public string SingGen(byte[] h, BigInteger d)
{
BigInteger alpha = BigInteger.Parse(SupportEDS.DecStringFromByteArray(h));
BigInteger e = alpha % this.curv.N;
if (e == 0)
{
e = 1;
}
BigInteger k = new BigInteger();
EllipticCurve_Point C = new EllipticCurve_Point();
BigInteger r = new BigInteger();
BigInteger s = new BigInteger();
do
{
Random rnd = new Random();
do
{
k = Maths.RandBigInteger(Maths.Length(this.curv.N), rnd);
}while ((k < 0) || (k > this.curv.N));
curv.Mult(k, this.curv.G, ref C);
r = C.X % this.curv.N;
s = ((r * d) + (k * e)) % this.curv.N;
}while ((r == 0) || (s == 0));
int midl = Maths.Length(this.curv.N) / 4;
string Rvector = SupportEDS.Add0PaddingToString(r.ToString("X"), midl);
string Svector = SupportEDS.Add0PaddingToString(s.ToString("X"), midl);
return(Rvector + Svector);
}
public bool SingVer(byte[] H, string sing, EllipticCurve_Point Q)
{
int midl = Maths.Length(this.curv.N) / 4;
string Rvector = sing.Substring(0, midl);
string Svector = sing.Substring(midl, midl);
BigInteger r = BigInteger.Parse(SupportEDS.DecStringFromHexString(Rvector));
BigInteger s = BigInteger.Parse(SupportEDS.DecStringFromHexString(Svector));
if ((r < 1) || (r > (this.curv.N - 1)) || (s < 1) || (s > (this.curv.N - 1)))
{
return(false);
}
BigInteger alpha = BigInteger.Parse(SupportEDS.DecStringFromByteArray(H));
BigInteger e = alpha % this.curv.N;
if (e == 0)
{
e = 1;
}
BigInteger v = Maths.GetInverse(e, this.curv.N);
BigInteger z1 = (s * v) % this.curv.N;
BigInteger z2 = this.curv.N + ((-(r * v)) % this.curv.N);
EllipticCurve_Point A = new EllipticCurve_Point();
EllipticCurve_Point B = new EllipticCurve_Point();
EllipticCurve_Point C = new EllipticCurve_Point();
curv.Mult(z1, this.curv.G, ref A);
curv.Mult(z2, Q, ref B);
curv.Sum(A, B, ref C);
BigInteger R = C.X % this.curv.N;
if (R == r)
{
return(true);
}
else
{
return(false);
}
}
public static BigInteger RandBigInteger(int len, Random rnd)
{
int b = len;
int ost = b % 8;
int b_count = (b / 8) + (ost == 0 ? 0 : 1);
if (b_count == 0)
{
return(BigInteger.Zero);
}
byte ml = (byte)Math.Pow(2, (b - 1) % 8);
for (int i = ((b - 1) % 8) - 1; i >= 0; i--)
{
ml += (byte)(Math.Pow(2, i) * rnd.Next(0, 2));
}
byte[] arr = new byte[b_count];
arr[0] = ml;
for (int i = 1; i < b_count; i++)
{
arr[i] = (byte)rnd.Next(0, 256);
}
return(BigInteger.Parse(SupportEDS.DecStringFromByteArray(arr)));
}
