Xbase++ Requires Chilkat v9.5.0.85+

Sign PDF with Timestamp from TSA (Timestamp Server Authority)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF that is both long-term validation (LTV) enabled and includes a validating timestamp from a TSA (Timestamp Server Authority). Xbase++

LOCAL nSuccess
LOCAL oPdf
LOCAL oJson
LOCAL oCert

nSuccess := 0

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

oPdf := CreateObject("Chilkat.Pdf")

//  Load a PDF to be signed.
//  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
nSuccess := oPdf:LoadFile("qa_data/pdf/hello.pdf")
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    RETURN
ENDIF

//  Options for signing are specified in JSON.
oJson := CreateObject("Chilkat.JsonObject")

//  In most cases, the signingCertificateV2 and signingTime attributes are required.
oJson:UpdateInt("signingCertificateV2", 1)
oJson:UpdateInt("signingTime", 1)

//  Tell Chilkat to create an LTV-enabled (long term validation) signature.
//  See PDF Long-Term Validation (LTV) Signature Example for more detailed comments about "ltvOcsp".
oJson:UpdateBool("ltvOcsp", 1)

//  Tell Chilkat to request a timestamp from a TSA server and include the timestamp token (1.2.840.113549.1.9.16.2.14)
//  in the CMS signature's authentication attributes
oJson:UpdateBool("timestampToken.enabled", 1)

//  In this example, we'll use a free TSA server (timestamp.digicert.com), but you may want to use your own timestamp authority server.
oJson:UpdateString("timestampToken.tsaUrl", "http://timestamp.digicert.com")

//  If the timestamp server requires a username/password, do the following.  Otherwise omit the following few lines of code.
oJson:UpdateString("timestampToken.tsaUsername", "the_tsa_username")
oJson:UpdateString("timestampToken.tsaPassword", "the_tsa_password")

//  When requesting the timestamp token, ask the server to include its certificate in the timestamp token response.
//  This allows for the timestamp server's certificate to be included in the LTV validation (i.e. if the timestamp server
//  has an OCSP URL, then Chilkat will also do the OCSP request for the timestamp server's certificate.)
oJson:UpdateBool("timestampToken.requestTsaCert", 1)

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

//  Load the signing certificate. (Use your own certificate.)
oCert := CreateObject("Chilkat.Cert")
nSuccess := oCert:LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx", "pfxPassword")
IF (nSuccess == 0)
    ? oCert:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oCert:destroy()
    RETURN
ENDIF

//  Tell the pdf object to use the certificate for signing.
nSuccess := oPdf:SetSigningCert(oCert)
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oCert:destroy()
    RETURN
ENDIF

nSuccess := oPdf:SignPdf(oJson, "qa_output/hello_ltv_signed_with_timestamp.pdf")
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oCert:destroy()
    RETURN
ENDIF

? "The PDF has been successfully cryptographically signed with TSA timestamp and long-term validation."

//  If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
//  and contains an embedded timestamp:
//  (image:https://example-code.com/images/ltv_signature_with_timestamp.jpg/endImage)

oPdf:destroy()
oJson:destroy()
oCert:destroy()