71cc9d9fe8
This adds SCRIPT_VERIFY_LOW_S to STANDARD_SCRIPT_VERIFY_FLAGS which
will make the node require the canonical 'low-s' encoding for
ECDSA signatures when relaying or mining.
Consensus behavior is unchanged.
The rational is explained in a81cd96805ce6b65cca3a40ebbd3b2eb428abb7b:
Absent this kind of test ECDSA is not a strong signature as given
a valid signature {r, s} both that value and {r, -s mod n} are valid.
These two encodings have different hashes allowing third parties a
vector to change users txids. These attacks are avoided by picking
a particular form as canonical and rejecting the other form(s); in
the of the LOW_S rule, the smaller of the two possible S values is
used.
If widely deployed this change would eliminate the last remaining
known vector for nuisance malleability on boring SIGHASH_ALL
p2pkh transactions. On the down-side it will block most
transactions made by sufficiently out of date software.
Unlike the other avenues to change txids on boring transactions this
one was randomly violated by all deployed bitcoin software prior to
its discovery. So, while other malleability vectors where made
non-standard as soon as they were discovered, this one has remained
permitted. Even BIP62 did not propose applying this rule to
old version transactions, but conforming implementations have become
much more common since BIP62 was initially written.
Bitcoin Core has produced compatible signatures since
|
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|---|---|---|
| .tx | ||
| build-aux/m4 | ||
| contrib | ||
| depends | ||
| doc | ||
| qa | ||
| share | ||
| src | ||
| .gitattributes | ||
| .gitignore | ||
| .travis.yml | ||
| COPYING | ||
| INSTALL | ||
| Makefile.am | ||
| README.md | ||
| autogen.sh | ||
| configure.ac | ||
| libbitcoinconsensus.pc.in | ||
README.md
Bitcoin Core integration/staging tree
What is Bitcoin?
Bitcoin is an experimental new 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, as well as an immediately useable, binary version of the Bitcoin Core software, see https://www.bitcoin.org/en/download.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see http://opensource.org/licenses/MIT.
Development process
Developers work in their own trees, then submit pull requests when they think their feature or bug fix is ready.
If it is a simple/trivial/non-controversial change, then one of the Bitcoin development team members simply pulls it.
If it is a more complicated or potentially controversial change, then the patch submitter will be asked to start a discussion (if they haven't already) on the mailing list
The patch will be accepted if there is broad consensus that it is a good thing. Developers should expect to rework and resubmit patches if the code doesn't match the project's coding conventions (see doc/developer-notes.md) or are controversial.
The master branch is regularly built and tested, but is not guaranteed to be
completely stable. Tags are created
regularly to indicate new official, stable release versions of Bitcoin.
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
Every pull request is built for both Windows and Linux on a dedicated server, and unit and sanity tests are automatically run. The binaries produced may be used for manual QA testing — a link to them will appear in a comment on the pull request posted by BitcoinPullTester. See https://github.com/TheBlueMatt/test-scripts for the build/test scripts.
Manual Quality Assurance (QA) Testing
Large changes should have a test plan, and should be tested by somebody other than the developer who wrote the code. See https://github.com/bitcoin/QA/ for how to create a test plan.
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.
Translators should also subscribe to the mailing list.