PowerBuilder
PowerBuilder
Verify the Digital Signatures on an Email
See more Email Object Examples
Demonstrates the read-only Chilkat Email.SignaturesValid property, which is true when the email was received with one or more digital signatures and all of them validated, indicating the message was not altered. It is only meaningful when ReceivedSigned is true, so this example checks that first.
Background: A valid signature proves integrity — the bytes that were signed are exactly the bytes you received — but that is not the same as trust. A message can carry a perfectly valid signature from a certificate you have no reason to trust (self-signed, expired, or from an unknown issuer). So after confirming
SignaturesValid, an application that needs assurance of who signed should separately examine the signer certificate and its chain (see LastSignerCert).Chilkat PowerBuilder Downloads
integer li_rc
integer li_Success
oleobject loo_Email
li_Success = 0
// Demonstrates the read-only Email.SignaturesValid property, which is true if the email
// was received with one or more digital signatures AND all of them validated (indicating
// the email was not altered). It is only meaningful when ReceivedSigned is true.
loo_Email = create oleobject
li_rc = loo_Email.ConnectToNewObject("Chilkat.Email")
if li_rc < 0 then
destroy loo_Email
MessageBox("Error","Connecting to COM object failed")
return
end if
li_Success = loo_Email.LoadEml("qa_data/eml/signed.eml")
if li_Success = 0 then
Write-Debug loo_Email.LastErrorText
destroy loo_Email
return
end if
if loo_Email.ReceivedSigned = 1 then
if loo_Email.SignaturesValid = 1 then
Write-Debug "The signature(s) verified: the email was not altered."
else
Write-Debug "Signature verification FAILED."
end if
else
Write-Debug "This email was not received with a digital signature."
end if
// Note: Paths such as "qa_data/..." are relative local filesystem paths,
// relative to the current working directory of the running application.
destroy loo_Email