/// <summary>
/// Generates signature.
/// </summary>
/// <param name="privateKey"></param>
/// <param name="message"></param>
/// <returns></returns>
public BigInteger[] SignMessage(BigInteger privateKey, BigInteger e)
{
BigInteger r = 0;
BigInteger s = 0;
while (r == 0 || s == 0)
{
BigInteger k = ECCMath.RandomIntegerBelow(ECCurve.n);
ECPoint point = ECCMath.ScalarMult(k, ECCurve.G);
r = ECCMath.MathMod(point.X, ECCurve.n);
s = ECCMath.MathMod((e + r * privateKey) * ECCMath.InverseMod(k, ECCurve.n), ECCurve.n);
}
BigInteger[] bigInteger = new BigInteger[3];
bigInteger[0] = r;
bigInteger[1] = s;
return(bigInteger);
}
public bool VerifySignature(ECPoint publicKey, BigInteger e, BigInteger[] signature)
{
if (!ECCMath.RangeBetween(signature[0], BigInteger.One, ECCurve.n - 1))
{
return(false);
}
if (!ECCMath.RangeBetween(signature[1], BigInteger.One, ECCurve.n - 1))
{
return(false);
}
BigInteger w = ECCMath.InverseMod(signature[1], ECCurve.n);
BigInteger u1 = ECCMath.MathMod((e * w), ECCurve.n);
BigInteger u2 = ECCMath.MathMod((signature[0] * w), ECCurve.n);
ECPoint point = ECCMath.PointAdd(ECCMath.ScalarMult(u1, ECCurve.G), ECCMath.ScalarMult(u2, publicKey));
//if (ECCMath.IsInfinityPoint(point))
// return false;
return(ECCMath.MathMod(signature[0], ECCurve.n) == ECCMath.MathMod(point.X, ECCurve.n));
}
public bool VerifySignature_SM2(ECPoint publicKey, BigInteger e, BigInteger[] signature)
{
if (!ECCMath.RangeBetween(signature[0], BigInteger.One, ECCurve.n - 1))
{
return(false);
}
if (!ECCMath.RangeBetween(signature[1], BigInteger.One, ECCurve.n - 1))
{
return(false);
}
BigInteger t = ECCMath.MathMod((signature[0] + signature[1]), ECCurve.n);
if (t.IsZero)
{
return(false);
}
ECPoint point = ECCMath.PointAdd(ECCMath.ScalarMult(signature[1], ECCurve.G),
ECCMath.ScalarMult(t, publicKey));
BigInteger R = ECCMath.MathMod((e + point.X), ECCurve.n);
return(R == signature[0]);
}
