mustberoot.subr revision 240684
1238438Sdteskeif [ ! "$_MUSTBEROOT_SUBR" ]; then _MUSTBEROOT_SUBR=1 2238438Sdteske# 3238438Sdteske# Copyright (c) 2006-2012 Devin Teske 4238438Sdteske# All Rights Reserved. 5238438Sdteske# 6238438Sdteske# Redistribution and use in source and binary forms, with or without 7238438Sdteske# modification, are permitted provided that the following conditions 8238438Sdteske# are met: 9238438Sdteske# 1. Redistributions of source code must retain the above copyright 10238438Sdteske# notice, this list of conditions and the following disclaimer. 11238438Sdteske# 2. Redistributions in binary form must reproduce the above copyright 12238438Sdteske# notice, this list of conditions and the following disclaimer in the 13238438Sdteske# documentation and/or other materials provided with the distribution. 14238438Sdteske# 15238438Sdteske# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16238438Sdteske# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE 17238438Sdteske# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18238438Sdteske# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19238438Sdteske# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20238438Sdteske# DAMAGES (INLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21238438Sdteske# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22238438Sdteske# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23238438Sdteske# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24238438Sdteske# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25238438Sdteske# SUCH DAMAGE. 26238438Sdteske# 27238438Sdteske# $FreeBSD: head/usr.sbin/bsdconfig/share/mustberoot.subr 240684 2012-09-18 22:28:42Z dteske $ 28238438Sdteske# 29238438Sdteske############################################################ INCLUDES 30238438Sdteske 31240684SdteskeBSDCFG_SHARE="/usr/share/bsdconfig" 32240684Sdteske. $BSDCFG_SHARE/common.subr || exit 1 33240684Sdteskef_include $BSDCFG_SHARE/dialog.subr 34240684Sdteske 35238438SdteskeBSDCFG_LIBE="/usr/libexec/bsdconfig" 36238438Sdteskef_include_lang $BSDCFG_LIBE/include/messages.subr 37238438Sdteske 38238438Sdteske############################################################ CONFIGURATION 39238438Sdteske# NOTE: These are not able to be overridden/inherited for security purposes. 40238438Sdteske 41238438Sdteske# 42238438Sdteske# Number of tries a user gets to enter his/her password before we log the 43238438Sdteske# sudo(8) failure and exit. 44238438Sdteske# 45238438SdteskePASSWD_TRIES=3 46238438Sdteske 47238438Sdteske# 48238438Sdteske# While in SECURE mode, should authentication as `root' be allowed? Set to 49238438Sdteske# non-NULL to enable authentication as `root', otherwise disabled. 50238438Sdteske# 51238438Sdteske# WARNING: 52238438Sdteske# Unless using a custom sudo(8) configuration, user `root' should not be 53238438Sdteske# allowed because no password is required to become `root' when already `root' 54238438Sdteske# and therefore, any value entered as password will work. 55238438Sdteske# 56238438SdteskeSECURE_ALLOW_ROOT= 57238438Sdteske 58238438Sdteske# 59238438Sdteske# While in SECURE mode, should we divulge (through error message) when the 60238438Sdteske# requested authentication user does not exist? Set to non-NULL to enable, 61238438Sdteske# otherwise a non-existent user is treated like an invalid password. 62238438Sdteske# 63238438SdteskeSECURE_DIVULGE_UNKNOWN_USER= 64238438Sdteske 65238438Sdteske############################################################ FUNCTIONS 66238438Sdteske 67238438Sdteske# f_become_root_via_sudo 68238438Sdteske# 69238438Sdteske# If not running as root, prompt for sudo(8) credentials to become root. 70238438Sdteske# Re-execution of the current program via sudo is automatically handled. 71238438Sdteske# 72238438Sdteske# The following environment variables effect functionality: 73238438Sdteske# 74238438Sdteske# USE_XDIALOG Either NULL or Non-NULL. If given a value will indicate 75238438Sdteske# that Xdialog(1) should be used instead of dialog(1). 76238438Sdteske# 77238438Sdteskef_become_root_via_sudo() 78238438Sdteske{ 79238438Sdteske local msg hline size 80238438Sdteske 81238438Sdteske [ "$( id -u )" = "0" ] && return $SUCCESS 82238438Sdteske 83238438Sdteske f_have sudo || f_die 1 "$msg_must_be_root_to_execute" "$pgm" 84238438Sdteske 85238438Sdteske # 86238438Sdteske # Check sudo(8) access before prompting for password. 87238438Sdteske # 88238438Sdteske :| sudo -S -v 2> /dev/null 89238438Sdteske if [ $? -ne $SUCCESS ]; then 90238438Sdteske # 91238438Sdteske # sudo(8) access denied. Prompt for their password. 92238438Sdteske # 93238438Sdteske msg="$msg_please_enter_password" 94238438Sdteske hline="$hline_alnum_punc_tab_enter" 95238438Sdteske size=$( f_dialog_inputbox_size \ 96238438Sdteske "$DIALOG_TITLE" \ 97238438Sdteske "$DIALOG_BACKTITLE" \ 98238438Sdteske "$msg" \ 99238438Sdteske "$hline" ) 100238438Sdteske 101238438Sdteske # 102238438Sdteske # Continue prompting until they either Cancel, succeed 103238438Sdteske # or exceed the number of allowed failures. 104238438Sdteske # 105238438Sdteske local password nfailures=0 retval 106238438Sdteske while [ $nfailures -lt $PASSWD_TRIES ]; do 107238438Sdteske if [ "$USE_XDIALOG" ]; then 108238438Sdteske password=$( $DIALOG \ 109238438Sdteske --title "$DIALOG_TITLE" \ 110238438Sdteske --backtitle "$DIALOG_BACKTITLE" \ 111238438Sdteske --hline "$hline" \ 112238438Sdteske --ok-label "$msg_ok" \ 113238438Sdteske --cancel-label "$msg_cancel" \ 114238438Sdteske --password --inputbox "$msg" $size \ 115238438Sdteske 2>&1 > /dev/null ) 116238438Sdteske retval=$? 117238438Sdteske 118238438Sdteske # Catch X11-related errors 119238438Sdteske [ $retval -eq 255 ] && 120238438Sdteske f_die $retval "$password" 121238438Sdteske else 122238438Sdteske $DIALOG \ 123238438Sdteske --title "$DIALOG_TITLE" \ 124238438Sdteske --backtitle "$DIALOG_BACKTITLE" \ 125238438Sdteske --hline "$hline" \ 126238438Sdteske --ok-label "$msg_ok" \ 127238438Sdteske --cancel-label "$msg_cancel" \ 128238438Sdteske --insecure \ 129238438Sdteske --passwordbox "$msg" $size \ 130238438Sdteske 2> "$DIALOG_TMPDIR/dialog.inputbox.$$" 131238438Sdteske retval=$? 132238438Sdteske password=$( f_dialog_inputstr ) 133238438Sdteske fi 134238438Sdteske 135238438Sdteske # Exit if the user cancelled. 136238438Sdteske [ $retval -eq $SUCCESS ] || exit $retval 137238438Sdteske 138238438Sdteske # 139238438Sdteske # Validate sudo(8) credentials 140238438Sdteske # 141238438Sdteske sudo -S -v 2> /dev/null <<-EOF 142238438Sdteske $password 143238438Sdteske EOF 144238438Sdteske retval=$? 145238438Sdteske unset password # scrub memory 146238438Sdteske if [ $retval -eq $SUCCESS ]; then 147238438Sdteske # Access granted... 148238438Sdteske break 149238438Sdteske else 150238438Sdteske # Access denied... 151238438Sdteske nfailures=$(( $nfailures + 1 )) 152238438Sdteske 153238438Sdteske # introduce a short delay 154238438Sdteske if [ $nfailures -lt $PASSWD_TRIES ]; then 155238438Sdteske f_dialog_info "$msg_sorry_try_again" 156238438Sdteske sleep 1 157238438Sdteske fi 158238438Sdteske fi 159238438Sdteske done 160238438Sdteske 161238438Sdteske # 162238438Sdteske # If user exhausted number of allowed password tries, log 163238438Sdteske # the security event and exit immediately. 164238438Sdteske # 165238438Sdteske if [ $nfailures -ge $PASSWD_TRIES ]; then 166238438Sdteske msg=$( printf "$msg_nfailed_attempts" "$nfailures" ) 167238438Sdteske logger -p auth.notice -t sudo " " \ 168238438Sdteske "$USER : $msg" \ 169238438Sdteske "; TTY=$(tty)" \ 170238438Sdteske "; PWD=$PWD" \ 171238438Sdteske "; USER=root" \ 172238438Sdteske "; COMMAND=$0" 173238438Sdteske f_die 1 "sudo: $msg" 174238438Sdteske fi 175238438Sdteske fi 176238438Sdteske 177238438Sdteske # Use xauth(1) to grant root the ability to use this X11/SSH session 178238438Sdteske if [ "$USE_XDIALOG" -a "$SSH_CONNECTION" -a "$DISPLAY" ]; then 179238438Sdteske f_have xauth || f_die 1 \ 180238438Sdteske "$msg_no_such_file_or_directory" "$pgm" "xauth" 181238438Sdteske local HOSTNAME displaynum 182238438Sdteske HOSTNAME=$(hostname) 183238438Sdteske displaynum="${DISPLAY#*:}" 184238438Sdteske xauth -f ~/.Xauthority extract - $HOSTNAME/unix:$displaynum \ 185238438Sdteske $HOSTNAME:$displaynum | sudo sh -c 'xauth -ivf \ 186238438Sdteske ~root/.Xauthority merge - > /dev/null 2>&1' 187238438Sdteske fi 188238438Sdteske 189238438Sdteske # Re-execute ourselves with sudo(8) 190238438Sdteske if [ $ARGC -gt 0 ]; then 191238438Sdteske exec sudo "$0" $ARGV 192238438Sdteske else 193238438Sdteske exec sudo "$0" 194238438Sdteske fi 195238438Sdteske exit $? # Never reached unless error 196238438Sdteske} 197238438Sdteske 198238438Sdteske# f_authenticate_some_user 199238438Sdteske# 200238438Sdteske# Only used if running as root and requires X11 (see USE_XDIALOG below). 201238438Sdteske# Prompts the user to enter a username and password to be authenticated via 202238438Sdteske# sudo(8) to proceed. 203238438Sdteske# 204238438Sdteske# The following environment variables effect functionality: 205238438Sdteske# 206238438Sdteske# USE_XDIALOG Either NULL or Non-NULL. If given a value will indicate 207238438Sdteske# that Xdialog(1) should be used instead of dialog(1). 208238438Sdteske# 209238438Sdteskef_authenticate_some_user() 210238438Sdteske{ 211238438Sdteske local msg hline size width height 212238438Sdteske 213238438Sdteske f_have sudo || f_die 1 "$msg_must_be_root_to_execute" "$pgm" 214238438Sdteske 215238438Sdteske # 216238438Sdteske # Secure-mode has been requested. 217238438Sdteske # 218238438Sdteske 219238438Sdteske [ "$USE_XDIALOG" ] || f_die 1 "$msg_secure_mode_requires_x11" 220238438Sdteske [ "$(id -u)" = "0" ] || f_die 1 "$msg_secure_mode_requires_root" 221238438Sdteske 222238438Sdteske # 223238438Sdteske # Prompt for sudo(8) credentials. 224238438Sdteske # 225238438Sdteske 226238438Sdteske msg="$msg_please_enter_username_password" 227238438Sdteske hline="$hline_alnum_punc_tab_enter" 228238438Sdteske size=$( f_xdialog_2inputsbox_size \ 229238438Sdteske "$DIALOG_TITLE" \ 230238438Sdteske "$DIALOG_BACKTITLE" \ 231238438Sdteske "$msg" \ 232238438Sdteske "$field_username" "" \ 233238438Sdteske "$field_password" "" ) 234238438Sdteske width="${size##*[$IFS]}" 235238438Sdteske height="${size%%[$IFS]*}" 236238438Sdteske height=$(( $height + 2 )) # Add height for --password 237238438Sdteske 238238438Sdteske # 239238438Sdteske # Continue prompting until they either Cancel, succeed or exceed the 240238438Sdteske # number of allowed failures. 241238438Sdteske # 242238438Sdteske local user_pass nfailures=0 retval 243238438Sdteske while [ $nfailures -lt $PASSWD_TRIES ]; do 244238438Sdteske user_pass=$( $DIALOG \ 245238438Sdteske --title "$DIALOG_TITLE" \ 246238438Sdteske --backtitle "$DIALOG_BACKTITLE" \ 247238438Sdteske --hline "$hline" \ 248238438Sdteske --ok-label "$msg_ok" \ 249238438Sdteske --cancel-label "$msg_cancel" \ 250238438Sdteske --password --2inputsbox "$msg" \ 251238438Sdteske $height $width \ 252238438Sdteske "$field_username" "" \ 253238438Sdteske "$field_password" "" \ 254238438Sdteske 2>&1 > /dev/null ) 255238438Sdteske retval=$? 256238438Sdteske 257238438Sdteske # Catch X11-related errors 258238438Sdteske [ $retval -eq 255 ] && f_die $retval "$user_pass" 259238438Sdteske 260238438Sdteske # Exit if the user cancelled. 261238438Sdteske [ $retval -eq $SUCCESS ] || exit $retval 262238438Sdteske 263238438Sdteske # 264238438Sdteske # Make sure the user exists and is non-root 265238438Sdteske # 266238438Sdteske local user password 267238438Sdteske user="${user_pass%%/*}" 268238438Sdteske password="${user_pass#*/}" 269238438Sdteske unset user_pass # scrub memory 270238438Sdteske if [ ! "$user" ]; then 271238438Sdteske nfailures=$(( $nfailures + 1 )) 272238438Sdteske f_dialog_msgbox "$msg_no_username" 273238438Sdteske continue 274238438Sdteske fi 275238438Sdteske if [ ! "$SECURE_ALLOW_ROOT" ]; then 276238438Sdteske case "$user" in 277238438Sdteske root|toor) 278238438Sdteske nfailures=$(( $nfailures + 1 )) 279238438Sdteske f_dialog_msgbox "$( printf \ 280238438Sdteske "$msg_user_disallowed" "$user" )" 281238438Sdteske continue 282238438Sdteske esac 283238438Sdteske fi 284238438Sdteske if ! f_quietly id "$user"; then 285238438Sdteske nfailures=$(( $nfailures + 1 )) 286238438Sdteske if [ "$SECURE_DIVULGE_UNKNOWN_USER" ]; then 287238438Sdteske f_dialog_msgbox "$( printf \ 288238438Sdteske "$msg_unknown_user" "$user" )" 289238438Sdteske elif [ $nfailures -lt $PASSWD_TRIES ]; then 290238438Sdteske f_dialog_info "$msg_sorry_try_again" 291238438Sdteske sleep 1 292238438Sdteske fi 293238438Sdteske continue 294238438Sdteske fi 295238438Sdteske 296238438Sdteske # 297238438Sdteske # Validate sudo(8) credentials for given user 298238438Sdteske # 299238438Sdteske su -m "$user" <<-EOF 300238438Sdteske sh <<EOS 301238438Sdteske sudo -k 302238438Sdteske sudo -S -v 2> /dev/null <<EOP 303238438Sdteske $password 304238438Sdteske EOP 305238438Sdteske EOS 306238438Sdteske EOF 307238438Sdteske retval=$? 308238438Sdteske unset user 309238438Sdteske unset password # scrub memory 310238438Sdteske 311238438Sdteske if [ $retval -eq $SUCCESS ]; then 312238438Sdteske # Access granted... 313238438Sdteske break 314238438Sdteske else 315238438Sdteske # Access denied... 316238438Sdteske nfailures=$(( $nfailures + 1 )) 317238438Sdteske 318238438Sdteske # introduce a short delay 319238438Sdteske if [ $nfailures -lt $PASSWD_TRIES ]; then 320238438Sdteske f_dialog_info "$msg_sorry_try_again" 321238438Sdteske sleep 1 322238438Sdteske fi 323238438Sdteske fi 324238438Sdteske done 325238438Sdteske 326238438Sdteske # 327238438Sdteske # If user exhausted number of allowed password tries, log 328238438Sdteske # the security event and exit immediately. 329238438Sdteske # 330238438Sdteske if [ $nfailures -ge $PASSWD_TRIES ]; then 331238438Sdteske msg=$( printf "$msg_nfailed_attempts" "$nfailures" ) 332238438Sdteske logger -p auth.notice -t sudo " " \ 333238438Sdteske "${SUDO_USER:-$USER} : $msg" \ 334238438Sdteske "; TTY=$(tty)" \ 335238438Sdteske "; PWD=$PWD" \ 336238438Sdteske "; USER=root" \ 337238438Sdteske "; COMMAND=$0" 338238438Sdteske f_die 1 "sudo: $message" 339238438Sdteske fi 340238438Sdteske} 341238438Sdteske 342238438Sdteske# f_mustberoot_init 343238438Sdteske# 344238438Sdteske# If not already root, make the switch to root by re-executing ourselves via 345238438Sdteske# sudo(8) using user-supplied credentials. 346238438Sdteske# 347238438Sdteske# The following environment variables effect functionality: 348238438Sdteske# 349238438Sdteske# SECURE Either NULL or Non-NULL. If given a value will indicate 350238438Sdteske# that (while running as root) sudo(8) authentication is 351238438Sdteske# required to proceed. 352238438Sdteske# 353238438Sdteskef_mustberoot_init() 354238438Sdteske{ 355238438Sdteske if [ "$(id -u)" != "0" -a ! "$SECURE" ]; then 356238438Sdteske f_become_root_via_sudo 357238438Sdteske elif [ "$SECURE" ]; then 358238438Sdteske f_authenticate_some_user 359238438Sdteske fi 360238438Sdteske} 361238438Sdteske 362238438Sdteskefi # ! $_MUSTBEROOT_SUBR 363