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 ChilkatJws
jws.Initialize

'  Protected header specifying HMAC-SHA256.
Dim header As ChilkatJsonObject
header.Initialize
header.UpdateString("alg", "HS256")
success = jws.SetProtectedHeader(0, header)
If success = False Then
    Log(jws.LastErrorText)
    Return
End If


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


Dim jwsCompact As String = jws.CreateJws
If jws.LastMethodSuccess = False Then
    Log(jws.LastErrorText)
    Return
End If

Log(jwsCompact)