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Visual Basic 6.0

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.

Background. HMAC-based JWS (for example HS256) authenticates the payload with a shared symmetric key that both signer and verifier possess.

Chilkat Visual Basic 6.0 Downloads

Visual Basic 6.0
Dim success As Long
success = 0

Dim jws As New ChilkatJws

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

Dim bIncludeBom As Long
bIncludeBom = 0
success = jws.SetPayload("This is the content to sign.","utf-8",bIncludeBom)
If (success = 0) Then
    Debug.Print 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
base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws.SetMacKey(0,base64Key,"base64")
If (success = 0) Then
    Debug.Print jws.LastErrorText
    Exit Sub
End If

Dim jwsCompact As String
jwsCompact = jws.CreateJws()
If (jws.LastMethodSuccess = 0) Then
    Debug.Print jws.LastErrorText
    Exit Sub
End If

Debug.Print jwsCompact