| 0f7de9479afef18835cdbfe3da07811a7993504e |
|
08-Mar-2017 |
David Zeuthen <zeuthen@google.com> |
Add memory leak tracing infrastructure and fix a memory leak.
Do this by instrumenting the malloc()/free() routines used by the
tests and have it record a stack trace for every allocation. Check at
the end of each unit test that all memory has been freed. If not,
print a list of all these stack traces.
Re-organize all tests so they derive from BaseAvbtoolTest and make
this super class do the requisite leak-reset and leak-check in Setup()
and Teardown() methods.
After doing this, the only leak identified in libavb (woot!) turned
out to be in avb_slot_verify(). Fix this. Also fix some tests that
knowingly leak memory.
Bug: None
Test: All unit tests pass.
Change-Id: I54da00ef0cc840e390cad118888affe5a86b76e3
/external/avb/libavb/avb_slot_verify.c
|
| a5fd3a4b5617b75ce5666e1bfd38be578e865e1f |
|
27-Feb-2017 |
David Zeuthen <zeuthen@google.com> |
Allow top-level vbmeta struct to be in 'boot' partition.
If there is no 'vbmeta' partition try to load the top-level vbmeta
struct from the end of 'boot' via a footer.
Two use-cases come to mind
- bring-up when the partition table doesn't yet mention vbmeta; and
- upgrades where it's not feasible to change the partition table
Bug: None
Test: New unit tests and all unit tests pass.
Change-Id: Id0c6c0f95ce157ffbeb0692d3c9547f49ab58640
/external/avb/libavb/avb_slot_verify.c
|
| e3cadcacd798effe83b1593dba1ee0e3d84cf6e4 |
|
23-Feb-2017 |
David Zeuthen <zeuthen@google.com> |
Rework how versioning work.
Instead of listing the version of avbtool that generated the struct
(which is not very useful), convey the minimum required libavb version
needed to parse the structure. This is a lot more useful as it can be
used at runtime to reject updates requiring a newer libavb than what
is on the device (conveyed via androidboot.vbmeta.avb_version).
Also add a human-readable release-string field that describes what
tool (typically avbtool) was used to generate the data. Emphasize that
one cannot make assumptions about the format and it's only there to
aid in debugging. Also make it possible to easily append
build-specific information to this string.
Add a third version number field that can be bumped when doing bug-fix
releases that don't add any new features. This is groundwork needed
for a release process.
Document all this in the README file.
Also rename androidboot.vbmeta.version to androidboot.vbmeta.avb_version
since it conveys the version of libavb used in the bootloader.
Add avb_version_string() and suggest that this should be used in
bootloaders to convey what version of libavb is being used on the
device in debug/diagnostics output. Update examples/uefi to use this.
Bug: 35322304
Bug: 32414650
Test: New unit tests and all unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: Iae52a751c84fe4ea4473803d6f4e978720737511
/external/avb/libavb/avb_slot_verify.c
|
| bc41cead048a90f63e3dd4335097c5588ec09345 |
|
16-Feb-2017 |
David Zeuthen <zeuthen@google.com> |
libavb: Include androidboot.vbmeta.version in the generated command-line.
This version number represents the version of the libavb embedded in
the bootloader. This can be used at run-time to reject updates that
would write a vbmeta partition with a newer version than what the
bootloader supports.
(Also include some fixes for the previous CL which didn't make the cut
before Treehugger merged it.)
Bug: 35416772
Test: New unit tests and all unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: Ie6aea68d0d5154be64cb1fff0699d16a0b123d39
/external/avb/libavb/avb_slot_verify.c
|
| 19c38437eb77101ac30b29135cca58fbc684eace |
|
16-Feb-2017 |
David Zeuthen <zeuthen@google.com> |
libavb: Don't pass androidboot.slot_suffix in generated kernel command-line.
It's not appropriate to do this since the boot loader's A/B stack will
likely do this. Also add new avb_strdupv() utility function so it's
easy to do this yourself and update UEFI example bootloader to use
this.
Bug: None
Test: New unit tests + all unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: I9f9596b1f273330e80a38d857233167fefcce01b
/external/avb/libavb/avb_slot_verify.c
|
| 57ac06e6e4fae29eb616613eb2e2623d79230290 |
|
10-Jan-2017 |
David Zeuthen <zeuthen@google.com> |
Set androidboot.vbmeta.device from libavb instead of descriptor.
When using an initrd --generate_dm_verity_cmdline_from_hashtree is not
set because the initrd is expected to set up the root filesystem. In
this case androidboot.vbmeta.device still needs to be set but right
now this is not how things work. Fix this by setting this kernel
command-line parameter from within libavb instead of in a descriptor.
Bug: 33590159
Test: Unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: I093c1b1f670082ca998f0a97a215676371ac0be2
/external/avb/libavb/avb_slot_verify.c
|
| 4b6a634e48353da1e119ebe0287299f7b919d778 |
|
03-Jan-2017 |
David Zeuthen <zeuthen@google.com> |
Fix-up coding style and add PREUPLOAD.cfg file.
Previous commits broke the style specified our .clang-format file -
fixed this by running it through clang-format(1). During this process
discovered that I've been invoking clang-format(1) without the
--style=file option meaning that our .clang-format file actually
hadn't been used at all. So there's a rather big amount of formatting
changes in this CL.
Also replaced the .clang-format symlink target to
../../build/tools/brillo-clang-format with our own file since the
brillo one may go away in the future or not exist at all.
Finally, added a PREULOAD.cfg file to do this on every commit. See
https://android.googlesource.com/platform/tools/repohooks/
for more information about how this works.
Bug: None
Test: Manually tested.
Test: All unit tests pass.
Change-Id: I6461478a62efd81689bc4316c22f758e7f98f59f
/external/avb/libavb/avb_slot_verify.c
|
| 4cfa3cdc879b93cb3e5bdf73016187aaecac2f5a |
|
02-Dec-2016 |
Dzmitry Yatsushkevich <dmitryya@nestlabs.com> |
libavb: fix -Werror=return-type compilation error.
There is an issue if build libavb for gcc:
external/avb/libavb/avb_slot_verify.c: In function 'result_should_continue':
external/avb/libavb/avb_slot_verify.c:62:1: error: control reaches end of non-void function [-Werror=return-type]
result_should_continue is a non-void function and has 'return' only in switch statement which actually covers all cases but gcc can't recognize that.
So add 'return false' at the end of function just to make gcc happy.
Change-Id: I07978eabfeea9d5d1d8e22be2c37c461e5e043b6
Signed-off-by: Dzmitry Yatsushkevich <dmitryya@nestlabs.com>
/external/avb/libavb/avb_slot_verify.c
|
| b82c411013faf511cf51230121881bc7c9ee7903 |
|
02-Dec-2016 |
Dzmitry Yatsushkevich <dmitryya@nestlabs.com> |
libavb: fix gcc compilation error.
There is an issue if build libavb for gcc:
external/avb/libavb/avb_slot_verify.c: In functioni 'load_and_verify_vbmeta':
external/avb/libavb/avb_slot_verify.c:171:11: error: 'desc_partition_name' may be used uninitialized in this function
[-Werror=maybe-uninitialized] found = avb_strv_find_str(requested_partitions,
^
external/avb/libavb/avb_slot_verify.c:71:18: note: 'desc_partition_name' was declared here
const uint8_t* desc_partition_name;
^
The problem in 'out' branch in load_and_verify_vbmeta function.
Execution may get there from line 86 before initializing desc_partition_name:
83 if (!avb_hash_descriptor_validate_and_byteswap(
84 (const AvbHashDescriptor*)descriptor, &hash_desc)) {
85 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
86 goto out;
87 }
But this is not a problem because 'ret' is AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA
and desc_partition_name will not be accessed in this case in 'out' branch
(`result_should_continue' returns false for this ret value):
167 out:
168
169 if (ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) {
170 /* If this is the requested partition, copy to slot_data. */
171 found = avb_strv_find_str(requested_partitions,
172 (const char*)desc_partition_name,
173 hash_desc.partition_name_len);
Change-Id: Ib404e83cfb4b06c8ea458a02afbb2d944da7428d
Signed-off-by: Dzmitry Yatsushkevich <dmitryya@nestlabs.com>
/external/avb/libavb/avb_slot_verify.c
|
| 40ee1da883c634ce94bb69e97a52598f8fbc151d |
|
23-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
Rename "rollback index slot" to "rollback index location".
This is because the word slot is already used in the context of
A/B. Less confusing this way.
Bug: 33100927
Test: New unit tests and all unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: Ic611b02dc18e7dd9f14c2c87b247be3cd8f4aaf2
/external/avb/libavb/avb_slot_verify.c
|
| 8681a33e249cb68c5159ebccb50b55c56867fcdf |
|
23-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
libavb: Pass all vbmeta images in AvbSlotVerifyData, not just 'vbmeta'.
Right now AvbSlotVerifyData only exposes the vbmeta struct from the
'vbmeta' partition and not from any chained partition. This is
problematic as applications (bootloader, fs_mgr, etc.) may need to
access descriptors no matter where they are stored. Of course such
applications could just reimplement avb_slot_verify() themselves but
this is error-prone and unnecessary. Instead, just make
avb_slot_verify() export what is needed.
Additionally, make androidboot.vbmeta.{hash_alg, size, digest} be a
digest of all these images, not just the root.
Before this change, user-space actually had no way to properly verify
vbmeta images in non-vbmeta partitions because it lacks access to
stored_rollback_indexes[] for comparison. Now, however, user-space can
use avb_slot_verify() for verification with an AvbOps struct where
validate_vbmeta_public_key() and read_rollback_index() will pass any
image. After this, all that is needed is comparing
androidboot.vbmeta.{hash_alg, size, digest} against the value computed
over vbmeta_images[] in AvbSlotVerifyData.
Additionally, all descriptors from all vbmeta images are now easily
available which is a feature which is needed in fs_mgr to set up
non-rootfs dm-verity partitions.
Bug: 31264231
Test: New unit tests + unit tests pass.
Test: Manually tested on UEFI based bootloader.
Change-Id: I8df1de246dba0b41cb3c9a7bfc93587bb55a666c
/external/avb/libavb/avb_slot_verify.c
|
| bc8f647d58db7490caef46c3d7ac85e4f481c389 |
|
21-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
Pass androidboot.vbmeta.device option on the kernel cmdline.
With these changes, avbtool and libavb will set this new option to the
partition GUID of the 'vbmeta' partition for the booted slot. This can
be used by an AVB-specific error handler to clear the 'vbmeta'
partition in question thereby forcing the bootloader to fall back to
another slot. Here's the debug output when manually tested with my toy
UEFI bootloader and a custom hacked up dm-verity error handler:
[ 0.000000] Kernel command line: rootfstype=ext4 init=/init console=ttyS0,115200 androidboot.console=ttyS0 androidboot.hardware=uefi_x86_64 enforcing=0 androidboot.selinux=permissive androidboot.debuggable=1 buildvariant=eng dm="1 vroot none ro 1,0 2080496 verity 1 PARTUUID=c2531a08-1ff2-4c3e-9d9d-a50e5abd02c8 PARTUUID=c2531a08-1ff2-4c3e-9d9d-a50e5abd02c8 4096 4096 260062 260062 sha1 e4806bc79e0d292901d10087d6e98dc70d8acca1 43f92ecfd184583d79f6ae8618559ca9b24c51d8 1 ignore_zero_blocks" root=0xfd00 androidboot.vbmeta.device=PARTUUID=b0868553-57db-4047-94fc-3673070128e2 androidboot.slot_suffix=_a androidboot.vbmeta.device_state=unlocked androidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3264 androidboot.vbmeta.digest=739a4c9ad3e034ac483614ced4083a2caad246387ce7fed8bd8eb92a2d08486e
[...]
[ 1.215488] device-mapper: init: attempting early device configuration.
[ 1.216648] device-mapper: init: adding target '0 2080496 verity 1 PARTUUID=c2531a08-1ff2-4c3e-9d9d-a50e5abd02c8 PARTUUID=c2531a08-1ff2-4c3e-9d9d-a50e5abd02c8 4096 4096 260062 260062 sha1 e4806bc79e0d292901d10087d6e98dc70d8acca1 43f92ecfd184583d79f6ae8618559ca9b24c51d8 1 ignore_zero_blocks'
[ 1.221667] device-mapper: init: dm-0 is ready
[ 1.230688] device-mapper: verity: 8:6: data block 0 is corrupted
[ 1.231567] device-mapper: verity-avb: AVB error handler called!
[ 1.238727] device-mapper: verity-avb: invalidate_vbmeta: found AVB0 vbmeta partition
[ 1.241937] device-mapper: verity-avb: invalidate_vbmeta: completed.
[ 1.244188] EXT4-fs (dm-0): unable to read superblock
[...]
where invalidate_vbmeta() replaces the AVB0 magic with AVE0 to signal
the error. On the reboot, the bootloader immediately selects slot '_b'
because 'vbmeta_a' fails to validate
UEFI AVB-based boot loader
../../../../external/avb/libavb/avb_vbmeta_image.c:388: ERROR: Magic is incorrect.
../../../../external/avb/libavb/avb_slot_verify.c:331: ERROR: vbmeta_a: Error verifying vbmeta image: invalid vbmeta header
../../../../external/avb/libavb_ab/avb_ab_flow.c:268: ERROR: Error verifying slot _a with result ERROR_INVALID_METADATA - setting unbootable.
[...]
[ 0.000000] Kernel command line: rootfstype=ext4 init=/init console=ttyS0,115200 androidboot.console=ttyS0 androidboot.hardware=uefi_x86_64 enforcing=0 androidboot.selinux=permissive androidboot.debuggable=1 buildvariant=eng dm="1 vroot none ro 1,0 2080496 verity 1 PARTUUID=62b098aa-dcf3-494f-8656-2aad5d0963a2 PARTUUID=62b098aa-dcf3-494f-8656-2aad5d0963a2 4096 4096 260062 260062 sha1 e4806bc79e0d292901d10087d6e98dc70d8acca1 43f92ecfd184583d79f6ae8618559ca9b24c51d8 1 ignore_zero_blocks" root=0xfd00 androidboot.vbmeta.device=PARTUUID=c386b78f-39cd-4cb8-9fc9-ab1023de5beb androidboot.slot_suffix=_b androidboot.vbmeta.device_state=unlocked androidboot.vbmeta.hash_alg=sha256 androidboot.vbmeta.size=3264 androidboot.vbmeta.digest=739a4c9ad3e034ac483614ced4083a2caad246387ce7fed8bd8eb92a2d08486e
[...]
# bootctl get-current-slot
1
as expected.
The AVB error handler featured above will be in a separate CL since
it's against the Linux kernel.
Bug: 31622239
Test: Updated unit tests and unit tests pass.
Test: Manually tested on UEFI based bootloader, see above.
Change-Id: I57e0b7876f02b2484188a2624420085ced3fbdbc
/external/avb/libavb/avb_slot_verify.c
|
| fd41eb9a7848ad8d2ae0a80186e461741bf134f1 |
|
17-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
Add way to disable dm-verity allowing rootfs to be writable.
This feature already exist in Android's current verified boot
implementation and can be enabled by running 'adb disable-verity'. As
it's very useful for developers (it allows replacing e.g. binaries on
the root filesystem) we want AVB to have this feature as well.
First, add a 'flags' field in the VBMeta struct with a single possible
flag value HASHTREE_DISABLED (we can add more flags in the future).
Second, to enable the feature we essentially need to pass
root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)
instead of
dm="1 vroot ... PARTUUID=$(ANDROID_SYSTEM_PARTUUID) ... " root=0xfd00
To do this cleanly and keep all the details about dm-verity setup
outside the bootloader binary, introduce a flags field to the
command-line descriptor allowing the bootloader to skip the
command-line snippet depending on whether HASHTREE_DISABLED is set or
not. With this in place, modify avbtool to generate two kernel
command-line descriptors - one if HASHTREE_DISABLED is set and one if
it's not.
One note is that the VBMeta flag HASHTREE_DISABLED will never be used
at image build time. Instead, it's expected that 'adb disable-verity'
will set the flag by writing to vbmeta_a or vbmeta_b directly. This
will of course cause the image to not be verified but if the device is
unlocked the bootloader will boot it anyway .. this is because of the
previous CL with subject "Enable operations on unlocked devices."
I tried all this using my toy UEFI-based bootloader using libavb and
here's the result. First the bootloader output when processing a
freshly built image (with lots of thing deleted for brevity):
ab_result=OK,
slot_suffix=_a,
command-line='dm="1 vroot none ro 1,0 [...]" root=0xfd00
androidboot.slot_suffix=_a
androidboot.vbmeta.device_state=unlocked [...]'
and once we've get a shell remounting rootfs rw fails:
$ su
# mount -orw,remount /
'/dev/root' is read-only
It's possible however to set the new HASHTREE_DISABLED flag by writing
to vbmeta_a:
# echo -n -e \\x01 | dd bs=1 oseek=123 count=1 \
of=/dev/block/pci/pci0000\:00/0000\:00\:01.1/by-name/vbmeta_a
1+0 records in
1+0 records out
1 bytes transferred in 0.001 secs (1000 bytes/sec)
When rebooting the bootloader now outputs the following:
ab_result=OK_WITH_VERIFICATION_ERROR,
slot_suffix=_a,
command-line='root=PARTUUID=c2531a08-1ff2-4c3e-9d9d-a50e5abd02c8
androidboot.slot_suffix=_a
androidboot.vbmeta.device_state=unlocked [...]'
and it's now possible to remount the root filesystem and write to it:
$ su
# mount -orw,remount /
# echo foo > /bar
# cat /bar
foo
with changes persisting across reboots.
Needless to say, disabling hashtree verification like this will ONLY
work if the device is unlocked. This is because the HASHTREE_DISABLED
flag is in the verified data.
Test: New unit tests and unit tests pass.
Test: Manually tested on UEFI based bootloader, see above.
Bug: 32949911
Change-Id: I9474ddd5f442be369cb0a551f03ac181cc41a265
/external/avb/libavb/avb_slot_verify.c
|
| 0155e6b158bdc5b3a442f16a5dc124d5dee9c71c |
|
16-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
Enable operations on unlocked devices.
If a device is unlocked the expected behavior is that slots are
rejected if, and only if, they are invalid, not if they fail
verification.
Verification failure includes rollback index comparison failures,
signature mismatch, signature made by an unknown key, vbmeta structs
without any signature, and so on. Basically the spirit here is that an
unlocked device should be able to boot an image built on your local
workstation and e.g. signed with your own keys.
To easily enable such operations with avb_slot_verify() and
avb_ab_flow(), we introduce a boolean |allow_verification_error|
parameter in each function. If this is false everything is as before
and we'll abort verification as soon as something doesn't verify.
On the other hand, if |allow_verification_error| is true then we'll
keep going and only bail if e.g. the AVB metadata is invalid, _not_ if
it fails verification.
This is designed so callers can set |allow_verification_error| to true
exactly if the device is unlocked.
Callers of avb_slot_verify() where |allow_verification_error| is set
to true are guaranteed that AVB_SLOT_VERIFY_RESULT_OK is returned if,
and only if, the slot verified correctly.
Introduce AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR in addition to
AVB_AB_FLOW_RESULT_OK so avb_ab_flow() users can make a distinction
whether the image verified or not. The new value can only returned if
|allow_verification_error| is set to true.
In both cases - avb_slot_verify() and avb_ab_flow() - the bootloader
has enough information to determine if the slot to boot cannot be
verified. For example, the device can convey to the user that the OS
it's about to boot is unverified and request the user to click
through. On the other hand if the slot did verify (despite the device
being unlocked) the bootloader can nicely avoid such a kludge.
Add some new test cases to verify correct operation both if
|allow_verification_error| is true or false.
Test: New unit tests and all unit tests pass.
Test: Tested in UEFI-based bootloader in qemu.
Bug: 32949911
Change-Id: I218c8761c201d2e8e4dc73eaebfb1ac2742e0726
/external/avb/libavb/avb_slot_verify.c
|
| 18666abc5d8276a743111e6c3608e66f6c85fb51 |
|
15-Nov-2016 |
David Zeuthen <zeuthen@google.com> |
Make it possible to include public key metadata.
A new option --public_key_metadata can be used at image build time to
include a "public key metadata" blob in the vbmeta struct and this
data is passed to the validate_vbmeta_public_key() AvbOps operation
along with the public key.
The use-case for this option is a device where the root-of-trust
embedded in the device is different from the key used to sign AVB
metadata. Specifically, the public key metadata blob can be data
signed by the device root-of-trust and the data could assert the trust
chain between this root-of-trust and the AVB public key used to sign
the AVB metadata.
(This change breaks the on-disk image format but that's OK because
we're still pre-1.0 with respect to image format stability
guarantees.)
Bug: 32736356
Test: New unit tests and all unit tests pass.
Test: Tested in UEFI-based bootloader in qemu.
Change-Id: I7b9c3bf2f9326b5bb5659b2a431a59a5c9016aff
/external/avb/libavb/avb_slot_verify.c
|
| a8bb9a0e8635e3562367ebfe89b1870b4e2cc8e2 |
|
28-Oct-2016 |
David Zeuthen <zeuthen@google.com> |
libavb: Make it possible to load other partitions than 'boot'.
Boot loaders may need to load other partitions than just 'boot'. For
example in a setup where both the Secure OS and Android is managed and
updated under the same A/B regime, the boot loader needs to load and
verify both of these and start both of them.
Concretely, make avb_slot_verify() and avb_ab_flow() take a list of
partition name to load and extend AvbSlotVerifyData to contain an array
of the partitions that were loaded.
Bug: None
Test: New unit tests and unit tests pass.
Test: Tested in UEFI-based bootloader and qemu.
Change-Id: I5c369faebf707f87df41418223ce94506d86058e
/external/avb/libavb/avb_slot_verify.c
|
| 88b13e12a0ebe3c5195dbb5f48ba00ec896d1517 |
|
03-Oct-2016 |
David Zeuthen <zeuthen@google.com> |
Include full vbmeta digest on the kernel cmdline.
While manually sanity-checking the androidboot.vbmeta.digest value (by
running sha256sum on the DUT) I discovered that only half the digest was
appended to the kernel command-line. While we already had unit tests for
checking this, the data hardcoded in the unit tests was also half the
size.
Here's the output from the DUT for manually testing the fix:
# getprop |grep vbmeta
[ro.boot.vbmeta.device_state]: [unlocked]
[ro.boot.vbmeta.digest]: [f75dc1643b48d19696d001b0f6ef90440ef2df43253c00c4675f53fa70b3ab64]
[ro.boot.vbmeta.hash_alg]: [sha256]
[ro.boot.vbmeta.size]: [2944]
# dd if=/dev/block/pci/pci0000\:00/0000\:00\:01.1/by-name/vbmeta_a bs=1 count=2944 |sha256sum
f75dc1643b48d19696d001b0f6ef90440ef2df43253c00c4675f53fa70b3ab64 -
Bug: None
Change-Id: I60ad123b9abaa5f271ffd256964eb63acfb3807d
Test: Manually tested on DUT, see above
Test: Updated unit tests and all unit tests pass.
/external/avb/libavb/avb_slot_verify.c
|
| 507752b2b5eed4340288d805b61e04d39ed4f618 |
|
29-Sep-2016 |
David Zeuthen <zeuthen@google.com> |
libavb: Allow AvbOps functions to fail with OOM.
To do this we have to slightly change some public library API so we can
bubble up OOM failures. Also fix up the boot_control implementation
since it's using some of this API.
Also fix two warnings found by compiling with gcc instead of clang.
Bug: None
Change-Id: I241ee10e10cef5d7f7ec8db418b279a2a2543c9e
Test: All unit tests pass.
/external/avb/libavb/avb_slot_verify.c
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| 8b6973be7468f5c0db42ff8fcd91f8e97a345a27 |
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20-Sep-2016 |
David Zeuthen <zeuthen@google.com> |
Add A/B implementation.
This CL add routines for working with A/B metadata, including A/B
selection and managing rollback indexes.
A/B metadata is stored in the 'misc' partition in the |slot_suffix|
field using a format private to libavb - see bootable/recovery/bootloader.h
for more details. A new set_ab_metadata sub-command has been added to
avbtool for initializing A/B metadata at build time.
A/B metadata integrity is provided by a simple magic marker and a CRC-32
checksum. If invalid A/B metadata is detected, the behavior is to reset
the A/B metadata to a known state where both slots are given seven boot
tries.
An implementation of the boot_control HAL using AVB-specific A/B
metadata is also provided.
Also factored out the test-side AvbOps into a FakeAvbOps class and put
it in its own file.
Saw a couple of references to things like "Brillo Boot Image" and the
like. Fixed these up.
This CL is based on work done by Kevin Chavez - see b/29072323 - during
his internship at Google.
BUG=31264229
TEST=New unit tests + all unit tests pass.
TEST=Manual testing of boot_control HAL using the bootctl command.
Change-Id: I594ea4173a051ecb72636058440372ff1ca5855b
/external/avb/libavb/avb_slot_verify.c
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| c612e2e353444f6ad714e43702c2afd057516254 |
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16-Sep-2016 |
David Zeuthen <zeuthen@google.com> |
Switch to MIT license.
BUG=31508897
TEST=Unit tests pass.
Change-Id: I790afce2889e3dfaf6a53c02ccaaec3544229a9c
/external/avb/libavb/avb_slot_verify.c
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| 21e95266704e572ced1c633bbc4aea9f42afa0a5 |
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27-Jul-2016 |
David Zeuthen <zeuthen@google.com> |
Add common verified boot tools and library.
This code is originally from the Brillo project but has been adapted for
use in all of Android. It consists of a tool - avbtool - for working
with images (e.g. boot.img, system.img). See the README file for how
it's integrated into the Android build system and how to enable it.
The main job of avbtool is to create vbmeta.img which is the
top-level object for verified boot. This image is designed to go into
the vbmeta partition (or, if using A/B, the slot in question
e.g. vbmeta_a or vbmeta_b) and be of minimal size (for out-of-band
updates). The vbmeta image is cryptographically signed and contains
verification data (e.g. cryptographic digests) for verifying boot.img,
system.img, and other partitions/images.
The vbmeta image can also contain references to other partitions where
verification data is stored as well as a public key indicating who
should sign the verification data. This indirection provides
delegation, that is, it allows a 3rd party to control content on a given
partition by including the public key said 3rd party is using to sign
the data with, in vbmeta.img. By design, this authority can be easily
revoked by simply updating vbmeta.img with new descriptors for the
partition in question.
Storing signed verification data on other images - for example
boot.img and system.img - is also done with avbtool.
In addition to avbtool, a library - libavb - is provided. This library
performs all verification on the device side e.g. it starts by loading
the vbmeta partition, checks the signature, and then goes on to load
the boot partition for verification.
The libavb library is intended to be used in both boot loaders and
inside Android. It has a simple abstraction for system dependencies
(see libavb/avb_sysdeps.h) as well as operations that the boot loader
or OS is expected to implement (see libavb/avb_ops.h).
In addition to handling verified boot, libavb will in the future be
extended to handle A/B selection in a way that can be used in the
device's fastboot implementation, its boot loader, and its
boot_control HAL implementation. This will be implemented in a future
CL.
BUG=29414516
TEST=Unit tests for avbtool and libavb + unit tests pass.
Change-Id: I69ee86878e21fa718faccfc56eb0b1f40707d847
/external/avb/libavb/avb_slot_verify.c
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