Module: psbt

This module provides functions for interacting with PSBTs, see BIP174 https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki

Source:

Methods

(static) addSignaturesToPSBT(network, psbt, pubkeys, signatures) → {null|string}

Given an unsigned PSBT, an array of signing public key(s) (one per input), an array of signature(s) (one per input) in the same order as the pubkey(s), adds partial signature object(s) to each input and returns the PSBT with partial signature(s) included.

FIXME - maybe we add functionality of sending in a single pubkey as well, which would assume all of the signature(s) are for that pubkey.

Parameters:
Name Type Description
network module:networks.NETWORKS

bitcoin network
psbt String

PSBT as base64 or hex string
pubkeys Array.<Buffer>

public keys map 1:1 with signature(s)
signatures Array.<Buffer>

transaction signatures map 1:1 with public key(s)
Source:
Returns:
  • partially signed PSBT in Base64
Type
null | string

(static) autoLoadPSBT(psbtFromFile, optionsopt) → {null|Psbt}

Given a string, try to create a Psbt object based on MAGIC (hex or Base64)

Parameters:
Name Type Attributes Description
psbtFromFile String

Base64 or hex PSBT
options Object <optional>

options, e.g. TESTNET
Source:
Returns:
  • Psbt object from bitcoinjs-lib or null if failed to detect
Type
null | Psbt

(static) parseSignatureArrayFromPSBT(psbtFromFile) → {Object}

Extracts signatures in order of inputs and returns as array (or array of arrays if multiple signature sets)

Parameters:
Name Type Description
psbtFromFile String

base64 or hex
Source:
Returns:

returns an array of arrays of ordered signatures or an array of signatures if only 1 signer

Type
Object

(static) parseSignaturesFromPSBT(psbtFromFile) → {Object}

Extracts the signature(s) from a PSBT. NOTE: there should be one signature per input, per signer.

ADDITIONAL NOTE: because of the restrictions we place on braids to march their multisig addresses (slices) forward at the same index across each chain of the braid, we do not run into a possible collision with this data structure. BUT - to have this method accommodate the most general form of signature parsing, it would be wise to wrap this one level deeper like:

                address: [pubkey : [signature(s)]]

that way if your braid only advanced one chain's (member's) index so that a pubkey could be used in more than one address, everything would still function properly.

Parameters:
Name Type Description
psbtFromFile String

base64 or hex
Source:
Returns:

returns an object with signatureSet(s) - an object with format {pubkey : [signature(s)]}

Type
Object

(static) psbtInputFormatter(input) → {module:inputs.MultisigTransactionPSBTInput}

Take a MultisigTransactionInput and turn it into a MultisigTransactionPSBTInput

Parameters:
Name Type Description
input module:inputs.MultisigTransactionInput

to decorate for PSBT
Source:
Returns:

outputs the PSBT-ready Transaction Input

Type
module:inputs.MultisigTransactionPSBTInput

(static) psbtOutputFormatter(output) → {module:outputs.TransactionPSBTOutput}

Take a MultisigTransactionOutput and turn it into a MultisigTransactionPSBTOutput

Parameters:
Name Type Description
output module:outputs.TransactionOutput

output to decorate for PSBT
Source:
Returns:

outputs the PSBT-ready Transaction Object

Type
module:outputs.TransactionPSBTOutput

(static) translatePSBT(network, addressType, psbt, signingKeyDetails) → {null|Object}

Translates a PSBT into inputs/outputs consumable by supported non-PSBT devices in the unchained-wallets library.

FIXME - Have only confirmed this is working for P2SH addresses on Ledger on regtest

Parameters:
Name Type Description
network module:networks.NETWORKS

bitcoin network
addressType String

address type
psbt String

PSBT as a base64 or hex string
signingKeyDetails Object

Object containing signing key details (Fingerprint + bip32path prefix)
Source:
Returns:

returns unchained-wallets transaction object with the format { inputs: [], outputs: [], bip32Derivations: [], }

Type
null | Object

(inner) filterRelevantBip32Derivations(psbt, signingKeyDetails) → {Array.<Object>}

Create unchained-wallets style transaction input objects

Parameters:
Name Type Description
psbt Object

Psbt bitcoinjs-lib object
signingKeyDetails Object

Object containing signing key details (Fingerprint + bip32path prefix)
Source:
Returns:

bip32Derivations - array of signing bip32Derivation objects

Type
Array.<Object>

(inner) getBip32Derivation(multisig, indexopt) → {Array.<Object>}

Return the getBip32Derivation (if known) for a given Multisig object.

Parameters:
Name Type Attributes Default Description
multisig module:multisig.Multisig

the Multisig object
index number <optional>
 0

the index to generate at
Source:
Returns:

the getBip32Derivation includes all paths/root fingerprints to all pubkeys in the multisig object

Type
Array.<Object>
Example
import {
  getBip32Derivation,
  generateBraidFromExtendedPublicKeys,
  generateMultisigFromPublicKeys, MAINNET, P2SH,
  braidConfig,
} from "unchained-bitcoin";
const multisig = generateMultisigFromPublicKeys(MAINNET, P2SH, 2, "03a...", "03b...", "03c...");
console.log(getBip32Derivation(multisig, 0)); // null, Multisig object isn't aware of its braid.

const braid = generateBraidFromExtendedPublicKeys(MAINNET, P2SH, {{'xpub...', bip32path: "m/45'/0'/0'"}, {'xpub...', bip32path: "m/45'/0/0"}, {'xpub...', bip32path: "m/45'/0/0"}}, 2);
const multisig = braid.deriveMultisigByIndex("0");
console.log(getBip32Derivation(multisig, 0)); // {
  {masterFingerprint: Buffer('1234..', 'hex'), path: "m/45'/0'/0'/0/0", pubkey: Buffer.from("02...", 'hex')}
  {masterFingerprint: Buffer('3453..', 'hex'), path: "m/45'/0/0/0/0", pubkey: Buffer.from("03...", 'hex')}
  {masterFingerprint: Buffer('1533..', 'hex'), path: "m/45'/0/0/0/0", pubkey: Buffer.from("02...", 'hex')}
}

(inner) getNumSigners(psbt) → {int}

Get number of signers in the PSBT

Parameters:
Name Type Description
psbt Psbt

bitcoinjs-lib object
Source:
Returns:

number of signers in the PSBT

Type
int

(inner) getUnchainedInputsFromPSBT(network, addressType, psbt) → {Array.<Object>}

Create unchained-wallets style transaction input objects from a PSBT

Parameters:
Name Type Description
network module:networks.NETWORKS

bitcoin network
addressType String

address type
psbt Object

Psbt bitcoinjs-lib object
Source:
Returns:

unchained multisig transaction inputs array

Type
Array.<Object>

(inner) getUnchainedOutputsFromPSBT(psbt) → {Array.<Object>}

Create unchained-wallets style transaction output objects from a PSBT

Parameters:
Name Type Description
psbt Object

Psbt bitcoinjs-lib object
Source:
Returns:

unchained multisig transaction outputs array

Type
Array.<Object>

(inner) getWitnessOutputScriptFromInput(input) → {Output}

Gets the Witness script from the ouput that generated the input

Parameters:
Name Type Description
input module:inputs.MultisigTransactionInput

input you are requesting output's script from
Source:
Returns:

bitcoinjs-lib Output object (amount+script)

Type
Output

(inner) psbtInputDerivation(input) → {Array.<Object>}

Grabs appropriate bip32Derivation based on the input's last index

Parameters:
Name Type Description
input module:inputs.MultisigTransactionInput

input you are requesting bip32Derivation from
Source:
Returns:

array of objects containing (rootFingerprints && pubkeys && bip32paths) for this Multisig

Type
Array.<Object>

(inner) psbtMultisigLock(multisig) → {Object}

Return the locking script for the given Multisig object in a PSBT consumable format

Parameters:
Name Type Description
multisig module:multisig.Multisig

the Multisig object
Source:
Returns:

returns an object with proper parameters attached that are needed to validate spending

Type
Object

(inner) psbtOutputDerivation(output) → {Array.<Object>}

Grabs appropriate bip32Derivation for a change output

Parameters:
Name Type Description
output module:outputs.TransactionOutput

output you are requesting bip32Derivation from
Source:
Returns:

array of objects containing (rootFingerprints && pubkeys && bip32paths) for this Multisig

Type
Array.<Object>

Type Definitions

MultisigTransactionPSBTInput

Represents a transaction PSBT input.

The Multisig object represents the address the corresponding UTXO belongs to.

Type:
  • Object
Properties:
Name Type Description
hash string

The transaction ID where funds were received
index number

The index in the transaction referred to by {txid}
utxoToVerify Buffer | Object

The UTXO to verify
multisigScript Multisig

Locking script(s) for the multisig address
bip32Derivation Object

the set of (rootFingerprints && pubkeys && bip32paths) for this Multisig
Source:

TransactionPSBTOutput

Represents an output in a PSBT transaction.

Type:
  • Object
Properties:
Name Type Attributes Description
address string

the output address
value number

output amount in Satoshis
redeemScript Object <optional>

For change addresses - Locking script(s) for the multisig address
witnessScript Object <optional>

For change addresses - Locking script(s) for the multisig address
bip32Derivation Object <optional>

For change addresses - the set of (rootFingerprints && pubkeys && bip32paths) for this Multisig
Source: