Visual FoxPro Requires Chilkat v11.7.0+

Password-Protect a PDF with AES-256 Encryption

See more PDF Protection Examples

Demonstrates the simplest way to encrypt a PDF so that it needs a password to open. The passwords come from the UserPassword and OwnerPassword properties, and Protection with the encrypt operation and an empty JSON uses the defaults: AES-256, everything encrypted, every permission granted. Protection only records the security the PDF will be saved with. Nothing is encrypted until WriteFile is called. Visual FoxPro

LOCAL lnSuccess
LOCAL loPdf
LOCAL loJson
LOCAL loJsonOut
LOCAL loChecker
LOCAL loInfo
LOCAL loReader

lnSuccess = 0

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

*  The PDF used in this example is available at two_page_memo.pdf

loPdf = CreateObject('Chilkat.Pdf')
lnSuccess = loPdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    CANCEL
ENDIF

*  The passwords are taken from these two properties at the time Protection is called.
*  The user password opens the PDF.  The owner password opens it too, and is the one needed
*  later to change or remove the protection.
loPdf.UserPassword = "user-secret"
loPdf.OwnerPassword = "owner-secret"

*  An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
loJson = CreateObject('Chilkat.JsonObject')
loJsonOut = CreateObject('Chilkat.JsonObject')
lnSuccess = loPdf.Protection("encrypt",loJson,loJsonOut)
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJsonOut
    CANCEL
ENDIF

*  Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
? "algorithm: " + loJsonOut.StringOf("pending.algorithm")
? "PDF version: " + loJsonOut.StringOf("pending.pdfVersion")
? "password needed to open: " + STR(loJsonOut.BoolOf("pending.userPasswordRequired"))

*  Writing the file applies it.
lnSuccess = loPdf.WriteFile("qa_output/memo_encrypted.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJsonOut
    CANCEL
ENDIF

*  PreLoadCheck reports a file's encryption without loading it, and needs no password.
loChecker = CreateObject('Chilkat.Pdf')
loInfo = CreateObject('Chilkat.JsonObject')
lnSuccess = loChecker.PreLoadCheck("qa_output/memo_encrypted.pdf",loInfo)
IF (lnSuccess = 0) THEN
    ? loChecker.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJsonOut
    RELEASE loChecker
    RELEASE loInfo
    CANCEL
ENDIF

? "encrypted: " + STR(loInfo.BoolOf("encrypted"))
? "openPasswordRequired: " + STR(loInfo.BoolOf("openPasswordRequired"))

*  With the password, the PDF opens normally.
loReader = CreateObject('Chilkat.Pdf')
loReader.UserPassword = "user-secret"
lnSuccess = loReader.LoadFile("qa_output/memo_encrypted.pdf")
IF (lnSuccess = 0) THEN
    ? loReader.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJsonOut
    RELEASE loChecker
    RELEASE loInfo
    RELEASE loReader
    CANCEL
ENDIF

? "pages: " + STR(loReader.NumPages)

*  Sample output:

*  algorithm: aes-256
*  PDF version: 1.7
*  password needed to open: True
*  encrypted: True
*  openPasswordRequired: True
*  pages: 2

RELEASE loPdf
RELEASE loJson
RELEASE loJsonOut
RELEASE loChecker
RELEASE loInfo
RELEASE loReader