public PreCompInfo Precompute(PreCompInfo existing)
{
if (existing is WTauNafPreCompInfo)
{
return(existing);
}
WTauNafPreCompInfo result = new WTauNafPreCompInfo();
result.PreComp = Tnaf.GetPreComp(m_p, m_a);
return(result);
}
/**
* Multiplies a {@link NBitcoin.BouncyCastle.math.ec.AbstractF2mPoint AbstractF2mPoint}
* by an element
* <code>λ</code>
* of
* <code><b>Z</b>[τ]</code>
* using the window
* <code>τ</code>
* -adic NAF (TNAF) method, given the
* WTNAF of
* <code>λ</code>
* .
* @param p The AbstractF2mPoint to multiply.
* @param u The the WTNAF of
* <code>λ</code>
* ..
* @return
* <code>λ * p</code>
*/
static AbstractF2mPoint MultiplyFromWTnaf(AbstractF2mPoint p, sbyte[] u, PreCompInfo preCompInfo)
{
var curve = (AbstractF2mCurve)p.Curve;
var a = (sbyte)curve.A.ToBigInteger().IntValue;
AbstractF2mPoint[] pu;
if (preCompInfo == null || !(preCompInfo is WTauNafPreCompInfo))
{
pu = Tnaf.GetPreComp(p, a);
var pre = new WTauNafPreCompInfo();
pre.PreComp = pu;
curve.SetPreCompInfo(p, PRECOMP_NAME, pre);
}
else
{
pu = ((WTauNafPreCompInfo)preCompInfo).PreComp;
}
// TODO Include negations in precomp (optionally) and use from here
var puNeg = new AbstractF2mPoint[pu.Length];
for (var i = 0; i < pu.Length; ++i)
{
puNeg[i] = (AbstractF2mPoint)pu[i].Negate();
}
// q = infinity
var q = (AbstractF2mPoint)p.Curve.Infinity;
var tauCount = 0;
for (var i = u.Length - 1; i >= 0; i--)
{
++tauCount;
int ui = u[i];
if (ui != 0)
{
q = q.TauPow(tauCount);
tauCount = 0;
ECPoint x = ui > 0 ? pu[ui >> 1] : puNeg[-ui >> 1];
q = (AbstractF2mPoint)q.Add(x);
}
}
if (tauCount > 0)
{
q = q.TauPow(tauCount);
}
return(q);
}
private static AbstractF2mPoint MultiplyFromWTnaf(AbstractF2mPoint p, sbyte[] u, PreCompInfo preCompInfo)
{
AbstractF2mPoint[] preComp;
AbstractF2mCurve curve = (AbstractF2mCurve)p.Curve;
sbyte intValue = (sbyte)curve.A.ToBigInteger().IntValue;
if ((preCompInfo == null) || !(preCompInfo is WTauNafPreCompInfo))
{
preComp = Tnaf.GetPreComp(p, intValue);
WTauNafPreCompInfo info = new WTauNafPreCompInfo {
PreComp = preComp
};
curve.SetPreCompInfo(p, PRECOMP_NAME, info);
}
else
{
preComp = ((WTauNafPreCompInfo)preCompInfo).PreComp;
}
AbstractF2mPoint[] pointArray2 = new AbstractF2mPoint[preComp.Length];
for (int i = 0; i < preComp.Length; i++)
{
pointArray2[i] = (AbstractF2mPoint)preComp[i].Negate();
}
AbstractF2mPoint infinity = (AbstractF2mPoint)p.Curve.Infinity;
int pow = 0;
for (int j = u.Length - 1; j >= 0; j--)
{
pow++;
int num5 = u[j];
if (num5 != 0)
{
infinity = infinity.TauPow(pow);
pow = 0;
ECPoint b = (num5 <= 0) ? pointArray2[-num5 >> 1] : preComp[num5 >> 1];
infinity = (AbstractF2mPoint)infinity.Add(b);
}
}
if (pow > 0)
{
infinity = infinity.TauPow(pow);
}
return(infinity);
}
private static AbstractF2mPoint MultiplyFromWTnaf(AbstractF2mPoint p, sbyte[] u, PreCompInfo preCompInfo)
{
AbstractF2mCurve abstractF2mCurve = (AbstractF2mCurve)p.Curve;
sbyte a = (sbyte)abstractF2mCurve.A.ToBigInteger().IntValue;
AbstractF2mPoint[] preComp;
if (preCompInfo == null || !(preCompInfo is WTauNafPreCompInfo))
{
preComp = Tnaf.GetPreComp(p, a);
WTauNafPreCompInfo wTauNafPreCompInfo = new WTauNafPreCompInfo();
wTauNafPreCompInfo.PreComp = preComp;
abstractF2mCurve.SetPreCompInfo(p, PRECOMP_NAME, wTauNafPreCompInfo);
}
else
{
preComp = ((WTauNafPreCompInfo)preCompInfo).PreComp;
}
AbstractF2mPoint[] array = new AbstractF2mPoint[preComp.Length];
for (int i = 0; i < preComp.Length; i++)
{
array[i] = (AbstractF2mPoint)preComp[i].Negate();
}
AbstractF2mPoint abstractF2mPoint = (AbstractF2mPoint)p.Curve.Infinity;
int num = 0;
for (int num2 = u.Length - 1; num2 >= 0; num2--)
{
num++;
int num3 = u[num2];
if (num3 != 0)
{
abstractF2mPoint = abstractF2mPoint.TauPow(num);
num = 0;
ECPoint b = ((num3 > 0) ? preComp[num3 >> 1] : array[-num3 >> 1]);
abstractF2mPoint = (AbstractF2mPoint)abstractF2mPoint.Add(b);
}
}
if (num > 0)
{
abstractF2mPoint = abstractF2mPoint.TauPow(num);
}
return(abstractF2mPoint);
}
/**
* Multiplies a {@link org.bouncycastle.math.ec.F2mPoint F2mPoint}
* by an element <code>λ</code> of <code><b>Z</b>[τ]</code>
* using the window <code>τ</code>-adic NAF (TNAF) method, given the
* WTNAF of <code>λ</code>.
* @param p The F2mPoint to multiply.
* @param u The the WTNAF of <code>λ</code>..
* @return <code>λ * p</code>
*/
private static F2mPoint MultiplyFromWTnaf(F2mPoint p, sbyte[] u, PreCompInfo preCompInfo)
{
F2mCurve curve = (F2mCurve)p.Curve;
sbyte a = (sbyte)curve.A.ToBigInteger().IntValue;
F2mPoint[] pu;
if ((preCompInfo == null) || !(preCompInfo is WTauNafPreCompInfo))
{
pu = Tnaf.GetPreComp(p, a);
WTauNafPreCompInfo pre = new WTauNafPreCompInfo();
pre.PreComp = pu;
curve.SetPreCompInfo(p, PRECOMP_NAME, pre);
}
else
{
pu = ((WTauNafPreCompInfo)preCompInfo).PreComp;
}
// q = infinity
F2mPoint q = (F2mPoint)curve.Infinity;
for (int i = u.Length - 1; i >= 0; i--)
{
q = Tnaf.Tau(q);
sbyte ui = u[i];
if (ui != 0)
{
if (ui > 0)
{
q = q.AddSimple(pu[ui]);
}
else
{
// u[i] < 0
q = q.SubtractSimple(pu[-ui]);
}
}
}
return(q);
}
/**
* Multiplies a {@link org.bouncycastle.math.ec.F2mPoint F2mPoint}
* by an element <code>λ</code> of <code><b>Z</b>[τ]</code>
* using the window <code>τ</code>-adic NAF (TNAF) method, given the
* WTNAF of <code>λ</code>.
* @param p The F2mPoint to multiply.
* @param u The the WTNAF of <code>λ</code>..
* @return <code>λ * p</code>
*/
private static F2MPoint MultiplyFromWTnaf(F2MPoint p, sbyte[] u,
IPreCompInfo preCompInfo)
{
F2MCurve curve = (F2MCurve)p.Curve;
sbyte a = (sbyte)curve.A.ToBigInteger().IntValue;
F2MPoint[] pu;
if ((preCompInfo == null) || !(preCompInfo is WTauNafPreCompInfo))
{
pu = Tnaf.GetPreComp(p, a);
p.PreCompInfo = new WTauNafPreCompInfo(pu);
}
else
{
pu = ((WTauNafPreCompInfo)preCompInfo).GetPreComp();
}
// q = infinity
F2MPoint q = (F2MPoint)p.Curve.Infinity;
for (int i = u.Length - 1; i >= 0; i--)
{
q = Tnaf.Tau(q);
if (u[i] != 0)
{
if (u[i] > 0)
{
q = q.AddSimple(pu[u[i]]);
}
else
{
// u[i] < 0
q = q.SubtractSimple(pu[-u[i]]);
}
}
}
return(q);
}