[pdf-devel] [PATCH] Crypt filters

[David Vazquez]

Hello, 

I include a patch for the crypt filters support. This patch adds:
  - AESV2 encoder/decoder filters
  - V2 encoder/decoder filters
  - MD5 encoder filter
  - Fix several bugs in crypt module

It is not complete. Although it works, it needs love. :)

I tell you a couple of issue.

On the first side, both AESV2 as MD5 filters cache all their input. It
is bad, but we cannot avoid this if we are using libgcrypt, I think. It
is specially important issue, since crypt filters will be used with all
PDF Streams and PDF Strings in a encrypted document.

On the other side, as I tell jemarch, I have written and documented
several new tests for both the crypt module and filters. However I
cannot write good tests for AESV2, since we decided that IV vector were
automatically added at beginning of the output buffer. By the way, the
output is not deterministic and I cannot add cases for test vectors. I
thought add a new function which it allows specify the IV, but it is not
very clean in the current APO. Jemarch suggested we could use an
external program.

The tests are `pdf_crypt_cipher_decrypt_003' and
`pdf_stm_write_010'. They are empty now.

Suggestion are welcome.

# Bazaar merge directive format 2 (Bazaar 0.90)
# revision_id: address@hidden
# target_branch: http://bzr.savannah.gnu.org/r/pdf/libgnupdf/branches\
#   /trunk/
# testament_sha1: 4b623565f4a6f58e389d5e56094d9bd78262ff9e
# timestamp: 2008-12-21 15:14:57 +0100
# base_revision_id: address@hidden
# 
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