[third_party/pigweed/src] Roll 35 commits

36cb582c288cba0 roll: host_tools
d3053025c29a167 pw_allocator: Add pool accessors
77a6a9d60461e36 pw_allocator: Move Resize assertion
5dfd9f5d63c10c8 roll: absolute_uploader, incremental_uploader
edd2210f4129e71 pw_async: Add OWNERS file
85303121eae1d5c docs: Add policy on incomplete docs changes
9ca879adddc61ff pw_toolchain: Link against pw_libc for host clang
8083daa9efb770b pw_libc: Don't implicitly link against global link
143d5992cf51e30 pw_web: TypeScript workarounds for disambiguation
fc91de7aee7f608 pw_{hdlc,rpc}: Add CancellableReader
69a6925451f7f0e pw_containers: Rename to VariableLengthEntryQueue
bc2dd6423e29079 pw_containers: Rename files to variable_length_ent
9c83e14502e595e build: Fix `all` target in GN build
e763ecc933e61e5 build: Add an extended default group
36acba889c22b8c roll: clang
aa5b0ffc3a07627 pw_build: Allow add_global_link_deps to be overrid
8ebb6a460d6439d pw_build: Expose pigweed_default_configs
bc3f8ff90d9c9c9 pw_analog: Migrate MicrovoltInput to Doxygen
7ea3c0814e1f56d docs: Start the glossary
4a65df27bf9e41d pw_cli: Narrow logic around colors
3a9727a30897a60 pw_containers: VariableLengthEntryDeque Entry stru
0f286e3de2e9893 docs: Update changelog
7dc954ca46bcbb1 pw_tokenizer: Test for C99 support
d7606ceb99cc91c pw_containers: VariableLengthEntryDeque C implemen
5883b6332831e2e pw_web: Throw error as an Error type
c1cafef91f81074 pw_allocator: Add AllocatorMetricProxy
63c5be9f1d5c8ab pw_ring_buffer: Minor build and docs updates
c08b1fa74398ba2 pw_transfer: Remove old test server
70ba43b50112cfb pw_unit_test: Add pw_unit_test_TESTONLY build arg
a836c804dc55398 pw_env_setup: Fix double bootstrap.bat failures on
d3bd2a975e113a6 Bazel: Retire pigweed_config (part 3)
2d88135efd1f920 pw_allocator: Add LibCAllocator
3cfe5d0c4759c58 pw_metric: Make constructors constexpr
571523313de9a41 pw_allocator: Add NullAllocator
b9656ecb22eabf4 pw_i2c: Add cmake integration

third_party/pigweed/src Rolled-Commits: 2ff4f59fdcad9e6..36cb582c288cba0
Roller-URL: https://ci.chromium.org/b/8768391609917358849
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I07752c76f13989cfec6ff13e4e38ca6d4d0806d8
Reviewed-on: https://pigweed-review.googlesource.com/c/open-dice/+/173739
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
1 file changed
tree: 5a72853fce169e68e741e830ab488c393fd34fd9
  1. build_overrides/
  2. docs/
  3. images/
  4. include/
  5. src/
  6. third_party/
  7. toolchains/
  8. tools/
  9. .clang-format
  10. .gitignore
  11. .gitmodules
  12. .gn
  13. banner.txt
  14. bootstrap.sh
  15. BUILD.gn
  17. generate_test_values.py
  19. navbar.md
  20. OWNERS
  21. pigweed.json
  22. pyproject.toml
  23. README.md
  24. run_fuzzer.sh

Open Profile for DICE

This repository contains the specification for the Open Profile for DICE along with production-quality code. This profile is a specialization of the Hardware Requirements for a Device Identifier Composition Engine and DICE Layering Architecture specifications published by the Trusted Computing Group (TCG). For readers already familiar with those specs, notable distinctives of this profile include:

  • Separate CDIs for attestation and sealing use cases
  • Categorized inputs, including values related to verified boot
  • Certified UDS values
  • X.509 or CBOR certificates

Mailing List

You can find us (and join us!) at https://groups.google.com/g/open-profile-for-dice. We're happy to answer questions and discuss proposed changes or features.


The specification can be found here. It is versioned using a major.minor scheme. Compatibility is maintained across minor versions but not necessarily across major versions.


Production quality, portable C code is included. The main code is in dice.h and dice.c. Cryptographic and certificate generation operations are injected via a set of callbacks. Multiple implementations of these operations are provided, all equally acceptable. Integrators should choose just one of these, or write their own.

Tests are included for all code and the build files in this repository can be used to build and run these tests.

Disclaimer: This is not an officially supported Google product.

Thirdparty Dependencies

Different implementations use different third party libraries. The third_party directory contains build files and git submodules for each of these. The submodules must be initialized once after cloning the repo, using git submodule update --init, and updated after pulling commits that roll the submodules using git submodule update.

Building and Running Tests

Quick setup

To setup the build environment the first time:

$ git submodule update --init
$ source bootstrap.sh
$ gn gen out

To build and run tests:

$ ninja -C out

More details

The easiest way, and currently the only supported way, to build and run tests is from a Pigweed environment on Linux. Pigweed does support other host platforms so it shouldn't be too hard to get this running on Windows for example, but we use Linux.

There are two scripts to help set this up:

  • bootstrap.sh will initialize submodules, bootstrap a Pigweed environment, and generate build files. This can take some time and may download on the order of 1GB of dependencies so the normal workflow is to just do this once.

  • activate.sh quickly reactivates an environment that has been previously bootstrapped.

These scripts must be sourced into the current session: source activate.sh.

In the environment, from the base directory of the dice-profile checkout, run ninja -C out to build everything and run all tests. You can also run pw watch which will build, run tests, and continue to watch for changes.

This will build and run tests on the host using the clang toolchain. Pigweed makes it easy to configure other targets and toolchains. See toolchains/BUILD.gn and the Pigweed documentation.


The code is designed to be portable and should work with a variety of modern toolchains and in a variety of environments. The main code in dice.h and dice.c is C99; it uses uint8_t, size_t, and memcpy from the C standard library. The various ops implementations are as portable as their dependencies (often not C99 but still very portable). Notably, this code uses designated initializers for readability. This is a feature available in C since C99 but missing from C++ until C++20 where it appears in a stricter form.


The Google C++ Style Guide is used. A .clang-format file is provided for convenience.


To incorporate the code into another project, there are a few options:

  • Copy only the necessary code. For example:

    1. Take the main code as is: include/dice/dice.h, src/dice.c

    2. Choose an implementation for crypto and certificate generation or choose to write your own. If you choose the boringssl implementation, for example, take include/dice/utils.h, include/dice/boringssl_ops.h, src/utils.c, and src/boringssl_ops.c. Taking a look at the library targets in BUILD.gn may be helpful.

  • Add this repository as a git submodule and integrate into the project build, optionally using the gn library targets provided.

  • Integrate into a project already using Pigweed using the gn build files provided.

Size Reports

The build reports code size using Bloaty McBloatface via the pw_bloat Pigweed module. There are two reports generated:

  • Library sizes - This report includes just the library code in this repository. It shows the baseline DICE code with no ops selected, and it shows the delta introduced by choosing various ops implementations. This report does not include the size of the third party dependencies.

  • Executable sizes - This report includes sizes for the library code in this repository plus all dependencies linked into a simple main function which makes a single DICE call with all-zero input. It shows the baseline DICE code with no ops (and therefore no dependencies other than libc), and it shows the delta introduced by choosing various ops implementations. This report does include the size of the third party dependencies. Note that rows specialized from ‘Boringssl Ops’ use that as a baseline for sizing.

The reports will be in the build output, but you can also find the reports in .txt files in the build output. For example, cat out/host_optimized/gen/*.txt | less will display all reports.

Thread Safety

This code does not itself use mutable global variables, or any other type of shared data structure so there is no thread-safety concerns. However, additional care is needed to ensure dependencies are configured to be thread-safe. For example, the current boringssl configuration defines OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED, and that would need to be changed before running in a threaded environment.

Clearing Sensitive Data

This code makes a reasonable effort to clear memory holding sensitive data. This may help with a broader strategy to clear sensitive data but it is not sufficient on its own. Here are a few things to consider.

  • The caller of this code is responsible for buffers they own (of course).
  • The ops implementations need to clear any copies they make of sensitive data. Both boringssl and mbedtls attempt to zeroize but this may need additional care to integrate correctly. For example, boringssl skips optimization prevention when OPENSSL_NO_ASM is defined (and it is currently defined).
  • Sensitive data may remain in cache.
  • Sensitive data may have been swapped out.
  • Sensitive data may be included in a crash dump.