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Add TransactionBuilder

fixTypes
junderw 6 years ago
parent
commit
fce08352f5
No known key found for this signature in database GPG Key ID: B256185D3A971908
  1. 15
      src/ecpair.ts
  2. 2
      src/index.ts
  3. 724
      src/transaction_builder.ts
  4. 2
      test/transaction_builder.js

15
src/ecpair.ts

@ -11,13 +11,24 @@ const isOptions = typeforce.maybe(typeforce.compile({
network: types.maybe(types.Network)
}))
export interface ECPairOptions {
interface ECPairOptions {
compressed?: boolean
network?: Network
rng?(Buffer): Buffer
}
class ECPair {
export interface ECPairInterface {
compressed: boolean
network: Network
privateKey: Buffer
publicKey: Buffer
toWIF(): string
sign(hash: Buffer): Buffer
verify(hash: Buffer, signature: Buffer): Buffer
getPublicKey?(): Buffer
}
class ECPair implements ECPairInterface {
compressed: boolean
network: Network
private __d: Buffer

2
src/index.ts

@ -3,7 +3,7 @@ const opcodes = require('bitcoin-ops')
import { Block } from './block'
import * as ECPair from './ecpair'
import { Transaction } from './transaction'
import * as TransactionBuilder from './transaction_builder'
import { TransactionBuilder } from './transaction_builder'
import * as address from './address'
import * as bip32 from 'bip32'
import * as crypto from './crypto'

724
src/transaction_builder.ts

@ -1,10 +1,11 @@
import { Network } from './networks'
import * as networks from './networks'
import { Transaction, Output } from './transaction'
import { ECPairInterface } from './ecpair'
const Buffer = require('safe-buffer').Buffer
const baddress = require('./address')
const bcrypto = require('./crypto')
const bscript = require('./script')
const networks = require('./networks')
const ops = require('bitcoin-ops')
const payments = require('./payments')
const typeforce = require('typeforce')
@ -14,7 +15,370 @@ const SCRIPT_TYPES = classify.types
const ECPair = require('./ecpair')
function expandInput (scriptSig, witnessStack, type, scriptPubKey) {
interface TxbInput {
value?: number
hasWitness?: boolean
signScript?: Buffer
signType?: string
prevOutScript?: Buffer
redeemScript?: Buffer
redeemScriptType?: string
prevOutType?: string
pubkeys?: Array<Buffer>
signatures?: Array<Buffer>
witness?: Array<Buffer>
witnessScript?: Buffer
witnessScriptType?: string
script?: Buffer
sequence?: number
scriptSig?: Buffer
maxSignatures?: number
}
interface TxbOutput {
type: string
pubkeys?: Array<Buffer>
signatures?: Array<Buffer>
maxSignatures?: number
}
function txIsString(tx: Buffer | string | Transaction): tx is string {
return typeof (<string>tx) === 'string' || tx instanceof String
}
function txIsTransaction(tx: Buffer | string | Transaction): tx is Transaction {
return (<Transaction>tx) instanceof Transaction
}
export class TransactionBuilder {
network: Network
maximumFeeRate: number
private __prevTxSet: Object
private __inputs: Array<TxbInput>
private __tx: Transaction
constructor (network: Network, maximumFeeRate?: number) {
this.__prevTxSet = {}
this.network = network || networks.bitcoin
// WARNING: This is __NOT__ to be relied on, its just another potential safety mechanism (safety in-depth)
this.maximumFeeRate = maximumFeeRate || 2500
this.__inputs = []
this.__tx = new Transaction()
this.__tx.version = 2
}
static fromTransaction (transaction: Transaction, network?: Network): TransactionBuilder {
const txb = new TransactionBuilder(network)
// Copy transaction fields
txb.setVersion(transaction.version)
txb.setLockTime(transaction.locktime)
// Copy outputs (done first to avoid signature invalidation)
transaction.outs.forEach(txOut => {
txb.addOutput(txOut.script, (<Output>txOut).value)
})
// Copy inputs
transaction.ins.forEach(txIn => {
txb.__addInputUnsafe(txIn.hash, txIn.index, {
sequence: txIn.sequence,
script: txIn.script,
witness: txIn.witness
})
})
// fix some things not possible through the public API
txb.__inputs.forEach((input, i) => {
fixMultisigOrder(input, transaction, i)
})
return txb
}
setLockTime (locktime: number): void {
typeforce(types.UInt32, locktime)
// if any signatures exist, throw
if (this.__inputs.some(input => {
if (!input.signatures) return false
return input.signatures.some(s => s !== undefined)
})) {
throw new Error('No, this would invalidate signatures')
}
this.__tx.locktime = locktime
}
setVersion (version: number): void {
typeforce(types.UInt32, version)
// XXX: this might eventually become more complex depending on what the versions represent
this.__tx.version = version
}
addInput (txHash: Buffer | string | Transaction, vout: number, sequence: number, prevOutScript: Buffer): number {
if (!this.__canModifyInputs()) {
throw new Error('No, this would invalidate signatures')
}
let value: number
// is it a hex string?
if (txIsString(txHash)) {
// transaction hashs's are displayed in reverse order, un-reverse it
txHash = <Buffer> Buffer.from(txHash, 'hex').reverse()
// is it a Transaction object?
} else if (txIsTransaction(txHash)) {
const txOut = txHash.outs[vout]
prevOutScript = txOut.script
value = (<Output>txOut).value
txHash = <Buffer> txHash.getHash(false)
}
return this.__addInputUnsafe(txHash, vout, {
sequence: sequence,
prevOutScript: prevOutScript,
value: value
})
}
private __addInputUnsafe (txHash: Buffer, vout: number, options: TxbInput): number {
if (Transaction.isCoinbaseHash(txHash)) {
throw new Error('coinbase inputs not supported')
}
const prevTxOut = txHash.toString('hex') + ':' + vout
if (this.__prevTxSet[prevTxOut] !== undefined) throw new Error('Duplicate TxOut: ' + prevTxOut)
let input = <TxbInput>{}
// derive what we can from the scriptSig
if (options.script !== undefined) {
input = expandInput(options.script, options.witness || [])
}
// if an input value was given, retain it
if (options.value !== undefined) {
input.value = options.value
}
// derive what we can from the previous transactions output script
if (!input.prevOutScript && options.prevOutScript) {
let prevOutType
if (!input.pubkeys && !input.signatures) {
const expanded = expandOutput(options.prevOutScript)
if (expanded.pubkeys) {
input.pubkeys = expanded.pubkeys
input.signatures = expanded.signatures
}
prevOutType = expanded.type
}
input.prevOutScript = options.prevOutScript
input.prevOutType = prevOutType || classify.output(options.prevOutScript)
}
const vin = this.__tx.addInput(txHash, vout, options.sequence, options.scriptSig)
this.__inputs[vin] = input
this.__prevTxSet[prevTxOut] = true
return vin
}
addOutput (scriptPubKey: string | Buffer, value): number {
if (!this.__canModifyOutputs()) {
throw new Error('No, this would invalidate signatures')
}
// Attempt to get a script if it's a base58 or bech32 address string
if (typeof scriptPubKey === 'string') {
scriptPubKey = baddress.toOutputScript(scriptPubKey, this.network)
}
return this.__tx.addOutput(<Buffer>scriptPubKey, value)
}
build (): Transaction {
return this.__build(false)
}
buildIncomplete (): Transaction {
return this.__build(true)
}
private __build (allowIncomplete?: boolean): Transaction {
if (!allowIncomplete) {
if (!this.__tx.ins.length) throw new Error('Transaction has no inputs')
if (!this.__tx.outs.length) throw new Error('Transaction has no outputs')
}
const tx = this.__tx.clone()
// create script signatures from inputs
this.__inputs.forEach((input, i) => {
if (!input.prevOutType && !allowIncomplete) throw new Error('Transaction is not complete')
const result = build(input.prevOutType, input, allowIncomplete)
if (!result) {
if (!allowIncomplete && input.prevOutType === SCRIPT_TYPES.NONSTANDARD) throw new Error('Unknown input type')
if (!allowIncomplete) throw new Error('Not enough information')
return
}
tx.setInputScript(i, result.input)
tx.setWitness(i, result.witness)
})
if (!allowIncomplete) {
// do not rely on this, its merely a last resort
if (this.__overMaximumFees(tx.virtualSize())) {
throw new Error('Transaction has absurd fees')
}
}
return tx
}
sign (vin: number, keyPair: ECPairInterface, redeemScript: Buffer, hashType: number, witnessValue: number, witnessScript: Buffer) {
// TODO: remove keyPair.network matching in 4.0.0
if (keyPair.network && keyPair.network !== this.network) throw new TypeError('Inconsistent network')
if (!this.__inputs[vin]) throw new Error('No input at index: ' + vin)
hashType = hashType || Transaction.SIGHASH_ALL
if (this.__needsOutputs(hashType)) throw new Error('Transaction needs outputs')
const input = this.__inputs[vin]
// if redeemScript was previously provided, enforce consistency
if (input.redeemScript !== undefined &&
redeemScript &&
!input.redeemScript.equals(redeemScript)) {
throw new Error('Inconsistent redeemScript')
}
const ourPubKey = keyPair.publicKey || keyPair.getPublicKey()
if (!canSign(input)) {
if (witnessValue !== undefined) {
if (input.value !== undefined && input.value !== witnessValue) throw new Error('Input didn\'t match witnessValue')
typeforce(types.Satoshi, witnessValue)
input.value = witnessValue
}
if (!canSign(input)) {
const prepared = prepareInput(input, ourPubKey, redeemScript, witnessValue, witnessScript)
// updates inline
Object.assign(input, prepared)
}
if (!canSign(input)) throw Error(input.prevOutType + ' not supported')
}
// ready to sign
let signatureHash
if (input.hasWitness) {
signatureHash = this.__tx.hashForWitnessV0(vin, input.signScript, input.value, hashType)
} else {
signatureHash = this.__tx.hashForSignature(vin, input.signScript, hashType)
}
// enforce in order signing of public keys
const signed = input.pubkeys.some((pubKey, i) => {
if (!ourPubKey.equals(pubKey)) return false
if (input.signatures[i]) throw new Error('Signature already exists')
// TODO: add tests
if (ourPubKey.length !== 33 && input.hasWitness) {
throw new Error('BIP143 rejects uncompressed public keys in P2WPKH or P2WSH')
}
const signature = keyPair.sign(signatureHash)
input.signatures[i] = bscript.signature.encode(signature, hashType)
return true
})
if (!signed) throw new Error('Key pair cannot sign for this input')
}
private __canModifyInputs (): boolean {
return this.__inputs.every(input => {
if (!input.signatures) return true
return input.signatures.every(signature => {
if (!signature) return true
const hashType = signatureHashType(signature)
// if SIGHASH_ANYONECANPAY is set, signatures would not
// be invalidated by more inputs
return (hashType & Transaction.SIGHASH_ANYONECANPAY) !== 0
})
})
}
private __needsOutputs (signingHashType: number): boolean {
if (signingHashType === Transaction.SIGHASH_ALL) {
return this.__tx.outs.length === 0
}
// if inputs are being signed with SIGHASH_NONE, we don't strictly need outputs
// .build() will fail, but .buildIncomplete() is OK
return (this.__tx.outs.length === 0) && this.__inputs.some((input) => {
if (!input.signatures) return false
return input.signatures.some((signature) => {
if (!signature) return false // no signature, no issue
const hashType = signatureHashType(signature)
if (hashType & Transaction.SIGHASH_NONE) return false // SIGHASH_NONE doesn't care about outputs
return true // SIGHASH_* does care
})
})
}
private __canModifyOutputs (): boolean {
const nInputs = this.__tx.ins.length
const nOutputs = this.__tx.outs.length
return this.__inputs.every(input => {
if (input.signatures === undefined) return true
return input.signatures.every(signature => {
if (!signature) return true
const hashType = signatureHashType(signature)
const hashTypeMod = hashType & 0x1f
if (hashTypeMod === Transaction.SIGHASH_NONE) return true
if (hashTypeMod === Transaction.SIGHASH_SINGLE) {
// if SIGHASH_SINGLE is set, and nInputs > nOutputs
// some signatures would be invalidated by the addition
// of more outputs
return nInputs <= nOutputs
}
})
})
}
private __overMaximumFees (bytes: number): boolean {
// not all inputs will have .value defined
const incoming = this.__inputs.reduce((a, x) => a + (x.value >>> 0), 0)
// but all outputs do, and if we have any input value
// we can immediately determine if the outputs are too small
const outgoing = this.__tx.outs.reduce((a, x) => a + (<Output>x).value, 0)
const fee = incoming - outgoing
const feeRate = fee / bytes
return feeRate > this.maximumFeeRate
}
}
function expandInput (scriptSig: Buffer, witnessStack: Array<Buffer>, type?: string, scriptPubKey?: Buffer): TxbInput {
if (scriptSig.length === 0 && witnessStack.length === 0) return {}
if (!type) {
let ssType = classify.input(scriptSig, true)
@ -103,7 +467,7 @@ function expandInput (scriptSig, witnessStack, type, scriptPubKey) {
const outputType = classify.output(redeem.output)
let expanded
if (outputType === SCRIPT_TYPES.P2WPKH) {
expanded = expandInput(redeem.input, redeem.witness, outputType, undefined)
expanded = expandInput(redeem.input, redeem.witness, outputType)
} else {
expanded = expandInput(bscript.compile(redeem.witness), [], outputType, redeem.output)
}
@ -127,18 +491,18 @@ function expandInput (scriptSig, witnessStack, type, scriptPubKey) {
}
// could be done in expandInput, but requires the original Transaction for hashForSignature
function fixMultisigOrder (input, transaction, vin) {
function fixMultisigOrder (input: TxbInput, transaction: Transaction, vin: number): void {
if (input.redeemScriptType !== SCRIPT_TYPES.P2MS || !input.redeemScript) return
if (input.pubkeys.length === input.signatures.length) return
const unmatched = input.signatures.concat()
input.signatures = input.pubkeys.map(function (pubKey) {
input.signatures = input.pubkeys.map(pubKey => {
const keyPair = ECPair.fromPublicKey(pubKey)
let match
// check for a signature
unmatched.some(function (signature, i) {
unmatched.some((signature, i) => {
// skip if undefined || OP_0
if (!signature) return false
@ -160,7 +524,7 @@ function fixMultisigOrder (input, transaction, vin) {
})
}
function expandOutput (script, ourPubKey) {
function expandOutput (script: Buffer, ourPubKey?: Buffer): TxbOutput {
typeforce(types.Buffer, script)
const type = classify.output(script)
@ -218,7 +582,7 @@ function expandOutput (script, ourPubKey) {
return { type }
}
function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScript) {
function prepareInput (input: TxbInput, ourPubKey: Buffer, redeemScript: Buffer, witnessValue: number, witnessScript: Buffer): TxbInput {
if (redeemScript && witnessScript) {
const p2wsh = payments.p2wsh({ redeem: { output: witnessScript } })
const p2wshAlt = payments.p2wsh({ output: redeemScript })
@ -231,7 +595,7 @@ function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScri
const expanded = expandOutput(p2wsh.redeem.output, ourPubKey)
if (!expanded.pubkeys) throw new Error(expanded.type + ' not supported as witnessScript (' + bscript.toASM(witnessScript) + ')')
if (input.signatures && input.signatures.some(x => x)) {
if (input.signatures && input.signatures.some(x => x !== undefined)) {
expanded.signatures = input.signatures
}
@ -271,7 +635,7 @@ function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScri
const expanded = expandOutput(p2sh.redeem.output, ourPubKey)
if (!expanded.pubkeys) throw new Error(expanded.type + ' not supported as redeemScript (' + bscript.toASM(redeemScript) + ')')
if (input.signatures && input.signatures.some(x => x)) {
if (input.signatures && input.signatures.some(x => x !== undefined)) {
expanded.signatures = input.signatures
}
@ -307,7 +671,7 @@ function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScri
const expanded = expandOutput(p2wsh.redeem.output, ourPubKey)
if (!expanded.pubkeys) throw new Error(expanded.type + ' not supported as witnessScript (' + bscript.toASM(witnessScript) + ')')
if (input.signatures && input.signatures.some(x => x)) {
if (input.signatures && input.signatures.some(x => x !== undefined)) {
expanded.signatures = input.signatures
}
@ -339,7 +703,7 @@ function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScri
const expanded = expandOutput(input.prevOutScript, ourPubKey)
if (!expanded.pubkeys) throw new Error(expanded.type + ' not supported (' + bscript.toASM(input.prevOutScript) + ')')
if (input.signatures && input.signatures.some(x => x)) {
if (input.signatures && input.signatures.some(x => x !== undefined)) {
expanded.signatures = input.signatures
}
@ -376,7 +740,7 @@ function prepareInput (input, ourPubKey, redeemScript, witnessValue, witnessScri
}
}
function build (type, input, allowIncomplete) {
function build (type: string, input: TxbInput, allowIncomplete: boolean): any { //TODO payment type
const pubkeys = input.pubkeys || []
let signatures = input.signatures || []
@ -439,201 +803,7 @@ function build (type, input, allowIncomplete) {
}
}
function TransactionBuilder (network, maximumFeeRate) {
this.__prevTxSet = {}
this.network = network || networks.bitcoin
// WARNING: This is __NOT__ to be relied on, its just another potential safety mechanism (safety in-depth)
this.maximumFeeRate = maximumFeeRate || 2500
this.__inputs = []
this.__tx = new Transaction()
this.__tx.version = 2
}
TransactionBuilder.prototype.setLockTime = function (locktime) {
typeforce(types.UInt32, locktime)
// if any signatures exist, throw
if (this.__inputs.some(function (input) {
if (!input.signatures) return false
return input.signatures.some(function (s) { return s })
})) {
throw new Error('No, this would invalidate signatures')
}
this.__tx.locktime = locktime
}
TransactionBuilder.prototype.setVersion = function (version) {
typeforce(types.UInt32, version)
// XXX: this might eventually become more complex depending on what the versions represent
this.__tx.version = version
}
TransactionBuilder.fromTransaction = function (transaction, network) {
const txb = new TransactionBuilder(network, undefined)
// Copy transaction fields
txb.setVersion(transaction.version)
txb.setLockTime(transaction.locktime)
// Copy outputs (done first to avoid signature invalidation)
transaction.outs.forEach(function (txOut) {
txb.addOutput(txOut.script, txOut.value)
})
// Copy inputs
transaction.ins.forEach(function (txIn) {
txb.__addInputUnsafe(txIn.hash, txIn.index, {
sequence: txIn.sequence,
script: txIn.script,
witness: txIn.witness
})
})
// fix some things not possible through the public API
txb.__inputs.forEach(function (input, i) {
fixMultisigOrder(input, transaction, i)
})
return txb
}
TransactionBuilder.prototype.addInput = function (txHash, vout, sequence, prevOutScript) {
if (!this.__canModifyInputs()) {
throw new Error('No, this would invalidate signatures')
}
let value
// is it a hex string?
if (typeof txHash === 'string') {
// transaction hashs's are displayed in reverse order, un-reverse it
txHash = Buffer.from(txHash, 'hex').reverse()
// is it a Transaction object?
} else if (txHash instanceof Transaction) {
const txOut = txHash.outs[vout]
prevOutScript = txOut.script
value = (<Output>txOut).value
txHash = txHash.getHash(false)
}
return this.__addInputUnsafe(txHash, vout, {
sequence: sequence,
prevOutScript: prevOutScript,
value: value
})
}
TransactionBuilder.prototype.__addInputUnsafe = function (txHash, vout, options) {
if (Transaction.isCoinbaseHash(txHash)) {
throw new Error('coinbase inputs not supported')
}
const prevTxOut = txHash.toString('hex') + ':' + vout
if (this.__prevTxSet[prevTxOut] !== undefined) throw new Error('Duplicate TxOut: ' + prevTxOut)
let input = {
value: undefined,
prevOutScript: undefined,
pubkeys: undefined,
signatures: undefined,
prevOutType: undefined,
}
// derive what we can from the scriptSig
if (options.script !== undefined) {
input = expandInput(options.script, options.witness || [], undefined, undefined)
}
// if an input value was given, retain it
if (options.value !== undefined) {
input.value = options.value
}
// derive what we can from the previous transactions output script
if (!input.prevOutScript && options.prevOutScript) {
let prevOutType
if (!input.pubkeys && !input.signatures) {
const expanded = expandOutput(options.prevOutScript, undefined)
if (expanded.pubkeys) {
input.pubkeys = expanded.pubkeys
input.signatures = expanded.signatures
}
prevOutType = expanded.type
}
input.prevOutScript = options.prevOutScript
input.prevOutType = prevOutType || classify.output(options.prevOutScript)
}
const vin = this.__tx.addInput(txHash, vout, options.sequence, options.scriptSig)
this.__inputs[vin] = input
this.__prevTxSet[prevTxOut] = true
return vin
}
TransactionBuilder.prototype.addOutput = function (scriptPubKey, value) {
if (!this.__canModifyOutputs()) {
throw new Error('No, this would invalidate signatures')
}
// Attempt to get a script if it's a base58 or bech32 address string
if (typeof scriptPubKey === 'string') {
scriptPubKey = baddress.toOutputScript(scriptPubKey, this.network)
}
return this.__tx.addOutput(scriptPubKey, value)
}
TransactionBuilder.prototype.build = function () {
return this.__build(false)
}
TransactionBuilder.prototype.buildIncomplete = function () {
return this.__build(true)
}
TransactionBuilder.prototype.__build = function (allowIncomplete) {
if (!allowIncomplete) {
if (!this.__tx.ins.length) throw new Error('Transaction has no inputs')
if (!this.__tx.outs.length) throw new Error('Transaction has no outputs')
}
const tx = this.__tx.clone()
// create script signatures from inputs
this.__inputs.forEach(function (input, i) {
if (!input.prevOutType && !allowIncomplete) throw new Error('Transaction is not complete')
const result = build(input.prevOutType, input, allowIncomplete)
if (!result) {
if (!allowIncomplete && input.prevOutType === SCRIPT_TYPES.NONSTANDARD) throw new Error('Unknown input type')
if (!allowIncomplete) throw new Error('Not enough information')
return
}
tx.setInputScript(i, result.input)
tx.setWitness(i, result.witness)
})
if (!allowIncomplete) {
// do not rely on this, its merely a last resort
if (this.__overMaximumFees(tx.virtualSize())) {
throw new Error('Transaction has absurd fees')
}
}
return tx
}
function canSign (input) {
function canSign (input: TxbInput): boolean {
return input.signScript !== undefined &&
input.signType !== undefined &&
input.pubkeys !== undefined &&
@ -646,140 +816,6 @@ function canSign (input) {
)
}
TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashType, witnessValue, witnessScript) {
// TODO: remove keyPair.network matching in 4.0.0
if (keyPair.network && keyPair.network !== this.network) throw new TypeError('Inconsistent network')
if (!this.__inputs[vin]) throw new Error('No input at index: ' + vin)
hashType = hashType || Transaction.SIGHASH_ALL
if (this.__needsOutputs(hashType)) throw new Error('Transaction needs outputs')
const input = this.__inputs[vin]
// if redeemScript was previously provided, enforce consistency
if (input.redeemScript !== undefined &&
redeemScript &&
!input.redeemScript.equals(redeemScript)) {
throw new Error('Inconsistent redeemScript')
}
const ourPubKey = keyPair.publicKey || keyPair.getPublicKey()
if (!canSign(input)) {
if (witnessValue !== undefined) {
if (input.value !== undefined && input.value !== witnessValue) throw new Error('Input didn\'t match witnessValue')
typeforce(types.Satoshi, witnessValue)
input.value = witnessValue
}
if (!canSign(input)) {
const prepared = prepareInput(input, ourPubKey, redeemScript, witnessValue, witnessScript)
// updates inline
Object.assign(input, prepared)
}
if (!canSign(input)) throw Error(input.prevOutType + ' not supported')
}
// ready to sign
let signatureHash
if (input.hasWitness) {
signatureHash = this.__tx.hashForWitnessV0(vin, input.signScript, input.value, hashType)
} else {
signatureHash = this.__tx.hashForSignature(vin, input.signScript, hashType)
}
// enforce in order signing of public keys
const signed = input.pubkeys.some(function (pubKey, i) {
if (!ourPubKey.equals(pubKey)) return false
if (input.signatures[i]) throw new Error('Signature already exists')
// TODO: add tests
if (ourPubKey.length !== 33 && input.hasWitness) {
throw new Error('BIP143 rejects uncompressed public keys in P2WPKH or P2WSH')
}
const signature = keyPair.sign(signatureHash)
input.signatures[i] = bscript.signature.encode(signature, hashType)
return true
})
if (!signed) throw new Error('Key pair cannot sign for this input')
}
function signatureHashType (buffer) {
function signatureHashType (buffer: Buffer): number {
return buffer.readUInt8(buffer.length - 1)
}
TransactionBuilder.prototype.__canModifyInputs = function () {
return (this.__inputs || []).every(function (input) {
if (!input.signatures) return true
return (input.signatures || []).every(function (signature) {
if (!signature) return true
const hashType = signatureHashType(signature)
// if SIGHASH_ANYONECANPAY is set, signatures would not
// be invalidated by more inputs
return hashType & Transaction.SIGHASH_ANYONECANPAY
})
})
}
TransactionBuilder.prototype.__needsOutputs = function (signingHashType) {
if (signingHashType === Transaction.SIGHASH_ALL) {
return this.__tx.outs.length === 0
}
// if inputs are being signed with SIGHASH_NONE, we don't strictly need outputs
// .build() will fail, but .buildIncomplete() is OK
return (this.__tx.outs.length === 0) && this.__inputs.some((input) => {
if (!input.signatures) return false
return input.signatures.some((signature) => {
if (!signature) return false // no signature, no issue
const hashType = signatureHashType(signature)
if (hashType & Transaction.SIGHASH_NONE) return false // SIGHASH_NONE doesn't care about outputs
return true // SIGHASH_* does care
})
})
}
TransactionBuilder.prototype.__canModifyOutputs = function () {
const nInputs = this.__tx.ins.length
const nOutputs = this.__tx.outs.length
return this.__inputs.every(function (input) {
if (input.signatures === undefined) return true
return input.signatures.every(function (signature) {
if (!signature) return true
const hashType = signatureHashType(signature)
const hashTypeMod = hashType & 0x1f
if (hashTypeMod === Transaction.SIGHASH_NONE) return true
if (hashTypeMod === Transaction.SIGHASH_SINGLE) {
// if SIGHASH_SINGLE is set, and nInputs > nOutputs
// some signatures would be invalidated by the addition
// of more outputs
return nInputs <= nOutputs
}
})
})
}
TransactionBuilder.prototype.__overMaximumFees = function (bytes) {
// not all inputs will have .value defined
const incoming = this.__inputs.reduce(function (a, x) { return a + (x.value >>> 0) }, 0)
// but all outputs do, and if we have any input value
// we can immediately determine if the outputs are too small
const outgoing = this.__tx.outs.reduce(function (a, x) { return a + x.value }, 0)
const fee = incoming - outgoing
const feeRate = fee / bytes
return feeRate > this.maximumFeeRate
}
module.exports = TransactionBuilder
export {}

2
test/transaction_builder.js

@ -6,7 +6,7 @@ const payments = require('../dist/src/payments')
const ECPair = require('../dist/src/ecpair')
const Transaction = require('..').Transaction
const TransactionBuilder = require('../dist/src/transaction_builder')
const TransactionBuilder = require('..').TransactionBuilder
const NETWORKS = require('../dist/src/networks')
const fixtures = require('./fixtures/transaction_builder')

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