[third_party/pigweed/src] Roll 37 commits

3fbcf41574028ef docs: Revamp Doxygen style guide
19d58a7afb51ced pw_transfer: Implement adaptive windowing in C++
28826a8a3014f44 pw_{cli,presubmit}: Move git_repo to pw_cli
acc3de9c3173a4a pw_cli: Add Python deprecation decorator
003d721ee784560 pw_blob_store: Fix CMakeLists.txt pw_add_library()
57d41af75d9459d pw_spi_linux: Add pw_spi_linux_cli
6d332ab9dbf286a pw_allocator: Add Pool
c47f14d48c690fd pw_allocator: Update OWNERS
9375570a863aa43 pw_allocator: Rename TrackingAllocatorImpl
f1f990d9174d855 pw_transfer: Convert arguments to std::fstream con
69ee1ccf3ef5680 emboss: Loosen Emboss cmake dependency tracking
23691711b80943a pw_sensor: Update validator schema to JSON schema
ef95198f19c71b6 pw_bluetooth: Add EventMask and temp field in SetE
54c7a6dbc4ad7fc pw_build: Collect wheel fix
c1e0bee4e3ec707 pw_sensor: Provide a validator
4a9b1e019b19eb4 pw_bluetooth: Store length max in virtual field
d8c170bbb03c587 pw_sensor: Add module stub
e79414ec1071a38 clang: Fix `std::array` iterators
c1a9043d74cf12d pw_cli: Update ToolRunner type hints
262a9aaf40ddbe6 pw_log_zephyr: Tokenize Zephyr shell fprintf
111df21a5bc108e pw_presubmit: Fix copy/paste bug in _value()
e1fa7dc22ad709d pw_build: Disable C23 extension warnings
e16b817993ed36d pw_{cli,presubmit}: Move ToolRunner
d578e9425943c63 pw_bluetooth_sapphire: Change CIPD upload path
f27ca9fe526eaec pw_web: Enable column order on init
fb7782c0299f501 pw_tls_client: Only include <sys/time.h> if availa
fb1c6c223a457a8 SEED-0117: pw_i3c
6987287d186eef8 pw_bluetooth_sapphire: Bump @fuchsia_sdk
5c8c8074339c641 pw_build_android: Make Common Backends static
bff185f46d3332f pw_async2: Add PendableAsTask
4c1a7158b663f11 pw_kvs: Depend on libraries for fake flash and sto
9da1d58cc8935c2 pw_kvs: Add libraries to reuse partition and store
2bd59a5ace13fb9 pw_web: Fix test format of log-source.test
28fa6003e1e2cf4 pw_build_info: Add missing header file for cmake
cd34143426e9907 docs: Add Zephyr quickstart
0f8f2149a9608ac roll: go
15c616d7bb75be7 docs: Update changelog

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed/src Rolled-Commits: 7ca22fc66b3aa3c..3fbcf41574028ef
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Reviewed-on: https://pigweed-review.googlesource.com/c/open-dice/+/203550
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tree: 985ba13966bc6e6ad76afd4638d1b23a4b703b38
  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
  16. BUILDCONFIG.gn
  17. generate_test_values.py
  18. LICENSE
  19. navbar.md
  20. OWNERS
  21. pigweed.json
  22. pyproject.toml
  23. README.md
  24. run_fuzzer.sh
README.md

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.

Specification

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.

Code

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.

Porting

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.

Style

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

Incorporating

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.