(Excel) 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

Download Excel Class Modules Chilkat Excel Class Modules

' 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.

Dim privKey As Chilkat.PrivateKey
Set privKey = Chilkat.NewPrivateKey

' Load an RSA private key from a PEM file.

success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
If (success <> True) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

Dim jwt As Chilkat.Jwt
Set jwt = Chilkat.NewJwt

' Build the JOSE header
Dim jose As Chilkat.JsonObject
Set jose = Chilkat.NewJsonObject
' 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)
Dim claims As Chilkat.JsonObject
Set claims = Chilkat.NewJsonObject
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.

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.

token = jwt.CreateJwtPk(jose.Emit(),claims.Emit(),privKey)

Debug.Print token