private static byte[] ReadPrimeFieldElement(XmlReader reader, string localName, string ns, int keyLength)
{
var isEmpty = reader.IsEmptyElement;
if (!reader.MoveToAttribute(TypeTag, XmlSchema.InstanceNamespace))
{
throw new NotImplementedException();
}
reader.ReadAttributeValue();
var xsiType = reader.Value;
if (xsiType != PrimeFieldElemTypeValue)
{
throw new NotImplementedException();
}
if (!reader.MoveToAttribute(ValueTag))
{
throw new NotImplementedException();
}
reader.ReadAttributeValue();
var result = CryptoUtils.ToNormalizedByteArray(
BigInteger.Parse(reader[ValueTag], CultureInfo.InvariantCulture),
keyLength);
reader.MoveToElement();
reader.ReadStartElement(localName, ns);
if (!isEmpty)
{
reader.ReadEndElement();
}
return(result);
}
public ECPoint ToECPoint(int keySize)
{
var size = keySize / 8;
return(new ECPoint
{
X = CryptoUtils.ToNormalizedByteArray(X, size),
Y = CryptoUtils.ToNormalizedByteArray(Y, size),
});
}
private static byte[] ReadPrimeFieldParameters(XmlReader reader, string localName, string ns, int keyLength)
{
reader.ReadStartElement(localName, ns);
reader.MoveToContent();
var value = CryptoUtils.ToNormalizedByteArray(
BigInteger.Parse(reader.ReadElementContentAsString(PTag, Namespace), CultureInfo.InvariantCulture),
keyLength);
reader.ReadEndElement();
return(value);
}
private static ECCurve ReadExplicitParameters(XmlReader reader, int keyLength)
{
reader.ReadStartElement(ExplicitParamsTag, Namespace);
reader.MoveToContent();
var prime = ReadPrimeFieldParameters(reader, FieldParamsTag, Namespace, keyLength);
reader.MoveToContent();
reader.ReadStartElement(CurveParamsTag, Namespace);
reader.MoveToContent();
var a = ReadPrimeFieldElement(reader, ATag, Namespace, keyLength);
reader.MoveToContent();
var b = ReadPrimeFieldElement(reader, BTag, Namespace, keyLength);
reader.ReadEndElement();
reader.MoveToContent();
reader.ReadStartElement(BasePointParamsTag, Namespace);
reader.MoveToContent();
var baseBoint = ReadECPoint(reader, BasePointTag, Namespace, keyLength);
reader.MoveToContent();
var order = CryptoUtils.ToNormalizedByteArray(
BigInteger.Parse(reader.ReadElementContentAsString(OrderTag, Namespace), CultureInfo.InvariantCulture),
keyLength);
byte[]? cofactor;
if (reader.IsStartElement(CofactorTag, Namespace))
{
cofactor = CryptoUtils.ToNormalizedByteArray(
BigInteger.Parse(reader.ReadElementContentAsString(), CultureInfo.InvariantCulture),
keyLength);
}
else
{
cofactor = null;
}
reader.ReadEndElement();
reader.ReadEndElement();
return(new ECCurve
{
CurveType = ECCurve.ECCurveType.PrimeShortWeierstrass,
Prime = prime,
A = a,
B = b,
G = baseBoint,
Order = order,
Cofactor = cofactor,
});
}