tests: add a test for guest authentication

This verifies that smbd always adds BUILTIN\Guests to the guest token which is
required for guest authentication.

Currently the guest token depends on the on-disk configured group mappings. If
there's an existing group mapping for BUILTIN\Guests, but LOCALSAM\Guest is not
a member, the final guest token won't contain BUILTIN\Guests.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13944

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit 0e88f98855e24cfddb55bef65c5910b8e662c630)

3 files changed, 109 insertions, 0 deletions

diff --git a/selftest/knownfail.d/samba3.blackbox.guest b/selftest/knownfail.d/samba3.blackbox.guest
new file mode 100644
index 00000000000..cbb62d71c87
--- /dev/null
+++ b/selftest/knownfail.d/samba3.blackbox.guest
@@ -0,0 +1 @@
+^samba3.blackbox.guest.*smbclient_guest_auth_without_members
diff --git a/source3/script/tests/test_guest_auth.sh b/source3/script/tests/test_guest_auth.sh
new file mode 100755
index 00000000000..4ad4a5cbd63
--- /dev/null
+++ b/source3/script/tests/test_guest_auth.sh
@@ -0,0 +1,103 @@
+#!/bin/sh
+#
+# Test guest authentication
+#
+# Copyright (C) 2019 Ralph Boehme
+#
+
+if [ $# -lt 5 ]; then
+cat <<EOF
+Usage: $0 SERVER SMBCLIENT SMBCONTROL NET CONFIGURATION
+EOF
+exit 1;
+fi
+
+SERVER=$1
+SMBCLIENT=$2
+SMBCONTROL=$3
+NET=$4
+CONFIGURATION=$5
+
+incdir=`dirname $0`/../../../testprogs/blackbox
+. $incdir/subunit.sh
+
+failed=0
+SIDS=""
+
+prepare_empty_builtin_guests() {
+    TMP=$($NET $CONFIGURATION groupmap listmem S-1-5-32-546 2>&1)
+    bg_exists=$?
+    if [ $bg_exists != 0 ] ; then
+	printf "Group map for BUILTIN\\Guests must exist for test\n"
+	return 1
+    fi
+
+    SIDS=$($NET $CONFIGURATION groupmap listmem S-1-5-32-546)
+    if [ $? != 0 ] ; then
+	printf "$NET $CONFIGURATION groupmap listmem S-1-5-32-546 failed. Returned:\n"
+	printf "$SIDS\n"
+	return 1
+    fi
+    printf "Got S-1-5-32-546 members:\n$SIDS\n"
+
+    if [ "$SIDS" != "" ] ; then
+	for SID in $SIDS ; do
+	    printf "Deleting member $SID from S-1-5-32-546\n"
+	    $NET $CONFIGURATION groupmap delmem S-1-5-32-546 $SID || return 1
+	done
+    fi
+
+    return 0
+}
+
+add_local_guest_to_builtin_guests() {
+    if [ "$SIDS" != "" ] ; then
+	for SID in $SIDS ; do
+	    printf "Adding $SID as member to S-1-5-32-546\n"
+	    $NET $CONFIGURATION groupmap addmem S-1-5-32-546 $SID || return 1
+	done
+    fi
+}
+
+test_smbclient() {
+    $SMBCLIENT -U foo%bar //$SERVER/tmpguest -c exit
+    if [ $? != 0 ] ; then
+	printf "smbclient failed\n"
+	return 1
+    fi
+    return 0
+}
+
+testit "smbclient_guest_at_startup" \
+    test_smbclient  ||
+    failed=$(expr $failed + 1)
+
+printf "Prepare BUILTIN\\Guests group mapping without members\n"
+
+prepare_empty_builtin_guests || {
+    printf "Setting up BUILTIN\\Guests without members failed\n"
+    exit 1
+}
+
+$SMBCONTROL $CONFIGURATION smbd reload-config || {
+    printf "Reloading parent smbd guest info failed\n"
+    exit 1
+}
+
+testit "smbclient_guest_auth_without_members" \
+    test_smbclient &&
+    failed=$(expr $failed + 1)
+
+# restore config
+add_local_guest_to_builtin_guests
+
+$SMBCONTROL $CONFIGURATION smbd reload-config || {
+    printf "Reloading parent smbd guest info failed\n"
+    exit 1
+}
+
+testit "smbclient_works_after_restored_setup" \
+    test_smbclient  ||
+    failed=$(expr $failed + 1)
+
+testok $0 $failed
diff --git a/source3/selftest/tests.py b/source3/selftest/tests.py
index e390ca390a8..64546900d83 100755
--- a/source3/selftest/tests.py
+++ b/source3/selftest/tests.py
@@ -737,3 +737,8 @@ for e in endianness_options:
 
 plansmbtorture4testsuite('rpc.epmapper', 'nt4_dc:local', 'ncalrpc: -U$USERNAME%$PASSWORD', 'over ncalrpc')
 plansmbtorture4testsuite('rpc.fsrvp', 'nt4_dc:local', 'ncacn_np:$SERVER_IP[/pipe/FssagentRpc] -U$USERNAME%$PASSWORD', 'over ncacn_np')
+
+for env in ["ad_member_idmap_rid:local", "maptoguest:local"]:
+    plantestsuite("samba3.blackbox.guest (%s)" % env , env,
+                  [os.path.join(samba3srcdir, "script/tests/test_guest_auth.sh"),
+                   '$SERVER', smbclient3, smbcontrol, net, configuration])