evince fails reading pdf with AESV3 256 encryption
Hi. This is created as suggested from evince issue 446.
Evince is unable to open PDFs encrypted with 256 bit AES (AESv3) encryption.
I'm seeing this problem with evince 3.30.2 running on Ubuntu (disco).
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Show some info on qpdf and evince versions.
$ dpkg-query --show evince evince 3.30.2-1 $ evince --version GNOME Document Viewer 3.30.2 $ qpdf --version qpdf version 8.2.1 -
Download a PDF to work with.
$ wget https://www.adobe.com/support/products/enterprise/knowledgecenter/media/c4611_sample_explain.pdf -q -O plain.pdf $ md5sum plain.pdf 88bb00da1e9bab21e9cb13248b8770b1 plain.pdf -
Encrypt it using qpdf and AES 256.
$ rm -f encrypted-256.pdf encrypted-128.pdf $ qpdf --encrypt user-secret owner-secret 256 -- plain.pdf encrypted-256.pdf $ egrep -a AES encrypted-256.pdf << /CF << /StdCF << /AuthEvent /DocOpen /CFM /AESV3 /Length 32 >> >> /Filter /Standard /Length 256 /O <a868eeb995f6ff82543b1f38ab35f99cd9fd3611ddcfbb93f845b895fe64633fbf4e2714dd4dae142ccb602a50ede355> /OE <95e714077d596a65fecf766c94144c09341c9ddedc6f4237852960de7fc6d417> /P -4 /Perms <f708e990e02ae1ddc85b5a120731edc1> /R 6 /StmF /StdCF /StrF /StdCF /U <f972aa5c9877fd6d6650ca7b2705e12141f9d9d711a3378cd5e51c77c5dbc291e5270b54a36015d38b111c1c562a0749> /UE <435b9bd03432ad84261eb3bf19e00ce236e3acc26d831359fa8d2bacf758d1d0> /V 5 >> $ qpdf --password=user-secret --show-encryption encrypted-256.pdf R = 6 P = -4 User password = user-secret extract for accessibility: allowed extract for any purpose: allowed print low resolution: allowed print high resolution: allowed modify document assembly: allowed modify forms: allowed modify annotations: allowed modify other: allowed modify anything: allowed stream encryption method: AESv3 string encryption method: AESv3 file encryption method: AESv3 -
Attempt to view with evince. supplying either user or owner password does not work.
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For comparision, try with AES 128 bit.. evince works fine here.
$ qpdf --encrypt user-secret owner-secret 128 --use-aes=y -- plain.pdf encrypted-128.pdf $ qpdf --password=owner-secret --show-encryption encrypted-128.pdf R = 4 P = -4 User password = user-secret extract for accessibility: allowed extract for any purpose: allowed print low resolution: allowed print high resolution: allowed modify document assembly: allowed modify forms: allowed modify annotations: allowed modify other: allowed modify anything: allowed stream encryption method: AESv2 string encryption method: AESv2 file encryption method: AESv2