(Visual FoxPro) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loPrivKey
LOCAL lnSuccess
LOCAL loJwt
LOCAL loJose
LOCAL loClaims
LOCAL lnCurDateTime
LOCAL lcToken

* 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.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.PrivateKey')
loPrivKey = CreateObject('Chilkat.PrivateKey')

* Load an RSA private key from a PEM file.
lnSuccess = loPrivKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
IF (lnSuccess <> 1) THEN
    ? loPrivKey.LastErrorText
    RELEASE loPrivKey
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Jwt')
loJwt = CreateObject('Chilkat.Jwt')

* Build the JOSE header
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJose = CreateObject('Chilkat.JsonObject')
* Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
lnSuccess = loJose.AppendString("alg","RS256")
lnSuccess = loJose.AppendString("typ","JWT")

* Now build the JWT claims (also known as the payload)
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loClaims = CreateObject('Chilkat.JsonObject')
lnSuccess = loClaims.AppendString("iss","http://example.org")
lnSuccess = loClaims.AppendString("sub","John")
lnSuccess = loClaims.AppendString("aud","http://example.com")

* Set the timestamp of when the JWT was created to now.
lnCurDateTime = loJwt.GenNumericDate(0)
lnSuccess = loClaims.AddIntAt(-1,"iat",lnCurDateTime)

* Set the "not process before" timestamp to now.
lnSuccess = loClaims.AddIntAt(-1,"nbf",lnCurDateTime)

* Set the timestamp defining an expiration time (end time) for the token
* to be now + 1 hour (3600 seconds)
lnSuccess = loClaims.AddIntAt(-1,"exp",lnCurDateTime + 3600)

* Produce the smallest possible JWT:
loJwt.AutoCompact = 1

* Create the JWT token.  This is where the RSA signature is created.
lcToken = loJwt.CreateJwtPk(loJose.Emit(),loClaims.Emit(),loPrivKey)

? lcToken

RELEASE loPrivKey
RELEASE loJwt
RELEASE loJose
RELEASE loClaims