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(); } }