Xojo Plugin

Set a Per-Recipient JWE Header

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.SetRecipientHeader, which sets the per-recipient unprotected header for a recipient index.

Background. Per-recipient headers carry recipient-specific values such as a key id (kid), and are used with the JSON serialization forms that support multiple recipients.

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Dim success As Boolean
success = False

Dim jwe As New Chilkat.Jwe

//  Protected header: AES key-wrap with AES-256-GCM content encryption.
Dim header As New Chilkat.JsonObject
success = header.UpdateString("alg","A256KW")
success = header.UpdateString("enc","A256GCM")
success = jwe.SetProtectedHeader(header)
If (success = False) Then
    System.DebugLog(jwe.LastErrorText)
    Return
End If

//  The 256-bit key-wrapping key (base64) for recipient index 0.  In production, obtain the key from a
//  secure source rather than hard-coding it.
Dim base64Key As String
base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jwe.SetWrappingKey(0,base64Key,"base64")
If (success = False) Then
    System.DebugLog(jwe.LastErrorText)
    Return
End If

//  Set the per-recipient unprotected header for recipient 0, for example a key id used to identify
//  which key a recipient should use.
Dim recipHeader As New Chilkat.JsonObject
success = recipHeader.UpdateString("kid","recipient-key-1")
success = jwe.SetRecipientHeader(0,recipHeader)
If (success = False) Then
    System.DebugLog(jwe.LastErrorText)
    Return
End If

Dim sbContent As New Chilkat.StringBuilder
success = sbContent.Append("This is the secret content.")
Dim sbJwe As New Chilkat.StringBuilder
success = jwe.EncryptSb(sbContent,"utf-8",sbJwe)
If (success = False) Then
    System.DebugLog(jwe.LastErrorText)
    Return
End If

System.DebugLog(sbJwe.GetAsString())