Classic ASP

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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Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

'  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.

plaintext = "Live long and prosper."

set jwe = Server.CreateObject("Chilkat.Jwe")

'  First build the JWE Protected Header..
set jweProtHdr = Server.CreateObject("Chilkat.JsonObject")
success = jweProtHdr.AppendString("alg","dir")
success = jweProtHdr.AppendString("enc","A128GCM")

'  Don't forget to actually provide the protected header to the JWE object:
success = jwe.SetProtectedHeader(jweProtHdr)

'  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.

recipientIndex = 0
success = jwe.SetWrappingKey(recipientIndex,"000102030405060708090A0B0C0D0E0F","hex")

'  Encrypt and return the JWE:
strJwe = jwe.Encrypt(plaintext,"utf-8")
If (jwe.LastMethodSuccess <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( jwe.LastErrorText) & "</pre>"
    Response.End
End If

'  Show the JWE we just created:
Response.Write "<pre>" & Server.HTMLEncode( strJwe) & "</pre>"

'  Decrypt the JWE.
set jwe2 = Server.CreateObject("Chilkat.Jwe")
success = jwe2.LoadJwe(strJwe)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( jwe2.LastErrorText) & "</pre>"
    Response.End
End If

success = jwe2.SetWrappingKey(0,"000102030405060708090A0B0C0D0E0F","hex")

'  Decrypt.
originalPlaintext = jwe2.Decrypt(0,"utf-8")
If (jwe2.LastMethodSuccess <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( jwe2.LastErrorText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "original text: ") & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( originalPlaintext) & "</pre>"

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

%>
</body>
</html>