VBScript Requires Chilkat v11.0.0+

Validate JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) using HMAC SHA-256. VBScript

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

'  This requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

'  This example takes a JSON signature in compact serialization format,
'  and uses a MAC key to validate and recover the protected header and payload.

set jws = CreateObject("Chilkat.Jws")

'  Set the HMAC key:
hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
signatureIndex = 0
success = jws.SetMacKey(signatureIndex,hmacKey,"base64url")

'  Load the JWS.
jwsCompact = "eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
success = jws.LoadJws(jwsCompact)

'  Validate the 1st (and only) signature at index 0..
v = jws.Validate(signatureIndex)
If (v < 0) Then
    '  Perhaps Chilkat was not unlocked or the trial expired..
    outFile.WriteLine("Method call failed for some other reason.")
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
End If

If (v = 0) Then
    outFile.WriteLine("Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both.")
    WScript.Quit
End If

'  If we get here, the signature was validated..
outFile.WriteLine("Signature validated.")

'  Recover the original content:
outFile.WriteLine("Recovered content:")
outFile.WriteLine(jws.GetPayload("utf-8"))

'  Examine the protected header:

set joseHeader = CreateObject("Chilkat.JsonObject")
success = jws.GetProtectedH(signatureIndex,joseHeader)
If (success = 0) Then
    outFile.WriteLine(jws.LastErrorText)
    WScript.Quit
End If

joseHeader.EmitCompact = 0

outFile.WriteLine("Protected (JOSE) header:")
outFile.WriteLine(joseHeader.Emit())

'  Output:

'  	Signature validated.
'  	Recovered content:
'  	{"iss":"joe",
'  	 "exp":1300819380,
'  	 "http://example.com/is_root":true}
'  	Protected (JOSE) header:
'  	{ 
'  	  "typ": "JWT",
'  	  "alg": "HS256"
'  	}

outFile.Close