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 fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

set jws = CreateObject("Chilkat.Jws")

'  Load the JWS compact serialization.
jwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
success = jws.LoadJws(jwsCompact)
If (success = 0) Then
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
End If

'  Provide the key for signature 0 (here an HMAC key).
base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws.SetMacKey(0,base64Key,"base64")
If (success = 0) Then
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
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.
v = jws.Validate(0)
If (v < 0) Then
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
End If

If (v <> 1) Then
    outFile.WriteLine("The signature is not valid.")
    WScript.Quit
End If

outFile.WriteLine("The signature is valid.")

outFile.Close