C# .NET library for reading and writing TLV (Tag Length Value) encoded data.

This library follows the encoding rules defined in the following standards:

• X.690 ASN.1 encoding rules (ISO/IEC 8825–1):
  • Basic Encoding Rules (BER)
  • Canonical Encoding Rules (CER)
  • Distinguished Encoding Rules (DER)
• EMV 4.2 Book 3, Annex B: Rules for BER-TLV Data Objects

To read all TLV encoded data from a stream/byte array:

TlvEncoding.ProcessTlvStream(stream, 
    (tag, data) => {
        Console.WriteLine($"Tag:{tag} Data:{BitConverter.ToString(data)}");
    });

To write a tag-length-value entry to a stream:

WriteTlv(stream, tag, tagData);

Low level read access:

var tag = TlvEncoding.ReadNextTag(stream);
var length = TlvEncoding.ReadLength(stream);

Low level write access:

TlvEncoding.WriteTag(stream, tag);
TlvEncoding.WriteLength(stream, length);

Available from NuGet: https://www.nuget.org/packages/TlvLib