bool NeedConversions() const {return true;}
+	Element ConvertIn(const Element &P) const
+		{return P.identity ? P : ECP::Point(m_ec->GetField().ConvertIn(P.x), m_ec->GetField().ConvertIn(P.y));};
+	Element ConvertOut(const Element &P) const
+		{return P.identity ? P : ECP::Point(m_ec->GetField().ConvertOut(P.x), m_ec->GetField().ConvertOut(P.y));}
+	const AbstractGroup<Element> & GetGroup() const {return *m_ec;}
+	Element BERDecodeElement(BufferedTransformation &bt) const {return m_ec->BERDecodePoint(bt);}
+	void DEREncodeElement(BufferedTransformation &bt, const Element &v) const {m_ec->DEREncodePoint(bt, v, false);}
+
+	// non-inherited
+	void SetCurve(const ECP &ec)
+	{
+		m_ec.reset(new ECP(ec, true));
+		m_ecOriginal = ec;
+	}
+	const ECP & GetCurve() const {return *m_ecOriginal;}
+
+private:
+	value_ptr<ECP> m_ec, m_ecOriginal;
+};
+
+NAMESPACE_END
+
+#endif