PowerBuilder

Check for an S/MIME Signing Time

Demonstrates the Chilkat Mime.HasSignatureSigningTime method, which returns whether the signer at a zero-based index included a CMS signingTime signed attribute. The only argument is the signer index; use NumSignerCerts for the count.

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 signing time records when the signer claims to have signed, which matters for auditing and for validating a certificate that has since expired. It is an optional signed attribute, so not every signature has one — this predicate lets you check before calling GetSignatureSigningTimeStr, avoiding an error for signers that omitted it. Being a signed attribute, it is covered by the signature and cannot be altered undetected.

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PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Mime
integer n
integer i

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

//  After verifying, check whether each signer included a CMS signingTime signed attribute.  The
//  only argument is the zero-based signer index.
li_Success = loo_Mime.Verify()
if li_Success <> 1 then
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    return
end if

n = loo_Mime.NumSignerCerts

for i = 0 to n - 1
    if loo_Mime.HasSignatureSigningTime(i) then
        Write-Debug "Signer " + string(i) + " included a signing time."
    else
        Write-Debug "Signer " + string(i) + " did not include a signing time."
    end if

next


destroy loo_Mime