(C# UWP/WinRT) Create JWT Using HS256, HS384, or HS512

Demonstrates how to create a JWT using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.) When HMAC is used, the secret is a shared secret (i.e. password) that both client and server know beforehand.

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// Demonstrates how to create an HMAC JWT using a shared secret (password).

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.Jwt jwt = new Chilkat.Jwt();

// Build the JOSE header
Chilkat.JsonObject jose = new Chilkat.JsonObject();
// Use HS256.  Pass the string "HS384" or "HS512" to use a different algorithm.
bool success = jose.AppendString("alg","HS256");
success = jose.AppendString("typ","JWT");

// Now build the JWT claims (also known as the payload)
Chilkat.JsonObject claims = new Chilkat.JsonObject();
success = claims.AppendString("iss","http://example.org");
success = claims.AppendString("sub","John");
success = claims.AppendString("aud","http://example.com");

// Set the timestamp of when the JWT was created to now.
int curDateTime = jwt.GenNumericDate(0);
success = claims.AddIntAt(-1,"iat",curDateTime);

// Set the "not process before" timestamp to now.
success = claims.AddIntAt(-1,"nbf",curDateTime);

// Set the timestamp defining an expiration time (end time) for the token
// to be now + 1 hour (3600 seconds)
success = claims.AddIntAt(-1,"exp",curDateTime + 3600);

// Produce the smallest possible JWT:
jwt.AutoCompact = true;

string strJwt = jwt.CreateJwt(jose.Emit(),claims.Emit(),"secret");

Debug.WriteLine(strJwt);