Ruby Requires Chilkat v11.7.0+

Find Out Whether a PDF Needs a Password Before Loading It

See more PDF Protection Examples

Demonstrates PreLoadCheck, which examines a PDF file without loading it and without any password. It reports whether the file is encrypted, by which method and algorithm, whether a password is needed to open it, and what its permissions are. An application uses it to decide whether to ask for a password, or which certificate it needs, before calling LoadFile. PreLoadCheckBd does the same for a PDF held in memory. 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

#  The PDF used in this example is available at encrypted_user_password.pdf

#  The PDF used in this example is available at no_copy_permission.pdf

pdf = Chilkat::CkPdf.new()
info = Chilkat::CkJsonObject.new()

#  A PDF that is not encrypted.  Nothing but "encrypted" is reported for it.
success = pdf.PreLoadCheck("qa_data/pdf/two_page_memo.pdf",info)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

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

#  A PDF that needs a password to open.
success = pdf.PreLoadCheck("qa_data/pdf/encrypted_user_password.pdf",info)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "encrypted_user_password.pdf" + "\n";
print "  encrypted: " + info.BoolOf("encrypted").to_s() + "\n";
print "  method: " + info.stringOf("method") + "\n";
print "  algorithm: " + info.stringOf("algorithm") + "\n";
print "  openPasswordRequired: " + info.BoolOf("openPasswordRequired").to_s() + "\n";

#  A PDF that opens without a password but is restricted.  The permissions are readable without
#  any password.
success = pdf.PreLoadCheck("qa_data/pdf/no_copy_permission.pdf",info)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "no_copy_permission.pdf" + "\n";
print "  encrypted: " + info.BoolOf("encrypted").to_s() + "\n";
print "  openPasswordRequired: " + info.BoolOf("openPasswordRequired").to_s() + "\n";
print "  may copy: " + info.BoolOf("permissions.copy").to_s() + "\n";

#  The typical use: ask for a password only when one is needed, then load.
success = pdf.PreLoadCheck("qa_data/pdf/encrypted_user_password.pdf",info)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

if (info.BoolOf("openPasswordRequired") == true)
    #  An application would prompt for the password here.
    pdf.put_UserPassword("secret")
end

success = pdf.LoadFile("qa_data/pdf/encrypted_user_password.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "loaded, pages: " + pdf.get_NumPages().to_s() + "\n";

#  Sample output:

#  two_page_memo.pdf
#    encrypted: False
#  encrypted_user_password.pdf
#    encrypted: True
#    method: password
#    algorithm: rc4-128
#    openPasswordRequired: True
#  no_copy_permission.pdf
#    encrypted: True
#    openPasswordRequired: False
#    may copy: False
#  loaded, pages: 1