- markus@cvs.openbsd.org 2012/12/11 22:42:11

[regress/Makefile regress/modpipe.c regress/integrity.sh]
     test the integrity of the packets; with djm@

ChangeLog

@@ -18,6 +18,9 @@
    - markus@cvs.openbsd.org 2012/12/11 22:32:56
      [regress/try-ciphers.sh]
      add etm modes
+   - markus@cvs.openbsd.org 2012/12/11 22:42:11
+     [regress/Makefile regress/modpipe.c regress/integrity.sh]
+     test the integrity of the packets; with djm@
 
 20121207
  - (dtucker) OpenBSD CVS Sync

regress/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.60 2012/12/02 20:47:48 djm Exp $
+#	$OpenBSD: Makefile,v 1.61 2012/12/11 22:42:11 markus Exp $
 
 REGRESS_TARGETS=	t1 t2 t3 t4 t5 t6 t7 t8 t9 t-exec
 tests:		$(REGRESS_TARGETS)
@@ -59,7 +59,8 @@ LTESTS= 	connect \
 		cert-userkey \
 		host-expand \
 		keys-command \
-		forward-control
+		forward-control \
+		integrity
 
 INTEROP_TESTS=	putty-transfer putty-ciphers putty-kex conch-ciphers
 #INTEROP_TESTS+=ssh-com ssh-com-client ssh-com-keygen ssh-com-sftp
@@ -142,7 +143,9 @@ t9: $(OBJ)/t9.out
 	test "${TEST_SSH_ECC}" != yes || \
 	${TEST_SSH_SSHKEYGEN} -Bf $(OBJ)/t9.out > /dev/null
 
-t-exec:	${LTESTS:=.sh}
+modpipe: modpipe.c
+
+t-exec:	modpipe ${LTESTS:=.sh}
 	@if [ "x$?" = "x" ]; then exit 0; fi; \
 	for TEST in ""$?; do \
 		echo "run test $${TEST}" ... 1>&2; \

regress/integrity.sh

@@ -0,0 +1,58 @@
+#	$OpenBSD: integrity.sh,v 1.1 2012/12/11 22:42:11 markus Exp $
+#	Placed in the Public Domain.
+
+tid="integrity"
+
+# start at byte 2300 (i.e. after kex) and corrupt at different offsets
+# XXX the test hangs if we modify the low bytes of the packet length
+# XXX and ssh tries to read...
+tries=10
+startoffset=2300
+macs="hmac-sha1 hmac-md5 umac-64@openssh.com umac-128@openssh.com
+	hmac-sha1-96 hmac-md5-96 hmac-sha2-256 hmac-sha2-512
+	hmac-sha1-etm@openssh.com hmac-md5-etm@openssh.com
+	umac-64-etm@openssh.com umac-128-etm@openssh.com
+	hmac-sha1-96-etm@openssh.com hmac-md5-96-etm@openssh.com
+	hmac-sha2-256-etm@openssh.com hmac-sha2-512-etm@openssh.com"
+
+# sshd-command for proxy (see test-exec.sh)
+cmd="sh ${SRC}/sshd-log-wrapper.sh ${SSHD} ${TEST_SSH_LOGFILE} -i -f $OBJ/sshd_proxy"
+
+for m in $macs; do
+	trace "test $tid: mac $m"
+	elen=0
+	epad=0
+	emac=0
+	ecnt=0
+	skip=0
+	for off in $(jot $tries $startoffset); do
+		if [ $((skip--)) -gt 0 ]; then
+			# avoid modifying the high bytes of the length
+			continue
+		fi
+		# modify output from sshd at offset $off
+		pxy="proxycommand=$cmd | $OBJ/modpipe -m xor:$off:1"
+		output=$(${SSH} -m $m -2F $OBJ/ssh_proxy -o "$pxy" \
+		    999.999.999.999 true 2>&1)
+		if [ $? -eq 0 ]; then
+			fail "ssh -m $m succeeds with bit-flip at $off"
+		fi
+		ecnt=$((ecnt+1))
+		output=$(echo $output | tr -s '\r\n' '.')
+		verbose "test $tid: $m @$off $output"
+		case "$output" in
+		Bad?packet*)	elen=$((elen+1)); skip=2;;
+		Corrupted?MAC*) emac=$((emac+1)); skip=0;;
+		padding*)	epad=$((epad+1)); skip=0;;
+		*)		fail "unexpected error mac $m at $off";;
+		esac
+	done
+	verbose "test $tid: $ecnt errors: mac $emac padding $epad length $elen"
+	if [ $emac -eq 0 ]; then
+		fail "$m: no mac errors"
+	fi
+	expect=$((ecnt-epad-elen))
+	if [ $emac -ne $expect ]; then
+		fail "$m: expected $expect mac errors, got $emac"
+	fi
+done

regress/modpipe.c

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2012 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: modpipe.c,v 1.1 2012/12/11 23:54:40 djm Exp $ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <err.h>
+#include <errno.h>
+
+static void
+usage(void)
+{
+	fprintf(stderr, "Usage: modpipe [-m modspec ...] < in > out\n");
+	fprintf(stderr, "modspec is one of:\n");
+	fprintf(stderr, "    xor:offset:value       - XOR \"value\" at \"offset\"\n");
+	fprintf(stderr, "    andor:offset:val1:val2 - AND \"val1\" then OR \"val2\" at \"offset\"\n");
+	exit(1);
+}
+
+#define MAX_MODIFICATIONS 256
+struct modification {
+	enum { MOD_XOR, MOD_AND_OR } what;
+	u_int64_t offset;
+	u_int8_t m1, m2;
+};
+
+static void
+parse_modification(const char *s, struct modification *m)
+{
+	char what[16+1];
+	int n;
+
+	bzero(m, sizeof(*m));
+	if ((n = sscanf(s, "%16[^:]%*[:]%lli%*[:]%hhi%*[:]%hhi",
+	    what, &m->offset, &m->m1, &m->m2)) < 3)
+		errx(1, "Invalid modification spec \"%s\"", s);
+	if (strcasecmp(what, "xor") == 0) {
+		m->what = MOD_XOR;
+		if (n > 3)
+			errx(1, "Invalid modification spec \"%s\"", s);
+	} else if (strcasecmp(what, "andor") == 0) {
+		m->what = MOD_AND_OR;
+		if (n != 4)
+			errx(1, "Invalid modification spec \"%s\"", s);
+	} else
+		errx(1, "Invalid modification type \"%s\"", what);
+}
+
+int
+main(int argc, char **argv)
+{
+	int ch;
+	u_char buf[8192];
+	size_t total;
+	ssize_t r, s, o;
+	struct modification mods[MAX_MODIFICATIONS];
+	u_int i, num_mods = 0;
+
+	while ((ch = getopt(argc, argv, "m:")) != -1) {
+		switch (ch) {
+		case 'm':
+			if (num_mods >= MAX_MODIFICATIONS)
+				errx(1, "Too many modifications");
+			parse_modification(optarg, &(mods[num_mods++]));
+			break;
+		default:
+			usage();
+			/* NOTREACHED */
+		}
+	}
+	for (total = 0;;) {
+		r = s = read(STDIN_FILENO, buf, sizeof(buf));
+		if (r == 0)
+			return 0;
+		if (r < 0) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			err(1, "read");
+		}
+		for (i = 0; i < num_mods; i++) {
+			if (mods[i].offset < total ||
+			    mods[i].offset >= total + s)
+				continue;
+			switch (mods[i].what) {
+			case MOD_XOR:
+				buf[mods[i].offset - total] ^= mods[i].m1;
+				break;
+			case MOD_AND_OR:
+				buf[mods[i].offset - total] &= mods[i].m1;
+				buf[mods[i].offset - total] |= mods[i].m2;
+				break;
+			}
+		}
+		for (o = 0; o < s; o += r) {
+			r = write(STDOUT_FILENO, buf, s - o);
+			if (r == 0)
+				return 0;
+			if (r < 0) {
+				if (errno == EAGAIN || errno == EINTR)
+					continue;
+				err(1, "write");
+			}
+		}
+		total += s;
+	}
+	return 0;
+}