Sign pdf with password may corrupt file

Hi

edit: I did a test with a non-empty password and I got the same result. Checking now endesive-2.0.5 edit2: Probably related to: pdf signing will not work correctly when only owner password is set for the pdf and the permission settings will be ignored by cms.sign

I use your nice library to sign automatically generated pdfs. Unfortunately sometime I run into problems.

1. The pdf is gererated using enscript and ps2pdf
2. Then I use qpdf --encrypt "" "" 128 --extract=n --accessibility=n --modify=none to apply some restrictions but without any password
3. Then I use your pdf-sign-cms.py script to sign the pdf

The unfortunate outcome is that sometimes my pdf reader asks for a password, even none is set. pdfcrack told me that the password is ‘’. But this works only for qpdf with the option --password-is-hex-key.

x:~$ qpdf --decrypt --password="" --password-is-hex-key /media/sf_shared_folder/TEST_encr-signed-cms.pdf x.pdf
WARNING: /media/sf_shared_folder/TEST_encr-signed-cms.pdf (offset 458): error decoding stream data for object 3 0: stream inflate: inflate: data: incorrect header check
WARNING: /media/sf_shared_folder/TEST_encr-signed-cms.pdf (offset 458): stream will be re-processed without filtering to avoid data loss
qpdf: operation succeeded with warnings; resulting file may have some problems

Attached are the files for the steps above:

1. TEST_unsec.pdf
2. TEST_encr.pdf
3. TEST_encr-signed-cms.pdf

The used version is endesive-2.0.2.tar.gz

[m32]

The ID was incorrectly copied from the previous document, try with 2.0.6

[chruetli]

Thank you!!