regress/principals-command.sh

#	$OpenBSD: principals-command.sh,v 1.1 2015/05/21 06:44:25 djm Exp $
#	Placed in the Public Domain.

tid="authorized principals command"

rm -f $OBJ/user_ca_key* $OBJ/cert_user_key*
cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak

if test -z "$SUDO" ; then
	echo "skipped (SUDO not set)"
	echo "need SUDO to create file in /var/run, test won't work without"
	exit 0
fi

# Establish a AuthorizedPrincipalsCommand in /var/run where it will have
# acceptable directory permissions.
PRINCIPALS_CMD="/var/run/principals_command_${LOGNAME}"
cat << _EOF | $SUDO sh -c "cat > '$PRINCIPALS_CMD'"
#!/bin/sh
test "x\$1" != "x${LOGNAME}" && exit 1
test -f "$OBJ/authorized_principals_${LOGNAME}" &&
	exec cat "$OBJ/authorized_principals_${LOGNAME}"
_EOF
test $? -eq 0 || fatal "couldn't prepare principals command"
$SUDO chmod 0755 "$PRINCIPALS_CMD"

if ! $OBJ/check-perm -m keys-command $PRINCIPALS_CMD ; then
	echo "skipping: $PRINCIPALS_CMD is unsuitable as " \
	    "AuthorizedPrincipalsCommand"
	$SUDO rm -f $PRINCIPALS_CMD
	exit 0
fi

# Create a CA key and a user certificate.
${SSHKEYGEN} -q -N '' -t ed25519  -f $OBJ/user_ca_key || \
	fatal "ssh-keygen of user_ca_key failed"
${SSHKEYGEN} -q -N '' -t ed25519 -f $OBJ/cert_user_key || \
	fatal "ssh-keygen of cert_user_key failed"
${SSHKEYGEN} -q -s $OBJ/user_ca_key -I "regress user key for $USER" \
    -z $$ -n ${USER},mekmitasdigoat $OBJ/cert_user_key || \
	fatal "couldn't sign cert_user_key"

if [ -x $PRINCIPALS_CMD ]; then
	# Test explicitly-specified principals
	for privsep in yes no ; do
		_prefix="privsep $privsep"

		# Setup for AuthorizedPrincipalsCommand
		rm -f $OBJ/authorized_keys_$USER
		(
			cat $OBJ/sshd_proxy_bak
			echo "UsePrivilegeSeparation $privsep"
			echo "AuthorizedKeysFile none"
			echo "AuthorizedPrincipalsCommand $PRINCIPALS_CMD %u"
			echo "AuthorizedPrincipalsCommandUser ${LOGNAME}"
			echo "TrustedUserCAKeys $OBJ/user_ca_key.pub"
		) > $OBJ/sshd_proxy

		# XXX test missing command
		# XXX test failing command

		# Empty authorized_principals
		verbose "$tid: ${_prefix} empty authorized_principals"
		echo > $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			fail "ssh cert connect succeeded unexpectedly"
		fi

		# Wrong authorized_principals
		verbose "$tid: ${_prefix} wrong authorized_principals"
		echo gregorsamsa > $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			fail "ssh cert connect succeeded unexpectedly"
		fi

		# Correct authorized_principals
		verbose "$tid: ${_prefix} correct authorized_principals"
		echo mekmitasdigoat > $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -ne 0 ]; then
			fail "ssh cert connect failed"
		fi

		# authorized_principals with bad key option
		verbose "$tid: ${_prefix} authorized_principals bad key opt"
		echo 'blah mekmitasdigoat' > $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			fail "ssh cert connect succeeded unexpectedly"
		fi

		# authorized_principals with command=false
		verbose "$tid: ${_prefix} authorized_principals command=false"
		echo 'command="false" mekmitasdigoat' > \
		    $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			fail "ssh cert connect succeeded unexpectedly"
		fi

		# authorized_principals with command=true
		verbose "$tid: ${_prefix} authorized_principals command=true"
		echo 'command="true" mekmitasdigoat' > \
		    $OBJ/authorized_principals_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost false >/dev/null 2>&1
		if [ $? -ne 0 ]; then
			fail "ssh cert connect failed"
		fi

		# Setup for principals= key option
		rm -f $OBJ/authorized_principals_$USER
		(
			cat $OBJ/sshd_proxy_bak
			echo "UsePrivilegeSeparation $privsep"
		) > $OBJ/sshd_proxy

		# Wrong principals list
		verbose "$tid: ${_prefix} wrong principals key option"
		(
			printf 'cert-authority,principals="gregorsamsa" '
			cat $OBJ/user_ca_key.pub
		) > $OBJ/authorized_keys_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			fail "ssh cert connect succeeded unexpectedly"
		fi

		# Correct principals list
		verbose "$tid: ${_prefix} correct principals key option"
		(
			printf 'cert-authority,principals="mekmitasdigoat" '
			cat $OBJ/user_ca_key.pub
		) > $OBJ/authorized_keys_$USER
		${SSH} -2i $OBJ/cert_user_key \
		    -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1
		if [ $? -ne 0 ]; then
			fail "ssh cert connect failed"
		fi
	done
else
	echo "SKIPPED: $PRINCIPALS_COMMAND not executable " \
	    "(/var/run mounted noexec?)"
fi