B4X

Encrypt StringBuilder Content to a JWE

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.EncryptSb, which encrypts content supplied in a StringBuilder and writes the resulting JWE into another StringBuilder.

Background. JWE (JSON Web Encryption) protects content with a content-encryption algorithm (the header enc value) while the content-encryption key is managed by the key-management algorithm (the header alg value). This example uses AES key wrapping with a symmetric wrapping key.

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Dim success As Boolean = False

Dim jwe As ChilkatJwe
jwe.Initialize

'  Set the JWE protected header, specifying the key-management algorithm (alg) and the content-
'  encryption algorithm (enc).
Dim header As ChilkatJsonObject
header.Initialize
header.UpdateString("alg", "A256KW")
header.UpdateString("enc", "A256GCM")
success = jwe.SetProtectedHeader(header)
If success = False Then
    Log(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 = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jwe.SetWrappingKey(0, base64Key, "base64")
If success = False Then
    Log(jwe.LastErrorText)
    Return
End If


'  Encrypt content supplied in a StringBuilder, writing the resulting JWE into another StringBuilder.
Dim sbContent As ChilkatStringBuilder
sbContent.Initialize
sbContent.Append("This is the secret content.")

Dim sbJwe As ChilkatStringBuilder
sbJwe.Initialize
success = jwe.EncryptSb(sbContent, "utf-8", sbJwe)
If success = False Then
    Log(jwe.LastErrorText)
    Return
End If

Log(sbJwe.GetAsString)