PowerBuilder

Add an S/MIME Detached Signature

Demonstrates the Chilkat Mime.AddDetachedSignature method, which creates an S/MIME detached signature. The only argument is the signing Cert, which must have access to its private key. On success the entity becomes a multipart/signed with the content and a separate signature part.

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: A detached signature (multipart/signed) keeps the original content readable alongside a separate signature part — so recipients whose software does not understand S/MIME still see the message, they just cannot verify it. That backward compatibility makes detached the usual choice for signed email. The signer proves authorship with a certificate that carries its private key.

Chilkat PowerBuilder Downloads

Download Chilkat for PowerBuilder

PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Mime
string ls_PfxPassword
oleobject loo_Cert

li_Success = 0

loo_Mime = create oleobject
li_rc = loo_Mime.ConnectToNewObject("Chilkat.Mime")
if li_rc < 0 then
    destroy loo_Mime
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_Success = loo_Mime.SetBodyFromPlainText("This message will be signed.")
if li_Success = 0 then
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    return
end if

//  Load the signing certificate (which must have access to its private key) from a PFX file.
//  The PFX password should come from a secure source rather than being hard-coded.
ls_PfxPassword = "myPfxPassword"
loo_Cert = create oleobject
li_rc = loo_Cert.ConnectToNewObject("Chilkat.Cert")

li_Success = loo_Cert.LoadPfxFile("qa_data/signer.pfx",ls_PfxPassword)
if li_Success = 0 then
    Write-Debug loo_Cert.LastErrorText
    destroy loo_Mime
    destroy loo_Cert
    return
end if

//  Create an S/MIME detached signature.  The object becomes a multipart/signed entity with the
//  original content and a separate signature part.
li_Success = loo_Mime.AddDetachedSignature(loo_Cert)
if li_Success = 0 then
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    destroy loo_Cert
    return
end if

li_Success = loo_Mime.SaveMime("qa_output/signed.eml")
if li_Success = 0 then
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    destroy loo_Cert
    return
end if

Write-Debug "Detached signature added."


destroy loo_Mime
destroy loo_Cert