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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.