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.

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


'  Provide the key for signature 0 (here an HMAC key).
Dim base64Key As String = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws.SetMacKey(0, base64Key, "base64")
If success = False Then
    Log(jws.LastErrorText)
    Return
End If


'  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.
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.")