public NtlmMessage(ReadOnlyMemory <byte> ntlm)
{
bool canRead;
BinaryReader reader;
do
{
canRead = CanReadNtlmMessage(ntlm, out byte[] actualSignature, out reader, out AsnReader asnReader);
if (!canRead)
{
throw new InvalidDataException($"Unknown NTLM message signature. Actual: 0x{actualSignature:X}; Expected: 0x{MessageSignature:X}");
}
if (asnReader == null)
{
break;
}
asnReader = asnReader.ReadSequence(NtlmContextTag);
NegTokenResp.Decode(asnReader, out NegTokenResp resp);
ntlm = resp.ResponseToken.Value;
}while (canRead);
MessageType = (NtlmMessageType)reader.ReadInt32();
if (MessageType != NtlmMessageType.Challenge)
{
return;
}
Flags = (NtlmNegotiateFlag)reader.ReadInt32();
var domainNameLength = reader.ReadInt16();
var domainNameMaxLength = reader.ReadInt16();
var domainNameBufferOffset = reader.ReadInt32();
var workstationLength = reader.ReadInt16();
var workstationMaxLength = reader.ReadInt16();
var workstationBufferOffset = reader.ReadInt32();
var version = reader.ReadInt64();
if ((Flags & NtlmNegotiateFlag.NTLMSSP_NEGOTIATE_OEM_DOMAIN_SUPPLIED) > 0)
{
reader.BaseStream.Seek(domainNameBufferOffset, SeekOrigin.Begin);
DomainName = Encoding.ASCII.GetString(reader.ReadBytes(domainNameLength));
}
if ((Flags & NtlmNegotiateFlag.NTLMSSP_NEGOTIATE_OEM_WORKSTATION_SUPPLIED) > 0)
{
reader.BaseStream.Seek(workstationBufferOffset, SeekOrigin.Begin);
Workstation = Encoding.ASCII.GetString(reader.ReadBytes(workstationLength));
}
reader.Dispose();
}
internal static void Decode <T>(AsnReader reader, out T decoded)
where T : NegotiationToken, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
Asn1Tag tag = reader.PeekTag();
AsnReader explicitReader;
if (tag.HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 0)))
{
explicitReader = reader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
NegTokenInit.Decode <NegTokenInit>(explicitReader, out NegTokenInit tmpInitialToken);
decoded.InitialToken = tmpInitialToken;
explicitReader.ThrowIfNotEmpty();
}
else if (tag.HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 1)))
{
explicitReader = reader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
NegTokenResp.Decode <NegTokenResp>(explicitReader, out NegTokenResp tmpResponseToken);
decoded.ResponseToken = tmpResponseToken;
explicitReader.ThrowIfNotEmpty();
}
else
{
throw new CryptographicException();
}
}