#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright 2018 Google LLC
#
# FS QA Test generic/575
#
# Test that fs-verity is using the correct measurement values.  This test
# verifies that fs-verity is doing its Merkle tree-based hashing correctly,
# i.e. that it hasn't been broken by a change.
#
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 /
	_restore_fsverity_signatures
	rm -f $tmp.*
}

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

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

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch_verity
if [ $FSV_BLOCK_SIZE != 4096 ]; then
	_notrun "4096-byte verity block size not supported on this platform"
fi
_disable_fsverity_signatures

_scratch_mkfs_verity &>> $seqres.full
_scratch_mount
fsv_orig_file=$SCRATCH_MNT/file
fsv_file=$SCRATCH_MNT/file.fsv

algs=(sha256 sha512)

# Try files with 0, 1, and multiple Merkle tree levels.
file_sizes=(0 4096 65536 65536 100000000)

# Try both unsalted and salted, and check that empty salt is the same as no salt
salts=('' '' '' '--salt=' '--salt=f3c93fa6fb828c0e1587e5714ecf6f56')

# The expected file measurements are here rather than in the expected output
# file because not all hash algorithms may be available.
sha256_vals=(
sha256:3d248ca542a24fc62d1c43b916eae5016878e2533c88238480b26128a1f1af95
sha256:babc284ee4ffe7f449377fbf6692715b43aec7bc39c094a95878904d34bac97e
sha256:011e3f2b1dc89b75d78cddcc2a1b85cd8a64b2883e5f20f277ae4c0617e0404f
sha256:011e3f2b1dc89b75d78cddcc2a1b85cd8a64b2883e5f20f277ae4c0617e0404f
sha256:9d33cab743468fcbe4edab91a275b30dd543c12dd5e6ce6f2f737f66a1558f06
)
sha512_vals=(
sha512:ccf9e5aea1c2a64efa2f2354a6024b90dffde6bbc017825045dce374474e13d10adb9dadcc6ca8e17a3c075fbd31336e8f266ae6fa93a6c3bed66f9e784e5abf
sha512:928922686c4caf32175f5236a7f964e9925d10a74dc6d8344a8bd08b23c228ff5792573987d7895f628f39c4f4ebe39a7367d7aeb16aaa0cd324ac1d53664e61
sha512:eab7224ce374a0a4babcb2db25e24836247f38b87806ad9be9e5ba4daac2f5b814fc0cbdfd9f1f8499b3c9a6c1b38fe08974cce49883ab4ccd04462fd2f9507f
sha512:eab7224ce374a0a4babcb2db25e24836247f38b87806ad9be9e5ba4daac2f5b814fc0cbdfd9f1f8499b3c9a6c1b38fe08974cce49883ab4ccd04462fd2f9507f
sha512:f7083a38644880d25539488313e9e5b41a4d431a0e383945129ad2c36e3c1d0f28928a424641bb1363c12b6e770578102566acea73baf1ce8ee15336f5ba2446
)

test_alg()
{
	local alg=$1
	local -n vals=${alg}_vals
	local i
	local file_size
	local expected actual salt_arg

	_fsv_scratch_begin_subtest "Check for expected measurement values ($alg)"

	if ! _fsv_have_hash_algorithm $alg $fsv_file; then
		if [ "$alg" = sha256 ]; then
			_fail "Something is wrong - sha256 hash should always be available"
		fi
		return 0
	fi

	for i in ${!file_sizes[@]}; do
		file_size=${file_sizes[$i]}
		expected=${vals[$i]}
		salt_arg=${salts[$i]}

		head -c $file_size /dev/zero > $fsv_orig_file
		cp $fsv_orig_file $fsv_file
		_fsv_enable --hash-alg=$alg $salt_arg $fsv_file
		actual=$(_fsv_measure $fsv_file)
		if [ "$actual" != "$expected" ]; then
			echo "Mismatch: expected $expected, kernel calculated $actual (file_size=$file_size)"
		fi
		cmp $fsv_orig_file $fsv_file
		rm -f $fsv_file
	done
}

for alg in ${algs[@]}; do
	test_alg $alg
done

# success, all done
status=0
exit