B4X

Set the Optional JWS Unprotected Header

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetUnprotectedHeader, which sets the optional unprotected header for a signature.

Background. Unlike the protected header, the unprotected header is not covered by the signature. It is carried in the JSON serialization forms of a JWS, so producing a JWS with an unprotected header yields a JSON serialization rather than compact form.

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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


'  Set the optional unprotected header for signature 0.  Unlike the protected header, it is not
'  covered by the signature.  It is carried in the JSON serialization forms of a JWS.
Dim unprotected As ChilkatJsonObject
unprotected.Initialize
unprotected.UpdateString("kid", "signer-key-1")
success = jws.SetUnprotectedHeader(0, unprotected)
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


Dim base64Key As String = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws.SetMacKey(0, base64Key, "base64")
If success = False Then
    Log(jws.LastErrorText)
    Return
End If


'  Because an unprotected header is present, the JWS is produced in a JSON serialization form.
Dim jwsJson As String = jws.CreateJws
If jws.LastMethodSuccess = False Then
    Log(jws.LastErrorText)
    Return
End If

Log(jwsJson)