tests/generic/624

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0-only
# Copyright 2021 Google LLC
#
# FS QA Test No. 624
#
# Test retrieving the Merkle tree and fs-verity descriptor of a verity file
# using FS_IOC_READ_VERITY_METADATA.
#
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.*
}

. ./common/rc
. ./common/filter
. ./common/verity

rm -f $seqres.full

_supported_fs generic
_require_scratch_verity
_disable_fsverity_signatures
# For the output of this test to always be the same, it has to use a specific
# Merkle tree block size.
if [ $FSV_BLOCK_SIZE != 4096 ]; then
	_notrun "4096-byte verity block size not supported on this platform"
fi

_scratch_mkfs_verity &>> $seqres.full
_scratch_mount

echo -e "\n# Creating a verity file"
fsv_file=$SCRATCH_MNT/file
# Always use the same file contents, so that the output of the test is always
# the same.  Also use a file that is large enough to have multiple Merkle tree
# levels, so that the test verifies that the blocks are returned in the expected
# order.  A 1 MB file with SHA-256 and a Merkle tree block size of 4096 will
# have 3 Merkle tree blocks (3*4096 bytes): two at level 0 and one at level 1.
head -c 1000000 /dev/zero > $fsv_file
merkle_tree_size=$((3 * FSV_BLOCK_SIZE))
fsverity_descriptor_size=256
_fsv_enable $fsv_file --salt=abcd
_require_fsverity_dump_metadata $fsv_file
_fsv_measure $fsv_file

echo -e "\n# Dumping Merkle tree"
_fsv_dump_merkle_tree $fsv_file | sha256sum

echo -e "\n# Dumping Merkle tree (in chunks)"
# The above test may get the whole tree in one read, so also try reading it in
# chunks.
for (( i = 0; i < merkle_tree_size; i += 997 )); do
	_fsv_dump_merkle_tree $fsv_file --offset=$i --length=997
done | sha256sum

echo -e "\n# Dumping descriptor"
# Note that the hash that is printed here should be the same hash that was
# printed by _fsv_measure above.
_fsv_dump_descriptor $fsv_file | sha256sum

echo -e "\n# Dumping descriptor (in chunks)"
for (( i = 0; i < fsverity_descriptor_size; i += 13 )); do
	_fsv_dump_descriptor $fsv_file --offset=$i --length=13
done | sha256sum

# success, all done
status=0
exit