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VBScript Requires Chilkat v11.7.0+

Encrypt a PDF for a Certificate Instead of a Password

See more PDF Protection Examples

Demonstrates certificate security, where a PDF is encrypted for one or more recipients and each opens it with their own certificate and private key. No password is involved. Only the public certificate of a recipient is needed to encrypt. Each recipient has its own permissions, and the changeSecurity permission gives a recipient owner rights. PreLoadCheck tells an application that a file is certificate-encrypted and which certificates can open it. A PDF that cannot be opened, because no matching certificate and private key were provided, fails to load.

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VBScript
Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 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

'  The recipient's certificate.  Only the public certificate is needed to encrypt.
set recipient = CreateObject("Chilkat.Cert")
success = recipient.LoadFromFile("qa_data/certs/recipient.cer")
If (success = 0) Then
    outFile.WriteLine(recipient.LastErrorText)
    WScript.Quit
End If

set pdf = CreateObject("Chilkat.Pdf")
success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

'  Call AddEncryptCert once for each recipient.
success = pdf.AddEncryptCert(recipient)
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

'  recipientPermissions[0] belongs to the first certificate added.  changeSecurity gives that
'  recipient owner rights, so the file can be managed later.
set json = CreateObject("Chilkat.JsonObject")
success = json.UpdateString("method","certificate")
success = json.UpdateBool("recipientPermissions[0].changeSecurity",1)

set jsonOut = CreateObject("Chilkat.JsonObject")
success = pdf.Protection("encrypt",json,jsonOut)
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("method: " & jsonOut.StringOf("pending.method"))
outFile.WriteLine("algorithm: " & jsonOut.StringOf("pending.algorithm"))
outFile.WriteLine("recipients: " & jsonOut.SizeOfArray("pending.recipients"))

success = pdf.WriteFile("qa_output/memo_for_recipient.pdf")
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

'  PreLoadCheck says how the file is protected, without loading it.
set reader = CreateObject("Chilkat.Pdf")
set info = CreateObject("Chilkat.JsonObject")
success = reader.PreLoadCheck("qa_output/memo_for_recipient.pdf",info)
If (success = 0) Then
    outFile.WriteLine(reader.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("saved file, method: " & info.StringOf("method"))
outFile.WriteLine("saved file, recipients: " & info.SizeOfArray("recipients"))

'  The recipient opens it with the certificate and its private key, here from a .pfx file.
'  (On Windows, a certificate that is installed in the Windows certificate store with its private
'  key is found automatically when the PDF is loaded, and SetDecryptCert is not needed for it.)
set myCert = CreateObject("Chilkat.Cert")
success = myCert.LoadPfxFile("qa_data/pfx/recipient.pfx","pfx-password")
If (success = 0) Then
    outFile.WriteLine(myCert.LastErrorText)
    WScript.Quit
End If

success = reader.SetDecryptCert(myCert)
If (success = 0) Then
    outFile.WriteLine(reader.LastErrorText)
    WScript.Quit
End If

success = reader.LoadFile("qa_output/memo_for_recipient.pdf")
If (success = 0) Then
    outFile.WriteLine(reader.LastErrorText)
    WScript.Quit
End If

set empty = CreateObject("Chilkat.JsonObject")
set loadedInfo = CreateObject("Chilkat.JsonObject")
success = reader.Protection("getInfo",empty,loadedInfo)
If (success = 0) Then
    outFile.WriteLine(reader.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("opened with: " & loadedInfo.StringOf("loaded.openedWith"))
outFile.WriteLine("pages: " & reader.NumPages)

'  Sample output:

'  method: certificate
'  algorithm: aes-256
'  recipients: 1
'  saved file, method: certificate
'  saved file, recipients: 1
'  opened with: certificate
'  pages: 2

outFile.Close