Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

Dim success As Boolean = False

Dim jws As New Chilkat.Jws

'  Protected header specifying HMAC-SHA256.
Dim header As New Chilkat.JsonObject
header.UpdateString("alg","HS256")
success = jws.SetProtectedHeader(0,header)
If (success = False) Then
    Debug.WriteLine(jws.LastErrorText)
    Exit Sub
End If


Dim bIncludeBom As Boolean = False
success = jws.SetPayload("This is the content to sign.","utf-8",bIncludeBom)
If (success = False) Then
    Debug.WriteLine(jws.LastErrorText)
    Exit Sub
End If


'  Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
'  base64).  In production, obtain the key from a secure source rather than hard-coding it.
Dim base64Key As String = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws.SetMacKey(0,base64Key,"base64")
If (success = False) Then
    Debug.WriteLine(jws.LastErrorText)
    Exit Sub
End If


Dim jwsCompact As String = jws.CreateJws()
If (jws.LastMethodSuccess = False) Then
    Debug.WriteLine(jws.LastErrorText)
    Exit Sub
End If

Debug.WriteLine(jwsCompact)