Bug#694154: debian-installer: Preseeding isn't possible for partman-crypto (encrypted LVM)

[Cyril Brulebois <kibi@debian.org>]

Package: debian-installer
Version: 20121114
Severity: normal
Tags: d-i

Hi,

if my understanding of partman-crypto's blockdev-keygen's code is
correct, one isn't able to preseed the passphrase for encrypted LVM:
  http://anonscm.debian.org/gitweb/?p=d-i/partman-crypto.git;a=blob;f=blockdev-keygen

(See get_passphrase; also, my experiments seem to agree.)

The comments at the top even say:
  # This handles sensitive data that must not be swapped out
  # or written out to disk unencrypted.
  #
  # Important: before running this script the caller has
  # to check for unsafe swap partitions. This is done in
  # choose_method/encrypt/do_options.
  #
  # Assumption: This runs as part of d-i. Therefore, temp
  # files outside of /target reside in a ramdisk. Process
  # information (think [ "$pass" ]) is not exposed to anyone
  # but the installing user.

If we are to continue disallowing preseeding those parts, I believe
it would be nice to have that documented in the example preseed file.

Comments anyone?

Mraw,
KiBi.