#!/bin/bash
chdir=0
kerberos=0
x11=0
copy=0
dir=
while getopts ":D:cd:kx" opt; do
case $opt in
D)
copy=1
dir=$OPTARG
;;
c) chdir=1;;
d) dir=$OPTARG;;
k) kerberos=1;;
x) x11=1;;
esac
done
shift $((OPTIND-1))
srcdir=${0%/*}
[ "$srcdir" = "$0" -o "$srcdir" = "." ] && srcdir=$PWD
if [ -n "$dir" ]; then
if [ $copy = 1 ]; then
if ! cp "$srcdir/became" "$dir/became"; then
echo >&2 "Failed to copy $srcdir/became to $dir!"
exit 100
fi
fi
else
dir=$srcdir
fi
user="$1"; shift
if [ -z "$user" ]; then
echo >&2 "Usage: become [-c] [-d
] [-k] [-x] "
echo >&2 "Options: -c Stay in current directory even if target user is not root."
echo >&2 " -d Look for \"became\" script in given directory."
echo >&2 " -k Delegate Kerberos credentials even if target user is not root."
echo >&2 " -x Delegate X11 cookie even if target user is not root."
exit 1
fi
uid=$(PATH=/usr/xpg4/bin:/usr/bin id -u "$user" 2>/dev/null)
if [ -z "$uid" ]; then
echo >&2 "Who is $user?"
exit 2
fi
if [ $uid = 0 ]; then
chdir=1
kerberos=1
x11=1
fi
PRINCIPAL=$(klist 2>/dev/null | sed -n 's/^Default principal: //p')
if [ $x11 = 1 -a -n "$DISPLAY" -a "${DISPLAY##localhost:}" = "$DISPLAY" ]; then
COOKIE="$(xauth list $DISPLAY)"
fi
ignore_profile_user=0
for candidate in "$HOME" "$PROFILE_HOME"; do
[ -n "$candidate" ] || continue
BECOME="$candidate/.become"
[ -d "$BECOME" ] || continue
# Script to run when becoming any user.
[ -z "$allusersprofile" ] && allusersprofile="$BECOME/all"
[ -f "$allusersprofile" ] || allusersprofile=
# Set $HOME/all sticky to ignore $PROFILE_HOME/$user.
if [ "$candidate" = "$HOME" ]; then
[ -k "$BECOME/all" ] && ignore_profile_user=1
else
[ $ignore_profile_user = 1 ] && continue
fi
# Script to run (after the one mentioned above) when becoming this user.
[ -z "$userprofile" ] && userprofile="$BECOME/$user"
[ -f "$userprofile" ] || userprofile=
done
# Preserve environment variables.
ignore_environment_user=0
for candidate in "$HOME" "$PROFILE_HOME"; do
[ -n "$candidate" ] || continue
BECOME="$candidate/.become/environment"
[ -d "$BECOME" ] || continue
# Script to run when becoming any user.
[ -z "$allusersenvironment" ] && allusersenvironment="$BECOME/all"
[ -f "$allusersenvironment" ] || allusersenvironment=
# Set $HOME/all sticky to ignore $PROFILE_HOME/$user.
if [ "$candidate" = "$HOME" ]; then
[ -k "$BECOME/all" ] && ignore_environment_user=1
else
[ $ignore_environment_user = 1 ] && continue
fi
# Environment variables to preserve when becomeing this user.
[ -z "$userenvironment" ] && userenvironment="$BECOME/$user"
[ -f "$userenvironment" ] || userenvironment=
done
file="${TMPDIR:-/tmp}/$USER.become.$user.$RANDOM.$$"
umask=$(builtin umask -p)
builtin umask 077
if exec 3>"$file" && exec <"$file" && rm "$file"; then
builtin $umask
echo >&3 "cd"
echo >&3 "PROFILE_HOME='${PROFILE_HOME:-$HOME}'"
if [ -n "$PRINCIPAL" ]; then
echo >&3 "PRINCIPAL='$PRINCIPAL'"
if [ $kerberos = 1 ]; then
ccname=$(klist 2>/dev/null | sed -n 's/^Ticket cache: [DF]I[LR][E:]://p')
if [ -f "$ccname" ]; then
echo >&3 "export KRB5CCNAME='$KRB5CCNAME'"
openssl=$(find_working openssl)
if [ -n "$openssl" ]; then
echo >&3 "KRB5OPENSSL='$openssl'"
echo >&3 "KRB5BASE64='$($openssl enc -a -in $ccname)'"
fi
fi
fi
fi
if [ -n "$DISPLAY" -a -n "$COOKIE" ]; then
echo >&3 "xauth add $COOKIE"
else
echo >&3 "unset DISPLAY"
fi
if [ ! "$PROFILE_HOME" = "$HOME" ]; then
echo >&3 "export SCREENRC=$PROFILE_HOME/.screenrc"
fi
else
exit 111
fi
echo >&3 ". ${PROFILE_HOME:-$HOME}/.bash_profile"
for profile in "$allusersprofile" "$userprofile"; do
[ -f "$profile" ] && cat >&3 2>/dev/null "$profile"
done
for environment in "$allusersenvironment" "$userenvironment"; do
[ -f "$environment" ] || continue
while read -d $'\n' variable; do
variable=${variable%%=*}
eval "[ -z \${$variable:+set} ] || echo >&3 \"$variable='\$$variable'\""
done < "$environment"
done
[ $chdir = 1 ] && echo >&3 2>/dev/null "cd - &>/dev/null"
exec 3>&-
exec sudo -H -u "$user" "$dir/became"
exit 111