Python 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. 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

# 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 = chilkat2.Pdf()
info = chilkat2.JsonObject()

# 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)
    sys.exit()

print("two_page_memo.pdf")
print("  encrypted: " + str(info.BoolOf("encrypted")))

# 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)
    sys.exit()

print("encrypted_user_password.pdf")
print("  encrypted: " + str(info.BoolOf("encrypted")))
print("  method: " + info.StringOf("method"))
print("  algorithm: " + info.StringOf("algorithm"))
print("  openPasswordRequired: " + str(info.BoolOf("openPasswordRequired")))

# 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)
    sys.exit()

print("no_copy_permission.pdf")
print("  encrypted: " + str(info.BoolOf("encrypted")))
print("  openPasswordRequired: " + str(info.BoolOf("openPasswordRequired")))
print("  may copy: " + str(info.BoolOf("permissions.copy")))

# 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)
    sys.exit()

if (info.BoolOf("openPasswordRequired") == True):
    # An application would prompt for the password here.
    pdf.UserPassword = "secret"

success = pdf.LoadFile("qa_data/pdf/encrypted_user_password.pdf")
if (success == False):
    print(pdf.LastErrorText)
    sys.exit()

print("loaded, pages: " + str(pdf.NumPages))

# 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