upstream: regress test for constrained PKCS#11 keys

OpenBSD-Regress-ID: b2f26ae95d609d12257b43aef7cd7714c82618ff

regress/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.129 2023/10/26 18:52:45 anton Exp $
+#	$OpenBSD: Makefile,v 1.130 2023/12/18 14:49:39 djm Exp $
 
 tests:		prep file-tests t-exec unit
 
@@ -107,7 +107,8 @@ LTESTS= 	connect \
 		hostbased \
 		channel-timeout \
 		connection-timeout \
-		match-subsystem
+		match-subsystem \
+		agent-pkcs11-restrict
 
 INTEROP_TESTS=	putty-transfer putty-ciphers putty-kex conch-ciphers
 INTEROP_TESTS+=	dropbear-ciphers dropbear-kex

regress/agent-pkcs11-restrict.sh

@@ -0,0 +1,193 @@
+#	$OpenBSD: agent-pkcs11-restrict.sh,v 1.1 2023/12/18 14:49:39 djm Exp $
+#	Placed in the Public Domain.
+
+tid="pkcs11 agent constraint test"
+
+p11_setup || skip "No PKCS#11 library found"
+
+rm -f $SSH_AUTH_SOCK $OBJ/agent.log $OBJ/host_[abcx]* $OBJ/user_[abcx]*
+rm -f $OBJ/sshd_proxy_host* $OBJ/ssh_output* $OBJ/expect_*
+rm -f $OBJ/ssh_proxy[._]* $OBJ/command $OBJ/authorized_keys_*
+
+trace "generate host keys"
+for h in a b x ca ; do
+	$SSHKEYGEN -q -t ed25519 -C host_$h -N '' -f $OBJ/host_$h || \
+		fatal "ssh-keygen hostkey failed"
+done
+
+# XXX test CA hostcerts too.
+
+key_for() {
+	case $h in
+	a) K="${SSH_SOFTHSM_DIR}/RSA.pub" ;;
+	b) K="${SSH_SOFTHSM_DIR}/EC.pub" ;;
+	*) K="" ;;
+	esac
+	export K
+}
+
+SSH_AUTH_SOCK="$OBJ/agent.sock"
+export SSH_AUTH_SOCK
+rm -f $SSH_AUTH_SOCK
+trace "start agent"
+${SSHAGENT} ${EXTRA_AGENT_ARGS} -d -a $SSH_AUTH_SOCK > $OBJ/agent.log 2>&1 &
+AGENT_PID=$!
+trap "kill $AGENT_PID" EXIT
+for x in 0 1 2 3 4 ; do
+	# Give it a chance to start
+	${SSHADD} -l > /dev/null 2>&1
+	r=$?
+	test $r -eq 1 && break
+	sleep 1
+done
+if [ $r -ne 1 ]; then
+	fatal "ssh-add -l did not fail with exit code 1 (got $r)"
+fi
+
+# XXX a lot of this is a copy of agent-restrict.sh, but I couldn't see a nice
+# way to factor it out -djm
+
+trace "prepare client config"
+egrep -vi '(identityfile|hostname|hostkeyalias|proxycommand)' \
+	$OBJ/ssh_proxy > $OBJ/ssh_proxy.bak
+cat << _EOF > $OBJ/ssh_proxy
+IdentitiesOnly yes
+ForwardAgent yes
+ExitOnForwardFailure yes
+_EOF
+cp $OBJ/ssh_proxy $OBJ/ssh_proxy_noid
+for h in a b ; do
+	key_for $h
+	cat << _EOF >> $OBJ/ssh_proxy
+Host host_$h
+	Hostname host_$h
+	HostkeyAlias host_$h
+	IdentityFile $K
+	ProxyCommand ${SUDO} env SSH_SK_HELPER=\"$SSH_SK_HELPER\" ${OBJ}/sshd-log-wrapper.sh -i -f $OBJ/sshd_proxy_host_$h
+_EOF
+	# Variant with no specified keys.
+	cat << _EOF >> $OBJ/ssh_proxy_noid
+Host host_$h
+	Hostname host_$h
+	HostkeyAlias host_$h
+	ProxyCommand ${SUDO} env SSH_SK_HELPER=\"$SSH_SK_HELPER\" ${OBJ}/sshd-log-wrapper.sh -i -f $OBJ/sshd_proxy_host_$h
+_EOF
+done
+cat $OBJ/ssh_proxy.bak >> $OBJ/ssh_proxy
+cat $OBJ/ssh_proxy.bak >> $OBJ/ssh_proxy_noid
+
+LC_ALL=C
+export LC_ALL
+echo "SetEnv LC_ALL=${LC_ALL}" >> sshd_proxy
+
+trace "prepare known_hosts"
+rm -f $OBJ/known_hosts
+for h in a b x ; do
+	(printf "host_$h " ; cat $OBJ/host_${h}.pub) >> $OBJ/known_hosts
+done
+
+trace "prepare server configs"
+egrep -vi '(hostkey|pidfile)' $OBJ/sshd_proxy \
+	> $OBJ/sshd_proxy.bak
+for h in a b ; do
+	cp $OBJ/sshd_proxy.bak $OBJ/sshd_proxy_host_$h
+	cat << _EOF >> $OBJ/sshd_proxy_host_$h
+ExposeAuthInfo yes
+Hostkey $OBJ/host_$h
+_EOF
+	cp $OBJ/sshd_proxy_host_$h $OBJ/sshd_proxy_host_${h}.bak
+done
+
+trace "prepare authorized_keys"
+cat >> $OBJ/command << EOF
+#!/bin/sh
+echo USERAUTH
+cat \$SSH_USER_AUTH
+echo AGENT
+if $SSHADD -ql >/dev/null 2>&1 ; then
+	$SSHADD -L | cut -d' ' -f1-2 | sort
+else
+	echo NONE
+fi
+EOF
+chmod a+x $OBJ/command
+>$OBJ/authorized_keys_$USER
+for h in a b ; do
+	key_for $h
+	(printf "%s" "restrict,agent-forwarding,command=\"$OBJ/command\" ";
+	 cat $K) >> $OBJ/authorized_keys_$USER
+done
+
+trace "unrestricted keys"
+$SSHADD -qD >/dev/null || fatal "clear agent failed"
+p11_ssh_add -qs ${TEST_SSH_PKCS11} ||
+	fatal "failed to add keys"
+for h in a b ; do
+	key_for $h
+	echo USERAUTH > $OBJ/expect_$h
+	printf "publickey " >> $OBJ/expect_$h
+	cat $K >> $OBJ/expect_$h
+	echo AGENT >> $OBJ/expect_$h
+	$SSHADD -L | cut -d' ' -f1-2 | sort >> $OBJ/expect_$h
+	${SSH} -F $OBJ/ssh_proxy -oIdentityFile=$K \
+	    host_$h true > $OBJ/ssh_output || fatal "test ssh $h failed"
+	cmp $OBJ/expect_$h $OBJ/ssh_output || fatal "unexpected output"
+done
+
+trace "restricted to different host"
+$SSHADD -qD >/dev/null || fatal "clear agent failed"
+p11_ssh_add -q -h host_x -s ${TEST_SSH_PKCS11} -H $OBJ/known_hosts ||
+	fatal "failed to add keys"
+for h in a b ; do
+	key_for $h
+	${SSH} -F $OBJ/ssh_proxy -oIdentityFile=$K \
+	    host_$h true > $OBJ/ssh_output && fatal "test ssh $h succeeded"
+done
+
+trace "restricted to destination host"
+$SSHADD -qD >/dev/null || fatal "clear agent failed"
+p11_ssh_add -q -h host_a -h host_b -s ${TEST_SSH_PKCS11} -H $OBJ/known_hosts ||
+	fatal "failed to add keys"
+for h in a b ; do
+	key_for $h
+	echo USERAUTH > $OBJ/expect_$h
+	printf "publickey " >> $OBJ/expect_$h
+	cat $K >> $OBJ/expect_$h
+	echo AGENT >> $OBJ/expect_$h
+	echo NONE >> $OBJ/expect_$h
+	${SSH} -F $OBJ/ssh_proxy -oIdentityFile=$K \
+	    host_$h true > $OBJ/ssh_output || fatal "test ssh $h failed"
+	cmp $OBJ/expect_$h $OBJ/ssh_output || fatal "unexpected output"
+done
+
+trace "restricted multihop"
+$SSHADD -qD >/dev/null || fatal "clear agent failed"
+p11_ssh_add -q -h host_a -h "host_a>host_b" \
+    -s ${TEST_SSH_PKCS11} -H $OBJ/known_hosts || fatal "failed to add keys"
+key_for a
+AK=$K
+key_for b
+BK=$K
+# Prepare authorized_keys file to additionally ssh to host_b
+_command="echo LOCAL ; ${OBJ}/command ; echo REMOTE; ${SSH} -AF $OBJ/ssh_proxy -oIdentityFile=$BK host_b"
+(printf "%s" "restrict,agent-forwarding,command=\"$_command\" ";
+ cat $BK) > $OBJ/authorized_keys_a
+grep -vi AuthorizedKeysFile $OBJ/sshd_proxy_host_a.bak > $OBJ/sshd_proxy_host_a
+echo "AuthorizedKeysFile $OBJ/authorized_keys_a" >> $OBJ/sshd_proxy_host_a
+# Prepare expected output from both hosts.
+echo LOCAL > $OBJ/expect_a
+echo USERAUTH >> $OBJ/expect_a
+printf "publickey " >> $OBJ/expect_a
+cat $AK >> $OBJ/expect_a
+echo AGENT >> $OBJ/expect_a
+$SSHADD -L | cut -d' ' -f1-2 | sort >> $OBJ/expect_a
+echo REMOTE >> $OBJ/expect_a
+echo USERAUTH >> $OBJ/expect_a
+printf "publickey " >> $OBJ/expect_a
+cat $BK >> $OBJ/expect_a
+echo AGENT >> $OBJ/expect_a
+echo NONE >> $OBJ/expect_a
+${SSH} -AF $OBJ/ssh_proxy -oIdentityFile=$AK \
+    host_a whatever > $OBJ/ssh_output || fatal "test ssh $h failed"
+cmp $OBJ/expect_a $OBJ/ssh_output || fatal "unexpected output"
+