#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2016 Google, Inc.  All Rights Reserved.
#
# FS QA Test generic/397
#
# Test accessing encrypted files and directories, both with and without the
# encryption key.  Access with the encryption key is more of a sanity check and
# is not intended to fully test all the encrypted I/O paths; to do that you'd
# need to run all the xfstests with encryption enabled.  Access without the
# encryption key, on the other hand, should result in some particular behaviors.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	cd /
	rm -f $tmp.*
}

# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/encrypt

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_symlinks
_require_scratch_encryption
_require_command "$KEYCTL_PROG" keyctl

_new_session_keyring

_scratch_mkfs_encrypted &>> $seqres.full
_scratch_mount

mkdir $SCRATCH_MNT/edir $SCRATCH_MNT/ref_dir
keydesc=$(_generate_session_encryption_key)
_set_encpolicy $SCRATCH_MNT/edir $keydesc
for dir in $SCRATCH_MNT/edir $SCRATCH_MNT/ref_dir; do
	touch $dir/empty > /dev/null
	$XFS_IO_PROG -t -f -c "pwrite 0 4k" $dir/a > /dev/null
	$XFS_IO_PROG -t -f -c "pwrite 0 33k" $dir/abcdefghijklmnopqrstuvwxyz > /dev/null
	maxname=$(head -c 255 /dev/zero | tr '\0' y) # 255 character filename
	$XFS_IO_PROG -t -f -c "pwrite 0 1k" $dir/$maxname > /dev/null
	ln -s a $dir/symlink
	ln -s abcdefghijklmnopqrstuvwxyz $dir/symlink2
	ln -s $maxname $dir/symlink3
	mkdir $dir/subdir
	mkdir $dir/subdir/subsubdir
done
# Diff encrypted directory with unencrypted reference directory
diff -r $SCRATCH_MNT/edir $SCRATCH_MNT/ref_dir
# Cycle mount and diff again
_scratch_cycle_mount
diff -r $SCRATCH_MNT/edir $SCRATCH_MNT/ref_dir

#
# Now try accessing the files without the encryption key.  It should still be
# possible to list the directory and remove files.  But filenames should be
# encrypted, and it should not be possible to read regular files or to create
# new files or subdirectories.
#
# Note that we cannot simply use ls -R to verify the files because the encrypted
# filenames are unpredictable.  By design, the key used to encrypt a directory's
# filenames is derived from the master key (the key in the keyring) and a nonce
# generated by the kernel.  Hence, the encrypted filenames will be different
# every time this test is run, even if we were to put a fixed key into the
# keyring instead of a random one.  The same applies to symlink targets.
#
# TODO: there are some inconsistencies in which error codes are returned on
# different kernel versions and filesystems when trying to create a file or
# subdirectory without access to the parent directory's encryption key.  It's
# planned to consistently use ENOKEY, but for now make this test accept multiple
# error codes...
#

filter_create_errors()
{
	sed -e 's/No such file or directory/Required key not available/' \
	    -e 's/Permission denied/Required key not available/' \
	    -e 's/Operation not permitted/Required key not available/'
}

_unlink_session_encryption_key $keydesc
_scratch_cycle_mount

# Check that unencrypted names aren't there
stat $SCRATCH_MNT/edir/empty |& _filter_scratch
stat $SCRATCH_MNT/edir/symlink |& _filter_scratch

# Check that the correct numbers of files and subdirectories are there
ls $SCRATCH_MNT/edir | wc -l
find $SCRATCH_MNT/edir -mindepth 2 -maxdepth 2 -type d | wc -l

# Try to read a nondirectory file (should fail with ENOKEY)
md5sum $(find $SCRATCH_MNT/edir -maxdepth 1 -type f | head -1) |& \
		cut -d ' ' -f3-

# Try to create new files, directories, and symlinks in the encrypted directory,
# both with and without using correctly base-64 encoded filenames.  These should
# all fail with ENOKEY.
$XFS_IO_PROG -f $SCRATCH_MNT/edir/newfile |& filter_create_errors | _filter_scratch
$XFS_IO_PROG -f $SCRATCH_MNT/edir/0123456789abcdef |& filter_create_errors | _filter_scratch
mkdir $SCRATCH_MNT/edir/newdir |& filter_create_errors | _filter_scratch
mkdir $SCRATCH_MNT/edir/0123456789abcdef |& filter_create_errors | _filter_scratch
ln -s foo $SCRATCH_MNT/edir/newlink |& filter_create_errors | _filter_scratch
ln -s foo $SCRATCH_MNT/edir/0123456789abcdef |& filter_create_errors | _filter_scratch

# Delete the encrypted directory (should succeed)
rm -r $SCRATCH_MNT/edir
stat $SCRATCH_MNT/edir |& _filter_scratch

# success, all done
status=0
exit