bitcoinjs-lib/src/transaction_builder.js
2019-03-07 14:03:04 +09:00

719 lines
28 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const baddress = require("./address");
const bufferutils_1 = require("./bufferutils");
const classify = require("./classify");
const bcrypto = require("./crypto");
const ECPair = require("./ecpair");
const networks = require("./networks");
const payments = require("./payments");
const bscript = require("./script");
const script_1 = require("./script");
const transaction_1 = require("./transaction");
const types = require("./types");
const typeforce = require('typeforce');
const SCRIPT_TYPES = classify.types;
function txIsString(tx) {
return typeof tx === 'string' || tx instanceof String;
}
function txIsTransaction(tx) {
return tx instanceof transaction_1.Transaction;
}
class TransactionBuilder {
static fromTransaction(transaction, network) {
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, 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;
}
constructor(network, maximumFeeRate) {
this.__PREV_TX_SET = {};
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_1.Transaction();
this.__TX.version = 2;
}
setLockTime(locktime) {
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) {
typeforce(types.UInt32, version);
// XXX: this might eventually become more complex depending on what the versions represent
this.__TX.version = version;
}
addInput(txHash, vout, sequence, prevOutScript) {
if (!this.__canModifyInputs()) {
throw new Error('No, this would invalidate signatures');
}
let value;
// is it a hex string?
if (txIsString(txHash)) {
// transaction hashs's are displayed in reverse order, un-reverse it
txHash = bufferutils_1.reverseBuffer(Buffer.from(txHash, 'hex'));
// is it a Transaction object?
}
else if (txIsTransaction(txHash)) {
const txOut = txHash.outs[vout];
prevOutScript = txOut.script;
value = txOut.value;
txHash = txHash.getHash(false);
}
return this.__addInputUnsafe(txHash, vout, {
sequence,
prevOutScript,
value,
});
}
addOutput(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);
}
build() {
return this.__build(false);
}
buildIncomplete() {
return this.__build(true);
}
sign(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_1.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 did not match witnessValue');
typeforce(types.Satoshi, witnessValue);
input.value = witnessValue;
}
if (!canSign(input)) {
const prepared = prepareInput(input, ourPubKey, redeemScript, 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');
}
__addInputUnsafe(txHash, vout, options) {
if (transaction_1.Transaction.isCoinbaseHash(txHash)) {
throw new Error('coinbase inputs not supported');
}
const prevTxOut = txHash.toString('hex') + ':' + vout;
if (this.__PREV_TX_SET[prevTxOut] !== undefined)
throw new Error('Duplicate TxOut: ' + prevTxOut);
let input = {};
// 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.__PREV_TX_SET[prevTxOut] = true;
return vin;
}
__build(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((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;
}
__canModifyInputs() {
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_1.Transaction.SIGHASH_ANYONECANPAY) !== 0;
});
});
}
__needsOutputs(signingHashType) {
if (signingHashType === transaction_1.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_1.Transaction.SIGHASH_NONE)
return false; // SIGHASH_NONE doesn't care about outputs
return true; // SIGHASH_* does care
});
}));
}
__canModifyOutputs() {
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_1.Transaction.SIGHASH_NONE)
return true;
if (hashTypeMod === transaction_1.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;
}
return false;
});
});
}
__overMaximumFees(bytes) {
// 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 + x.value, 0);
const fee = incoming - outgoing;
const feeRate = fee / bytes;
return feeRate > this.maximumFeeRate;
}
}
exports.TransactionBuilder = TransactionBuilder;
function expandInput(scriptSig, witnessStack, type, scriptPubKey) {
if (scriptSig.length === 0 && witnessStack.length === 0)
return {};
if (!type) {
let ssType = classify.input(scriptSig, true);
let wsType = classify.witness(witnessStack, true);
if (ssType === SCRIPT_TYPES.NONSTANDARD)
ssType = undefined;
if (wsType === SCRIPT_TYPES.NONSTANDARD)
wsType = undefined;
type = ssType || wsType;
}
switch (type) {
case SCRIPT_TYPES.P2WPKH: {
const { output, pubkey, signature } = payments.p2wpkh({
witness: witnessStack,
});
return {
prevOutScript: output,
prevOutType: SCRIPT_TYPES.P2WPKH,
pubkeys: [pubkey],
signatures: [signature],
};
}
case SCRIPT_TYPES.P2PKH: {
const { output, pubkey, signature } = payments.p2pkh({
input: scriptSig,
});
return {
prevOutScript: output,
prevOutType: SCRIPT_TYPES.P2PKH,
pubkeys: [pubkey],
signatures: [signature],
};
}
case SCRIPT_TYPES.P2PK: {
const { signature } = payments.p2pk({ input: scriptSig });
return {
prevOutType: SCRIPT_TYPES.P2PK,
pubkeys: [undefined],
signatures: [signature],
};
}
case SCRIPT_TYPES.P2MS: {
const { m, pubkeys, signatures } = payments.p2ms({
input: scriptSig,
output: scriptPubKey,
}, { allowIncomplete: true });
return {
prevOutType: SCRIPT_TYPES.P2MS,
pubkeys,
signatures,
maxSignatures: m,
};
}
}
if (type === SCRIPT_TYPES.P2SH) {
const { output, redeem } = payments.p2sh({
input: scriptSig,
witness: witnessStack,
});
const outputType = classify.output(redeem.output);
const expanded = expandInput(redeem.input, redeem.witness, outputType, redeem.output);
if (!expanded.prevOutType)
return {};
return {
prevOutScript: output,
prevOutType: SCRIPT_TYPES.P2SH,
redeemScript: redeem.output,
redeemScriptType: expanded.prevOutType,
witnessScript: expanded.witnessScript,
witnessScriptType: expanded.witnessScriptType,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
};
}
if (type === SCRIPT_TYPES.P2WSH) {
const { output, redeem } = payments.p2wsh({
input: scriptSig,
witness: witnessStack,
});
const outputType = classify.output(redeem.output);
let expanded;
if (outputType === SCRIPT_TYPES.P2WPKH) {
expanded = expandInput(redeem.input, redeem.witness, outputType);
}
else {
expanded = expandInput(bscript.compile(redeem.witness), [], outputType, redeem.output);
}
if (!expanded.prevOutType)
return {};
return {
prevOutScript: output,
prevOutType: SCRIPT_TYPES.P2WSH,
witnessScript: redeem.output,
witnessScriptType: expanded.prevOutType,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
};
}
return {
prevOutType: SCRIPT_TYPES.NONSTANDARD,
prevOutScript: scriptSig,
};
}
// could be done in expandInput, but requires the original Transaction for hashForSignature
function fixMultisigOrder(input, transaction, vin) {
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(pubKey => {
const keyPair = ECPair.fromPublicKey(pubKey);
let match;
// check for a signature
unmatched.some((signature, i) => {
// skip if undefined || OP_0
if (!signature)
return false;
// TODO: avoid O(n) hashForSignature
const parsed = bscript.signature.decode(signature);
const hash = transaction.hashForSignature(vin, input.redeemScript, parsed.hashType);
// skip if signature does not match pubKey
if (!keyPair.verify(hash, parsed.signature))
return false;
// remove matched signature from unmatched
unmatched[i] = undefined;
match = signature;
return true;
});
return match;
});
}
function expandOutput(script, ourPubKey) {
typeforce(types.Buffer, script);
const type = classify.output(script);
switch (type) {
case SCRIPT_TYPES.P2PKH: {
if (!ourPubKey)
return { type };
// does our hash160(pubKey) match the output scripts?
const pkh1 = payments.p2pkh({ output: script }).hash;
const pkh2 = bcrypto.hash160(ourPubKey);
if (!pkh1.equals(pkh2))
return { type };
return {
type,
pubkeys: [ourPubKey],
signatures: [undefined],
};
}
case SCRIPT_TYPES.P2WPKH: {
if (!ourPubKey)
return { type };
// does our hash160(pubKey) match the output scripts?
const wpkh1 = payments.p2wpkh({ output: script }).hash;
const wpkh2 = bcrypto.hash160(ourPubKey);
if (!wpkh1.equals(wpkh2))
return { type };
return {
type,
pubkeys: [ourPubKey],
signatures: [undefined],
};
}
case SCRIPT_TYPES.P2PK: {
const p2pk = payments.p2pk({ output: script });
return {
type,
pubkeys: [p2pk.pubkey],
signatures: [undefined],
};
}
case SCRIPT_TYPES.P2MS: {
const p2ms = payments.p2ms({ output: script });
return {
type,
pubkeys: p2ms.pubkeys,
signatures: p2ms.pubkeys.map(() => undefined),
maxSignatures: p2ms.m,
};
}
}
return { type };
}
function prepareInput(input, ourPubKey, redeemScript, witnessScript) {
if (redeemScript && witnessScript) {
const p2wsh = payments.p2wsh({
redeem: { output: witnessScript },
});
const p2wshAlt = payments.p2wsh({ output: redeemScript });
const p2sh = payments.p2sh({ redeem: { output: redeemScript } });
const p2shAlt = payments.p2sh({ redeem: p2wsh });
// enforces P2SH(P2WSH(...))
if (!p2wsh.hash.equals(p2wshAlt.hash))
throw new Error('Witness script inconsistent with prevOutScript');
if (!p2sh.hash.equals(p2shAlt.hash))
throw new Error('Redeem script inconsistent with prevOutScript');
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 !== undefined)) {
expanded.signatures = input.signatures;
}
const signScript = witnessScript;
if (expanded.type === SCRIPT_TYPES.P2WPKH)
throw new Error('P2SH(P2WSH(P2WPKH)) is a consensus failure');
return {
redeemScript,
redeemScriptType: SCRIPT_TYPES.P2WSH,
witnessScript,
witnessScriptType: expanded.type,
prevOutType: SCRIPT_TYPES.P2SH,
prevOutScript: p2sh.output,
hasWitness: true,
signScript,
signType: expanded.type,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
maxSignatures: expanded.maxSignatures,
};
}
if (redeemScript) {
const p2sh = payments.p2sh({ redeem: { output: redeemScript } });
if (input.prevOutScript) {
let p2shAlt;
try {
p2shAlt = payments.p2sh({ output: input.prevOutScript });
}
catch (e) {
throw new Error('PrevOutScript must be P2SH');
}
if (!p2sh.hash.equals(p2shAlt.hash))
throw new Error('Redeem script inconsistent with prevOutScript');
}
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 !== undefined)) {
expanded.signatures = input.signatures;
}
let signScript = redeemScript;
if (expanded.type === SCRIPT_TYPES.P2WPKH) {
signScript = payments.p2pkh({ pubkey: expanded.pubkeys[0] }).output;
}
return {
redeemScript,
redeemScriptType: expanded.type,
prevOutType: SCRIPT_TYPES.P2SH,
prevOutScript: p2sh.output,
hasWitness: expanded.type === SCRIPT_TYPES.P2WPKH,
signScript,
signType: expanded.type,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
maxSignatures: expanded.maxSignatures,
};
}
if (witnessScript) {
const p2wsh = payments.p2wsh({ redeem: { output: witnessScript } });
if (input.prevOutScript) {
const p2wshAlt = payments.p2wsh({ output: input.prevOutScript });
if (!p2wsh.hash.equals(p2wshAlt.hash))
throw new Error('Witness script inconsistent with prevOutScript');
}
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 !== undefined)) {
expanded.signatures = input.signatures;
}
const signScript = witnessScript;
if (expanded.type === SCRIPT_TYPES.P2WPKH)
throw new Error('P2WSH(P2WPKH) is a consensus failure');
return {
witnessScript,
witnessScriptType: expanded.type,
prevOutType: SCRIPT_TYPES.P2WSH,
prevOutScript: p2wsh.output,
hasWitness: true,
signScript,
signType: expanded.type,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
maxSignatures: expanded.maxSignatures,
};
}
if (input.prevOutType && input.prevOutScript) {
// embedded scripts are not possible without extra information
if (input.prevOutType === SCRIPT_TYPES.P2SH)
throw new Error('PrevOutScript is ' + input.prevOutType + ', requires redeemScript');
if (input.prevOutType === SCRIPT_TYPES.P2WSH)
throw new Error('PrevOutScript is ' + input.prevOutType + ', requires witnessScript');
if (!input.prevOutScript)
throw new Error('PrevOutScript is missing');
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 !== undefined)) {
expanded.signatures = input.signatures;
}
let signScript = input.prevOutScript;
if (expanded.type === SCRIPT_TYPES.P2WPKH) {
signScript = payments.p2pkh({ pubkey: expanded.pubkeys[0] })
.output;
}
return {
prevOutType: expanded.type,
prevOutScript: input.prevOutScript,
hasWitness: expanded.type === SCRIPT_TYPES.P2WPKH,
signScript,
signType: expanded.type,
pubkeys: expanded.pubkeys,
signatures: expanded.signatures,
maxSignatures: expanded.maxSignatures,
};
}
const prevOutScript = payments.p2pkh({ pubkey: ourPubKey }).output;
return {
prevOutType: SCRIPT_TYPES.P2PKH,
prevOutScript,
hasWitness: false,
signScript: prevOutScript,
signType: SCRIPT_TYPES.P2PKH,
pubkeys: [ourPubKey],
signatures: [undefined],
};
}
function build(type, input, allowIncomplete) {
const pubkeys = (input.pubkeys || []);
let signatures = (input.signatures || []);
switch (type) {
case SCRIPT_TYPES.P2PKH: {
if (pubkeys.length === 0)
break;
if (signatures.length === 0)
break;
return payments.p2pkh({ pubkey: pubkeys[0], signature: signatures[0] });
}
case SCRIPT_TYPES.P2WPKH: {
if (pubkeys.length === 0)
break;
if (signatures.length === 0)
break;
return payments.p2wpkh({ pubkey: pubkeys[0], signature: signatures[0] });
}
case SCRIPT_TYPES.P2PK: {
if (pubkeys.length === 0)
break;
if (signatures.length === 0)
break;
return payments.p2pk({ signature: signatures[0] });
}
case SCRIPT_TYPES.P2MS: {
const m = input.maxSignatures;
if (allowIncomplete) {
signatures = signatures.map(x => x || script_1.OPS.OP_0);
}
else {
signatures = signatures.filter(x => x);
}
// if the transaction is not not complete (complete), or if signatures.length === m, validate
// otherwise, the number of OP_0's may be >= m, so don't validate (boo)
const validate = !allowIncomplete || m === signatures.length;
return payments.p2ms({ m, pubkeys, signatures }, { allowIncomplete, validate });
}
case SCRIPT_TYPES.P2SH: {
const redeem = build(input.redeemScriptType, input, allowIncomplete);
if (!redeem)
return;
return payments.p2sh({
redeem: {
output: redeem.output || input.redeemScript,
input: redeem.input,
witness: redeem.witness,
},
});
}
case SCRIPT_TYPES.P2WSH: {
const redeem = build(input.witnessScriptType, input, allowIncomplete);
if (!redeem)
return;
return payments.p2wsh({
redeem: {
output: input.witnessScript,
input: redeem.input,
witness: redeem.witness,
},
});
}
}
}
function canSign(input) {
return (input.signScript !== undefined &&
input.signType !== undefined &&
input.pubkeys !== undefined &&
input.signatures !== undefined &&
input.signatures.length === input.pubkeys.length &&
input.pubkeys.length > 0 &&
(input.hasWitness === false || input.value !== undefined));
}
function signatureHashType(buffer) {
return buffer.readUInt8(buffer.length - 1);
}