14ba286556
fa1dc9b36ap2p: Always serialize local timestamp for version msg (MarcoFalke) Pull request description: Currently we serialize the local time when connecting to outbound connections and the "adjusted network" time when someone connects to us. I presume the reason is to avoid a fingerprint in case the local time is misconfigured. However, the fingerprint still exits when: * The local time goes out-of-sync after timedata is filled up, in which case the adjusted time is *not* adjusted. See comment in `src/timedata.cpp`. (In practise I expect no adjustment to happen after timedata is filled up by one entry more than half its size). * The local time is off by more than 70 minutes. See `DEFAULT_MAX_TIME_ADJUSTMENT`. While there is a warning in this case, the warning might be missed by the node operator. * The adjusted time is poisoned by an attacker. This is only a theoretical concern after commite457513eb1. Using the adjusted time does help in a the case where the local time is off by a constant less than 70 minutes and the node quickly connects to 5 outbound peers to retrieve the adjusted time. Still, I think using `GetAdjustedTime` here gives a false sense of security. It will be better for node operators to instead set the correct time. ACKs for top commit: naumenkogs: ACKfa1dc9b36alaanwj: Code review ACKfa1dc9b36aw0xlt: crACKfa1dc9bTree-SHA512: 70a0f4ab3500e6ddcde291620e35273018cefd1d9e94b91ad333e360139ed18862718bb1a9854af2bf79990bf74b05d95492f77d0747c7b9bdd276c020116dcb
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
Further information about Bitcoin Core is available in the doc folder.
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information read the original Bitcoin whitepaper.
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 in configure) with: make check. 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: test/functional/test_runner.py
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.