116b8c5573
a6ca8f324396522e9748c9a7bbefb3bf1c74a436 fuzz: Fix difficulty target generation in p2p_headers_presync (marcofleon) fa327c77e34e0cfb7994842c23f539ab11bf5d3b util: Add ConsumeArithUInt256InRange fuzzing helper (marcofleon) Pull request description: In the `p2p_headers_presync` fuzz target, this assertion failed: ``` assert(total_work < chainman.MinimumChainWork()); ``` Input that triggered the failure: [p2ppresync_crash.txt](https://github.com/user-attachments/files/17620203/p2ppresync_crash.txt) The test previously used `ConsumeIntegralInRange` to generate header difficulty targets within a hardcoded range. The fuzzer found specific values in that range that correspond to very low thresholds due to how [`SetCompact`][setcompact-link] works. The total work of a long enough test chain ended up exceeding `MinimumChainWork`. Fix this by adding a new `ConsumeArithUInt256InRange` helper function and use it in the fuzz test to generate target values within the originally intended range. The target is then converted to an `nBits` value using `GetCompact()`. For some more context, see https://github.com/bitcoin/bitcoin/pull/30918. [setcompact-link]:6463117a29/src/arith_uint256.h (L251-L271)ACKs for top commit: instagibbs: ACKa6ca8f3243dergoegge: Code review ACK a6ca8f324396522e9748c9a7bbefb3bf1c74a436 brunoerg: code review ACK a6ca8f324396522e9748c9a7bbefb3bf1c74a436 Tree-SHA512: 92013d9d37bd3f11992ee678ba9745196efbdc4d773fd14994116629260bea46ffc9fa3923d443af7b623d39c6211900ce98a349c62ad1976e12312c37ef9df0
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
What is Bitcoin Core?
Bitcoin Core connects to the Bitcoin peer-to-peer network to download and fully validate blocks and transactions. It also includes a wallet and graphical user interface, which can be optionally built.
Further information about Bitcoin Core is available in the doc folder.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled during the generation of the build system) with: ctest. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: build/test/functional/test_runner.py
(assuming build is your build directory).
The CI (Continuous Integration) systems make sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.