Classic ASP
Sign PDF with Long-Term Validation (LTV Enabled)

This example demonstrates how to a sign a PDF with long-term validation (LTV) enabled.
Note: This example requires Chilkat v9.5.0.85 or greater.
Chilkat Classic ASP Downloads

Classic ASP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

'  This example requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

set pdf = Server.CreateObject("Chilkat.Pdf")

'  Load a PDF to be signed.
'  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
success = pdf.LoadFile("qa_data/pdf/hello.pdf")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( pdf.LastErrorText) & "</pre>"
    Response.End
End If

'  Options for signing are specified in JSON.
set json = Server.CreateObject("Chilkat.JsonObject")

'  In most cases, the signingCertificateV2 and signingTime attributes are required.
success = json.UpdateInt("signingCertificateV2",1)
success = json.UpdateInt("signingTime",1)

'  Add the "ltvOcsp" instruction to the JSON passed to SignPdf.
'  This is what causes Chilkat to create an LTV-enabled signature.
'  
'  If we are signing a PDF that already has signatures, then the existing signatures
'  are automatically verified, and Chilkat will do OCSP certificate status checking (if possible) 
'  for those certs in existing signatures (including certs in the certificate chains) 
'  that do not yet have a valid OCSP response in the DSS (Document Security Store).
'  Chilkat will add the OCSP responses to the /OCSPs in the Document Security Store (/DSS).
'  Also, and certificates from existing signatures not yet in the DSS are added to the /Certs 
'  in the DSS.
'  
'  Also, the "ltvOcsp" causes Chilkat to add the pdfRevocationInfoArchival authenticated attribute
'  to the CMS signature.  The pdfRevocationInfoArchival attribute (1.2.840.113583.1.1.8)
'  contains OCSP responses and the CRL for the issuer of the signing certificate.
'  Therefore, Chilkat will send an OCSP request to the signing certificate's OCSP URl (if one exists)
'  and will download the CRL from the issuer certificate's CRL Distribution Point (if one exists).
success = json.UpdateBool("ltvOcsp",1)

'  -----------------------------------------------------------------------------------
'  Note: If Chilkat produces a signed PDF, but the signature is not LTV-enabled,
'  the cause might be related to a failure to download CRL's or OCSP requests.
'  See Possible Solution for Failure to Produce LTV-enabled PDF Signature
'  -----------------------------------------------------------------------------------
'  You can add the following to UncommonOptions to get detailed information about the CRL and OCSP requests
'  You shouldn't set the following logging options unless there is a need, because it adds a large amount of information to the LastErrorText.
pdf.UncommonOptions = "LOG_OCSP_HTTP,LOG_CRL_HTTP"

'  Define the appearance of the signature.
success = json.UpdateInt("page",1)
success = json.UpdateString("appearance.y","top")
success = json.UpdateString("appearance.x","left")
success = json.UpdateString("appearance.fontScale","10.0")
success = json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn")
success = json.UpdateString("appearance.text[1]","current_dt")
success = json.UpdateString("appearance.text[2]","This is an LTV-enabled signature.")

'  Load the signing certificate. (Use your own certificate.)
set cert = Server.CreateObject("Chilkat.Cert")
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfxPassword")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( cert.LastErrorText) & "</pre>"
    Response.End
End If

'  Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( pdf.LastErrorText) & "</pre>"
    Response.End
End If

success = pdf.SignPdf(json,"qa_output/hello_ltv_signed.pdf")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( pdf.LastErrorText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "The PDF has been successfully cryptographically signed with long-term validation.") & "</pre>"

'  If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
'  as shown here:
'  (image:https://example-code.com/images/ltv_signature.jpg/endImage)

%>
</body>
</html>