From 7ddf27668f0e21233f08c0ab2fe9ee3fdd6ab1e2 Mon Sep 17 00:00:00 2001
From: "djm@openbsd.org" <djm@openbsd.org>
Date: Wed, 1 Nov 2023 00:29:46 +0000
Subject: [PATCH] upstream: add some tests of forced commands overriding
 Subsystem

directives

OpenBSD-Regress-ID: eb48610282f6371672bdf2a8b5d2aa33cfbd322b
---
 regress/forcecommand.sh | 56 ++++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 12 deletions(-)

diff --git a/regress/forcecommand.sh b/regress/forcecommand.sh
index e756600a6..8d0114b40 100644
--- a/regress/forcecommand.sh
+++ b/regress/forcecommand.sh
@@ -1,35 +1,67 @@
-#	$OpenBSD: forcecommand.sh,v 1.5 2023/05/12 06:36:27 djm Exp $
+#	$OpenBSD: forcecommand.sh,v 1.6 2023/11/01 00:29:46 djm Exp $
 #	Placed in the Public Domain.
 
 tid="forced command"
 
 cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak
 
-cp /dev/null $OBJ/authorized_keys_$USER
-for t in ${SSH_KEYTYPES}; do
-	printf 'command="true" ' >>$OBJ/authorized_keys_$USER
-	cat $OBJ/$t.pub >> $OBJ/authorized_keys_$USER
-done
+authorized_keys() {
+	cmd=$1
+	cp /dev/null $OBJ/authorized_keys_$USER
+	for t in ${SSH_KEYTYPES}; do
+		test -z "$cmd" || \
+			printf "command=\"$cmd\" " >>$OBJ/authorized_keys_$USER
+		cat $OBJ/$t.pub >> $OBJ/authorized_keys_$USER
+	done
+}
+
+trace "test config with sftp"
+authorized_keys
+rm -f $OBJ/ssh_proxy.tmp
+echo "@get $OBJ/ssh_proxy $OBJ/ssh_proxy.tmp" | \
+	${SFTP} -b - -qF $OBJ/ssh_proxy somehost 2>/dev/null || \
+	fail "sftp failed"
+test -f "$OBJ/ssh_proxy.tmp" || fail "sftp did not download file"
+rm -f $OBJ/ssh_proxy.tmp
 
 trace "forced command in key option"
+authorized_keys true
 ${SSH} -F $OBJ/ssh_proxy somehost false || fail "forced command in key option"
 
-cp /dev/null $OBJ/authorized_keys_$USER
-for t in ${SSH_KEYTYPES}; do
-	printf 'command="false" ' >> $OBJ/authorized_keys_$USER
-	cat $OBJ/$t.pub >> $OBJ/authorized_keys_$USER
-done
-
+authorized_keys false
 cp $OBJ/sshd_proxy_bak $OBJ/sshd_proxy
 echo "ForceCommand true" >> $OBJ/sshd_proxy
 
 trace "forced command in sshd_config overrides key option"
 ${SSH} -F $OBJ/ssh_proxy somehost false || fail "forced command config"
 
+authorized_keys
 cp $OBJ/sshd_proxy_bak $OBJ/sshd_proxy
 echo "ForceCommand false" >> $OBJ/sshd_proxy
+
+trace "force command overriding subsystem"
+echo "@get $OBJ/ssh_proxy $OBJ/ssh_proxy.tmp" | \
+	${SFTP} -F $OBJ/ssh_proxy -oLoglevel=quiet somehost && \
+	fail "sftp succeeded"
+
 echo "Match User $USER" >> $OBJ/sshd_proxy
 echo "    ForceCommand true" >> $OBJ/sshd_proxy
 
 trace "forced command with match"
 ${SSH} -F $OBJ/ssh_proxy somehost false || fail "forced command match"
+
+trace "force command in match overriding subsystem"
+echo "@get $OBJ/ssh_proxy $OBJ/ssh_proxy.tmp" | \
+	${SFTP} -F $OBJ/ssh_proxy -oLoglevel=quiet somehost && \
+	fail "sftp succeeded"
+
+trace "force command to sftpserver"
+grep -vi subsystem $OBJ/sshd_proxy_bak > $OBJ/sshd_proxy
+echo "Subsystem sftp /bin/false" >> $OBJ/sshd_proxy
+echo "ForceCommand ${SFTPSERVER}" >> $OBJ/sshd_proxy
+rm -f $OBJ/ssh_proxy.tmp
+echo "@get $OBJ/ssh_proxy $OBJ/ssh_proxy.tmp" | \
+	${SFTP} -b - -qF $OBJ/ssh_proxy somehost 2>/dev/null || \
+	fail "sftp failed"
+test -f "$OBJ/ssh_proxy.tmp" || fail "sftp did not download file"
+rm -f $OBJ/ssh_proxy.tmp