Ruby

Sign PDF with Long-Term Validation (LTV Enabled)

See more PDF Signatures Examples

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.

Ruby

require 'chilkat'

success = false

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

pdf = Chilkat::CkPdf.new()

#  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 == false)
    print pdf.lastErrorText() + "\n";
    exit
end

#  Options for signing are specified in JSON.
json = Chilkat::CkJsonObject.new()

#  In most cases, the signingCertificateV2 and signingTime attributes are required.
json.UpdateInt("signingCertificateV2",1)
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).
json.UpdateBool("ltvOcsp",true)

#  -----------------------------------------------------------------------------------
#  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.put_UncommonOptions("LOG_OCSP_HTTP,LOG_CRL_HTTP")

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

#  Load the signing certificate. (Use your own certificate.)
cert = Chilkat::CkCert.new()
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfxPassword")
if (success == false)
    print cert.lastErrorText() + "\n";
    exit
end

#  Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

success = pdf.SignPdf(json,"qa_output/hello_ltv_signed.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "The PDF has been successfully cryptographically signed with long-term validation." + "\n";

#  If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
#  as shown here:
#