Validate a JWS Signature

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.Validate, which validates exactly one signature, identified by a zero-based index, using the key configured at that same index.

LOCAL lnSuccess
LOCAL loJws
LOCAL lcJwsCompact
LOCAL lcBase64Key
LOCAL v

lnSuccess = 0

loJws = CreateObject('Chilkat.Jws')

*  Load the JWS compact serialization.
lcJwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
lnSuccess = loJws.LoadJws(lcJwsCompact)
IF (lnSuccess = 0) THEN
    ? loJws.LastErrorText
    RELEASE loJws
    CANCEL
ENDIF

*  Provide the key for signature 0 (here an HMAC key).
lcBase64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
lnSuccess = loJws.SetMacKey(0,lcBase64Key,"base64")
IF (lnSuccess = 0) THEN
    ? loJws.LastErrorText
    RELEASE loJws
    CANCEL
ENDIF

*  Validate the signature identified by the zero-based index, using the key configured at that index.
*  Validate returns 1 when the signature or MAC is cryptographically valid, 0 when it is not, or a
*  negative value on error.
v = loJws.Validate(0)
IF (v < 0) THEN
    ? loJws.LastErrorText
    RELEASE loJws
    CANCEL
ENDIF

IF (v <> 1) THEN
    ? "The signature is not valid."
    RELEASE loJws
    CANCEL
ENDIF

? "The signature is valid."

RELEASE loJws