diff --git a/tests/generators/generate-luks2-invalid-json-size-c2.img.sh b/tests/generators/generate-luks2-invalid-json-size-c2.img.sh
new file mode 100755
index 00000000..6de411af
--- /dev/null
+++ b/tests/generators/generate-luks2-invalid-json-size-c2.img.sh
@@ -0,0 +1,85 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary header with config json size mismatching
+# value in binary header
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	JS=$(((LUKS2_HDR_SIZE-LUKS2_BIN_HDR_SIZE)*512))
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_32K
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+
+	json_str=$(jq -c '.' $TMPDIR/json0)
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0
+	local str_res1=$(head -c 4 $TMPDIR/hdr_res0)
+	test "$str_res1" = "LUKS" || exit 2
+
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 4 $TMPDIR/hdr_res1)
+	test "$str_res1" = "SKUL" || exit 2
+
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0
+	jq -c --arg js $JS 'if .config.json_size != ( $js | tostring )
+	       then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-128k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-128k-secondary.img.sh
new file mode 100755
index 00000000..62d0fb80
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-128k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 128 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_128K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-128k.img.sh b/tests/generators/generate-luks2-metadata-size-128k.img.sh
new file mode 100755
index 00000000..fe765988
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-128k.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 128KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_128K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-16k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-16k-secondary.img.sh
new file mode 100755
index 00000000..30a41a5d
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-16k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 16 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-1m-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-1m-secondary.img.sh
new file mode 100755
index 00000000..fb9a99a7
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-1m-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 1 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_1M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-1m.img.sh b/tests/generators/generate-luks2-metadata-size-1m.img.sh
new file mode 100755
index 00000000..25722ddc
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-1m.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 1 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_1M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-256k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-256k-secondary.img.sh
new file mode 100755
index 00000000..9ca9a65c
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-256k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 256 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_256K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-256k.img.sh b/tests/generators/generate-luks2-metadata-size-256k.img.sh
new file mode 100755
index 00000000..aa5df054
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-256k.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 256KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_256K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-2m-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-2m-secondary.img.sh
new file mode 100755
index 00000000..4773c940
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-2m-secondary.img.sh
@@ -0,0 +1,96 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 2 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_2M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-2m.img.sh b/tests/generators/generate-luks2-metadata-size-2m.img.sh
new file mode 100755
index 00000000..ae9bc301
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-2m.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 2 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_2M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-32k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-32k-secondary.img.sh
new file mode 100755
index 00000000..2d819a35
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-32k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 32 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_32K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-32k.img.sh b/tests/generators/generate-luks2-metadata-size-32k.img.sh
new file mode 100755
index 00000000..40c921e6
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-32k.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary header with non-default metadata json_size.
+# There's only limited set of values allowed as json size in
+# config section of LUKS2 metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 32KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_32K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-4m-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-4m-secondary.img.sh
new file mode 100755
index 00000000..332d67e4
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-4m-secondary.img.sh
@@ -0,0 +1,96 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 4 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_4M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-4m.img.sh b/tests/generators/generate-luks2-metadata-size-4m.img.sh
new file mode 100755
index 00000000..21715fb5
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-4m.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 4 MiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_4M
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-512k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-512k-secondary.img.sh
new file mode 100755
index 00000000..015c69bb
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-512k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 512 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_512K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-512k.img.sh b/tests/generators/generate-luks2-metadata-size-512k.img.sh
new file mode 100755
index 00000000..8b196e63
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-512k.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 512KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_512K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-64k-secondary.img.sh b/tests/generators/generate-luks2-metadata-size-64k-secondary.img.sh
new file mode 100755
index 00000000..39b48de0
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-64k-secondary.img.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate secondary header with one of allowed json area
+# size values. Test wheter auto-recovery code is able
+# to validate secondary header with non-default json area
+# size.
+#
+# primary header is corrupted on purpose.
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 64 KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_64K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	write_bin_hdr_offset $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area0
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr_res0 $TEST_MDA_SIZE
+	local str_res0=$(head -c 6 $TMPDIR/hdr_res0)
+	test "$str_res0" = "VACUUM" || exit 2
+	read_luks2_json1 $TGT_IMG $TMPDIR/json_res1 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res1 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/generate-luks2-metadata-size-64k.img.sh b/tests/generators/generate-luks2-metadata-size-64k.img.sh
new file mode 100755
index 00000000..4e320f22
--- /dev/null
+++ b/tests/generators/generate-luks2-metadata-size-64k.img.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+
+. lib.sh
+
+#
+# *** Description ***
+#
+# generate primary with predefined json_size. There's only limited
+# set of values allowed as json size in config section of LUKS2
+# metadata
+#
+# secondary header is corrupted on purpose as well
+#
+
+# $1 full target dir
+# $2 full source luks2 image
+
+function prepare()
+{
+	cp $SRC_IMG $TGT_IMG
+	test -d $TMPDIR || mkdir $TMPDIR
+	read_luks2_json0 $TGT_IMG $TMPDIR/json0
+	read_luks2_bin_hdr0 $TGT_IMG $TMPDIR/hdr0
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr1
+}
+
+function generate()
+{
+	# 64KiB metadata
+	TEST_MDA_SIZE=$LUKS2_HDR_SIZE_64K
+
+	TEST_MDA_SIZE_BYTES=$((TEST_MDA_SIZE*512))
+	TEST_JSN_SIZE=$((TEST_MDA_SIZE-LUKS2_BIN_HDR_SIZE))
+	KEYSLOTS_OFFSET=$((TEST_MDA_SIZE*1024))
+	JSON_DIFF=$(((TEST_MDA_SIZE-LUKS2_HDR_SIZE)*1024))
+	JSON_SIZE=$((TEST_JSN_SIZE*512))
+	DATA_OFFSET=16777216
+
+	json_str=$(jq -c --arg jdiff $JSON_DIFF --arg jsize $JSON_SIZE --arg off $DATA_OFFSET \
+		   '.keyslots[].area.offset |= ( . | tonumber + ($jdiff | tonumber) | tostring) |
+		    .config.json_size = $jsize |
+		    .segments."0".offset = $off' $TMPDIR/json0)
+	test -n "$json_str" || exit 2
+	test ${#json_str} -lt $((LUKS2_JSON_SIZE*512)) || exit 2
+
+	write_luks2_json "$json_str" $TMPDIR/json0 $TEST_JSN_SIZE
+
+	write_bin_hdr_size $TMPDIR/hdr0 $TEST_MDA_SIZE_BYTES
+	write_bin_hdr_size $TMPDIR/hdr1 $TEST_MDA_SIZE_BYTES
+
+	merge_bin_hdr_with_json $TMPDIR/hdr0 $TMPDIR/json0 $TMPDIR/area0 $TEST_JSN_SIZE
+	merge_bin_hdr_with_json $TMPDIR/hdr1 $TMPDIR/json0 $TMPDIR/area1 $TEST_JSN_SIZE
+
+	erase_checksum $TMPDIR/area0
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area0)
+	write_checksum $chks0 $TMPDIR/area0
+
+	erase_checksum $TMPDIR/area1
+	chks0=$(calc_sha256_checksum_file $TMPDIR/area1)
+	write_checksum $chks0 $TMPDIR/area1
+
+	kill_bin_hdr $TMPDIR/area1
+
+	write_luks2_hdr0 $TMPDIR/area0 $TGT_IMG $TEST_MDA_SIZE
+	write_luks2_hdr1 $TMPDIR/area1 $TGT_IMG $TEST_MDA_SIZE
+}
+
+function check()
+{
+	read_luks2_bin_hdr1 $TGT_IMG $TMPDIR/hdr_res1 $TEST_MDA_SIZE
+	local str_res1=$(head -c 6 $TMPDIR/hdr_res1)
+	test "$str_res1" = "VACUUM" || exit 2
+	read_luks2_json0 $TGT_IMG $TMPDIR/json_res0 $TEST_JSN_SIZE
+	jq -c --arg koff $KEYSLOTS_OFFSET --arg jsize $JSON_SIZE \
+		'if ([.keyslots[].area.offset] | map(tonumber) | min | tostring != $koff) or
+		    (.config.json_size != $jsize)
+		then error("Unexpected value in result json") else empty end' $TMPDIR/json_res0 || exit 5
+}
+
+function cleanup()
+{
+	rm -f $TMPDIR/*
+	rm -fd $TMPDIR
+}
+
+test $# -eq 2 || exit 1
+
+TGT_IMG=$1/$(test_img_name $0)
+SRC_IMG=$2
+
+prepare
+generate
+check
+cleanup
diff --git a/tests/generators/lib.sh b/tests/generators/lib.sh
index 95e11076..b1a5d44d 100644
--- a/tests/generators/lib.sh
+++ b/tests/generators/lib.sh
@@ -1,9 +1,17 @@
 #!/bin/bash
 
-# all in 512 bytes blocks
-# LUKS2 with 16KiB header
-LUKS2_HDR_SIZE=32 # 16 KiB
-LUKS2_BIN_HDR_SIZE=8 # 4096 B
+# all in 512 bytes blocks (including binary hdr (4KiB))
+LUKS2_HDR_SIZE=32		#  16 KiB
+LUKS2_HDR_SIZE_32K=64		#  32 KiB
+LUKS2_HDR_SIZE_64K=128		#  64 KiB
+LUKS2_HDR_SIZE_128K=256		# 128 KiB
+LUKS2_HDR_SIZE_256K=512		# 256 KiB
+LUKS2_HDR_SIZE_512K=1024	# 512 KiB
+LUKS2_HDR_SIZE_1M=2048		#   1 MiB
+LUKS2_HDR_SIZE_2M=4096		#   2 MiB
+LUKS2_HDR_SIZE_4M=8192		#   4 MiB
+
+LUKS2_BIN_HDR_SIZE=8		#   4 KiB
 LUKS2_JSON_SIZE=$((LUKS2_HDR_SIZE-LUKS2_BIN_HDR_SIZE))
 
 LUKS2_BIN_HDR_CHKS_OFFSET=0x1C0
@@ -30,57 +38,88 @@ function test_img_name()
 	echo $str
 }
 
+# read primary bin hdr
+# 1:from 2:to
 function read_luks2_bin_hdr0()
 {
 	_dd if=$1 of=$2 bs=512 count=$LUKS2_BIN_HDR_SIZE
 }
 
+# read primary json area
+# 1:from 2:to 3:[json only size (defaults to 12KiB)]
 function read_luks2_json0()
 {
-	_dd if=$1 of=$2 bs=512 skip=$LUKS2_BIN_HDR_SIZE count=$LUKS2_JSON_SIZE
+	local _js=${4:-$LUKS2_JSON_SIZE}
+	local _js=$((_js*512/4096))
+	_dd if=$1 of=$2 bs=4096 skip=1 count=$_js
 }
 
+# read secondary bin hdr
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function read_luks2_bin_hdr1()
 {
-	_dd if=$1 of=$2 skip=$LUKS2_HDR_SIZE bs=512 count=$LUKS2_BIN_HDR_SIZE
+	_dd if=$1 of=$2 skip=${3:-$LUKS2_HDR_SIZE} bs=512 count=$LUKS2_BIN_HDR_SIZE
 }
 
+# read secondary json area
+# 1:from 2:to 3:[json only size (defaults to 12KiB)]
 function read_luks2_json1()
 {
-	_dd if=$1 of=$2 bs=512 skip=$((LUKS2_BIN_HDR_SIZE+LUKS2_HDR_SIZE)) count=$LUKS2_JSON_SIZE
+	local _js=${3:-$LUKS2_JSON_SIZE}
+	_dd if=$1 of=$2 bs=512 skip=$((2*LUKS2_BIN_HDR_SIZE+_js)) count=$_js
 }
 
+# read primary metadata area (bin + json)
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function read_luks2_hdr_area0()
 {
-	_dd if=$1 of=$2 bs=512 count=$LUKS2_HDR_SIZE
+	local _as=${3:-$LUKS2_HDR_SIZE}
+	local _as=$((_as*512))
+	_dd if=$1 of=$2 bs=$_as count=1
 }
 
+# read secondary metadata area (bin + json)
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function read_luks2_hdr_area1()
 {
-	_dd if=$1 of=$2 bs=512 skip=$LUKS2_HDR_SIZE count=$LUKS2_HDR_SIZE
+	local _as=${3:-$LUKS2_HDR_SIZE}
+	local _as=$((_as*512))
+	_dd if=$1 of=$2 bs=$_as skip=1 count=1
 }
 
+# write secondary bin hdr
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function write_luks2_bin_hdr1()
 {
-	_dd if=$1 of=$2 bs=512 seek=$LUKS2_HDR_SIZE count=$LUKS2_BIN_HDR_SIZE conv=notrunc
+	_dd if=$1 of=$2 bs=512 seek=${3:-$LUKS2_HDR_SIZE} count=$LUKS2_BIN_HDR_SIZE conv=notrunc
 }
 
+# write primary metadata area (bin + json)
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function write_luks2_hdr0()
 {
-	_dd if=$1 of=$2 bs=512 count=$LUKS2_HDR_SIZE conv=notrunc
+	local _as=${3:-$LUKS2_HDR_SIZE}
+	local _as=$((_as*512))
+	_dd if=$1 of=$2 bs=$_as count=1 conv=notrunc
 }
 
+# write secondary metadata area (bin + json)
+# 1:from 2:to 3:[metadata size (defaults to 16KiB)]
 function write_luks2_hdr1()
 {
-	_dd if=$1 of=$2 bs=512 seek=$LUKS2_HDR_SIZE count=$LUKS2_HDR_SIZE conv=notrunc
+	local _as=${3:-$LUKS2_HDR_SIZE}
+	local _as=$((_as*512))
+	_dd if=$1 of=$2 bs=$_as seek=1 count=1 conv=notrunc
 }
 
-# 1 - json str
+# write json (includes padding)
+# 1:json_string 2:to 3:[json size (defaults to 12KiB)]
 function write_luks2_json()
 {
+	local _js=${3:-$LUKS2_JSON_SIZE}
 	local len=${#1}
-	printf '%s' "$1" | _dd of=$2 bs=1 count=$len conv=notrunc
-	_dd if=/dev/zero of=$2 bs=1 seek=$len count=$((LUKS2_JSON_SIZE*512-len))
+	_dd if=/dev/zero of=$2 bs=$((_js*512)) count=1
+	printf '%s' "$1" | _dd of=$2 bs=$len count=1 conv=notrunc
 }
 
 function kill_bin_hdr()
@@ -117,13 +156,14 @@ function calc_sha256_checksum_stdin()
 	sha256sum - | cut -d ' ' -f 1
 }
 
-# 1 - bin
-# 2 - json
-# 3 - luks2_hdr_area
+# merge bin hdr with json to form metadata area
+# 1:bin_hdr 2:json 3:to 4:[json size (defaults to 12KiB)]
 function merge_bin_hdr_with_json()
 {
-	_dd if=$1 of=$3 bs=512 count=$LUKS2_BIN_HDR_SIZE
-	_dd if=$2 of=$3 bs=512 seek=$LUKS2_BIN_HDR_SIZE count=$LUKS2_JSON_SIZE
+	local _js=${4:-$LUKS2_JSON_SIZE}
+	local _js=$((_js*512/4096))
+	_dd if=$1 of=$3 bs=4096 count=1
+	_dd if=$2 of=$3 bs=4096 seek=1 count=$_js
 }
 
 function _dd()
@@ -131,3 +171,11 @@ function _dd()
 	dd $@ 2>/dev/null
 	#dd $@
 }
+
+function write_bin_hdr_size() {
+        printf '%016x' $2 | xxd -r -p -l 16 | _dd of=$1 bs=8 count=1 seek=1 conv=notrunc
+}
+
+function write_bin_hdr_offset() {
+        printf '%016x' $2 | xxd -r -p -l 16 | _dd of=$1 bs=8 count=1 seek=32 conv=notrunc
+}
diff --git a/tests/luks2-validation-test b/tests/luks2-validation-test
index dcbb93a0..fe3f2738 100755
--- a/tests/luks2-validation-test
+++ b/tests/luks2-validation-test
@@ -8,9 +8,6 @@ CRYPTSETUP=../cryptsetup
 CRYPTSETUP_VALGRIND=../.libs/cryptsetup
 CRYPTSETUP_LIB_VALGRIND=../.libs
 
-DM_CRYPT_SECTOR=512
-LUKS2_HDR_SIZE=2112 # 16 KiB version, stored twice, including luks2 areas with keyslots
-
 START_DIR=$(pwd)
 
 IMG=luks2-backend.img
@@ -19,6 +16,8 @@ TST_IMGS=$START_DIR/luks2-images
 
 GEN_DIR=generators
 
+FAILS=0
+
 [ -z "$srcdir" ] && srcdir="."
 
 function remove_mapping()
@@ -35,6 +34,12 @@ function fail()
 	exit 2
 }
 
+fail_count()
+{
+	echo "$1"
+	FAILS=$((FAILS+1))
+}
+
 function skip()
 {
 	[ -n "$1" ] && echo "$1"
@@ -61,23 +66,24 @@ function test_load()
 	case "$1" in
 	R)
 		if [ -n "$_debug" ]; then
-			$CRYPTSETUP luksDump $_debug $IMG || fail "$2"
+			$CRYPTSETUP luksDump $_debug $IMG
 		else
-			$CRYPTSETUP luksDump $_debug $IMG > /dev/null || fail "$2"
+			$CRYPTSETUP luksDump $_debug $IMG > /dev/null 2>&1
 		fi
+		test $? -eq 0 || return 1
 		;;
 	F)
 		if [ -n "$_debug" ]; then
-			$CRYPTSETUP luksDump $_debug $IMG && fail "$2"
+			$CRYPTSETUP luksDump $_debug $IMG
 		else
-			$CRYPTSETUP luksDump $_debug $IMG > /dev/null 2>&1 && fail "$2"
+			$CRYPTSETUP luksDump $_debug $IMG > /dev/null 2>&1
 		fi
+		test $? -ne 0 || return 1
 		;;
 	*)
 		fail "Internal test error"
 		;;
 	esac
-
 }
 
 function RUN()
@@ -85,7 +91,11 @@ function RUN()
 	echo -n "Test image: $1..."
 	cp $TST_IMGS/$1 $IMG || fail "Missing test image"
 	test_load $2 "$3"
-	echo "OK"
+	if [ $? -ne 0 ]; then
+		fail_count "$3"
+	else
+		echo "OK"
+	fi
 }
 
 function valgrind_setup()
@@ -194,5 +204,25 @@ RUN luks2-invalid-keyslots-size-c1.img			"F" "Failed to detect unaligned keyslot
 RUN luks2-invalid-keyslots-size-c2.img			"F" "Failed to detect too small keyslots_size config section"
 RUN luks2-invalid-json-size-c0.img			"F" "Failed to detect invalid json_size config section"
 RUN luks2-invalid-json-size-c1.img			"F" "Failed to detect invalid json_size config section"
+RUN luks2-invalid-json-size-c2.img			"F" "Failed to detect mismatching json size in config and binary hdr"
+RUN luks2-metadata-size-32k.img				"R" "Valid 32KiB metadata size failed to validate"
+RUN luks2-metadata-size-64k.img				"R" "Valid 64KiB metadata size failed to validate"
+RUN luks2-metadata-size-128k.img			"R" "Valid 128KiB metadata size failed to validate"
+RUN luks2-metadata-size-256k.img			"R" "Valid 256KiB metadata size failed to validate"
+RUN luks2-metadata-size-512k.img			"R" "Valid 512KiB metadata size failed to validate"
+RUN luks2-metadata-size-1m.img				"R" "Valid 1MiB metadata size failed to validate"
+RUN luks2-metadata-size-2m.img				"R" "Valid 2MiB metadata size failed to validate"
+RUN luks2-metadata-size-4m.img				"R" "Valid 4MiB metadata size failed to validate"
+RUN luks2-metadata-size-16k-secondary.img		"R" "Valid 16KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-32k-secondary.img		"R" "Valid 32KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-64k-secondary.img		"R" "Valid 64KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-128k-secondary.img		"R" "Valid 128KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-256k-secondary.img		"R" "Valid 256KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-512k-secondary.img		"R" "Valid 512KiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-1m-secondary.img		"R" "Valid 1MiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-2m-secondary.img		"R" "Valid 2MiB metadata size in secondary hdr failed to validate"
+RUN luks2-metadata-size-4m-secondary.img		"R" "Valid 4MiB metadata size in secondary hdr failed to validate"
 
 remove_mapping
+
+test $FAILS -eq 0 || fail "($FAILS wrong result(s) in total)"