Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

Dim success As Boolean = False

Dim jws As ChilkatJws
jws.Initialize

'  Load the JWS compact serialization.
Dim jwsCompact As String = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
success = jws.LoadJws(jwsCompact)
If success = False Then
    Log(jws.LastErrorText)
    Return
End If


'  The file path is relative to the application's current working directory.  An absolute path
'  may also be used.  Supply the path appropriate to your own environment.
'  Load the signer's public key and set it for validating signature 0.
Dim pubKey As ChilkatPublicKey
pubKey.Initialize
success = pubKey.LoadFromFile("qa_data/signer_pubkey.pem")
If success = False Then
    Log(pubKey.LastErrorText)
    Return
End If

success = jws.SetPublicKey(0, pubKey)
If success = False Then
    Log(jws.LastErrorText)
    Return
End If


'  Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
Dim v As Int = jws.Validate(0)
If v < 0 Then
    Log(jws.LastErrorText)
    Return
End If

If v <> 1 Then
    Log("The signature is not valid.")
    Return
End If

Log("The signature is valid.")