Bug#326027: ssh: sshd server does not encode banner in ISO-10646

[Lars Persson Fink <persson@bluetail.com>]

Package: ssh
Version: 1:3.8.1p1-8.sarge.4
Severity: minor

Hi,

I do not know if this classifies as a bug or feature request and if
there are any security implications from the problem below.

I noticed that sshd does not encode the banner file in ISO-10646 UTF-8
before sending it to the client as specified in
draft-ietf-secsh-userauth-27.txt. Instead it seems to send the file as
is.

It also seems as the client does not convert the banner from UTF-8 to
the codepage it runs in.

To test that the server does not encode the banner properly one can
create a banner with non-ascii characters and save it with a non
ISO-10646 UTF-8 codepage (iso-8859-1 in my case). Then connect to the
server with a ssh client running in a UTF-8 environment.

To test that the client does not convert the banner to the current
codepage one can create a banner same as above, but save it in UTF-8
(with gedit for instance) and then connect to the server using a ssh
client running in a non UTF-8 environment.


/Lars.

-- System Information:
Debian Release: 3.1
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.8-686
Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ISO-8859-1)

Versions of packages ssh depends on:
ii  adduser                     3.63         Add and remove users and groups
ii  debconf                     1.4.30.13    Debian configuration management sy
ii  dpkg                        1.10.27      Package maintenance system for Deb
ii  libc6                       2.3.2.ds1-21 GNU C Library: Shared libraries an
ii  libpam-modules              0.76-22      Pluggable Authentication Modules f
ii  libpam-runtime              0.76-22      Runtime support for the PAM librar
ii  libpam0g                    0.76-22      Pluggable Authentication Modules l
ii  libssl0.9.7                 0.9.7e-3     SSL shared libraries
ii  libwrap0                    7.6.dbs-8    Wietse Venema's TCP wrappers libra
ii  zlib1g                      1:1.2.2-3    compression library - runtime

-- debconf information:
  ssh/insecure_rshd:
  ssh/ssh2_keys_merged:
  ssh/user_environment_tell:
* ssh/forward_warning:
  ssh/insecure_telnetd:
  ssh/new_config: true
* ssh/use_old_init_script: true
  ssh/protocol2_only: true
  ssh/encrypted_host_key_but_no_keygen:
  ssh/run_sshd: true
  ssh/SUID_client: true
  ssh/disable_cr_auth: false