public static ReadOnlyMemory <byte> GetBitStringBytes(this AsnReader reader, Asn1Tag expectedTag)
{
if (reader.TryGetPrimitiveBitStringValue(expectedTag, out _, out ReadOnlyMemory <byte> contents))
{
return(contents);
}
// Guaranteed too big, because it has the tag and length.
int length = reader.PeekEncodedValue().Length;
byte[] rented = ArrayPool <byte> .Shared.Rent(length);
try
{
if (reader.TryCopyBitStringBytes(expectedTag, rented, out _, out int bytesWritten))
{
return(new ReadOnlyMemory <byte>(rented.AsSpan(0, bytesWritten).ToArray()));
}
Debug.Fail("TryCopyBitStringBytes produced more data than the encoded size");
throw new CryptographicException();
}
finally
{
Array.Clear(rented, 0, length);
ArrayPool <byte> .Shared.Return(rented);
}
}
internal static void Decode(AsnReader reader, Asn1Tag expectedTag, out CurveAsn decoded)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = default;
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
if (sequenceReader.TryGetPrimitiveOctetStringBytes(out ReadOnlyMemory <byte> tmpA))
{
decoded.A = tmpA;
}
else
{
decoded.A = sequenceReader.ReadOctetString();
}
if (sequenceReader.TryGetPrimitiveOctetStringBytes(out ReadOnlyMemory <byte> tmpB))
{
decoded.B = tmpB;
}
else
{
decoded.B = sequenceReader.ReadOctetString();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(Asn1Tag.PrimitiveBitString))
{
if (sequenceReader.TryGetPrimitiveBitStringValue(out _, out ReadOnlyMemory <byte> tmpSeed))
{
decoded.Seed = tmpSeed;
}
else
{
decoded.Seed = sequenceReader.ReadBitString(out _);
}
}
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode(AsnReader reader, Asn1Tag expectedTag, out SubjectPublicKeyInfoAsn decoded)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = default;
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
System.Security.Cryptography.Asn1.AlgorithmIdentifierAsn.Decode(sequenceReader, out decoded.Algorithm);
if (sequenceReader.TryGetPrimitiveBitStringValue(out _, out ReadOnlyMemory <byte> tmpSubjectPublicKey))
{
decoded.SubjectPublicKey = tmpSubjectPublicKey;
}
else
{
decoded.SubjectPublicKey = sequenceReader.ReadBitString(out _);
}
sequenceReader.ThrowIfNotEmpty();
}
