rename Ec::setParam to Ec::init

8 files changed, 79 insertions, 14 deletions

diff --git a/include/mcl/ec.hpp b/include/mcl/ec.hpp
index a6f9003..3e6fb0e 100644
--- a/include/mcl/ec.hpp
+++ b/include/mcl/ec.hpp
@@ -76,6 +76,7 @@ public:
 private:
 	void normalizeJacobi() const
 	{
+		assert(!z.isZero());
 		Fp rz2;
 		Fp::inv(z, z);
 		Fp::sqr(rz2, z);
@@ -86,11 +87,45 @@ private:
 	}
 	void normalizeProj() const
 	{
+		assert(!z.isZero());
 		Fp::inv(z, z);
 		x *= z;
 		y *= z;
 		z = 1;
 	}
+	// Y^2 == X(X^2 + aZ^4) + bZ^6
+	bool isValidJacobi() const
+	{
+puts("isValidJacobi");
+		Fp y2, x2, z2, z4, t;
+		Fp::sqr(x2, x);
+		Fp::sqr(y2, y);
+		Fp::sqr(z2, z);
+		Fp::sqr(z4, z2);
+		Fp::mul(t, z4, a_);
+		t += x2;
+		t *= x;
+		z4 *= z2;
+		z4 *= b_;
+		t += z4;
+		return y2 == t;
+	}
+	// (Y^2 - bZ^2)Z = X^2(X + aZ)
+	bool isValidProj() const
+	{
+puts("isValidProj");
+		Fp y2, x2, z2, t;
+		Fp::sqr(x2, x);
+		Fp::sqr(y2, y);
+		Fp::sqr(z2, z);
+		Fp::mul(t, a_, z);
+		t += x;
+		t *= x2;
+		z2 *= b_;
+		y2 -= z2;
+		y2 *= z;
+		return y2 == t;
+	}
 public:
 #endif
 	void normalize() const
@@ -107,7 +142,7 @@ public:
 		}
 #endif
 	}
-	static inline void setParam(const Fp& a, const Fp& b, int mode = ec::Jacobi)
+	static inline void init(const Fp& a, const Fp& b, int mode = ec::Jacobi)
 	{
 		a_ = a;
 		b_ = b;
@@ -127,22 +162,43 @@ public:
 			mode_ = mode;
 			break;
 		default:
-			throw cybozu::Exception("ec:EcT:setParam:bad mode") << mode;
+			throw cybozu::Exception("ec:EcT:init:bad mode") << mode;
 		}
 #endif
 	}
+	// backward compatilibity
 	static inline void setParam(const std::string& astr, const std::string& bstr, int mode = ec::Jacobi)
 	{
-		setParam(Fp(astr), Fp(bstr), mode);
+		init(astr, bstr, mode);
+	}
+	static inline void init(const std::string& astr, const std::string& bstr, int mode = ec::Jacobi)
+	{
+		init(Fp(astr), Fp(bstr), mode);
 	}
+	// y^2 == (x^2 + a)x + b
 	static inline bool isValid(const Fp& _x, const Fp& _y)
 	{
-		return _y * _y == (_x * _x + a_) * _x + b_;
+		Fp y2, t;
+		Fp::sqr(y2, _y);
+		Fp::sqr(t, _x);
+		t += a_;
+		t *= _x;
+		t += b_;
+		return y2 == t;
 	}
 	bool isValid() const
 	{
 		if (isZero()) return true;
-		normalize();
+#ifndef MCL_EC_USE_AFFINE
+		if (!z.isOne()) {
+			switch (mode_) {
+			case ec::Jacobi:
+				return isValidJacobi();
+			case ec::Proj:
+				return isValidProj();
+			}
+		}
+#endif
 		return isValid(x, y);
 	}
 	void set(const Fp& _x, const Fp& _y, bool verify = true)
diff --git a/java/mcl_if.hpp b/java/mcl_if.hpp
index 54ed4bb..36d67e3 100644
--- a/java/mcl_if.hpp
+++ b/java/mcl_if.hpp
@@ -31,7 +31,7 @@ void SystemInit(const std::string& param) throw(std::exception)
 		p.ecParam = mcl::getEcParam(ecParamStr);
 		Zn::setModulo(p.ecParam->n);
 		Fp::setModulo(p.ecParam->p);
-		Ec::setParam(p.ecParam->a, p.ecParam->b);
+		Ec::init(p.ecParam->a, p.ecParam->b);
 		p.hashName = cybozu::crypto::Hash::getName(hashNameStr);
 		return;
 	}
diff --git a/sample/bench.cpp b/sample/bench.cpp
index cd85c52..a0e790d 100644
--- a/sample/bench.cpp
+++ b/sample/bench.cpp
@@ -88,7 +88,7 @@ void benchEcSub(const mcl::EcParam& para, mcl::fp::Mode mode, mcl::ec::Mode ecMo
 {
 	Fp::setModulo(para.p, 0, mode);
 	Zn::setModulo(para.n);
-	Ec::setParam(para.a, para.b, ecMode);
+	Ec::init(para.a, para.b, ecMode);
 	Fp x(para.gx);
 	Fp y(para.gy);
 	Ec P(x, y);
diff --git a/sample/ecdh.cpp b/sample/ecdh.cpp
index e70303b..90104c0 100644
--- a/sample/ecdh.cpp
+++ b/sample/ecdh.cpp
@@ -22,7 +22,7 @@ int main()
 	const mcl::EcParam& para = mcl::ecparam::secp192k1;
 	Zn::setModulo(para.n);
 	Fp::setModulo(para.p);
-	Ec::setParam(para.a, para.b);
+	Ec::init(para.a, para.b);
 	const Ec P(Fp(para.gx), Fp(para.gy));
 
 	/*
diff --git a/sample/vote.cpp b/sample/vote.cpp
index c2d27bc..7b877dc 100644
--- a/sample/vote.cpp
+++ b/sample/vote.cpp
@@ -63,7 +63,7 @@ void SysInit()
 	const mcl::EcParam& para = mcl::ecparam::secp192k1;
 	Zn::setModulo(para.n);
 	Fp::setModulo(para.p);
-	Ec::setParam(para.a, para.b);
+	Ec::init(para.a, para.b);
 }
 
 template<class T>
diff --git a/test/ec_test.cpp b/test/ec_test.cpp
index 5b8181b..c4bee58 100644
--- a/test/ec_test.cpp
+++ b/test/ec_test.cpp
@@ -16,12 +16,12 @@ typedef mcl::EcT<Fp> Ec;
 
 struct Test {
 	const mcl::EcParam& para;
-	Test(const mcl::EcParam& para)
+	Test(const mcl::EcParam& para, mcl::ec::Mode mode)
 		: para(para)
 	{
 		Fp::setModulo(para.p);
 		Zn::setModulo(para.n);
-		Ec::setParam(para.a, para.b);
+		Ec::init(para.a, para.b, mode);
 	}
 	void cstr() const
 	{
@@ -61,7 +61,9 @@ struct Test {
 		Fp y(para.gy);
 		Zn n = 0;
 		CYBOZU_TEST_ASSERT(Ec::isValid(x, y));
+		CYBOZU_TEST_ASSERT(!Ec::isValid(x, y + 1));
 		Ec P(x, y), Q, R, O;
+		CYBOZU_TEST_ASSERT(P.isNormalized());
 		{
 			Ec::neg(Q, P);
 			CYBOZU_TEST_EQUAL(Q.x, P.x);
@@ -69,6 +71,8 @@ struct Test {
 
 			R = P + Q;
 			CYBOZU_TEST_ASSERT(R.isZero());
+			CYBOZU_TEST_ASSERT(R.isNormalized());
+			CYBOZU_TEST_ASSERT(R.isValid());
 
 			R = P + O;
 			CYBOZU_TEST_EQUAL(R, P);
@@ -78,6 +82,8 @@ struct Test {
 
 		{
 			Ec::dbl(R, P);
+			CYBOZU_TEST_ASSERT(!R.isNormalized());
+			CYBOZU_TEST_ASSERT(R.isValid());
 			Ec R2 = P + P;
 			CYBOZU_TEST_EQUAL(R, R2);
 			{
@@ -314,7 +320,10 @@ void test_sub(const mcl::EcParam *para, size_t paraNum)
 {
 	for (size_t i = 0; i < paraNum; i++) {
 		puts(para[i].name);
-		Test(para[i]).run();
+		puts("Jacobi");
+		Test(para[i], mcl::ec::Jacobi).run();
+		puts("Proj");
+		Test(para[i], mcl::ec::Proj).run();
 	}
 }
 
diff --git a/test/elgamal_test.cpp b/test/elgamal_test.cpp
index 0d8ccf8..92f9fb0 100644
--- a/test/elgamal_test.cpp
+++ b/test/elgamal_test.cpp
@@ -18,7 +18,7 @@ CYBOZU_TEST_AUTO(testEc)
 {
 	Fp::setModulo(para.p);
 	Zn::setModulo(para.n);
-	Ec::setParam(para.a, para.b);
+	Ec::init(para.a, para.b);
 	const Fp x0(para.gx);
 	const Fp y0(para.gy);
 	const size_t bitSize = Zn::getBitSize();
diff --git a/test/window_method_test.cpp b/test/window_method_test.cpp
index d761004..b56fa62 100644
--- a/test/window_method_test.cpp
+++ b/test/window_method_test.cpp
@@ -30,7 +30,7 @@ CYBOZU_TEST_AUTO(int)
 	typedef mcl::EcT<Fp> Ec;
 	const struct mcl::EcParam& para = mcl::ecparam::secp192k1;
 	Fp::setModulo(para.p);
-	Ec::setParam(para.a, para.b);
+	Ec::init(para.a, para.b);
 	const Fp x(para.gx);
 	const Fp y(para.gy);
 	const Ec P(x, y);