a81cd96805
To fix a minor malleability found by Sergio Lerner (reported here: https://bitcointalk.org/index.php?topic=8392.msg1245898#msg1245898) The problem is that if (R,S) is a valid ECDSA signature for a given message and public key, (R,-S) is also valid. Modulo N (the order of the secp256k1 curve), this means that both (R,S) and (R,N-S) are valid. Given that N is odd, S and N-S have a different lowest bit. We solve the problem by forcing signatures to have an even S value, excluding one of the alternatives. This commit just changes the signing code to always produce even S values, and adds a verification mode to check it. This code is not enabled anywhere yet. Existing tests in key_tests.cpp verify that the produced signatures are still valid. |
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| doc | ||
| share | ||
| src | ||
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| COPYING | ||
| INSTALL | ||
| README.md | ||
| bitcoin-qt.pro | ||
README.md
Bitcoin integration/staging tree
Copyright (c) 2009-2013 Bitcoin Developers
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 is also the name of the open source software which enables the use of this currency.
For more information, as well as an immediately useable, binary version of the Bitcoin client software, see http://www.bitcoin.org.
License
Bitcoin 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/coding.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. Please be patient and help out, 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 for the core code are in src/test/. To compile and run them:
cd src; make -f makefile.unix test
Unit tests for the GUI code are in src/qt/test/. To compile and run them:
qmake BITCOIN_QT_TEST=1 -o Makefile.test bitcoin-qt.pro
make -f Makefile.test
./bitcoin-qt_test
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.