btcutil

README

btcutil

Package btcutil provides bitcoin-specific convenience functions and types. A comprehensive suite of tests is provided to ensure proper functionality. See test_coverage.txt for the gocov coverage report. Alternatively, if you are running a POSIX OS, you can run the cov_report.sh script for a real-time report.

This package was developed for btcd, an alternative full-node implementation of bitcoin which is under active development by Conformal. Although it was primarily written for btcd, this package has intentionally been designed so it can be used as a standalone package for any projects needing the functionality provided.

Installation and Updating

$ go get -u github.com/btcsuite/btcutil

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_NAME is a placeholder for the specific tag:

  git tag -v TAG_NAME
  

License

Package btcutil is licensed under the copyfree ISC License.

Documentation

Overview

Package btcutil provides bitcoin-specific convenience functions and types.

Block Overview

A Block defines a bitcoin block that provides easier and more efficient manipulation of raw wire protocol blocks. It also memoizes hashes for the block and its transactions on their first access so subsequent accesses don't have to repeat the relatively expensive hashing operations.

Tx Overview

A Tx defines a bitcoin transaction that provides more efficient manipulation of raw wire protocol transactions. It memoizes the hash for the transaction on its first access so subsequent accesses don't have to repeat the relatively expensive hashing operations.

Address Overview

The Address interface provides an abstraction for a Bitcoin address. While the most common type is a pay-to-pubkey-hash, Bitcoin already supports others and may well support more in the future. This package currently provides implementations for the pay-to-pubkey, pay-to-pubkey-hash, and pay-to-script-hash address types.

To decode/encode an address:

// NOTE: The default network is only used for address types which do not
// already contain that information.  At this time, that is only
// pay-to-pubkey addresses.
addrString := "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962" +
	"e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d57" +
	"8a4c702b6bf11d5f"
defaultNet := &chaincfg.MainNetParams
addr, err := btcutil.DecodeAddress(addrString, defaultNet)
if err != nil {
	fmt.Println(err)
	return
}
fmt.Println(addr.EncodeAddress())

Index

• Variables
• func DoubleHashB(b []byte) []byte
• type WIF
  • func DecodeWIF(wif string) (*WIF, error)
  • func NewWIF(privKey *btcec.PrivateKey, privateKeyID byte, compress bool) (*WIF, error)
  • func (w *WIF) SerializePubKey() []byte
  • func (w *WIF) String() string

Variables

var ErrChecksumMismatch = errors.New("checksum mismatch")

ErrChecksumMismatch describes an error where decoding failed due to a bad checksum.

var ErrMalformedPrivateKey = errors.New("malformed private key")

ErrMalformedPrivateKey describes an error where a WIF-encoded private key cannot be decoded due to being improperly formatted. This may occur if the byte length is incorrect or an unexpected magic number was encountered.

Functions

func DoubleHashB

func DoubleHashB(b []byte) []byte

DoubleHashB calculates hash(hash(b)) and returns the resulting bytes.

Types

type WIF

type WIF struct {
	// PrivKey is the private key being imported or exported.
	PrivKey *btcec.PrivateKey

	// CompressPubKey specifies whether the address controlled by the
	// imported or exported private key was created by hashing a
	// compressed (33-byte) serialized public key, rather than an
	// uncompressed (65-byte) one.
	CompressPubKey bool
	// contains filtered or unexported fields
}

WIF contains the individual components described by the Wallet Import Format (WIF). A WIF string is typically used to represent a private key and its associated address in a way that may be easily copied and imported into or exported from wallet software. WIF strings may be decoded into this structure by calling DecodeWIF or created with a user-provided private key by calling NewWIF.

func DecodeWIF

func DecodeWIF(wif string) (*WIF, error)

DecodeWIF creates a new WIF structure by decoding the string encoding of the import format.

The WIF string must be a base58-encoded string of the following byte sequence:

• 1 byte to identify the network, must be 0x80 for mainnet or 0xef for either testnet3 or the regression test network
• 32 bytes of a binary-encoded, big-endian, zero-padded private key
• Optional 1 byte (equal to 0x01) if the address being imported or exported was created by taking the RIPEMD160 after SHA256 hash of a serialized compressed (33-byte) public key
• 4 bytes of checksum, must equal the first four bytes of the double SHA256 of every byte before the checksum in this sequence

If the base58-decoded byte sequence does not match this, DecodeWIF will return a non-nil error. ErrMalformedPrivateKey is returned when the WIF is of an impossible length or the expected compressed pubkey magic number does not equal the expected value of 0x01. ErrChecksumMismatch is returned if the expected WIF checksum does not match the calculated checksum.

func NewWIF

func NewWIF(privKey *btcec.PrivateKey, privateKeyID byte, compress bool) (*WIF, error)

NewWIF creates a new WIF structure to export an address and its private key as a string encoded in the Wallet Import Format. The compress argument specifies whether the address intended to be imported or exported was created by serializing the public key compressed rather than uncompressed.

func (*WIF) SerializePubKey

func (w *WIF) SerializePubKey() []byte

SerializePubKey serializes the associated public key of the imported or exported private key in either a compressed or uncompressed format. The serialization format chosen depends on the value of w.CompressPubKey.

func (*WIF) String

func (w *WIF) String() string

String creates the Wallet Import Format string encoding of a WIF structure. See DecodeWIF for a detailed breakdown of the format and requirements of a valid WIF string.