integrity.sh revision 323136 
1#	$OpenBSD: integrity.sh,v 1.20 2017/01/06 02:26:10 dtucker Exp $
2#	Placed in the Public Domain.
3
4tid="integrity"
5cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak
6
7# start at byte 2900 (i.e. after kex) and corrupt at different offsets
8tries=10
9startoffset=2900
10macs=`${SSH} -Q mac`
11# The following are not MACs, but ciphers with integrated integrity. They are
12# handled specially below.
13macs="$macs `${SSH} -Q cipher-auth`"
14
15# avoid DH group exchange as the extra traffic makes it harder to get the
16# offset into the stream right.
17echo "KexAlgorithms diffie-hellman-group14-sha1,diffie-hellman-group1-sha1" \
18	>> $OBJ/ssh_proxy
19
20# sshd-command for proxy (see test-exec.sh)
21cmd="$SUDO sh ${SRC}/sshd-log-wrapper.sh ${TEST_SSHD_LOGFILE} ${SSHD} -i -f $OBJ/sshd_proxy"
22
23for m in $macs; do
24	trace "test $tid: mac $m"
25	elen=0
26	epad=0
27	emac=0
28	etmo=0
29	ecnt=0
30	skip=0
31	for off in `jot $tries $startoffset`; do
32		skip=`expr $skip - 1`
33		if [ $skip -gt 0 ]; then
34			# avoid modifying the high bytes of the length
35			continue
36		fi
37		cp $OBJ/sshd_proxy_bak $OBJ/sshd_proxy
38		# modify output from sshd at offset $off
39		pxy="proxycommand=$cmd | $OBJ/modpipe -wm xor:$off:1"
40		if ${SSH} -Q cipher-auth | grep "^${m}\$" >/dev/null 2>&1 ; then
41			echo "Ciphers=$m" >> $OBJ/sshd_proxy
42			macopt="-c $m"
43		else
44			echo "Ciphers=aes128-ctr" >> $OBJ/sshd_proxy
45			echo "MACs=$m" >> $OBJ/sshd_proxy
46			macopt="-m $m -c aes128-ctr"
47		fi
48		verbose "test $tid: $m @$off"
49		${SSH} $macopt -2F $OBJ/ssh_proxy -o "$pxy" \
50		    -oServerAliveInterval=1 -oServerAliveCountMax=30 \
51		    999.999.999.999 'printf "%4096s" " "' >/dev/null
52		if [ $? -eq 0 ]; then
53			fail "ssh -m $m succeeds with bit-flip at $off"
54		fi
55		ecnt=`expr $ecnt + 1`
56		out=$(egrep -v "^debug" $TEST_SSH_LOGFILE | tail -2 | \
57		     tr -s '\r\n' '.')
58		case "$out" in
59		Bad?packet*)	elen=`expr $elen + 1`; skip=3;;
60		Corrupted?MAC* | *message?authentication?code?incorrect*)
61				emac=`expr $emac + 1`; skip=0;;
62		padding*)	epad=`expr $epad + 1`; skip=0;;
63		*)		fail "unexpected error mac $m at $off: $out";;
64		esac
65	done
66	verbose "test $tid: $ecnt errors: mac $emac padding $epad length $elen"
67	if [ $emac -eq 0 ]; then
68		fail "$m: no mac errors"
69	fi
70	expect=`expr $ecnt - $epad - $elen`
71	if [ $emac -ne $expect ]; then
72		fail "$m: expected $expect mac errors, got $emac"
73	fi
74done
75