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authorlloyd <[email protected]>2010-02-25 03:27:31 +0000
committerlloyd <[email protected]>2010-02-25 03:27:31 +0000
commitc13f576834a52b03b88366cb243da49fc784b284 (patch)
tree600b5deb1d8445498c1600be5c30bb2a438958f3 /src/math
parentd4bae68ed363df12ed15e41ba503813343dc896f (diff)
Change PointGFp to store BigInts instead of GFpElements
Diffstat (limited to 'src/math')
-rw-r--r--src/math/gfpmath/point_gfp.cpp121
-rw-r--r--src/math/gfpmath/point_gfp.h12
2 files changed, 68 insertions, 65 deletions
diff --git a/src/math/gfpmath/point_gfp.cpp b/src/math/gfpmath/point_gfp.cpp
index 6e0e834b9..f9aaf5c3c 100644
--- a/src/math/gfpmath/point_gfp.cpp
+++ b/src/math/gfpmath/point_gfp.cpp
@@ -41,9 +41,9 @@ BigInt decompress_point(bool yMod2,
// construct the point at infinity or a random point
PointGFp::PointGFp(const CurveGFp& curve) :
curve(curve),
- point_x(curve.get_p(), 0),
- point_y(curve.get_p(), 1),
- point_z(curve.get_p(), 0)
+ coord_x(0),
+ coord_y(1),
+ coord_z(0)
{
}
@@ -53,9 +53,9 @@ PointGFp::PointGFp(const CurveGFp& curve,
const BigInt& y,
const BigInt& z) :
curve(curve),
- point_x(curve.get_p(), x),
- point_y(curve.get_p(), y),
- point_z(curve.get_p(), z)
+ coord_x(x),
+ coord_y(y),
+ coord_z(z)
{
}
@@ -63,9 +63,9 @@ PointGFp::PointGFp(const CurveGFp& curve,
const BigInt& x,
const BigInt& y) :
curve(curve),
- point_x(curve.get_p(), x),
- point_y(curve.get_p(), y),
- point_z(curve.get_p(), 1)
+ coord_x(x),
+ coord_y(y),
+ coord_z(1)
{
}
@@ -81,19 +81,19 @@ PointGFp& PointGFp::operator+=(const PointGFp& rhs)
return *this;
}
- GFpElement U1 = point_x;
- GFpElement S1 = point_y;
+ GFpElement U1 = point_x();
+ GFpElement S1 = point_y();
- GFpElement rhs_z2 = rhs.point_z * rhs.point_z;
+ GFpElement rhs_z2 = rhs.point_z() * rhs.point_z();
U1 *= rhs_z2;
- S1 *= rhs_z2 * rhs.point_z;
+ S1 *= rhs_z2 * rhs.point_z();
- GFpElement U2 = rhs.point_x;
- GFpElement S2 = rhs.point_y;
+ GFpElement U2 = rhs.point_x();
+ GFpElement S2 = rhs.point_y();
- GFpElement lhs_z2 = point_z * point_z;
+ GFpElement lhs_z2 = point_z() * point_z();
U2 *= lhs_z2;
- S2 *= lhs_z2 * point_z;
+ S2 *= lhs_z2 * point_z();
GFpElement H(U2 - U1);
GFpElement r(S2 - S1);
@@ -122,11 +122,11 @@ PointGFp& PointGFp::operator+=(const PointGFp& rhs)
GFpElement y(r * (U2-x) - z);
- z = (point_z * rhs.point_z) * H;
+ z = (point_z() * rhs.point_z()) * H;
- point_x = x;
- point_y = y;
- point_z = z;
+ coord_x = x.get_value();
+ coord_y = y.get_value();
+ coord_z = z.get_value();
return *this;
}
@@ -185,7 +185,7 @@ PointGFp& PointGFp::operator*=(const BigInt& scalar)
PointGFp& PointGFp::negate()
{
if(!is_zero())
- point_y.negate();
+ coord_y = curve.get_p() - coord_y;
return *this;
}
@@ -195,15 +195,15 @@ PointGFp& PointGFp::mult2_in_place()
{
if(is_zero())
return *this;
- else if(point_y.is_zero())
+ else if(coord_y.is_zero())
{
*this = PointGFp(curve); // setting myself to zero
return *this;
}
- GFpElement Y_squared = point_y*point_y;
+ GFpElement Y_squared = point_y()*point_y();
- GFpElement S = point_x * Y_squared;
+ GFpElement S = point_x() * Y_squared;
GFpElement x = S + S;
@@ -211,11 +211,11 @@ PointGFp& PointGFp::mult2_in_place()
GFpElement a_z4 = curve.get_a();
- GFpElement z2 = point_z * point_z;
+ GFpElement z2 = point_z() * point_z();
a_z4 *= z2;
a_z4 *= z2;
- GFpElement y(point_x * point_x);
+ GFpElement y(point_x() * point_x());
GFpElement M(y + y + y + a_z4);
@@ -231,13 +231,13 @@ PointGFp& PointGFp::mult2_in_place()
y = M * (S - x) - U;
- z = point_y * point_z;
+ z = point_y() * point_z();
z = z + z;
- point_x = x;
- point_y = y;
- point_z = z;
+ coord_x = x.get_value();
+ coord_y = y.get_value();
+ coord_z = z.get_value();
return *this;
}
@@ -260,20 +260,21 @@ PointGFp PointGFp::get_z_to_one()
*/
const PointGFp& PointGFp::set_z_to_one()
{
- if(point_z.is_zero())
+ if(coord_z.is_zero())
throw Illegal_Transformation("cannot convert Z to one");
- if(point_z.get_value() != 1)
+ if(coord_z != 1)
{
// Converts to affine coordinates
- GFpElement z = inverse(point_z);
+ GFpElement z = inverse(point_z());
GFpElement z2 = z * z;
z *= z2;
- GFpElement x = point_x * z2;
- GFpElement y = point_y * z;
- point_z = GFpElement(curve.get_p(), BigInt(1));
- point_x = x;
- point_y = y;
+ GFpElement x = point_x() * z2;
+ GFpElement y = point_y() * z;
+
+ coord_x = x.get_value();
+ coord_y = y.get_value();
+ coord_z = 1;
}
return *this;
@@ -284,9 +285,9 @@ BigInt PointGFp::get_affine_x() const
if(is_zero())
throw Illegal_Transformation("cannot convert to affine");
- GFpElement z2 = point_z * point_z;
+ GFpElement z2 = point_z() * point_z();
z2.inverse_in_place();
- z2 *= point_x;
+ z2 *= point_x();
return z2.get_value();
}
@@ -296,9 +297,9 @@ BigInt PointGFp::get_affine_y() const
if(is_zero())
throw Illegal_Transformation("cannot convert to affine");
- GFpElement z3 = point_z * point_z * point_z;
+ GFpElement z3 = point_z() * point_z() * point_z();
z3.inverse_in_place();
- z3 *= point_y;
+ z3 *= point_y();
return z3.get_value();
}
@@ -306,7 +307,7 @@ BigInt PointGFp::get_affine_y() const
// Is this the point at infinity?
bool PointGFp::is_zero() const
{
- return(point_x.is_zero() && point_z.is_zero());
+ return(coord_x.is_zero() && coord_z.is_zero());
}
void PointGFp::check_invariants() const
@@ -321,20 +322,20 @@ void PointGFp::check_invariants() const
if(is_zero())
return;
- const GFpElement y2 = point_y * point_y;
- const GFpElement x3 = point_x * point_x * point_x;
+ const GFpElement y2 = point_y() * point_y();
+ const GFpElement x3 = point_x() * point_x() * point_x();
- if(point_z.get_value() == BigInt(1))
+ if(coord_z == BigInt(1))
{
- GFpElement ax = curve.get_a() * point_x;
+ GFpElement ax = curve.get_a() * point_x();
if(y2 != (x3 + ax + curve.get_b()))
throw Illegal_Point();
}
- GFpElement Zpow2 = point_z * point_z;
- GFpElement Zpow3 = Zpow2 * point_z;
- GFpElement AZpow4 = Zpow3 * point_z * curve.get_a();
- const GFpElement aXZ4 = AZpow4 * point_x;
+ GFpElement Zpow2 = point_z() * point_z();
+ GFpElement Zpow3 = Zpow2 * point_z();
+ GFpElement AZpow4 = Zpow3 * point_z() * curve.get_a();
+ const GFpElement aXZ4 = AZpow4 * point_x();
const GFpElement bZ6 = curve.get_b() * Zpow3 * Zpow3;
if(y2 != (x3 + aXZ4 + bZ6))
@@ -345,9 +346,9 @@ void PointGFp::check_invariants() const
void PointGFp::swap(PointGFp& other)
{
curve.swap(other.curve);
- point_x.swap(other.point_x);
- point_y.swap(other.point_y);
- point_z.swap(other.point_z);
+ coord_x.swap(other.coord_x);
+ coord_y.swap(other.coord_y);
+ coord_z.swap(other.coord_z);
}
bool PointGFp::operator==(const PointGFp& other) const
@@ -355,9 +356,9 @@ bool PointGFp::operator==(const PointGFp& other) const
if(get_curve() != other.get_curve())
return false;
- return (point_x == other.point_x &&
- point_y == other.point_y &&
- point_z == other.point_z);
+ return (coord_x == other.coord_x &&
+ coord_y == other.coord_y &&
+ coord_z == other.coord_z);
}
// arithmetic operators
@@ -396,9 +397,7 @@ SecureVector<byte> EC2OSP(const PointGFp& point, byte format)
if(point.is_zero())
return SecureVector<byte>(1); // single 0 byte
- const u32bit p_bits = point.get_curve().get_p().bits();
-
- u32bit p_bytes = point.get_curve().get_p().bytes();
+ const u32bit p_bytes = point.get_curve().get_p().bytes();
BigInt x = point.get_affine_x();
BigInt y = point.get_affine_y();
diff --git a/src/math/gfpmath/point_gfp.h b/src/math/gfpmath/point_gfp.h
index 6c4b012c5..2da4b0506 100644
--- a/src/math/gfpmath/point_gfp.h
+++ b/src/math/gfpmath/point_gfp.h
@@ -134,19 +134,19 @@ class BOTAN_DLL PointGFp
* get the jacobian projective x coordinate
* @result jacobian projective x coordinate
*/
- const BigInt& get_jac_proj_x() const { return point_x.get_value(); }
+ const BigInt& get_jac_proj_x() const { return coord_x; }
/**
* get the jacobian projective y coordinate
* @result jacobian projective y coordinate
*/
- const BigInt& get_jac_proj_y() const { return point_y.get_value(); }
+ const BigInt& get_jac_proj_y() const { return coord_y; }
/**
* get the jacobian projective z coordinate
* @result jacobian projective z coordinate
*/
- const BigInt& get_jac_proj_z() const { return point_z.get_value(); }
+ const BigInt& get_jac_proj_z() const { return coord_z; }
/**
* Is this the point at infinity?
@@ -173,8 +173,12 @@ class BOTAN_DLL PointGFp
*/
bool operator==(const PointGFp& other) const;
private:
+ GFpElement point_x() const { return GFpElement(curve.get_p(), coord_x); }
+ GFpElement point_y() const { return GFpElement(curve.get_p(), coord_y); }
+ GFpElement point_z() const { return GFpElement(curve.get_p(), coord_z); }
+
CurveGFp curve;
- GFpElement point_x, point_y, point_z;
+ BigInt coord_x, coord_y, coord_z;
};
// relational operators