b564111aff
This commit fixes an off-by-one error which is only manifested by the new behavior of OP_CODESEPARATOR within sig hashes triggered by the segwit behavior. The current behavior within the Script VM (txscript.Engine) is known to be fully correct to the extent that it has been verified. However, once segwit activates a consensus divergence would emerge due to *when* the program counter was incremented in the previous code (pre-this-commit). Currently (pre-segwit) when calculating the pre-image to a transaction sighash for signature verification, *all* instances of OP_CODESEPARATOR are removed from the subScript being signed before generating the final sighash. SegWit has additional nerfed the behavior of OP_CODESEPARATOR by no longer removing them (and starting after the last instance), but instead simply starting the subScript to be directly *after* the last instance of an OP_CODESEPARATOR within the pkScript. Due to this new behavior, without this commit, an off-by-one error (which only matters post-segwit), would cause txscript to generate an incorrect subScript since the instance of OP_CODESEPARATOR would remain as part of the subScript instead of being sliced off as the new behavior dictates. The off-by-one error itself is manifested due to a slight divergence in txscript.Engine’s logic compared to Bitcoin Core. In Bitcoin Core script verification is as follows: first the next op-code is fetched, then program counter is incremented, and finally the op-code itself is executed. Before this commit, btcd flipped the order of the last two steps, executing the op-code *before* the program counter was incremented. This commit fixes the post-segwit consensus divergence by incrementing the program-counter *before* the next op-code is executed. It is important to note that this divergence is only significant post-segwit, meaning that txscript.Engine is still consensus compliant independent of this commit. |
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|---|---|---|
| addrmgr | ||
| blockchain | ||
| btcec | ||
| btcjson | ||
| chaincfg | ||
| cmd | ||
| connmgr | ||
| database | ||
| docs | ||
| integration | ||
| limits | ||
| mempool | ||
| mining | ||
| peer | ||
| release | ||
| txscript | ||
| wire | ||
| .gitignore | ||
| .travis.yml | ||
| blocklogger.go | ||
| blockmanager.go | ||
| btcd.go | ||
| CHANGES | ||
| config.go | ||
| config_test.go | ||
| doc.go | ||
| glide.lock | ||
| glide.yaml | ||
| goclean.sh | ||
| LICENSE | ||
| log.go | ||
| params.go | ||
| README.md | ||
| rpcserver.go | ||
| rpcserverhelp.go | ||
| rpcserverhelp_test.go | ||
| rpcwebsocket.go | ||
| sample-btcd.conf | ||
| server.go | ||
| service_windows.go | ||
| signal.go | ||
| signalsigterm.go | ||
| upgrade.go | ||
| upnp.go | ||
| version.go | ||
btcd
btcd is an alternative full node bitcoin implementation written in Go (golang).
This project is currently under active development and is in a Beta state. It is extremely stable and has been in production use since October 2013.
It properly downloads, validates, and serves the block chain using the exact rules (including consensus bugs) for block acceptance as Bitcoin Core. We have taken great care to avoid btcd causing a fork to the block chain. It includes a full block validation testing framework which contains all of the 'official' block acceptance tests (and some additional ones) that is run on every pull request to help ensure it properly follows consensus. Also, it passes all of the JSON test data in the Bitcoin Core code.
It also properly relays newly mined blocks, maintains a transaction pool, and relays individual transactions that have not yet made it into a block. It ensures all individual transactions admitted to the pool follow the rules required by the block chain and also includes more strict checks which filter transactions based on miner requirements ("standard" transactions).
One key difference between btcd and Bitcoin Core is that btcd does NOT include wallet functionality and this was a very intentional design decision. See the blog entry here for more details. This means you can't actually make or receive payments directly with btcd. That functionality is provided by the btcwallet and Paymetheus (Windows-only) projects which are both under active development.
Requirements
Go 1.6 or newer.
Installation
Windows - MSI Available
https://github.com/btcsuite/btcd/releases
Linux/BSD/MacOSX/POSIX - Build from Source
-
Install Go according to the installation instructions here: http://golang.org/doc/install
-
Ensure Go was installed properly and is a supported version:
$ go version
$ go env GOROOT GOPATH
NOTE: The GOROOT and GOPATH above must not be the same path. It is
recommended that GOPATH is set to a directory in your home directory such as
~/goprojects to avoid write permission issues. It is also recommended to add
$GOPATH/bin to your PATH at this point.
- Run the following commands to obtain btcd, all dependencies, and install it:
$ go get -u github.com/Masterminds/glide
$ git clone https://github.com/btcsuite/btcd $GOPATH/src/github.com/btcsuite/btcd
$ cd $GOPATH/src/github.com/btcsuite/btcd
$ glide install
$ go install . ./cmd/...
- btcd (and utilities) will now be installed in
$GOPATH/bin. If you did not already add the bin directory to your system path during Go installation, we recommend you do so now.
Updating
Windows
Install a newer MSI
Linux/BSD/MacOSX/POSIX - Build from Source
- Run the following commands to update btcd, all dependencies, and install it:
$ cd $GOPATH/src/github.com/btcsuite/btcd
$ git pull && glide install
$ go install . ./cmd/...
Getting Started
btcd has several configuration options avilable to tweak how it runs, but all of the basic operations described in the intro section work with zero configuration.
Windows (Installed from MSI)
Launch btcd from your Start menu.
Linux/BSD/POSIX/Source
$ ./btcd
IRC
- irc.freenode.net
- channel #btcd
- webchat
Mailing lists
- btcd: discussion of btcd and its packages.
- btcd-commits: readonly mail-out of source code changes.
To subscribe to a given list, send email to list+subscribe@opensource.conformal.com
Issue Tracker
The integrated github issue tracker is used for this project.
Documentation
The documentation is a work-in-progress. It is located in the docs folder.
GPG Verification Key
All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:
-
Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt
-
Import the public key into your GPG keyring:
gpg --import GIT-GPG-KEY-conformal.txt -
Verify the release tag with the following command where
TAG_NAMEis a placeholder for the specific tag:git tag -v TAG_NAME
License
btcd is licensed under the copyfree ISC License.