[Pkg-gnupg-maint] Bug#494194: gnupg: Choice of algorithms for --symmetric is obscure

[Marc A. Donges]

Package: gnupg
Version: 1.4.9-2
Severity: normal

Hi!

The choice of algorithms used for conventional encryption of messages
(--symmetric) is quite obscure. The user must provide a passphrase which
is hashed, the result of which is used as an encryption key. Now, the
hash is selected by "s2k-digest-algo", not "digest-algo", while the
symmetric cipher is selected by "cipher-algo" (or the first cipher in
"personal-cipher-preferences"), not "s2k-cipher-algo".

This is surprising, as in the case of existing
personal-cipher-preferences (in a configuration file), in order to
explicitly set the cipher and digest, one has to use --cipher-algo and
--s2k-digest-algo. There should be explicit options for the choice of
cipher and digest algorithm used for --symmetric encryption. That way,
one could set sane defaults in a configuration file.

Marc

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (745, 'testing'), (367, 'unstable'), (234, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.26
Locale: LANG=C, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages gnupg depends on:
ii  gpgv                   1.4.9-2           GNU privacy guard - signature veri
ii  libbz2-1.0             1.0.5-0.1         high-quality block-sorting file co
ii  libc6                  2.7-10            GNU C Library: Shared libraries
ii  libreadline5           5.2-3             GNU readline and history libraries
ii  libusb-0.1-4           2:0.1.12-12       userspace USB programming library
ii  zlib1g                 1:1.2.3.3.dfsg-12 compression library - runtime

Versions of packages gnupg recommends:
ii  libldap-2.4-2            2.4.10-2+lenny1 OpenLDAP libraries

Versions of packages gnupg suggests:
ii  eog                 2.22.3-1             Eye of GNOME graphics viewer progr
pn  gnupg-doc           <none>               (no description available)
ii  imagemagick         7:6.3.7.9.dfsg1-2+b2 image manipulation programs
pn  libpcsclite1        <none>               (no description available)

-- no debconf information