Bug#524190: bash-completion: SSH completion of know hosts doesn't handle multiple host files

[Thomas Nilsson]

Package: bash-completion
Version: 1:1.0-2
Severity: normal
Tags: patch


I have a few IPs that has their OS replaced on a regular basis, for
these I have /dev/null set as their UserKnownHostsFile.

The eval line used to expand $HOME etc, is dangerous (probably only for
the users of a system if you have a BOFH). With multiple entries the
next entry will be tried to be executed;

kni...@traktor:~$ grep UserKnownHostsFile .ssh/config 
        UserKnownHostsFile "/tmp/lo l"
        #UserKnownHostsFile /dev/null
        UserKnownHostsFile /dev/null
kni...@traktor:~$ ssh [TAB]bash: /dev/null: Permission denied

-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-1-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=sv_SE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages bash-completion depends on:
ii  bash                          3.2-5      The GNU Bourne Again SHell

bash-completion recommends no packages.

bash-completion suggests no packages.

-- debconf-show failed

--- bash_completion     2009-04-02 22:01:39.000000000 +0200
+++ /etc/bash_completion.new    2009-04-15 13:19:36.000000000 +0200
@@ -2635,6 +2635,7 @@
        local configfile
        local cur curd ocur user suffix aliases global_kh user_kh hosts i host
        local -a kh khd config
+       local IFS=$'\n'
 
        COMPREPLY=()
        cur=`_get_cword`
@@ -2667,14 +2668,20 @@
 
        if [ ${#conf...@]} -gt 0 ]; then
            # expand path (if present) to global known hosts file
-           global_kh=$( eval echo "$( sed -ne 's/^[ 
\t]*[Gg][Ll][Oo][Bb][Aa][Ll][Kk][Nn][Oo][Ww][Nn][Hh][Oo][Ss][Tt][Ss][Ff][Ii][Ll][Ee]['"$'\t
 '"']*\(.*\)$/\1/p' "${conf...@]}" )" )
+           global_kh=($( sed -ne 's/^[ 
\t]*[Gg][Ll][Oo][Bb][Aa][Ll][Kk][Nn][Oo][Ww][Nn][Hh][Oo][Ss][Tt][Ss][Ff][Ii][Ll][Ee]['"$'\t
 '"']*\(.*\)$/\1/p' "${conf...@]}" ))
+           for (( i=0; i < ${#global_...@]}; i++ )); do
+               global_kh[i]=$(eval echo "${global_kh[i]//\"/}")
+           done
            # expand path (if present) to user known hosts file
-           user_kh=$( eval echo "$( sed -ne 's/^[ 
\t]*[Uu][Ss][Ee][Rr][Kk][Nn][Oo][Ww][Nn][Hh][Oo][Ss][Tt][Ss][Ff][Ii][Ll][Ee]['"$'\t
 '"']*\(.*\)$/\1/p' "${conf...@]}" )" )
+           user_kh=($( sed -ne 's/^[ 
\t]*[Uu][Ss][Ee][Rr][Kk][Nn][Oo][Ww][Nn][Hh][Oo][Ss][Tt][Ss][Ff][Ii][Ll][Ee]['"$'\t
 '"']*\(.*\)$/\1/p' "${conf...@]}" ))
+           for (( i=0; i < ${#user_...@]}; i++ )); do
+               user_kh[i]=$(eval echo "${user_kh[i]//\"/}")
+           done
        fi
 
        # Global known_hosts files
        [ -r "$global_kh" ] &&
-               kh=( "${...@]}" "$global_kh" )
+               kh=( "${...@]}" "${global_...@]}" )
        if [ -z "$configfile" ]; then
                [ -r /etc/ssh/ssh_known_hosts ] &&
                  kh=( "${...@]}" /etc/ssh/ssh_known_hosts )
@@ -2690,7 +2697,7 @@
 
        # User known_hosts files
        [ -r "$user_kh" ] &&
-               kh=( "${...@]}" "$user_kh" )
+               kh=( "${...@]}" "${user_...@]}" )
        if [ -z "$configfile" ]; then
                [ -r ~/.ssh/known_hosts ] &&
                  kh=( "${...@]}" ~/.ssh/known_hosts )