summaryrefslogtreecommitdiffstats
path: root/CryptoPP/ecp.h
diff options
context:
space:
mode:
Diffstat (limited to 'CryptoPP/ecp.h')
-rw-r--r--CryptoPP/ecp.h126
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