Ruby 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. Ruby

require 'chilkat'

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

pdf = Chilkat::CkPdf.new()
success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

#  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.
pdf.put_UserPassword("user-secret")
pdf.put_OwnerPassword("owner-secret")

#  An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.new()
success = pdf.Protection("encrypt",json,jsonOut)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

#  Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
print "algorithm: " + jsonOut.stringOf("pending.algorithm") + "\n";
print "PDF version: " + jsonOut.stringOf("pending.pdfVersion") + "\n";
print "password needed to open: " + jsonOut.BoolOf("pending.userPasswordRequired").to_s() + "\n";

#  Writing the file applies it.
success = pdf.WriteFile("qa_output/memo_encrypted.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

#  PreLoadCheck reports a file's encryption without loading it, and needs no password.
checker = Chilkat::CkPdf.new()
info = Chilkat::CkJsonObject.new()
success = checker.PreLoadCheck("qa_output/memo_encrypted.pdf",info)
if (success == false)
    print checker.lastErrorText() + "\n";
    exit
end

print "encrypted: " + info.BoolOf("encrypted").to_s() + "\n";
print "openPasswordRequired: " + info.BoolOf("openPasswordRequired").to_s() + "\n";

#  With the password, the PDF opens normally.
reader = Chilkat::CkPdf.new()
reader.put_UserPassword("user-secret")
success = reader.LoadFile("qa_output/memo_encrypted.pdf")
if (success == false)
    print reader.lastErrorText() + "\n";
    exit
end

print "pages: " + reader.get_NumPages().to_s() + "\n";

#  Sample output:

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