B4X

Add a Detached Signature (Separate Key, Header Control)

Demonstrates the Chilkat Mime.AddDetachedSignaturePk2 method, which creates a detached signature with a separately supplied certificate and private key, and a third argument controlling transfer of the existing message header fields to the new outer entity.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This combines the two variations — certificate and key supplied separately, plus explicit header placement — for the case that needs both. It is the most flexible of the detached-signature methods; choose it when your key material is separate and you also care about where the message headers end up on the signed result.

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Dim success As Boolean = False

Dim mime As ChilkatMime
mime.Initialize
success = mime.SetBodyFromPlainText("This message will be signed.")
If success = False Then
    Log(mime.LastErrorText)
    Return
End If

'  Load the certificate and its private key separately.
Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadFromFile("qa_data/signer.cer")
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")
success = privKey.LoadPemFile("qa_data/signer_privkey.pem")
If success = False Then
    Log(privKey.LastErrorText)
    Return
End If


'  Create a detached signature with separately supplied cert and private key, where the 3rd
'  argument controls whether the existing message header fields are transferred to the new outer
'  multipart/signed entity.
Dim transferHeaderFields As Boolean = True
success = mime.AddDetachedSignaturePk2(cert, privKey, transferHeaderFields)
If success = False Then
    Log(mime.LastErrorText)
    Return
End If


success = mime.SaveMime("qa_output/signed.eml")
If success = False Then
    Log(mime.LastErrorText)
    Return
End If

Log("Detached signature added (headers transferred).")