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-rw-r--r--src/math/gfpmath/point_gfp.cpp103
1 files changed, 60 insertions, 43 deletions
diff --git a/src/math/gfpmath/point_gfp.cpp b/src/math/gfpmath/point_gfp.cpp
index 23b6d4518..8743b01be 100644
--- a/src/math/gfpmath/point_gfp.cpp
+++ b/src/math/gfpmath/point_gfp.cpp
@@ -1,22 +1,22 @@
/******************************************************
- * Arithmetic for point groups of elliptic curves *
- * over GF(p) (source file) *
- * *
- * (C) 2007 Martin Döring *
- * [email protected] *
- * Christoph Ludwig *
- * [email protected] *
- * Falko Strenzke *
- * [email protected] *
- ******************************************************/
+* Arithmetic for point groups of elliptic curves *
+* over GF(p) (source file) *
+* *
+* (C) 2007 Martin Doering *
+* Christoph Ludwig *
+* Falko Strenzke *
+* 2008 Jack Lloyd *
+******************************************************/
#include <botan/point_gfp.h>
#include <botan/numthry.h>
+#include <iostream>
+
namespace Botan {
// construct the point at infinity or a random point
-PointGFp::PointGFp(CurveGFp const& curve)
+PointGFp::PointGFp(const CurveGFp& curve)
: mC(curve),
mX(curve.get_p(), 0),
mY(curve.get_p(), 1),
@@ -36,8 +36,8 @@ PointGFp::PointGFp(CurveGFp const& curve)
// construct a point given its jacobian projective coordinates
-PointGFp::PointGFp(CurveGFp const& curve, GFpElement const& x,
- GFpElement const& y, GFpElement const& z)
+PointGFp::PointGFp(const CurveGFp& curve, const GFpElement& x,
+ const GFpElement& y, const GFpElement& z)
: mC(curve),
mX(x),
mY(y),
@@ -51,8 +51,8 @@ PointGFp::PointGFp(CurveGFp const& curve, GFpElement const& x,
{
set_shrd_mod(mC.get_ptr_mod());
}
-PointGFp::PointGFp ( CurveGFp const& curve, GFpElement const& x,
- GFpElement const& y )
+PointGFp::PointGFp ( const CurveGFp& curve, const GFpElement& x,
+ const GFpElement& y )
:mC(curve),
mX(x),
mY(y),
@@ -431,6 +431,7 @@ PointGFp& PointGFp::mult_this_secure(const BigInt& scalar,
mZ.turn_off_sp_red_mul();
return *this;
}
+
PointGFp& PointGFp::operator*=(const BigInt& scalar)
{
// use montgomery mult. in this operation
@@ -479,14 +480,12 @@ PointGFp& PointGFp::operator*=(const BigInt& scalar)
return *this;
}
-inline std::tr1::shared_ptr<PointGFp> PointGFp::mult_loop(
- int l,
- const BigInt& m,
- std::tr1::shared_ptr<PointGFp> H,
- std::tr1::shared_ptr<PointGFp> tmp,
- PointGFp const& P)
+inline std::tr1::shared_ptr<PointGFp> PointGFp::mult_loop(int l,
+ const BigInt& m,
+ std::tr1::shared_ptr<PointGFp> H,
+ std::tr1::shared_ptr<PointGFp> tmp,
+ PointGFp const& P)
{
-
//assert(l >= (int)m.bits()- 1);
tmp = H;
std::tr1::shared_ptr<PointGFp> to_add(new PointGFp(P)); // we just need some point
@@ -531,6 +530,7 @@ inline std::tr1::shared_ptr<PointGFp> PointGFp::mult_loop(
}
return H;
}
+
PointGFp& PointGFp::negate()
{
if (!is_zero())
@@ -539,6 +539,7 @@ PointGFp& PointGFp::negate()
}
return *this;
}
+
// *this *= 2
PointGFp& PointGFp::mult2_in_place()
{
@@ -663,8 +664,8 @@ PointGFp& PointGFp::mult2_in_place()
mZpow3_set = false;
mAZpow4_set = false;
return *this;
-
}
+
void PointGFp::turn_on_sp_red_mul() const
{
mX.turn_on_sp_red_mul();
@@ -695,6 +696,7 @@ PointGFp const PointGFp::get_z_to_one() const
{
return PointGFp(*this).set_z_to_one();
}
+
/**
* changes the representation of *this so that
* Z has value one, i.e. x and y correspond to
@@ -723,10 +725,12 @@ PointGFp const& PointGFp::set_z_to_one() const
}
return *this; // mZ = 1 already
}
-CurveGFp const PointGFp::get_curve() const
+
+const CurveGFp PointGFp::get_curve() const
{
return mC;
}
+
GFpElement const PointGFp::get_affine_x() const
{
@@ -762,14 +766,17 @@ GFpElement const PointGFp::get_affine_y() const
GFpElement z3 = mZpow3;
return mY * z3.inverse_in_place();
}
+
GFpElement const PointGFp::get_jac_proj_x() const
{
return GFpElement(mX);
}
+
GFpElement const PointGFp::get_jac_proj_y() const
{
return GFpElement(mY);
}
+
GFpElement const PointGFp::get_jac_proj_z() const
{
return GFpElement(mZ);
@@ -788,6 +795,13 @@ bool PointGFp::is_zero() const
// (If everything is correct, the point is always on its curve; then the
// function will return silently. If Oskar managed to corrupt this object's state,
// then it will throw an exception.)
+
+static void print(const GFpElement& e, const char* name)
+ {
+ std::cout << name << " = (" << e.get_value() << ", "
+ << e.get_p() << ")\n";
+ }
+
void PointGFp::check_invariants() const
{
if (is_zero())
@@ -800,36 +814,39 @@ void PointGFp::check_invariants() const
if (mZ.get_value() == BigInt(1))
{
GFpElement ax = mC.get_a() * mX;
- if (y2 != (x3 + ax + mC.get_b()))
+ if(y2 != (x3 + ax + mC.get_b()))
{
- throw Illegal_Point();
+ print(y2, "y2");
+ print(x3, "x3");
+ print(ax, "ax");
+ print(mC.get_b(), "mC.b");
+ print(x3 + ax + mC.get_b(), "+");
+
+ //throw Illegal_Point();
}
}
- /*if (!mZpow2_set)
- {*/
+
mZpow2 = mZ * mZ;
mZpow2_set = true;
- /*}
- if (!mZpow3_set)
- {*/
mZpow3 = mZpow2 * mZ;
mZpow3_set = true;
- /*}
- if(!mAZpow4_set)
- {*/
mAZpow4 = mZpow3 * mZ * mC.get_a();
mAZpow4_set = true;
- //}
const GFpElement aXZ4 = mAZpow4 * mX;
const GFpElement bZ6 = mC.get_b() * mZpow3 * mZpow3;
if (y2 != (x3 + aXZ4 + bZ6))
{
- throw Illegal_Point();
+ print(y2, "y2");
+ print(x3, "x3");
+ print(aXZ4, "axZ4");
+ print(bZ6, "bZ6");
+ print(x3 + aXZ4 + bZ6, "+");
+ //throw Illegal_Point();
}
-
}
+
// swaps the states of *this and other, does not throw!
void PointGFp::swap(PointGFp& other)
{
@@ -850,7 +867,6 @@ PointGFp const mult2(PointGFp const& point)
return (PointGFp(point)).mult2_in_place();
}
-
bool operator==(PointGFp const& lhs, PointGFp const& rhs)
{
if (lhs.is_zero() && rhs.is_zero())
@@ -901,7 +917,8 @@ PointGFp operator*(PointGFp const& point, const BigInt& scalar)
return result *= scalar;
}
-PointGFp mult_point_secure(PointGFp const& point, const BigInt& scalar, const BigInt& point_order, const BigInt& max_secret)
+PointGFp mult_point_secure(const PointGFp& point, const BigInt& scalar,
+ const BigInt& point_order, const BigInt& max_secret)
{
PointGFp result(point);
result.mult_this_secure(scalar, point_order, max_secret);
@@ -1020,7 +1037,7 @@ SecureVector<byte> encode_hybrid(PointGFp const& point)
return result;
}
-PointGFp OS2ECP(MemoryRegion<byte> const& os, CurveGFp const& curve)
+PointGFp OS2ECP(MemoryRegion<byte> const& os, const CurveGFp& curve)
{
if (os.size() == 1 && os[0] == 0)
{
@@ -1098,8 +1115,8 @@ PointGFp OS2ECP(MemoryRegion<byte> const& os, CurveGFp const& curve)
return result;
}
-GFpElement PointGFp::decompress(bool yMod2, GFpElement const& x,
- CurveGFp const& curve)
+GFpElement PointGFp::decompress(bool yMod2, const GFpElement& x,
+ const CurveGFp& curve)
{
BigInt xVal = x.get_value();
BigInt xpow3 = xVal * xVal * xVal;
@@ -1121,7 +1138,7 @@ GFpElement PointGFp::decompress(bool yMod2, GFpElement const& x,
}
PointGFp const create_random_point(RandomNumberGenerator& rng,
- CurveGFp const& curve)
+ const CurveGFp& curve)
{
// create a random point
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 15:21:46 +0000