PowerShell 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. PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  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.
$recipient = New-Object Chilkat.Cert
$success = $recipient.LoadFromFile("qa_data/certs/recipient.cer")
if ($success -eq $false) {
    $($recipient.LastErrorText)
    exit
}

$pdf = New-Object Chilkat.Pdf
$success = $pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
if ($success -eq $false) {
    $($pdf.LastErrorText)
    exit
}

#  Call AddEncryptCert once for each recipient.
$success = $pdf.AddEncryptCert($recipient)
if ($success -eq $false) {
    $($pdf.LastErrorText)
    exit
}

#  recipientPermissions[0] belongs to the first certificate added.  changeSecurity gives that
#  recipient owner rights, so the file can be managed later.
$json = New-Object Chilkat.JsonObject
$json.UpdateString("method","certificate")
$json.UpdateBool("recipientPermissions[0].changeSecurity",$true)

$jsonOut = New-Object Chilkat.JsonObject
$success = $pdf.Protection("encrypt",$json,$jsonOut)
if ($success -eq $false) {
    $($pdf.LastErrorText)
    exit
}

$("method: " + $jsonOut.StringOf("pending.method"))
$("algorithm: " + $jsonOut.StringOf("pending.algorithm"))
$("recipients: " + $jsonOut.SizeOfArray("pending.recipients"))

$success = $pdf.WriteFile("qa_output/memo_for_recipient.pdf")
if ($success -eq $false) {
    $($pdf.LastErrorText)
    exit
}

#  PreLoadCheck says how the file is protected, without loading it.
$reader = New-Object Chilkat.Pdf
$info = New-Object Chilkat.JsonObject
$success = $reader.PreLoadCheck("qa_output/memo_for_recipient.pdf",$info)
if ($success -eq $false) {
    $($reader.LastErrorText)
    exit
}

$("saved file, method: " + $info.StringOf("method"))
$("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.)
$myCert = New-Object Chilkat.Cert
$success = $myCert.LoadPfxFile("qa_data/pfx/recipient.pfx","pfx-password")
if ($success -eq $false) {
    $($myCert.LastErrorText)
    exit
}

$success = $reader.SetDecryptCert($myCert)
if ($success -eq $false) {
    $($reader.LastErrorText)
    exit
}

$success = $reader.LoadFile("qa_output/memo_for_recipient.pdf")
if ($success -eq $false) {
    $($reader.LastErrorText)
    exit
}

$empty = New-Object Chilkat.JsonObject
$loadedInfo = New-Object Chilkat.JsonObject
$success = $reader.Protection("getInfo",$empty,$loadedInfo)
if ($success -eq $false) {
    $($reader.LastErrorText)
    exit
}

$("opened with: " + $loadedInfo.StringOf("loaded.openedWith"))
$("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