Visual FoxPro

Verify JWT Using an ECC Public Key (ES256, ES384, ES512)

See more JSON Web Token (JWT) Examples

Demonstrates how to verify a JWT that was signed using an ECC private key.

This example verifies the ECC signature. It also does the following:

• Checks to see if the time constraints ("nbf" and "exp") are valid.
• Recovers the original JOSE header.
• Recovers the original claims JSON.

Visual FoxPro

LOCAL lnSuccess
LOCAL loPubKey
LOCAL loJwt
LOCAL lcToken
LOCAL lnSigVerified
LOCAL lnLeeway
LOCAL lnBTimeValid
LOCAL lcPayload
LOCAL loJson
LOCAL lcJoseHeader

lnSuccess = 0

* Demonstrates how to verify an JWT using an ECC public key.

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

loPubKey = CreateObject('Chilkat.PublicKey')
lnSuccess = loPubKey.LoadFromFile("qa_data/pem/ecc_public.pem")

loJwt = CreateObject('Chilkat.Jwt')

lcToken = "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDg1NzA4NzkyLCJuYmYiOjE0ODU3MDg3OTIsImV4cCI6MTQ4NTcxMjM5Mn0.wqsuyJpxJ073ox-lOiLFqG1lQocXe4hGf2XGZJRrO3qn0UusxI_bu3Gzky8gBsH4sA4u9TWZn5M-1wYMMIJk6Q"

* First verify the signature.
lnSigVerified = loJwt.VerifyJwtPk(lcToken,loPubKey)
? "verified: " + STR(lnSigVerified)

* Let's see if the time constraints, if any, are valid.
* The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
* If the current system time is before the "nbf" time, or after the "exp" time,
* then IsTimeValid will return false/0.
* Also, we'll allow a leeway of 60 seconds to account for any clock skew.
* Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
lnLeeway = 60
lnBTimeValid = loJwt.IsTimeValid(lcToken,lnLeeway)
? "time constraints valid: " + STR(lnBTimeValid)

* Now let's recover the original claims JSON (the payload).
lcPayload = loJwt.GetPayload(lcToken)
* The payload will likely be in compact form:
? lcPayload

* We can format for human viewing by loading it into Chilkat's JSON object
* and emit.
loJson = CreateObject('Chilkat.JsonObject')
lnSuccess = loJson.Load(lcPayload)
loJson.EmitCompact = 0
? loJson.Emit()

* We can recover the original JOSE header in the same way:
lcJoseHeader = loJwt.GetHeader(lcToken)
* The payload will likely be in compact form:
? lcJoseHeader

* We can format for human viewing by loading it into Chilkat's JSON object
* and emit.
lnSuccess = loJson.Load(lcJoseHeader)
loJson.EmitCompact = 0
? loJson.Emit()

RELEASE loPubKey
RELEASE loJwt
RELEASE loJson