internal static KeyPair GetKeyPair(byte[] encoded)
{
var parser = new Asn1StreamParser(encoded);
var keyPair = new KeyPair();
parser.ReadObject <DerSequenceParser>();
var version = parser.ReadObject <DerInteger>().Value.IntValue;
if (1 != version)
{
throw new ParsingException($"Expected version 1, got {version}");
}
var octetString = (DerOctetString)parser.ReadObject <DerOctetStringParser>().ToAsn1Object();
keyPair.PrivateKey = new BigInteger(1, octetString.GetOctets());
parser.ReadObject <BerTaggedObjectParser>();
var oid = parser.ReadObject <DerObjectIdentifier>();
if (!BrainpoolP320R1.ObjectIdentifier.Equals(oid))
{
throw new ParsingException($"Expected BrainpoolP320r1 ({BrainpoolP320R1.ObjectIdentifier}), got {oid}");
}
var obj = parser.ReadObject();
if (obj == null)
{
return(keyPair);
}
Asn1StreamParserExtensions.CheckObject <BerTaggedObjectParser>(obj);
try
{
keyPair.PublicKey = BrainpoolP320R1.Curve.DecodePoint(parser.ReadObject <DerBitString>().GetBytes()).Normalize();
}
catch (ArgumentException e)
{
throw new ParsingException("Could not decode point on curve", e);
}
BrainpoolP320R1.G.Multiply(keyPair.PrivateKey).Normalize();
if (!BrainpoolP320R1.G.Multiply(keyPair.PrivateKey).Equals(keyPair.PublicKey))
{
throw new ParsingException("Public key does not belong to private key");
}
return(keyPair);
}
public static T GetEncryptedEntity <T>(byte[] encoded, bool isPseudonym) where T : EncryptedEntity, new()
{
var parser = new Asn1StreamParser(encoded);
var entity = new T();
parser.ReadObject <DerSequenceParser>();
parser.ReadObject <DerSequenceParser>();
var oid = parser.ReadObject <DerObjectIdentifier>().Id;
AssertBsnkTypeIsCorrect(oid, isPseudonym);
entity.SchemeVersion = parser.ReadObject <DerInteger>().Value.IntValue;
entity.SchemeKeyVersion = parser.ReadObject <DerInteger>().Value.IntValue;
parser.ReadObject <DerIA5String>(); //Creator, not used
entity.Recipient = parser.ReadObject <DerIA5String>().GetString();
entity.RecipientKeySetVersion = parser.ReadObject <DerInteger>().Value.IntValue;
if (isPseudonym)
{
var obj = parser.ReadObject();
if (obj is DerIA5String derIa5String)
{
derIa5String.GetString();
parser.ReadObject <DerInteger>(); //Type, not used
}
else
{
Asn1StreamParserExtensions.CheckObject <DerInteger>(obj); //Type, not used
}
}
parser.ReadObject <DerSequenceParser>();
for (var i = 0; i < entity.Points.Length; i++)
{
var octet =
(DerOctetString)parser.ReadObject <DerOctetStringParser>().ToAsn1Object();
try
{
entity.Points[i] = BrainpoolP320R1.Curve.DecodePoint(octet.GetOctets());
}
catch (ArgumentException e)
{
throw new ParsingException("Could not decode point on curve", e);
}
}
return(entity);
}