DCodec

Schema-based and Schema-less messages for JSON and binary


β	Dynamic Profile Why DCodec Why ASN1 Samples

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Easy to use

Simple and natural interface, works with both, user defined and dynamic data types.

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Text and Binary in one tool

JSON and DER encoding and decoding, easy to switch from one to the other.

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Schema-based validation

Validate that your messages conform to the format you expect.

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No schema? No problem

Works with or without a schema. It's up to you to adhere to a schema or just decode any message.

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Schema versioning and evolution

Supports schema evolution scenarios. You will be able to decode messages that are encoded using a different version of your schema.

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Based on proven standards

DCodec is based on a set of international standards (ISO8824, ISO8825, etc, also known as ASN.1) popular for many protocols, small and large.

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Advanced mismatch detection

DCodec will report what fields are missing from a message and what extra fields there are, and you get to decide how to act.

    // 1. Schema-less (just serialization, no validation)
	var pocoRocket = new {Name = "Falcon", Speed = 30000, Payload = new List<string>{"car", "fuel"}}; // support of plain objects (POCO) 
	var dcodec = new JsonCodec();
	string json = dcodec.Encode(pocoRocket); // {"Name":"Falcon", "Speed":30000, "Payload":[ "car", "fuel"]}
	dynamic dynRocket = dcodec.Decode(json); // dynamic objects 
	if (dynRocket.Speed > 25000)
		Console.WriteLine(dynRocket.Name + " is leaving the Earth orbit.");

	// 2. Schema-based: MySchema DEFINITIONS::=BEGIN Rocket::=SEQUENCE{name[10] UTF8String, speed[11] INTEGER, payload[12] SEQUENCE OF UTF8String} END
	var dvRocket = new DValueObject {{"name", "Atlas"}, {"speed",50000}, {"payload", new DValueArray{"car","fuel"}}}; // dynamic objects
	var codec = new DerCodec(); // DER works as well as JSON
	var schema = new DSchema("Zb5qQl..."); // schema dkey generated at https://asn1.io/dynamic/dkey.aspx
	var msg = codec.Encode(dvRocket, schema.FindType("MySchema.Rocket")); // 301faa070c0541746c6173ab05020300c350ac0d300b0c036361720c046675656c 
	dvRocket = codec.Decode(msg, schema.FindType("MySchema.Rocket")) as DValueObject; // decodes and validates
	if (dvRocket["speed"] > 25000)...

	// 3. Partial decoding, skipping unwanted 
	var coolCodec = new JsonCodec(); // or DerCodec()
	var fullRocket = "{'Name':'Delta', 'Speed':40000, 'Payload':['car','fuel','lot of stuff']}"; // or DER bytes
	var partialRocket = new RocketInfo { Name = "unknown" }; // interested just the Name
	coolCodec.DecoderOptions.ConflictHandler = c => Oss.DCodec.DResponse.Drop;
	partialRocket = coolCodec.Decode<RocketInfo>(fullRocket); // drop unwanted properties (e.g. drop the Payload)
	Console.WriteLine("Countdown for " + partialRocket.Name); // Countdown for Delta

	// 4. TLV decode, schemaless DER parsing
	var tlvs = derCodec.Decode(stream); // DER stream, e.g. 301faa070c0541746c6173ab05020300c350ac0d300b0c036361720c046675656c
	foreach (var tlv in tlvs.Iterator.DescendantsAndSelf)
		Console.WriteLine(tlv);
	// = (Raw)
	//   10=Falcon (String)
	//   11=50000 (Int) ...

How does the DCodec differ from other OSS ASN.1 Tools?

The goal of the DCodec is to offer a familiar, JSON-like, development experience to developers whose applications would benefit from the use of a schema. The dynamic aspect of DCodec offers both, a dynamic API (reflection based) and dynamic schema updates (during runtime).

DCodec is compliant with the Dynamic Profile.
DCodec does not require an ASN.1 compiler to generate bindings, it uses dynamic and/or user defined types.
Schema is loaded dynamically at runtime (in a form of DKey file).
Schema is required to validate the data, but not to parse self-describing formats (JSON or DER). Fields "outside" the schema are available to the application.

If you already have a standardized ASN.1 schema (such as those specified by 3GPP, ETSI, IEEE, SAE, etc.) the full featured OSS ASN.1 Tools may be the right solution for you.

☞ DCodec is a free tool in beta stage with the objective to solidify the API based on your feedback. Currently available only as .NET Standard 2.0 library.

License

You can find the latest license agreement as part of the DCodec library.