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cos / mirrors / cros / chromiumos / platform / dm-verity / 4c1a3b764ca301f5a28a681f537f1a9298f3d0ce
commit4c1a3b764ca301f5a28a681f537f1a9298f3d0ce[log] [tgz]
authorAmin Hassani <ahassani@chromium.org>Thu Aug 13 13:32:19 2020 -0700
committerCommit Bot <commit-bot@chromium.org>Tue Aug 18 19:41:05 2020 +0000
treea7b2614d0a6403bb90e0310341a4eaf666d3659e
parentf13b57c80f069e276a5316fe881c442a6b33366f [diff]
Prepare for presubmit pass in platform2

All manual changes that is reqiured for repo upload to passes when we
move verity to platform2.

BUG=chromium:886953
TEST=presubmit passes
TEST=CQ passes

Change-Id: I50b7bfa1b28564068fdfa4fc48eba1af92262973
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dm-verity/+/2353062
Tested-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
19 files changed
tree: a7b2614d0a6403bb90e0310341a4eaf666d3659e
  1. include/
  2. kernel/
  3. logging/
  4. simple_file/
  5. .clang-format ⇨ ../../platform2/.clang-format
  6. .gitignore
  7. common.mk
  8. dm-bht-userspace.c
  9. dm-bht-userspace.h
  10. dm-bht.c
  11. dm-bht.h
  12. dm-bht_unittest.cc
  13. file_hasher.cc
  14. file_hasher.h
  15. file_hasher_unittest.cc
  16. LICENSE
  17. LICENSE.makefile
  18. logging.h
  19. Makefile
  20. OWNERS
  21. PRESUBMIT.cfg
  22. README.md
  23. utils.cc
  24. utils.h
  25. verity_main.cc
  26. verity_testrunner.cc
README.md

Verity

Verity is the userspace tool for creating integrity hashes for a device image.

This tool is a frontend for dm-bht, a device-mapper friendly block hash table structure. `verity' produces dm-bht-based images for use with dm-verity. The dm-verity module provides a transparent, integrity-checking layer over a given block device. This expects a backing device and a secondary device which provides cryptographic digests of the blocks on the primary device

Note, the secondary device image can be appended to the primary device or used as a standalone device.

This tool creates an image of the format:

  • [hash of hash of blocks n ... n+n-1]
  • [hash of hash of blocks 0 ... n-1]
  • [...]
  • [hash of block 1]
  • [hash of block 0]

Upon completion, the hash of the root hash will be printed to standard out. The root hash, tree depth, number of hashed blocks, and cryptographic hash algorithm used must be supplied to the dm-verity when configuring a device.

Building

To build outside of Chromium OS:

make

Example Usage

To use:

./verity mode depth alg image hash_image [root_hexdigest]

For example:

dd if=/dev/zero of=/tmp/image bs=4k count=512
./verity create 2 sha256 /tmp/image /tmp/hash | tee table
# ...
cat table
ls -la /tmp/hash

Licensing

All the source code is licensed GPLv2 to be completely kernel compatible. The Makefiles are from the parent project and are licensed under a BSD-style license.