Python 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. Chilkat2-Python

import sys
import chilkat2

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 = chilkat2.JsonObject()
jsonOut = chilkat2.JsonObject()
info = chilkat2.JsonObject()

# AES-256, the default.  Saved as PDF 1.7 with Adobe extension level 8.
pdf1 = chilkat2.Pdf()
success = pdf1.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == False):
    print(pdf1.LastErrorText)
    sys.exit()

pdf1.UserPassword = "user-secret"
pdf1.OwnerPassword = "owner-secret"
json.UpdateString("algorithmChoice","aes-256")
success = pdf1.Protection("encrypt",json,jsonOut)
if (success == False):
    print(pdf1.LastErrorText)
    sys.exit()

print("aes-256 will be saved as PDF " + jsonOut.StringOf("pending.pdfVersion") + ", Adobe extension level " + str(jsonOut.IntOf("pending.adobeExtensionLevel")))
success = pdf1.WriteFile("qa_output/memo_aes256.pdf")
if (success == False):
    print(pdf1.LastErrorText)
    sys.exit()

success = pdf1.PreLoadCheck("qa_output/memo_aes256.pdf",info)
if (success == False):
    print(pdf1.LastErrorText)
    sys.exit()

print("  saved file: " + info.StringOf("algorithm") + ", PDF " + info.StringOf("pdfVersion"))

# AES-128, for readers that predate AES-256.  Saved as PDF 1.6.
pdf2 = chilkat2.Pdf()
success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

pdf2.UserPassword = "user-secret"
pdf2.OwnerPassword = "owner-secret"
json.UpdateString("algorithmChoice","aes-128")
success = pdf2.Protection("encrypt",json,jsonOut)
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

print("aes-128 will be saved as PDF " + jsonOut.StringOf("pending.pdfVersion"))
success = pdf2.WriteFile("qa_output/memo_aes128.pdf")
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

success = pdf2.PreLoadCheck("qa_output/memo_aes128.pdf",info)
if (success == False):
    print(pdf2.LastErrorText)
    sys.exit()

print("  saved file: " + info.StringOf("algorithm") + ", PDF " + info.StringOf("pdfVersion"))

# RC4-128, a broken cipher, only for readers too old for AES.  Saved as PDF 1.4.
pdf3 = chilkat2.Pdf()
success = pdf3.LoadFile("qa_data/pdf/two_page_memo.pdf")
if (success == False):
    print(pdf3.LastErrorText)
    sys.exit()

pdf3.UserPassword = "user-secret"
pdf3.OwnerPassword = "owner-secret"
json.UpdateString("algorithmChoice","rc4-128")
success = pdf3.Protection("encrypt",json,jsonOut)
if (success == False):
    print(pdf3.LastErrorText)
    sys.exit()

print("rc4-128 will be saved as PDF " + jsonOut.StringOf("pending.pdfVersion"))
success = pdf3.WriteFile("qa_output/memo_rc4_128.pdf")
if (success == False):
    print(pdf3.LastErrorText)
    sys.exit()

success = pdf3.PreLoadCheck("qa_output/memo_rc4_128.pdf",info)
if (success == False):
    print(pdf3.LastErrorText)
    sys.exit()

print("  saved file: " + info.StringOf("algorithm") + ", PDF " + info.StringOf("pdfVersion"))

# 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