Tcl

Certify a PDF and Lock the Entire Document

See more PDF Signatures Examples

This example demonstrates how to a sign a certify a PDF and lock the entire document. Normally this is intended to seal the document with a final approving (or dissapproving) signature; usually after a review workflow is completed and normally reserved for the creator or author of a document. Tcl

load ./chilkat.dll

set success 0

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

set pdf [new_CkPdf]

# Load a PDF to be certified and locked.
# The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
set success [CkPdf_LoadFile $pdf "qa_data/pdf/hello.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    exit
}

# Options for signing are specified in JSON.
set json [new_CkJsonObject]

# In most cases, the signingCertificateV2 and signingTime attributes are required.
CkJsonObject_UpdateInt $json "signingCertificateV2" 1
CkJsonObject_UpdateInt $json "signingTime" 1

# The only coding difference with certifying and locking a PDF
# as compared with an approval signature (also known as recipient signature)
# is to add the "lockAfterSigning" and "docMDP.add" to the json.
CkJsonObject_UpdateBool $json "lockAfterSigning" 1
CkJsonObject_UpdateBool $json "docMDP.add" 1

# Put the signature on page 1, top left
CkJsonObject_UpdateInt $json "page" 1
CkJsonObject_UpdateString $json "appearance.y" "top"
CkJsonObject_UpdateString $json "appearance.x" "left"

# Use a font scale of 10.0
CkJsonObject_UpdateString $json "appearance.fontScale" "10.0"

# In this example, the appearance of the digital signature will contain three lines:
# 1) The signing certificate's common name
# 2) The current date/time
# 3) Some arbitrary text.
# The keyword "cert_cn" is replaced with the Certificate's Subject Common Name.
# The keyword "current_dt" is replaced with the current date/time.
# Any number of appearance text lines can be added.
CkJsonObject_UpdateString $json "appearance.text[0]" "Digitally signed by: cert_cn"
CkJsonObject_UpdateString $json "appearance.text[1]" "current_dt"
CkJsonObject_UpdateString $json "appearance.text[2]" "The crazy brown fox jumps over the lazy dog."

# Load the signing certificate. (Use your own certificate.)
set cert [new_CkCert]

set success [CkCert_LoadPfxFile $cert "qa_data/pfx/myPdfSigningCert.pfx" "secret"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    exit
}

# Tell the pdf object to use the certificate for signing.
set success [CkPdf_SetSigningCert $pdf $cert]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    exit
}

set success [CkPdf_SignPdf $pdf $json "qa_output/hello_signed.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    exit
}

puts "The PDF has been successfully certified and locked."

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkCert $cert