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JWE using "dir" Direct use of Shared Symmetric Key

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create a JWE using the "dir" alg -- which is to directly use a shared symmetric key.

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

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Local $bSuccess = False

; 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.

Local $sPlaintext = "Live long and prosper."

$oJwe = ObjCreate("Chilkat.Jwe")

; First build the JWE Protected Header..
$oJweProtHdr = ObjCreate("Chilkat.JsonObject")
$oJweProtHdr.AppendString("alg","dir")
$oJweProtHdr.AppendString("enc","A128GCM")

; Don't forget to actually provide the protected header to the JWE object:
$oJwe.SetProtectedHeader($oJweProtHdr)

; The JWE is to use 128-bit AES GCM encryption as specified by the "enc" parameter.
; Given that the "alg" = "dir", we are to directly specify the AES GCM key.
; (It is assumed that the decrypting side also has knowledge of the direct key to be used..)

; Our key will be these 16 hex bytes: 000102030405060708090A0B0C0D0E0F

; The SetWrappingKey method is also used for "dir" direct keys.
; However, if there are multiple recipients, they must all share the same CEK (Content Encryption Key),
; which is specified by calling SetWrappingKey with an index of 0.

Local $iRecipientIndex = 0
$oJwe.SetWrappingKey($iRecipientIndex,"000102030405060708090A0B0C0D0E0F","hex")

; Encrypt and return the JWE:
Local $strJwe = $oJwe.Encrypt($sPlaintext,"utf-8")
If ($oJwe.LastMethodSuccess <> True) Then
    ConsoleWrite($oJwe.LastErrorText & @CRLF)
    Exit
EndIf

; Show the JWE we just created:
ConsoleWrite($strJwe & @CRLF)

; Decrypt the JWE.
$oJwe2 = ObjCreate("Chilkat.Jwe")
$bSuccess = $oJwe2.LoadJwe($strJwe)
If ($bSuccess <> True) Then
    ConsoleWrite($oJwe2.LastErrorText & @CRLF)
    Exit
EndIf

$oJwe2.SetWrappingKey(0,"000102030405060708090A0B0C0D0E0F","hex")

; Decrypt.
Local $sOriginalPlaintext = $oJwe2.Decrypt(0,"utf-8")
If ($oJwe2.LastMethodSuccess <> True) Then
    ConsoleWrite($oJwe2.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("original text: " & @CRLF)
ConsoleWrite($sOriginalPlaintext & @CRLF)

; Sample output:
; eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..20HX5Huc7f1nQC4pBUtiCQ.axFZIxtZy5j0ifJQUzGXLKIpsBuxJA.eBrOC-NrsreN6JeGuOPk1g
; original text: 
; Live long and prosper.