wire

Package wire implements the bitcoin wire protocol. A comprehensive suite of tests with 100% test coverage is provided to ensure proper functionality.

There is an associated blog post about the release of this package here.

This package has intentionally been designed so it can be used as a standalone package for any projects needing to interface with bitcoin peers at the wire protocol level.

Installation and Updating

$ go get -u github.com/gcash/bchd/wire

Bitcoin Message Overview

The bitcoin protocol consists of exchanging messages between peers. Each message is preceded by a header which identifies information about it such as which bitcoin network it is a part of, its type, how big it is, and a checksum to verify validity. All encoding and decoding of message headers is handled by this package.

To accomplish this, there is a generic interface for bitcoin messages named Message which allows messages of any type to be read, written, or passed around through channels, functions, etc. In addition, concrete implementations of most of the currently supported bitcoin messages are provided. For these supported messages, all of the details of marshalling and unmarshalling to and from the wire using bitcoin encoding are handled so the caller doesn't have to concern themselves with the specifics.

Reading Messages Example

In order to unmarshal bitcoin messages from the wire, use the ReadMessage function. It accepts any io.Reader, but typically this will be a net.Conn to a remote node running a bitcoin peer. Example syntax is:

	// Use the most recent protocol version supported by the package and the
	// main bitcoin network.
	pver := wire.ProtocolVersion
	bchnet := wire.MainNet

	// Reads and validates the next bitcoin message from conn using the
	// protocol version pver and the bitcoin network bchnet.  The returns
	// are a wire.Message, a []byte which contains the unmarshalled
	// raw payload, and a possible error.
	msg, rawPayload, err := wire.ReadMessage(conn, pver, bchnet)
	if err != nil {
		// Log and handle the error
	}

See the package documentation for details on determining the message type.

Writing Messages Example

In order to marshal bitcoin messages to the wire, use the WriteMessage function. It accepts any io.Writer, but typically this will be a net.Conn to a remote node running a bitcoin peer. Example syntax to request addresses from a remote peer is:

	// Use the most recent protocol version supported by the package and the
	// main bitcoin network.
	pver := wire.ProtocolVersion
	bchnet := wire.MainNet

	// Create a new getaddr bitcoin message.
	msg := wire.NewMsgGetAddr()

	// Writes a bitcoin message msg to conn using the protocol version
	// pver, and the bitcoin network bchnet.  The return is a possible
	// error.
	err := wire.WriteMessage(conn, msg, pver, bchnet)
	if err != nil {
		// Log and handle the error
	}

License

Package wire is licensed under the copyfree ISC License.