Lianja

Get an S/MIME Signing Time

Demonstrates the Chilkat Mime.GetSignatureSigningTimeStr method, which returns the CMS signingTime attribute for the signer at a zero-based index, as an RFC 822-style date string in GMT. The only argument is the signer index.

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 is the timestamp the signer asserted at signing — useful for "when was this signed" audit trails and for evaluating whether the signing certificate was valid at that moment. Because it is a signed attribute, it is tamper-evident. Guard the call with HasSignatureSigningTime, since the attribute is optional. Note it is the signer's claim, not a trusted third-party timestamp.

Chilkat Lianja Downloads

Download Chilkat for Lianja

Lianja

llSuccess = .F.

loMime = createobject("CkMime")
llSuccess = loMime.LoadMimeFile("qa_data/signed.eml")
if (llSuccess = .F.) then
    ? loMime.LastErrorText
    release loMime
    return
endif

//  After verifying, get the CMS signingTime for each signer that has one, as an RFC 822 date string
//  in GMT.  The only argument is the zero-based signer index.
llSuccess = loMime.Verify()
if (llSuccess <> .T.) then
    ? loMime.LastErrorText
    release loMime
    return
endif

n = loMime.NumSignerCerts

for i = 0 to n - 1
    //  Only signers that included a signing time have one to retrieve.
    if (loMime.HasSignatureSigningTime(i)) then
        lcSigningTime = loMime.GetSignatureSigningTimeStr(i)
        if (loMime.LastMethodSuccess = .F.) then
            ? loMime.LastErrorText
            release loMime
            return
        endif

        ? "Signer " + str(i) + " signing time: " + lcSigningTime
    endif

next


release loMime