public X9ECParameters(Asn1Sequence seq)
{
if (!(seq[0] is DerInteger) || !((DerInteger)seq[0]).Value.Equals(BigInteger.One))
{
throw new ArgumentException("bad version in X9ECParameters");
}
X9Curve x9Curve = new X9Curve(X9FieldID.GetInstance(seq[1]), Asn1Sequence.GetInstance(seq[2]));
curve = x9Curve.Curve;
object obj = seq[3];
if (obj is X9ECPoint)
{
g = (X9ECPoint)obj;
}
else
{
g = new X9ECPoint(curve, (Asn1OctetString)obj);
}
n = ((DerInteger)seq[4]).Value;
seed = x9Curve.GetSeed();
if (seq.Count == 6)
{
h = ((DerInteger)seq[5]).Value;
}
}
public X9ECParameters(ECCurve curve, X9ECPoint g, BigInteger n, BigInteger h, byte[] seed)
{
this.curve = curve;
this.g = g;
this.n = n;
this.h = h;
this.seed = seed;
if (ECAlgorithms.IsFpCurve(curve))
{
fieldID = new X9FieldID(curve.Field.Characteristic);
return;
}
if (ECAlgorithms.IsF2mCurve(curve))
{
IPolynomialExtensionField polynomialExtensionField = (IPolynomialExtensionField)curve.Field;
int[] exponentsPresent = polynomialExtensionField.MinimalPolynomial.GetExponentsPresent();
if (exponentsPresent.Length == 3)
{
fieldID = new X9FieldID(exponentsPresent[2], exponentsPresent[1]);
return;
}
if (exponentsPresent.Length == 5)
{
fieldID = new X9FieldID(exponentsPresent[4], exponentsPresent[1], exponentsPresent[2], exponentsPresent[3]);
return;
}
throw new ArgumentException("Only trinomial and pentomial curves are supported");
}
throw new ArgumentException("'curve' is of an unsupported type");
}
public X9Curve(X9FieldID fieldID, Asn1Sequence seq)
{
if (fieldID == null)
{
throw new ArgumentNullException("fieldID");
}
if (seq == null)
{
throw new ArgumentNullException("seq");
}
fieldIdentifier = fieldID.Identifier;
if (fieldIdentifier.Equals(X9ObjectIdentifiers.PrimeField))
{
BigInteger value = ((DerInteger)fieldID.Parameters).Value;
X9FieldElement x9FieldElement = new X9FieldElement(value, (Asn1OctetString)seq[0]);
X9FieldElement x9FieldElement2 = new X9FieldElement(value, (Asn1OctetString)seq[1]);
curve = new FpCurve(value, x9FieldElement.Value.ToBigInteger(), x9FieldElement2.Value.ToBigInteger());
}
else if (fieldIdentifier.Equals(X9ObjectIdentifiers.CharacteristicTwoField))
{
DerSequence derSequence = (DerSequence)fieldID.Parameters;
int intValue = ((DerInteger)derSequence[0]).Value.IntValue;
DerObjectIdentifier derObjectIdentifier = (DerObjectIdentifier)derSequence[1];
int num = 0;
int k = 0;
int k2 = 0;
if (derObjectIdentifier.Equals(X9ObjectIdentifiers.TPBasis))
{
num = ((DerInteger)derSequence[2]).Value.IntValue;
}
else
{
DerSequence derSequence2 = (DerSequence)derSequence[2];
num = ((DerInteger)derSequence2[0]).Value.IntValue;
k = ((DerInteger)derSequence2[1]).Value.IntValue;
k2 = ((DerInteger)derSequence2[2]).Value.IntValue;
}
X9FieldElement x9FieldElement3 = new X9FieldElement(intValue, num, k, k2, (Asn1OctetString)seq[0]);
X9FieldElement x9FieldElement4 = new X9FieldElement(intValue, num, k, k2, (Asn1OctetString)seq[1]);
curve = new F2mCurve(intValue, num, k, k2, x9FieldElement3.Value.ToBigInteger(), x9FieldElement4.Value.ToBigInteger());
}
if (seq.Count == 3)
{
seed = ((DerBitString)seq[2]).GetBytes();
}
}
