Classic ASP

JWE using PBES2 Key Wrapping

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create and decrypt a JWE that using PBES2 key wrapping.

This example demonstrates PBES2 with HMAC SHA-256 and A128KW wrapping. It is also possible to do the following by simply changing the "alg" parameter:

PBES2 with HMAC SHA-384 and A192KW wrapping
PBES2 with HMAC SHA-512 and A256KW wrapping

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","PBES2-HS256+A128KW")
success = jweProtHdr.AppendString("enc","A128GCM")

'  PBES2 requires two additional parameters:
'  1) A random salt parameter ("p2s") containing 8 or more bytes in base64url format.
'  2) An iteration count parameter ("p2c").  A minimum count of 1000 is recommended.
'     The iteration count is intended to make the PBES2 computation more expensive (time consuming)
'     to prevent brute-force attacks.
set prng = Server.CreateObject("Chilkat.Prng")
success = jweProtHdr.AppendString("p2s",prng.GenRandom(16,"base64url"))
success = jweProtHdr.AppendString("p2c","1000")

Response.Write "<pre>" & Server.HTMLEncode( "JWE Protected Header: " & jweProtHdr.Emit()) & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "--") & "</pre>"

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

'  Set the PBES2 password
recipientIndex = 0
success = jwe.SetPassword(recipientIndex,"top secret")

'  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

'  Set the PBES2 password
success = jwe2.SetPassword(recipientIndex,"top secret")

'  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:

'  JWE Protected Header: {"alg":"PBES2-HS256+A128KW","enc":"A128GCM","p2s":"z39rTEfRy1T1Yn_D1mZRlg","p2c":"1000"}
'  --
'  eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJzIjoiejM5clRFZlJ5MVQxWW5fRDFtWlJsZyIsInAyYyI6IjEwMDAifQ.koYt6PrFmYwcwdcT7ZcvXHA1d-Xez5h4.luGlbvEnZp-7IsBOj42Yhw.YMTcfLf8Qe4zazozGV2OAu3cUdQ8Kg.rWub47ESWkc6IqZJTvSTmg
'  original text: 
'  Live long and prosper.

%>
</body>
</html>