roll: third_party/pigweed/src 560f88e..665f9ab (22 commits) 665f9ab:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349673 roll: luci 5292430:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349593 roll: fuchsia-infra-bazel-rules 5a0e3c6..a65d990 (46 commits) cb7ccab:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349592 roll: python-wheel ab421e2:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/314054 pw_toolchain: Ensure Bazel warnings match GN e1a57a6:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349133 pw_bluetooth_sapphire: Silence -Wshadow violations e8d3556:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349318 workflows.json: Add python linting builds c4c8c7b:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349317 pw_web: Clean up migration shim b4e8539:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/347732 pw_bluetooth_proxy: Encapsulate internal allocator ee8b6ee:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348653 pw_build: Split Bazel docs 8db2d07:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349253 pw_async2: Add NotifiedDispatcher 295a4fb:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349273 pw_rpc_transport: Replace constant std::vector with std::array 0537186:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/349252 docs: Remove unused imports 0d38b28:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348973 changelog: Remove caching logic ed1729e:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348930 pw_web: Add alias for pw_web at old path f9b2c52:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348940 pw_toolchain: Minor macOS sysroot handling cleanup f2b0dcd:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348972 docs: Add Armando as secondary owner for changelog automation c9a0060:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348753 pw_build: Remove deprecated constraints 614fac9:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348734 pw_sys_io_baremetal_lm3s6965evb: Use compatibilty constraint c7bb6d3:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348752 pw_rust: Remove use of deprecated constraints 4d6a49d:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/341272 pw_containers: Public StorageBase / StorageBaseFor utility e5ee473:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/347792 pw_async2: Deregister tasks on destruction; remove PendableAsTask 3be40f8:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/348652 pw_build: New docs landing page Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed Rolled-Commits: 560f88ec3e7772..665f9abbef344f Roll-Count: 1 Roller-URL: https://cr-buildbucket.appspot.com/build/8696729407452392865 GitWatcher: ignore CQ-Do-Not-Cancel-Tryjobs: true Change-Id: I53be68991f9d6ba995763adf038d837974f9ffaa Reviewed-on: https://pigweed-review.googlesource.com/c/open-dice/+/349773 Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com> Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com> Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
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:
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.
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.
To setup the build environment the first time:
$ git submodule update --init --recursive $ source bootstrap.sh $ gn gen out
To build and run tests:
$ ninja -C out
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:
Take the main code as is: include/dice/dice.h, src/dice.c
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.
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.
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.
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.