public static byte[] GenerarFirmaElectronica(byte[] message, BigInteger privateKey)
{
while (true)
{
//Genero un valor 'k' aleatorio
BigInteger k = Helper.Random(Params.n);
//Calculo el punto P = k*G
Punto kP = k * Params.G;
BigInteger r = Arithmetic.Mod(kP.x, Params.n);
if (r.IsZero)
{
continue;
}
var eHash = FirmaElectronica.ObtenerHash(message);
var e = new BigInteger(eHash);
if (e.Sign == -1)
{
e = BigInteger.Negate(e);
}
BigInteger s = Arithmetic.Mod(
Arithmetic.Inversion_ExtendedEuclidean(k, Params.n) * (e + privateKey * r), Params.n
);
var asn1 = new ASN1_Generator.ASN1_Generator();
var seq = new ASN1_Generator.ASN1_Sequence();
seq.content.Add(new ASN1_Generator.ASN1_Integer()
{
Value = r
});
seq.content.Add(new ASN1_Generator.ASN1_Integer()
{
Value = s
});
asn1.Elements.Add(seq);
return(asn1.GetBytes());
}
}
private static ASN1_Element parseSequence(byte[] content)
{
var thisSequence = new ASN1_Sequence();
int cursor = 0;
while (cursor < content.Length)
{
var type = content[cursor];
var size = content[cursor + 1];
switch (type)
{
case 0x02:
thisSequence.content.Add(parseInteger(content.Skip(cursor + 2).Take(size).ToArray()));
break;
}
cursor += size + 2;
}
return(thisSequence);
}
