avbtool: add_hashtree_footer: Add --setup_as_rootfs_from_kernel option.
This option makes it possible to generate system.img with kernel
command-line descriptors for setting up the partition with dm-verity
as the root filesystem. This is different from the existing option
--setup_rootfs_from_kernel which takes a path to system.img and adds
the kernel command-line descriptors to e.g. vbmeta.img.
This option can be used when using chained partitions for system.img.
Also fix README.md to use --include_descriptors_from_image and not
--include_descriptors_from_footer.
Bug: 38304536
Test: New unit tests + all unit tests pass.
Change-Id: I6285877cdb3b63a7c9117c270459d1fbb93e3309
diff --git a/README.md b/README.md
index 31d579b..3e60e37 100644
--- a/README.md
+++ b/README.md
@@ -297,7 +297,7 @@
--output OUTPUT \
[--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \
[--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \
- [--include_descriptors_from_footer /path/to/image.bin] \
+ [--include_descriptors_from_image /path/to/image.bin] \
[--setup_rootfs_from_kernel /path/to/image.bin] \
[--chain_partition part_name:rollback_index_location:/path/to/key1.bin] \
[--signing_helper /path/to/external/signer] \
@@ -312,7 +312,7 @@
[--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \
[--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \
[--hash_algorithm HASH_ALG] [--salt HEX] \
- [--include_descriptors_from_footer /path/to/image.bin] \
+ [--include_descriptors_from_image /path/to/image.bin] \
[--setup_rootfs_from_kernel /path/to/image.bin] \
[--output_vbmeta_image OUTPUT_IMAGE] [--do_not_append_vbmeta_image] \
[--signing_helper /path/to/external/signer] \
@@ -328,8 +328,9 @@
[--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \
[--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \
[--hash_algorithm HASH_ALG] [--salt HEX] [--block_size SIZE] \
- [--include_descriptors_from_footer /path/to/image.bin] \
+ [--include_descriptors_from_image /path/to/image.bin] \
[--setup_rootfs_from_kernel /path/to/image.bin] \
+ [--setup_as_rootfs_from_kernel] \
[--output_vbmeta_image OUTPUT_IMAGE] [--do_not_append_vbmeta_image] \
[--do_not_generate_fec] [--fec_num_roots FEC_NUM_ROOTS] \
[--signing_helper /path/to/external/signer] \
diff --git a/avbtool b/avbtool
index 7c18d46..1b459f7 100755
--- a/avbtool
+++ b/avbtool
@@ -2039,11 +2039,11 @@
data_size += h.auxiliary_data_block_size
return image.read(data_size)
- def _get_cmdline_descriptors_for_dm_verity(self, image):
+ def _get_cmdline_descriptors_for_hashtree_descriptor(self, ht):
"""Generate kernel cmdline descriptors for dm-verity.
Arguments:
- image: An ImageHandler (vbmeta or footer) with a hashtree descriptor.
+ ht: A AvbHashtreeDescriptor
Returns:
A list with two AvbKernelCmdlineDescriptor with dm-verity kernel cmdline
@@ -2055,17 +2055,6 @@
"""
- (_, _, descriptors, _) = self._parse_image(image)
-
- ht = None
- for desc in descriptors:
- if isinstance(desc, AvbHashtreeDescriptor):
- ht = desc
- break
-
- if not ht:
- raise AvbError('No hashtree descriptor in given image')
-
c = 'dm="1 vroot none ro 1,'
c += '0' # start
c += ' {}'.format((ht.image_size / 512)) # size (# sectors)
@@ -2111,6 +2100,35 @@
return [desc, desc_no_ht]
+ def _get_cmdline_descriptors_for_dm_verity(self, image):
+ """Generate kernel cmdline descriptors for dm-verity.
+
+ Arguments:
+ image: An ImageHandler (vbmeta or footer) with a hashtree descriptor.
+
+ Returns:
+ A list with two AvbKernelCmdlineDescriptor with dm-verity kernel cmdline
+ instructions. There is one for when hashtree is not disabled and one for
+ when it is.
+
+ Raises:
+ AvbError: If |image| doesn't have a hashtree descriptor.
+
+ """
+
+ (_, _, descriptors, _) = self._parse_image(image)
+
+ ht = None
+ for desc in descriptors:
+ if isinstance(desc, AvbHashtreeDescriptor):
+ ht = desc
+ break
+
+ if not ht:
+ raise AvbError('No hashtree descriptor in given image')
+
+ return self._get_cmdline_descriptors_for_hashtree_descriptor(ht)
+
def make_vbmeta_image(self, output, chain_partitions, algorithm_name,
key_path, public_key_metadata_path, rollback_index,
flags, props, props_from_file, kernel_cmdlines,
@@ -2142,10 +2160,11 @@
"""
descriptors = []
+ ht_desc_to_setup = None
vbmeta_blob = self._generate_vbmeta_blob(
algorithm_name, key_path, public_key_metadata_path, descriptors,
chain_partitions, rollback_index, flags, props, props_from_file,
- kernel_cmdlines, setup_rootfs_from_kernel,
+ kernel_cmdlines, setup_rootfs_from_kernel, ht_desc_to_setup,
include_descriptors_from_image, signing_helper, release_string,
append_to_release_string)
@@ -2159,6 +2178,7 @@
rollback_index, flags, props, props_from_file,
kernel_cmdlines,
setup_rootfs_from_kernel,
+ ht_desc_to_setup,
include_descriptors_from_image, signing_helper,
release_string, append_to_release_string):
"""Generates a VBMeta blob.
@@ -2184,6 +2204,8 @@
kernel_cmdlines: Kernel cmdlines to insert (list of strings).
setup_rootfs_from_kernel: None or file to generate
dm-verity kernel cmdline from.
+ ht_desc_to_setup: If not None, an AvbHashtreeDescriptor to
+ generate dm-verity kernel cmdline descriptors from.
include_descriptors_from_image: List of file objects for which
to insert descriptors from.
signing_helper: Program which signs a hash and return signature.
@@ -2258,7 +2280,7 @@
desc.value = open(file_path, 'rb').read()
encoded_descriptors.extend(desc.encode())
- # Add AvbKernelCmdline descriptor for dm-verity, if requested.
+ # Add AvbKernelCmdline descriptor for dm-verity from an image, if requested.
if setup_rootfs_from_kernel:
image_handler = ImageHandler(
setup_rootfs_from_kernel.name)
@@ -2266,6 +2288,13 @@
encoded_descriptors.extend(cmdline_desc[0].encode())
encoded_descriptors.extend(cmdline_desc[1].encode())
+ # Add AvbKernelCmdline descriptor for dm-verity from desc, if requested.
+ if ht_desc_to_setup:
+ cmdline_desc = self._get_cmdline_descriptors_for_hashtree_descriptor(
+ ht_desc_to_setup)
+ encoded_descriptors.extend(cmdline_desc[0].encode())
+ encoded_descriptors.extend(cmdline_desc[1].encode())
+
# Add kernel command-lines.
if kernel_cmdlines:
for i in kernel_cmdlines:
@@ -2558,10 +2587,11 @@
h_desc.digest = digest
# Generate the VBMeta footer.
+ ht_desc_to_setup = None
vbmeta_blob = self._generate_vbmeta_blob(
algorithm_name, key_path, public_key_metadata_path, [h_desc],
chain_partitions, rollback_index, flags, props, props_from_file,
- kernel_cmdlines, setup_rootfs_from_kernel,
+ kernel_cmdlines, setup_rootfs_from_kernel, ht_desc_to_setup,
include_descriptors_from_image, signing_helper, release_string,
append_to_release_string)
@@ -2619,6 +2649,7 @@
public_key_metadata_path, rollback_index, flags,
props, props_from_file, kernel_cmdlines,
setup_rootfs_from_kernel,
+ setup_as_rootfs_from_kernel,
include_descriptors_from_image,
calc_max_image_size, signing_helper,
release_string, append_to_release_string,
@@ -2648,6 +2679,8 @@
kernel_cmdlines: Kernel cmdlines to insert (list of strings).
setup_rootfs_from_kernel: None or file to generate
dm-verity kernel cmdline from.
+ setup_as_rootfs_from_kernel: If True, generate dm-verity kernel
+ cmdline to set up rootfs.
include_descriptors_from_image: List of file objects for which
to insert descriptors from.
calc_max_image_size: Don't store the hashtree or footer - instead
@@ -2785,12 +2818,16 @@
ht_desc.fec_offset = fec_offset
ht_desc.fec_size = len(fec_data)
+ ht_desc_to_setup = None
+ if setup_as_rootfs_from_kernel:
+ ht_desc_to_setup = ht_desc
+
# Generate the VBMeta footer and add padding as needed.
vbmeta_offset = tree_offset + len_hashtree_and_fec
vbmeta_blob = self._generate_vbmeta_blob(
algorithm_name, key_path, public_key_metadata_path, [ht_desc],
chain_partitions, rollback_index, flags, props, props_from_file,
- kernel_cmdlines, setup_rootfs_from_kernel,
+ kernel_cmdlines, setup_rootfs_from_kernel, ht_desc_to_setup,
include_descriptors_from_image, signing_helper, release_string,
append_to_release_string)
padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) -
@@ -3308,6 +3345,12 @@
help=('Do not append vbmeta struct or footer '
'to the image'),
action='store_true')
+ # This is different from --setup_rootfs_from_kernel insofar that
+ # it doesn't take an IMAGE, the generated cmdline will be for the
+ # hashtree we're adding.
+ sub_parser.add_argument('--setup_as_rootfs_from_kernel',
+ action='store_true',
+ help='Adds kernel cmdline for setting up rootfs')
self._add_common_args(sub_parser)
sub_parser.set_defaults(func=self.add_hashtree_footer)
@@ -3510,6 +3553,7 @@
args.prop_from_file,
args.kernel_cmdline,
args.setup_rootfs_from_kernel,
+ args.setup_as_rootfs_from_kernel,
args.include_descriptors_from_image,
args.calc_max_image_size, args.signing_helper,
args.internal_release_string,
diff --git a/test/avb_slot_verify_unittest.cc b/test/avb_slot_verify_unittest.cc
index 76ce2f5..a51daf2 100644
--- a/test/avb_slot_verify_unittest.cc
+++ b/test/avb_slot_verify_unittest.cc
@@ -45,6 +45,7 @@
}
void CmdlineWithHashtreeVerification(bool hashtree_verification_on);
+ void CmdlineWithChainedHashtreeVerification(bool hashtree_verification_on);
FakeAvbOps ops_;
};
@@ -1407,6 +1408,181 @@
CmdlineWithHashtreeVerification(true);
}
+void AvbSlotVerifyTest::CmdlineWithChainedHashtreeVerification(
+ bool hashtree_verification_on) {
+ const size_t system_size = 1028 * 1024;
+ const size_t system_partition_size = 1536 * 1024;
+
+ // Generate a 1028 KiB file with known content.
+ std::vector<uint8_t> contents;
+ contents.resize(system_size);
+ for (size_t n = 0; n < system_size; n++)
+ contents[n] = uint8_t(n);
+ base::FilePath system_path = testdir_.Append("system_a.img");
+ EXPECT_EQ(system_size,
+ static_cast<const size_t>(
+ base::WriteFile(system_path,
+ reinterpret_cast<const char*>(contents.data()),
+ contents.size())));
+
+ // Check that we correctly generate dm-verity kernel cmdline
+ // snippets, if requested.
+ EXPECT_COMMAND(0,
+ "./avbtool add_hashtree_footer --salt d00df00d --image %s "
+ "--partition_size %d --partition_name foobar "
+ "--algorithm SHA256_RSA2048 "
+ "--key test/data/testkey_rsa2048.pem "
+ "--internal_release_string \"\" "
+ "--do_not_generate_fec "
+ "--setup_as_rootfs_from_kernel",
+ system_path.value().c_str(),
+ (int)system_partition_size);
+
+ EXPECT_EQ(
+ "Footer version: 1.0\n"
+ "Image size: 1572864 bytes\n"
+ "Original image size: 1052672 bytes\n"
+ "VBMeta offset: 1069056\n"
+ "VBMeta size: 1664 bytes\n"
+ "--\n"
+ "Minimum libavb version: 1.0\n"
+ "Header Block: 256 bytes\n"
+ "Authentication Block: 320 bytes\n"
+ "Auxiliary Block: 1088 bytes\n"
+ "Algorithm: SHA256_RSA2048\n"
+ "Rollback Index: 0\n"
+ "Flags: 0\n"
+ "Release String: ''\n"
+ "Descriptors:\n"
+ " Hashtree descriptor:\n"
+ " Version of dm-verity: 1\n"
+ " Image Size: 1052672 bytes\n"
+ " Tree Offset: 1052672\n"
+ " Tree Size: 16384 bytes\n"
+ " Data Block Size: 4096 bytes\n"
+ " Hash Block Size: 4096 bytes\n"
+ " FEC num roots: 0\n"
+ " FEC offset: 0\n"
+ " FEC size: 0 bytes\n"
+ " Hash Algorithm: sha1\n"
+ " Partition Name: foobar\n"
+ " Salt: d00df00d\n"
+ " Root Digest: e811611467dcd6e8dc4324e45f706c2bdd51db67\n"
+ " Kernel Cmdline descriptor:\n"
+ " Flags: 1\n"
+ " Kernel Cmdline: 'dm=\"1 vroot none ro 1,0 2056 verity 1 "
+ "PARTUUID=$(ANDROID_SYSTEM_PARTUUID) PARTUUID=$(ANDROID_SYSTEM_PARTUUID) "
+ "4096 4096 257 257 sha1 e811611467dcd6e8dc4324e45f706c2bdd51db67 "
+ "d00df00d 2 $(ANDROID_VERITY_MODE) ignore_zero_blocks\" root=/dev/dm-0'\n"
+ " Kernel Cmdline descriptor:\n"
+ " Flags: 2\n"
+ " Kernel Cmdline: "
+ "'root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)'\n",
+ InfoImage(system_path));
+
+ base::FilePath pk_path = testdir_.Append("testkey_rsa2048.avbpubkey");
+ EXPECT_COMMAND(
+ 0,
+ "./avbtool extract_public_key --key test/data/testkey_rsa2048.pem"
+ " --output %s",
+ pk_path.value().c_str());
+
+ GenerateVBMetaImage(
+ "vbmeta_a.img",
+ "SHA256_RSA2048",
+ 4,
+ base::FilePath("test/data/testkey_rsa2048.pem"),
+ base::StringPrintf("--kernel_cmdline should_be_in_both=1 "
+ "--algorithm SHA256_RSA2048 "
+ "--flags %d "
+ "--chain_partition system:1:%s "
+ "--internal_release_string \"\"",
+ hashtree_verification_on
+ ? 0
+ : AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED,
+ pk_path.value().c_str()));
+
+ EXPECT_EQ(
+ base::StringPrintf("Minimum libavb version: 1.0\n"
+ "Header Block: 256 bytes\n"
+ "Authentication Block: 320 bytes\n"
+ "Auxiliary Block: 1216 bytes\n"
+ "Algorithm: SHA256_RSA2048\n"
+ "Rollback Index: 4\n"
+ "Flags: %d\n"
+ "Release String: ''\n"
+ "Descriptors:\n"
+ " Chain Partition descriptor:\n"
+ " Partition Name: system\n"
+ " Rollback Index Location: 1\n"
+ " Public key (sha1): "
+ "cdbb77177f731920bbe0a0f94f84d9038ae0617d\n"
+ " Kernel Cmdline descriptor:\n"
+ " Flags: 0\n"
+ " Kernel Cmdline: 'should_be_in_both=1'\n",
+ hashtree_verification_on
+ ? 0
+ : AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED),
+ InfoImage(vbmeta_image_path_));
+
+ ops_.set_expected_public_key(
+ PublicKeyAVB(base::FilePath("test/data/testkey_rsa2048.pem")));
+
+ // Check that avb_slot_verify() picks the cmdline descriptors based
+ // on their flags value... note that these descriptors are in the
+ // 'system' partition.
+ AvbSlotVerifyData* slot_data = NULL;
+ const char* requested_partitions[] = {"boot", NULL};
+ EXPECT_EQ(AVB_SLOT_VERIFY_RESULT_OK,
+ avb_slot_verify(ops_.avb_ops(),
+ requested_partitions,
+ "_a",
+ AVB_SLOT_VERIFY_FLAGS_NONE,
+ AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
+ &slot_data));
+ EXPECT_NE(nullptr, slot_data);
+ if (hashtree_verification_on) {
+ EXPECT_EQ(
+ "dm=\"1 vroot none ro 1,0 2056 verity 1 "
+ "PARTUUID=1234-fake-guid-for:system_a "
+ "PARTUUID=1234-fake-guid-for:system_a 4096 4096 257 257 sha1 "
+ "e811611467dcd6e8dc4324e45f706c2bdd51db67 d00df00d 2 "
+ "restart_on_corruption ignore_zero_blocks\" root=/dev/dm-0 "
+ "should_be_in_both=1 "
+ "androidboot.vbmeta.device=PARTUUID=1234-fake-guid-for:vbmeta_a "
+ "androidboot.vbmeta.avb_version=1.0 "
+ "androidboot.vbmeta.device_state=locked "
+ "androidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3456 "
+ "androidboot.vbmeta.digest="
+ "5ee1669b112625322657b83ec932c73dad9b0222011b5aa3e8273f4e0ee025dc "
+ "androidboot.vbmeta.invalidate_on_error=yes "
+ "androidboot.veritymode=enforcing",
+ std::string(slot_data->cmdline));
+ } else {
+ // NOTE: androidboot.veritymode is 'disabled', not 'enforcing' and
+ // androidboot.vbmeta.invalidate_on_error isn't set.
+ EXPECT_EQ(
+ "root=PARTUUID=1234-fake-guid-for:system_a should_be_in_both=1 "
+ "androidboot.vbmeta.device=PARTUUID=1234-fake-guid-for:vbmeta_a "
+ "androidboot.vbmeta.avb_version=1.0 "
+ "androidboot.vbmeta.device_state=locked "
+ "androidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3456 "
+ "androidboot.vbmeta.digest="
+ "ae792c45a9d898b532ff9625b60043a8d9eae7e6106b9cba31837d50ba40f81c "
+ "androidboot.veritymode=disabled",
+ std::string(slot_data->cmdline));
+ }
+ avb_slot_verify_data_free(slot_data);
+}
+
+TEST_F(AvbSlotVerifyTest, CmdlineWithChainedHashtreeVerificationOff) {
+ CmdlineWithChainedHashtreeVerification(false);
+}
+
+TEST_F(AvbSlotVerifyTest, CmdlineWithChainedHashtreeVerificationOn) {
+ CmdlineWithChainedHashtreeVerification(true);
+}
+
// In the event that there's no vbmeta partition, we treat the vbmeta
// struct from 'boot' as the top-level partition. Check that this
// works.
