Ruby Requires Chilkat v11.7.0+

Choose the PDF Encryption Algorithm: AES-256, AES-128 or RC4

See more PDF Protection Examples

Demonstrates the algorithmChoice option of the encrypt operation. aes-256 is the default and the one to use unless an older reader must open the file. aes-128 is for readers that predate AES-256. rc4-128 and rc4-40 are broken ciphers kept only for very old readers. Each algorithm needs a minimum PDF version, and the file header is raised to it when the PDF is saved, never lowered. A PDF saved with RC4 is written with a classic cross-reference table so that those old readers can parse it. 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

json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.new()
info = Chilkat::CkJsonObject.new()

#  AES-256, the default.  Saved as PDF 1.7 with Adobe extension level 8.
pdf1 = Chilkat::CkPdf.new()
success = pdf1.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

pdf1.put_UserPassword("user-secret")
pdf1.put_OwnerPassword("owner-secret")
json.UpdateString("algorithmChoice","aes-256")
success = pdf1.Protection("encrypt",json,jsonOut)
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

print "aes-256 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion") + ", Adobe extension level " + jsonOut.IntOf("pending.adobeExtensionLevel").to_s() + "\n";
success = pdf1.WriteFile("qa_output/memo_aes256.pdf")
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

success = pdf1.PreLoadCheck("qa_output/memo_aes256.pdf",info)
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

print "  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion") + "\n";

#  AES-128, for readers that predate AES-256.  Saved as PDF 1.6.
pdf2 = Chilkat::CkPdf.new()
success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

pdf2.put_UserPassword("user-secret")
pdf2.put_OwnerPassword("owner-secret")
json.UpdateString("algorithmChoice","aes-128")
success = pdf2.Protection("encrypt",json,jsonOut)
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

print "aes-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion") + "\n";
success = pdf2.WriteFile("qa_output/memo_aes128.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

success = pdf2.PreLoadCheck("qa_output/memo_aes128.pdf",info)
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

print "  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion") + "\n";

#  RC4-128, a broken cipher, only for readers too old for AES.  Saved as PDF 1.4.
pdf3 = Chilkat::CkPdf.new()
success = pdf3.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

pdf3.put_UserPassword("user-secret")
pdf3.put_OwnerPassword("owner-secret")
json.UpdateString("algorithmChoice","rc4-128")
success = pdf3.Protection("encrypt",json,jsonOut)
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

print "rc4-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion") + "\n";
success = pdf3.WriteFile("qa_output/memo_rc4_128.pdf")
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

success = pdf3.PreLoadCheck("qa_output/memo_rc4_128.pdf",info)
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

print "  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion") + "\n";

#  Sample output:

#  aes-256 will be saved as PDF 1.7, Adobe extension level 8
#    saved file: aes-256, PDF 1.7
#  aes-128 will be saved as PDF 1.6
#    saved file: aes-128, PDF 1.6
#  rc4-128 will be saved as PDF 1.4
#    saved file: rc4-128, PDF 1.4