1# $OpenBSD: keys-command.sh,v 1.3 2015/05/21 06:40:02 djm Exp $ 2# Placed in the Public Domain. 3 4tid="authorized keys from command" 5 6if [ -z "$SUDO" ]; then 7 fatal "need SUDO to create file in /var/run, test won't work without" 8fi 9 10rm -f $OBJ/keys-command-args 11 12touch $OBJ/keys-command-args 13chmod a+rw $OBJ/keys-command-args 14 15expected_key_text=`awk '{ print $2 }' < $OBJ/rsa.pub` 16expected_key_fp=`$SSHKEYGEN -lf $OBJ/rsa.pub | awk '{ print $2 }'` 17 18# Establish a AuthorizedKeysCommand in /var/run where it will have 19# acceptable directory permissions. 20KEY_COMMAND="/var/run/keycommand_${LOGNAME}" 21cat << _EOF | $SUDO sh -c "rm -f '$KEY_COMMAND' ; cat > '$KEY_COMMAND'" 22#!/bin/sh 23echo args: "\$@" >> $OBJ/keys-command-args 24echo "$PATH" | grep -q mekmitasdigoat && exit 7 25test "x\$1" != "x${LOGNAME}" && exit 1 26if test $# -eq 6 ; then 27 test "x\$2" != "xblah" && exit 2 28 test "x\$3" != "x${expected_key_text}" && exit 3 29 test "x\$4" != "xssh-rsa" && exit 4 30 test "x\$5" != "x${expected_key_fp}" && exit 5 31 test "x\$6" != "xblah" && exit 6 32fi 33exec cat "$OBJ/authorized_keys_${LOGNAME}" 34_EOF 35$SUDO chmod 0755 "$KEY_COMMAND" 36 37if [ -x $KEY_COMMAND ]; then 38 cp $OBJ/sshd_proxy $OBJ/sshd_proxy.bak 39 40 verbose "AuthorizedKeysCommand with arguments" 41 ( 42 grep -vi AuthorizedKeysFile $OBJ/sshd_proxy.bak 43 echo AuthorizedKeysFile none 44 echo AuthorizedKeysCommand $KEY_COMMAND %u blah %k %t %f blah 45 echo AuthorizedKeysCommandUser ${LOGNAME} 46 ) > $OBJ/sshd_proxy 47 48 # Ensure that $PATH is sanitised in sshd 49 env PATH=$PATH:/sbin/mekmitasdigoat \ 50 ${SSH} -F $OBJ/ssh_proxy somehost true 51 if [ $? -ne 0 ]; then 52 fail "connect failed" 53 fi 54 55 verbose "AuthorizedKeysCommand without arguments" 56 # Check legacy behavior of no-args resulting in username being passed. 57 ( 58 grep -vi AuthorizedKeysFile $OBJ/sshd_proxy.bak 59 echo AuthorizedKeysFile none 60 echo AuthorizedKeysCommand $KEY_COMMAND 61 echo AuthorizedKeysCommandUser ${LOGNAME} 62 ) > $OBJ/sshd_proxy 63 64 # Ensure that $PATH is sanitised in sshd 65 env PATH=$PATH:/sbin/mekmitasdigoat \ 66 ${SSH} -F $OBJ/ssh_proxy somehost true 67 if [ $? -ne 0 ]; then 68 fail "connect failed" 69 fi 70else 71 echo "SKIPPED: $KEY_COMMAND not executable (/var/run mounted noexec?)" 72fi 73 74$SUDO rm -f $KEY_COMMAND 75