B4X

Create JWT using Smart Card

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an RSA private key and certificate on a smart card. 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

Note: This example requires Chilkat v9.5.0.99 or later.

B4X

Dim success As Boolean = False

'  Demonstrates how to create a JWT using an RSA private key and certificate on a smart card.

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

Dim jwt As ChilkatJwt
jwt.Initialize
Dim cert As ChilkatCert
cert.Initialize("cert")

success = cert.LoadFromSmartcard("")
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  Build the JOSE header
Dim jose As ChilkatJsonObject
jose.Initialize
'  Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
jose.UpdateString("alg", "RS256")
jose.UpdateString("typ", "JWT")
jose.UpdateString("x5c[0]", cert.GetEncoded)

'  Now build the JWT claims (also known as the payload)
Dim claims As ChilkatJsonObject
claims.Initialize
claims.UpdateString("iss", "http://example.org")
claims.UpdateString("sub", "John")
claims.UpdateString("aud", "http://example.com")

'  Set the timestamp of when the JWT was created to now.
Dim curDateTime As Int = jwt.GenNumericDate(0)
claims.UpdateInt("iat", curDateTime)

'  Set the "not process before" timestamp to now.
claims.UpdateInt("nbf", curDateTime)

'  Set the timestamp defining an expiration time (end time) for the token
'  to be now + 1 hour (3600 seconds)
claims.UpdateInt("exp", curDateTime + 3600)

'  Produce the smallest possible JWT:
jwt.AutoCompact = True

'  Create the JWT token.  This is where the RSA signature is created.
Dim token As String = jwt.CreateJwtCert(jose.Emit, claims.Emit, cert)

Log(token)