Add ecpoint.h header file. Add EncodedPoint interface. Add documntation

Filelist.txt

@@ -92,6 +92,7 @@ eccrypto.cpp
 eccrypto.h
 ecp.cpp
 ecp.h
+ecpoint.h
 elgamal.cpp
 elgamal.h
 emsa2.cpp

cryptdll.vcxproj

@@ -263,6 +263,7 @@
     <ClInclude Include="ec2n.h" />
     <ClInclude Include="eccrypto.h" />
     <ClInclude Include="ecp.h" />
+    <ClInclude Include="ecpoint.h" />
     <ClInclude Include="emsa2.h" />
     <ClInclude Include="eprecomp.h" />
     <ClInclude Include="files.h" />

cryptdll.vcxproj.filters

@@ -241,6 +241,9 @@
     <ClInclude Include="ecp.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="ecpoint.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="emsa2.h">
       <Filter>Header Files</Filter>
     </ClInclude>

cryptlib.vcxproj

@@ -374,6 +374,7 @@
     <ClInclude Include="ec2n.h" />
     <ClInclude Include="eccrypto.h" />
     <ClInclude Include="ecp.h" />
+    <ClInclude Include="ecpoint.h" />
     <ClInclude Include="elgamal.h" />
     <ClInclude Include="emsa2.h" />
     <ClInclude Include="eprecomp.h" />

cryptlib.vcxproj.filters

@@ -513,6 +513,9 @@
     <ClInclude Include="ecp.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="ecpoint.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="elgamal.h">
       <Filter>Header Files</Filter>
     </ClInclude>

ec2n.h

@@ -12,38 +12,16 @@
 #include "gf2n.h"
 #include "integer.h"
 #include "algebra.h"
+#include "ecpoint.h"
 #include "eprecomp.h"
 #include "smartptr.h"
 #include "pubkey.h"
 
 NAMESPACE_BEGIN(CryptoPP)
 
-//! \class EC2NPoint
-//! \brief Elliptical Curve Point over GF(2^n)
-struct CRYPTOPP_DLL EC2NPoint
-{
-#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
-	virtual ~EC2NPoint() {}
-#endif
-
-	EC2NPoint() : identity(true) {}
-	EC2NPoint(const PolynomialMod2 &x, const PolynomialMod2 &y)
-		: x(x), y(y), identity(false) {}
-
-	bool operator==(const EC2NPoint &t) const
-		{return (identity && t.identity) || (!identity && !t.identity && x==t.x && y==t.y);}
-	bool operator< (const EC2NPoint &t) const
-		{return identity ? !t.identity : (!t.identity && (x<t.x || (x==t.x && y<t.y)));}
-
-	PolynomialMod2 x, y;
-	bool identity;
-};
-
-CRYPTOPP_DLL_TEMPLATE_CLASS AbstractGroup<EC2NPoint>;
-
 //! \class EC2N
 //! \brief Elliptic Curve over GF(2^n)
-class CRYPTOPP_DLL EC2N : public AbstractGroup<EC2NPoint>
+class CRYPTOPP_DLL EC2N : public AbstractGroup<EC2NPoint>, public EncodedPoint<EC2NPoint>
 {
 public:
 	typedef GF2NP Field;

ecp.h

@@ -10,43 +10,16 @@
 #include "integer.h"
 #include "algebra.h"
 #include "modarith.h"
+#include "ecpoint.h"
 #include "eprecomp.h"
 #include "smartptr.h"
 #include "pubkey.h"
 
 NAMESPACE_BEGIN(CryptoPP)
 
-//! \class ECPPoint
-//! \brief Elliptical Curve Point over GF(p), where p is prime
-struct CRYPTOPP_DLL ECPPoint
-{
-#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
-	virtual ~ECPPoint() {}
-#endif
-
-	//! \brief Construct an ECPPoint
-	//! \details identity is set to <tt>true</tt>
-	ECPPoint() : identity(true) {}
-
-	//! \brief Construct an ECPPoint from coordinates
-	//! \details identity is set to <tt>false</tt>
-	ECPPoint(const Integer &x, const Integer &y)
-		: x(x), y(y), identity(false) {}
-
-	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)));}
-
-	Integer x, y;
-	bool identity;
-};
-
-CRYPTOPP_DLL_TEMPLATE_CLASS AbstractGroup<ECPPoint>;
-
 //! \class ECP
 //! \brief Elliptic Curve over GF(p), where p is prime
-class CRYPTOPP_DLL ECP : public AbstractGroup<ECPPoint>
+class CRYPTOPP_DLL ECP : public AbstractGroup<ECPPoint>, public EncodedPoint<ECPPoint>
 {
 public:
 	typedef ModularArithmetic Field;

ecpoint.h

@@ -0,0 +1,149 @@
+// ecpoint.h - written and placed in the public domain by Jeffrey Walton
+//             Data structures moved from ecp.h and ec2n.h. Added EncodedPoint interface
+
+//! \file ecpoint.h
+//! \brief Classes for Elliptic Curve points
+//! \since Crypto++ 5.7
+
+#ifndef CRYPTOPP_ECPOINT_H
+#define CRYPTOPP_ECPOINT_H
+
+#include "cryptlib.h"
+#include "integer.h"
+#include "algebra.h"
+#include "gf2n.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+//! \class ECPPoint
+//! \brief Elliptical Curve Point over GF(p), where p is prime
+//! \since Crypto++ 2.0
+struct CRYPTOPP_DLL ECPPoint
+{
+	virtual ~ECPPoint() {}
+
+	//! \brief Construct an ECPPoint
+	//! \details identity is set to <tt>true</tt>
+	ECPPoint() : identity(true) {}
+
+	//! \brief Construct an ECPPoint from coordinates
+	//! \details identity is set to <tt>false</tt>
+	ECPPoint(const Integer &x, const Integer &y)
+		: x(x), y(y), identity(false) {}
+
+	//! \brief Tests points for equality
+	//! \param t the other point
+	//! \returns true if the points are equal, false otherwise
+	bool operator==(const ECPPoint &t) const
+		{return (identity && t.identity) || (!identity && !t.identity && x==t.x && y==t.y);}
+
+	//! \brief Tests points for ordering
+	//! \param t the other point
+	//! \returns true if this point is less than other, false otherwise
+	bool operator< (const ECPPoint &t) const
+		{return identity ? !t.identity : (!t.identity && (x<t.x || (x==t.x && y<t.y)));}
+
+	Integer x, y;
+	bool identity;
+};
+
+CRYPTOPP_DLL_TEMPLATE_CLASS AbstractGroup<ECPPoint>;
+
+//! \class EC2NPoint
+//! \brief Elliptical Curve Point over GF(2^n)
+//! \since Crypto++ 2.0
+struct CRYPTOPP_DLL EC2NPoint
+{
+	virtual ~EC2NPoint() {}
+
+	//! \brief Construct an EC2NPoint
+	//! \details identity is set to <tt>true</tt>
+	EC2NPoint() : identity(true) {}
+
+	//! \brief Construct an EC2NPoint from coordinates
+	//! \details identity is set to <tt>false</tt>
+	EC2NPoint(const PolynomialMod2 &x, const PolynomialMod2 &y)
+		: x(x), y(y), identity(false) {}
+
+	//! \brief Tests points for equality
+	//! \param t the other point
+	//! \returns true if the points are equal, false otherwise
+	bool operator==(const EC2NPoint &t) const
+		{return (identity && t.identity) || (!identity && !t.identity && x==t.x && y==t.y);}
+
+	//! \brief Tests points for ordering
+	//! \param t the other point
+	//! \returns true if this point is less than other, false otherwise
+	bool operator< (const EC2NPoint &t) const
+		{return identity ? !t.identity : (!t.identity && (x<t.x || (x==t.x && y<t.y)));}
+
+	PolynomialMod2 x, y;
+	bool identity;
+};
+
+CRYPTOPP_DLL_TEMPLATE_CLASS AbstractGroup<EC2NPoint>;
+
+//! \class EncodedPoint
+//! \brief Abstract class for encoding and decoding ellicptic curve points
+//! \tparam Point ellicptic curve point
+//! \details EncodedPoint is an interface for encoding and decoding elliptic curve points.
+//!   The template parameter <tt>Point</tt> should be a class like ECP or EC2N.
+//! \since Crypto++ 5.7
+template <class Point>
+class EncodedPoint
+{
+public:
+	virtual ~EncodedPoint() {}
+
+	//! \brief Decodes an elliptic curve point
+	//! \param P point which is decoded
+	//! \param bt source BufferedTransformation
+	//! \param len number of bytes to read from the BufferedTransformation
+	//! \returns true if a point was decoded, false otherwise
+	virtual bool DecodePoint(Point &P, BufferedTransformation &bt, size_t len) const =0;
+
+	//! \brief Decodes an elliptic curve point
+	//! \param P point which is decoded
+	//! \param encodedPoint byte array with the encoded point
+	//! \param len the size of the array
+	//! \returns true if a point was decoded, false otherwise
+	virtual bool DecodePoint(Point &P, const byte *encodedPoint, size_t len) const =0;
+
+	//! \brief Verifies points on elliptic curve
+	//! \param P point to verify
+	//! \returns true if the point is valid, false otherwise
+	virtual bool VerifyPoint(const Point &P) const =0;
+
+	//! \brief Determines encoded point size
+	//! \param compressed flag indicating if the point is compressed
+	//! \returns the minimum number of bytes required to encode the point
+	virtual unsigned int EncodedPointSize(bool compressed = false) const =0;
+
+	//! \brief Encodes an elliptic curve point
+	//! \param P point which is decoded
+	//! \param encodedPoint byte array for the encoded point
+	//! \param compressed flag indicating if the point is compressed
+	//! \details <tt>encodedPoint</tt> must be at least EncodedPointSize() in length
+	virtual void EncodePoint(byte *encodedPoint, const Point &P, bool compressed) const =0;
+
+	//! \brief Encodes an elliptic curve point
+	//! \param bt target BufferedTransformation
+	//! \param P point which is encoded
+	//! \param compressed flag indicating if the point is compressed
+	virtual void EncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const =0;
+
+	//! \brief BER Decodes an elliptic curve point
+	//! \param bt source BufferedTransformation
+	//! \returns the decoded elliptic curve point
+	virtual Point BERDecodePoint(BufferedTransformation &bt) const =0;
+
+	//! \brief DER Encodes an elliptic curve point
+	//! \param bt target BufferedTransformation
+	//! \param P point which is encoded
+	//! \param compressed flag indicating if the point is compressed
+	virtual void DEREncodePoint(BufferedTransformation &bt, const Point &P, bool compressed) const =0;
+};
+
+NAMESPACE_END
+
+#endif  // CRYPTOPP_ECPOINT_H