Crate btc_transaction_utils

BTC transaction utils is a small library that will help to create multisig addresses and sign a some types of segwit transactions.

By using this library you can make the following things:

• Create a redeem script and a corresponding multisig address (3 of 4).
• Sign the P2WPK inputs.
• Sign the P2WSH inputs.

Examples

Create a redeem script and a corresponding multisig address (3 of 4).

extern crate bitcoin;
extern crate btc_transaction_utils;

use bitcoin::network::constants::Network;
use btc_transaction_utils::multisig::RedeemScriptBuilder;
use btc_transaction_utils::test_data::secp_gen_keypair;
use btc_transaction_utils::p2wsh;

fn main() {
    // Generate four key pairs.
    let keypairs = (0..4)
        .map(|_| secp_gen_keypair())
        .collect::<Vec<_>>();
    // Create a corresponding redeem script.
    let public_keys = keypairs.iter().map(|keypair| keypair.0);
    let script = RedeemScriptBuilder::with_public_keys(public_keys)
        .quorum(3)
        .to_script()
        .unwrap();
    // Create a corresponding testnet address for the given redeem script.
    let address = p2wsh::address(&script, Network::Testnet);
    println!("{}", address.to_string());
}

Sign P2WPK input

extern crate bitcoin;
extern crate btc_transaction_utils;
extern crate rand;

use bitcoin::blockdata::opcodes::All;
use bitcoin::blockdata::script::{Builder, Script};
use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxIn, TxOut};
use bitcoin::network::constants::Network;
use btc_transaction_utils::p2wpk;
use btc_transaction_utils::test_data::{secp_gen_keypair_with_rng, btc_tx_from_hex};
use btc_transaction_utils::TxInRef;
use rand::{SeedableRng, StdRng};

fn main() {
    // Take a transaction with the unspent P2WPK output.
    let prev_tx = btc_tx_from_hex(
        "02000000000101beccab33bc72bfc81b63fdec8a4a9a4719e4418bdb7b20e47b0\
         2074dc42f2d800000000017160014f3b1b3819c1290cd5d675c1319dc7d9d98d5\
         71bcfeffffff02dceffa0200000000160014368c6b7c38f0ff0839bf78d77544d\
         a96cb685bf28096980000000000160014284175e336fa10865fb4d1351c9e18e7\
         30f5d6f90247304402207c893c85d75e2230dde04f5a1e2c83c4f0b7d93213372\
         746eb2227b068260d840220705484b6ec70a8fc0d1f80c3a98079602595351b7a\
         9bca7caddb9a6adb0a3440012103150514f05f3e3f40c7b404b16f8a09c2c71ba\
         d3ba8da5dd1e411a7069cc080a004b91300",
    );
    // Take the corresponding key pair.
    let mut rng: StdRng = SeedableRng::from_seed([1, 2, 3, 4].as_ref());
    let keypair = secp_gen_keypair_with_rng(&mut rng);
    // Create an unsigned transaction
    let mut transaction = Transaction {
        version: 2,
        lock_time: 0,
        input: vec![
            TxIn {
                previous_output: OutPoint {
                    txid: prev_tx.txid(),
                    vout: 1,
                },
                script_sig: Script::default(),
                sequence: 0xFFFFFFFF,
                witness: Vec::default(),
            },
        ],
        output: vec![
            TxOut {
                value: 0,
                script_pubkey: Builder::new()
                    .push_opcode(All::OP_RETURN)
                    .push_slice(b"Hello Exonum!")
                    .into_script(),
            },
        ],
    };
    // Create a signature for the given input.
    let mut signer = p2wpk::InputSigner::new(keypair.0, Network::Testnet);
    let signature = signer
        .sign_input(TxInRef::new(&transaction, 0), &prev_tx, &keypair.1)
        .unwrap();
    // Finalize the transaction.
    signer.spend_input(&mut transaction.input[0], signature);
}

Sign P2WSH input

extern crate bitcoin;
extern crate btc_transaction_utils;
extern crate rand;

use bitcoin::blockdata::opcodes::All;
use bitcoin::blockdata::script::{Builder, Script};
use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxIn, TxOut};
use bitcoin::network::constants::Network;
use btc_transaction_utils::multisig::RedeemScriptBuilder;
use btc_transaction_utils::p2wsh;
use btc_transaction_utils::test_data::{secp_gen_keypair_with_rng, btc_tx_from_hex};
use btc_transaction_utils::TxInRef;
use rand::{SeedableRng, StdRng};

fn main() {
    // Take a transaction with the unspent P2WSH output.
    let prev_tx = btc_tx_from_hex(
        "02000000000101f8c16000cc59f9505046303944d42a6c264a322f80b46bb4361\
         15b6e306ba9950000000000feffffff02f07dc81600000000160014f65eb9d72a\
         8475dd8e26f4fa748796e211aa8869102700000000000022002001fb25c3db04c\
         a5580da43a7d38dd994650d9aa6d6ee075b4578388deed338ed0247304402206b\
         5f211cd7f9b89e80c734b61113c33f437ba153e7ba6bc275eed857e54fcb26022\
         0038562e88b805f0cdfd4873ab3579d52268babe6af9c49086c00343187cdf28a\
         012103979dff5cd9045f4b6fa454d2bc5357586a85d4789123df45f83522963d9\
         4e3217fb91300",
    );
    // Take the corresponding key pairs and the redeem script.
    let total_count = 18;
    let quorum = 12;

    let mut rng: StdRng = SeedableRng::from_seed([1, 2, 3, 4].as_ref());
    let keypairs = (0..total_count)
        .into_iter()
        .map(|_| secp_gen_keypair_with_rng(&mut rng))
        .collect::<Vec<_>>();
    let public_keys = keypairs.iter().map(|keypair| keypair.0);
    let redeem_script = RedeemScriptBuilder::with_public_keys(public_keys)
        .quorum(quorum)
        .to_script()
        .unwrap();
    // Create an unsigned transaction.
    let mut transaction = Transaction {
        version: 2,
        lock_time: 0,
        input: vec![
            TxIn {
                previous_output: OutPoint {
                    txid: prev_tx.txid(),
                    vout: 1,
                },
                script_sig: Script::default(),
                sequence: 0xFFFFFFFF,
                witness: Vec::default(),
            },
        ],
        output: vec![
            TxOut {
                value: 0,
                script_pubkey: Builder::new()
                    .push_opcode(All::OP_RETURN)
                    .push_slice(b"Hello Exonum with multisig!")
                    .into_script(),
            },
        ],
    };
    // Create signatures for the given input.
    let mut signer = p2wsh::InputSigner::new(redeem_script.clone());
    let signatures = keypairs[0..quorum]
        .iter()
        .map(|keypair| {
            let txin = TxInRef::new(&transaction, 0);
            signer.sign_input(txin, &prev_tx, &keypair.1).unwrap()
        })
        .collect::<Vec<_>>();
    // Finalize the transaction.
    signer.spend_input(&mut transaction.input[0], signatures);
}

Modules

multisig	Helpers for manipulating with the redeem scripts which used in multisignature transactions.
p2wpk	A native P2WPK input signer.
p2wsh	A native P2WSH input signer.
test_data	A set of helpers for testing.

Structs

InputSignature	A signature data with the embedded sighash type byte.
InputSignatureRef	A borrowed equivalent of the InputSignature data type. It can be useful for checking incoming signatures from unauthorized sources.
TxInRef	A borrowed reference to a transaction input.

Enums

UnspentTxOutValue

An auxiliary enumeration that helps to get the balance of the previous unspent transaction output.