(AutoIt) Create a JWS Using ECDSA P-256 SHA-256

Creates and validates a JSON Web Signature (JWS) that uses ECDSA P-256 SHA-256

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

; 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.

; Use the following ECC key loaded from JWK format.
$oSbJwk = ObjCreate("Chilkat.StringBuilder")
$oSbJwk.Append("{""kty"":""EC"",")
$oSbJwk.Append("""crv"":""P-256"",")
$oSbJwk.Append("""x"":""f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU"",")
$oSbJwk.Append("""y"":""x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"",")
$oSbJwk.Append("""d"":""jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI""")
$oSbJwk.Append("}")

$oEccKey = ObjCreate("Chilkat.PrivateKey")
; Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
; into the private key object. (See the online reference documentation..)
Local $bSuccess = $oEccKey.LoadJwk($oSbJwk.GetAsString())
If ($bSuccess <> True) Then
    ConsoleWrite($oEccKey.LastErrorText & @CRLF)
    Exit
EndIf

; Create the JWS Protected Header
$oJwsProtHdr = ObjCreate("Chilkat.JsonObject")
$oJwsProtHdr.AppendString("alg","ES256")

$oJws = ObjCreate("Chilkat.Jws")

; Set the protected header:
Local $iSignatureIndex = 0
$oJws.SetProtectedHeader($iSignatureIndex,$oJwsProtHdr)

; Set the ECC key:
$oJws.SetPrivateKey($iSignatureIndex,$oEccKey)

; Set the payload.
Local $bIncludeBom = False
Local $sPayloadStr = "In our village, folks say God crumbles up the old moon into stars."
$oJws.SetPayload($sPayloadStr,"utf-8",$bIncludeBom)

; Create the JWS
; By default, the compact serialization is used.
Local $sJwsCompact = $oJws.CreateJws()
If ($oJws.LastMethodSuccess <> True) Then
    ConsoleWrite($oJws.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("JWS: " & $sJwsCompact & @CRLF)

; Note: ECC signatures use random values, so the output will be different each time a signature is produced.
; sample output:
; JWS: eyJhbGciOiJFUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.J6EGTNkeuEjehHHBu0SOKzifm8r35wbx49A5964pxzB7gannyZZPMkK7vmlaPJ-K8Xmm8cZsQySAPC12Xd8avw

; Now load the JWS, validate, and recover the original text.
$oJws2 = ObjCreate("Chilkat.Jws")

; Load the JWS.
$bSuccess = $oJws2.LoadJws($sJwsCompact)

Local $oEccPubKey = $oEccKey.GetPublicKey()

; Set the ECC public key used for validation.
$iSignatureIndex = 0
$oJws2.SetPublicKey($iSignatureIndex,$oEccPubKey)

; Validate the 1st (and only) signature at index 0..
Local $iV = $oJws2.Validate($iSignatureIndex)
If ($iV < 0) Then
    ; Perhaps Chilkat was not unlocked or the trial expired..
    ConsoleWrite("Method call failed for some other reason." & @CRLF)
    ConsoleWrite($oJws2.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)

; Recover the original content:
ConsoleWrite($oJws2.GetPayload("utf-8") & @CRLF)

; Examine the protected header:
Local $oJoseHeader = $oJws2.GetProtectedHeader($iSignatureIndex)
If ($oJws2.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:

; Signature validated.
; In our village, folks say God crumbles up the old moon into stars.
; Protected (JOSE) header:
; { 
;   "alg": "ES256"
; }