#!/bin/bash
-user="$1"
+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 <user>"
+ echo >&2 "Usage: become [-c] [-d <dir>] [-k] [-x] <user>"
+ echo >&2 "Options: -c Stay in current directory even if target user is not root."
+ echo >&2 " -d <dir> 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
-BECOME="$HOME/.become"
-profile="$BECOME/$user"
-[ -f "$profile" ] || profile="$BECOME/all"
+uid=$(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
+[ $chdir = 1 ] && echo >&3 2>/dev/null "cd - &>/dev/null"
-exec sudo -H -u "$user" env BECOME_HOME="$HOME" /bin/bash --rcfile "$profile"
+exec 3>&-
+exec sudo -H -u "$user" "$dir/became"
+exit 111