(C# UWP/WinRT) Create JWT Using RSA (RS256, RS384, or RS512)

Demonstrates how to create a JWT using an RSA private key. This is for JOSE headers with an "alg" of RS256, RS384, or RS512. When RSA is used, the private key signs (creates) the JWT, and the public key is for verification.

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 a JWT using an RSA private key.

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

Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();

// Load an RSA private key from a PEM file.
bool success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd");
if (success != true) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

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

// Build the JOSE header
Chilkat.JsonObject jose = new Chilkat.JsonObject();
// Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
success = jose.AppendString("alg","RS256");
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;

// Create the JWT token.  This is where the RSA signature is created.
string token = jwt.CreateJwtPk(jose.Emit(),claims.Emit(),privKey);

Debug.WriteLine(token);