(AutoIt) Validate a JWS Using ECDSA P-521 SHA-512

Validates a JSON Web Signature (JWS) that uses ECDSA P-521 SHA-512

Note: This example requires Chilkat v9.5.0.66 or greater.

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

; Note: This example requires Chilkat v9.5.0.66 or greater.

; This example takes a JSON signature in compact serialization format,
; and uses an ECDSA public key to validate and recover the protected header and payload.

; We only need a public key for signature validation.  This is the ECDSA public key
; that is used:

;      {"kty":"EC", 
;       "crv":"P-521", 
;       "x":"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk", 
;       "y":"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2" 
;      } 

$oSbPubKey = ObjCreate("Chilkat.StringBuilder")
$oSbPubKey.Append("{""kty"":""EC"",")
$oSbPubKey.Append("""crv"":""P-521"",")
$oSbPubKey.Append("""x"":""AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk"",")
$oSbPubKey.Append("""y"":""ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2""")
$oSbPubKey.Append("}")

$oPubKey = ObjCreate("Chilkat.PublicKey")
Local $bSuccess = $oPubKey.LoadFromString($oSbPubKey.GetAsString())
If ($bSuccess <> True) Then
    ConsoleWrite($oPubKey.LastErrorText & @CRLF)
    Exit
EndIf

$oJws = ObjCreate("Chilkat.Jws")

; Set the ECC public key:
Local $iSignatureIndex = 0
$oJws.SetPublicKey($iSignatureIndex,$oPubKey)

; Load the JWS.
$oSbJws = ObjCreate("Chilkat.StringBuilder")
$oSbJws.Append("eyJhbGciOiJFUzUxMiJ9")
$oSbJws.Append(".")
$oSbJws.Append("UGF5bG9hZA")
$oSbJws.Append(".")
$oSbJws.Append("AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq")
$oSbJws.Append("wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp")
$oSbJws.Append("EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn")

$bSuccess = $oJws.LoadJwsSb($oSbJws)
If ($bSuccess <> True) Then
    ConsoleWrite($oJws.LastErrorText & @CRLF)
    Exit
EndIf

; Validate the 1st (and only) signature at index 0..
Local $iV = $oJws.Validate($iSignatureIndex)
If ($iV < 0) Then
    ; Perhaps Chilkat was not unlocked or the trial expired..
    ConsoleWrite("Method call failed for some other reason." & @CRLF)
    ConsoleWrite($oJws.LastErrorText & @CRLF)
    Exit
EndIf

If ($iV = 0) Then
    ConsoleWrite("Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both." & @CRLF)
    Exit
EndIf

; If we get here, the signature was validated..
ConsoleWrite("Signature validated." & @CRLF)
ConsoleWrite("--" & @CRLF)

; Recover the original content:
ConsoleWrite("Recovered content:" & @CRLF)
ConsoleWrite($oJws.GetPayload("utf-8") & @CRLF)
ConsoleWrite("--" & @CRLF)

; Examine the protected header:
Local $oJoseHeader = $oJws.GetProtectedHeader($iSignatureIndex)
If ($oJws.LastMethodSuccess <> True) Then
    ConsoleWrite("No protected header found at the given index." & @CRLF)
    Exit
EndIf

$oJoseHeader.EmitCompact = False

ConsoleWrite("Protected (JOSE) header:" & @CRLF)
ConsoleWrite($oJoseHeader.Emit() & @CRLF)

; Output:
; (the string "Payload" was the content that was signed.)

; 	Signature validated.
; 	--
; 	Recovered content:
; 	Payload
; 	--
; 	Protected (JOSE) header:
; 	{
; 	  "alg": "ES512"
; 	}