Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

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

'  The file path is relative to the application's current working directory.  An absolute path
'  may also be used.  Supply the path appropriate to your own environment.
'  Load the signer's public key and set it for validating signature 0.
set pubKey = CreateObject("Chilkat.PublicKey")
success = pubKey.LoadFromFile("qa_data/signer_pubkey.pem")
If (success = 0) Then
    outFile.WriteLine(pubKey.LastErrorText)
    WScript.Quit
End If

success = jws.SetPublicKey(0,pubKey)
If (success = 0) Then
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
End If

'  Validate the signature.  Validate returns 1 when valid, 0 when 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