/*!
* script.js - script interpreter for hsd
* Copyright (c) 2017-2018, Christopher Jeffrey (MIT License).
* https://github.com/handshake-org/hsd
*/
'use strict';
const assert = require('bsert');
const bio = require('bufio');
const ripemd160 = require('bcrypto/lib/ripemd160');
const sha1 = require('bcrypto/lib/sha1');
const sha256 = require('bcrypto/lib/sha256');
const hash160 = require('bcrypto/lib/hash160');
const hash256 = require('bcrypto/lib/hash256');
const blake2b = require('bcrypto/lib/blake2b');
const sha3 = require('bcrypto/lib/sha3');
const keccak = require('bcrypto/lib/keccak');
const secp256k1 = require('bcrypto/lib/secp256k1');
const consensus = require('../protocol/consensus');
const Opcode = require('./opcode');
const Stack = require('./stack');
const ScriptError = require('./scripterror');
const ScriptNum = require('./scriptnum');
const common = require('./common');
const opcodes = common.opcodes;
const scriptTypes = common.types;
const {encoding} = bio;
/** @typedef {import('@handshake-org/bfilter').BloomFilter} BloomFilter */
/** @typedef {import('../types').BufioWriter} BufioWriter */
/** @typedef {import('../types').SighashType} SighashType */
/** @typedef {import('../types').VerifyFlags} VerifyFlags */
/** @typedef {import('../types').Amount} AmountValue */
/** @typedef {import('../types').Hash} Hash */
/** @typedef {import('./witness')} Witness */
/** @typedef {import('../primitives/address')} Address */
/** @typedef {import('../primitives/tx')} TX */
/*
* Constants
*/
const EMPTY_BUFFER = Buffer.alloc(0);
/**
* Script
* Represents a input or output script.
* @alias module:script.Script
* @property {Array} code - Parsed script code.
* @property {Buffer?} raw - Serialized script.
* @property {Number} length - Number of parsed opcodes.
*/
class Script extends bio.Struct {
/**
* Create a script.
* @constructor
* @param {Object?} [options]
*/
constructor(options) {
super();
this.raw = EMPTY_BUFFER;
/** @type {Opcode[]} */
this.code = [];
if (options)
this.fromOptions(options);
}
/**
* Get length.
* @returns {Number}
*/
get length() {
return this.code.length;
}
/**
* Set length.
* @param {Number} value
*/
set length(value) {
this.code.length = value;
}
/**
* Inject properties from options object.
* @param {Object} options
* @returns {this}
*/
fromOptions(options) {
assert(options, 'Script data is required.');
if (Buffer.isBuffer(options))
return this.decode(options);
if (Array.isArray(options))
return this.fromArray(options);
if (options.raw) {
if (!options.code)
return this.decode(options.raw);
assert(Buffer.isBuffer(options.raw), 'Raw must be a Buffer.');
this.raw = options.raw;
}
if (options.code) {
if (!options.raw)
return this.fromArray(options.code);
assert(Array.isArray(options.code), 'Code must be an array.');
this.code = options.code;
}
return this;
}
/**
* Instantiate a value-only iterator.
*/
values() {
return this.code.values();
}
/**
* Instantiate a key and value iterator.
*/
entries() {
return this.code.entries();
}
/**
* Instantiate a value-only iterator.
*/
[Symbol.iterator]() {
return this.code[Symbol.iterator]();
}
/**
* Convert the script to an array of
* Buffers (pushdatas) and Numbers
* (opcodes).
* @returns {Array}
*/
toArray() {
return this.code.slice();
}
/**
* Inject properties from an array of
* of buffers and numbers.
* @param {Opcode[]} code
* @returns {this}
*/
fromArray(code) {
assert(Array.isArray(code));
this.clear();
for (const op of code)
this.push(op);
return this.compile();
}
/**
* Instantiate script from an array
* of buffers and numbers.
* @param {Opcode[]} code
* @returns {Script}
*/
static fromArray(code) {
return new this().fromArray(code);
}
/**
* Convert script to stack items.
* @returns {Buffer[]}
*/
toItems() {
const items = [];
for (const op of this.code) {
const data = op.toPush();
if (!data)
throw new Error('Non-push opcode in script.');
items.push(data);
}
return items;
}
/**
* Inject data from stack items.
* @param {Buffer[]} items
* @returns {this}
*/
fromItems(items) {
assert(Array.isArray(items));
this.clear();
for (const item of items)
this.pushData(item);
return this.compile();
}
/**
* Instantiate script from stack items.
* @param {Buffer[]} items
* @returns {Script}
*/
static fromItems(items) {
return new this().fromItems(items);
}
/**
* Convert script to stack.
* @returns {Stack}
*/
toStack() {
return new Stack(this.toItems());
}
/**
* Inject data from stack.
* @param {Stack} stack
* @returns {this}
*/
fromStack(stack) {
return this.fromItems(stack.items);
}
/**
* Instantiate script from stack.
* @param {Stack} stack
* @returns {Script}
*/
static fromStack(stack) {
return new this().fromStack(stack);
}
/**
* Inject properties from script.
* Used for cloning.
* @param {this} script
* @returns {this}
*/
inject(script) {
this.raw = script.raw;
this.code = script.code.slice();
return this;
}
/**
* Test equality against script.
* @param {Script} script
* @returns {Boolean}
*/
equals(script) {
assert(Script.isScript(script));
return this.raw.equals(script.raw);
}
/**
* Compare against another script.
* @param {Script} script
* @returns {Number}
*/
compare(script) {
assert(Script.isScript(script));
return this.raw.compare(script.raw);
}
/**
* Clear the script.
* @returns {this}
*/
clear() {
this.raw = EMPTY_BUFFER;
this.code.length = 0;
return this;
}
/**
* Inspect the script.
* @returns {String} Human-readable script code.
*/
format() {
return `<Script: ${this.toString()}>`;
}
/**
* Convert the script to a bitcoind test string.
* @returns {String} Human-readable script code.
*/
toString() {
const out = [];
for (const op of this.code)
out.push(op.toFormat());
return out.join(' ');
}
/**
* Format the script as bitcoind asm.
* @param {Boolean?} decode - Attempt to decode hash types.
* @returns {String} Human-readable script.
*/
toASM(decode) {
const out = [];
for (const op of this.code)
out.push(op.toASM(decode));
return out.join(' ');
}
/**
* Re-encode the script internally. Useful if you
* changed something manually in the `code` array.
*/
compile() {
if (this.code.length === 0)
return this.clear();
let size = 0;
for (const op of this.code)
size += op.getSize();
const bw = bio.write(size);
for (const op of this.code)
op.write(bw);
this.raw = bw.render();
return this;
}
/**
* Write the script to a buffer writer.
* @param {BufioWriter} bw
* @returns {BufioWriter}
*/
write(bw) {
bw.writeVarBytes(this.raw);
return bw;
}
/**
* Encode the script to a Buffer. See {@link Script#encode}.
* @returns {Buffer} Serialized script.
*/
encode() {
return this.raw;
}
/**
* Convert script to a hex string.
* @returns {String}
*/
getJSON() {
return this.toHex();
}
/**
* Inject properties from json object.
* @param {String} json
*/
fromJSON(json) {
assert(typeof json === 'string', 'Code must be a string.');
return this.decode(Buffer.from(json, 'hex'));
}
/**
* Get the script's "subscript" starting at a separator.
* @param {Number} index - The last separator to sign/verify beyond.
* @returns {this} Subscript.
*/
getSubscript(index) {
if (index === 0)
return this.clone();
/** @type {this} */
const script = new Script();
for (let i = index; i < this.code.length; i++) {
const op = this.code[i];
if (op.value === -1)
break;
script.code.push(op);
}
return script.compile();
}
/**
* Get the script's "subscript" starting at a separator.
* Remove all OP_CODESEPARATORs if present. This bizarre
* behavior is necessary for signing and verification when
* code separators are present.
* @returns {this}.
*/
removeSeparators() {
let found = false;
// Optimizing for the common case:
// Check for any separators first.
for (const op of this.code) {
if (op.value === -1)
break;
if (op.value === opcodes.OP_CODESEPARATOR) {
found = true;
break;
}
}
if (!found)
return this;
// Uncommon case: someone actually
// has a code separator. Go through
// and remove them all.
/** @type {this} */
const script = new Script();
for (const op of this.code) {
if (op.value === -1)
break;
if (op.value !== opcodes.OP_CODESEPARATOR)
script.code.push(op);
}
return script.compile();
}
/**
* Execute and interpret the script.
* @param {Stack} stack - Script execution stack.
* @param {Number?} flags - Script standard flags.
* @param {TX?} tx - Transaction being verified.
* @param {Number?} index - Index of input being verified.
* @param {AmountValue?} value - Previous output value.
* @throws {ScriptError} Will be thrown on VERIFY failures.
*/
execute(stack, flags, tx, index, value) {
if (flags == null)
flags = Script.flags.STANDARD_VERIFY_FLAGS;
if (this.raw.length > consensus.MAX_SCRIPT_SIZE)
throw new ScriptError('SCRIPT_SIZE');
const state = [];
const alt = [];
let lastSep = 0;
let opCount = 0;
let negate = 0;
let minimal = false;
if (flags & Script.flags.VERIFY_MINIMALDATA)
minimal = true;
for (let ip = 0; ip < this.code.length; ip++) {
const op = this.code[ip];
if (op.value === -1)
throw new ScriptError('BAD_OPCODE', op, ip);
if (op.data && op.data.length > consensus.MAX_SCRIPT_PUSH)
throw new ScriptError('PUSH_SIZE', op, ip);
if (op.value > opcodes.OP_16 && ++opCount > consensus.MAX_SCRIPT_OPS)
throw new ScriptError('OP_COUNT', op, ip);
if (op.isDisabled())
throw new ScriptError('DISABLED_OPCODE', op, ip);
if (negate && !op.isBranch()) {
if (stack.length + alt.length > consensus.MAX_SCRIPT_STACK)
throw new ScriptError('STACK_SIZE', op, ip);
continue;
}
if (op.data) {
if (minimal && !op.isMinimal())
throw new ScriptError('MINIMALDATA', op, ip);
stack.push(op.data);
if (stack.length + alt.length > consensus.MAX_SCRIPT_STACK)
throw new ScriptError('STACK_SIZE', op, ip);
continue;
}
switch (op.value) {
case opcodes.OP_0: {
stack.pushInt(0);
break;
}
case opcodes.OP_1NEGATE: {
stack.pushInt(-1);
break;
}
case opcodes.OP_1:
case opcodes.OP_2:
case opcodes.OP_3:
case opcodes.OP_4:
case opcodes.OP_5:
case opcodes.OP_6:
case opcodes.OP_7:
case opcodes.OP_8:
case opcodes.OP_9:
case opcodes.OP_10:
case opcodes.OP_11:
case opcodes.OP_12:
case opcodes.OP_13:
case opcodes.OP_14:
case opcodes.OP_15:
case opcodes.OP_16: {
stack.pushInt(op.value - 0x50);
break;
}
case opcodes.OP_NOP: {
break;
}
case opcodes.OP_TYPE: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (index >= tx.outputs.length) {
stack.pushInt(0);
break;
}
const {covenant} = tx.outputs[index];
stack.pushInt(covenant.type);
break;
}
case opcodes.OP_CHECKLOCKTIMEVERIFY: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const num = stack.getNum(-1, minimal, 5);
if (num.isNeg())
throw new ScriptError('NEGATIVE_LOCKTIME', op, ip);
const locktime = num.toDouble();
if (!tx.verifyLocktime(index, locktime))
throw new ScriptError('UNSATISFIED_LOCKTIME', op, ip);
break;
}
case opcodes.OP_CHECKSEQUENCEVERIFY: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const num = stack.getNum(-1, minimal, 5);
if (num.isNeg())
throw new ScriptError('NEGATIVE_LOCKTIME', op, ip);
const locktime = num.toDouble();
if (!tx.verifySequence(index, locktime))
throw new ScriptError('UNSATISFIED_LOCKTIME', op, ip);
break;
}
case opcodes.OP_NOP1:
case opcodes.OP_NOP4:
case opcodes.OP_NOP5:
case opcodes.OP_NOP6:
case opcodes.OP_NOP7:
case opcodes.OP_NOP8:
case opcodes.OP_NOP9:
case opcodes.OP_NOP10: {
if (flags & Script.flags.VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
throw new ScriptError('DISCOURAGE_UPGRADABLE_NOPS', op, ip);
break;
}
case opcodes.OP_IF:
case opcodes.OP_NOTIF: {
let val = false;
if (!negate) {
if (stack.length < 1)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
if (flags & Script.flags.VERIFY_MINIMALIF) {
const item = stack.get(-1);
if (item.length > 1)
throw new ScriptError('MINIMALIF');
if (item.length === 1 && item[0] !== 1)
throw new ScriptError('MINIMALIF');
}
val = stack.getBool(-1);
if (op.value === opcodes.OP_NOTIF)
val = !val;
stack.pop();
}
state.push(val);
if (!val)
negate += 1;
break;
}
case opcodes.OP_ELSE: {
if (state.length === 0)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
state[state.length - 1] = !state[state.length - 1];
if (!state[state.length - 1])
negate += 1;
else
negate -= 1;
break;
}
case opcodes.OP_ENDIF: {
if (state.length === 0)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
if (!state.pop())
negate -= 1;
break;
}
case opcodes.OP_VERIFY: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
if (!stack.getBool(-1))
throw new ScriptError('VERIFY', op, ip);
stack.pop();
break;
}
case opcodes.OP_RETURN: {
throw new ScriptError('OP_RETURN', op, ip);
}
case opcodes.OP_TOALTSTACK: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
alt.push(stack.pop());
break;
}
case opcodes.OP_FROMALTSTACK: {
if (alt.length === 0)
throw new ScriptError('INVALID_ALTSTACK_OPERATION', op, ip);
stack.push(alt.pop());
break;
}
case opcodes.OP_2DROP: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.pop();
stack.pop();
break;
}
case opcodes.OP_2DUP: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const v1 = stack.get(-2);
const v2 = stack.get(-1);
stack.push(v1);
stack.push(v2);
break;
}
case opcodes.OP_3DUP: {
if (stack.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const v1 = stack.get(-3);
const v2 = stack.get(-2);
const v3 = stack.get(-1);
stack.push(v1);
stack.push(v2);
stack.push(v3);
break;
}
case opcodes.OP_2OVER: {
if (stack.length < 4)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const v1 = stack.get(-4);
const v2 = stack.get(-3);
stack.push(v1);
stack.push(v2);
break;
}
case opcodes.OP_2ROT: {
if (stack.length < 6)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const v1 = stack.get(-6);
const v2 = stack.get(-5);
stack.erase(-6, -4);
stack.push(v1);
stack.push(v2);
break;
}
case opcodes.OP_2SWAP: {
if (stack.length < 4)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.swap(-4, -2);
stack.swap(-3, -1);
break;
}
case opcodes.OP_IFDUP: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
if (stack.getBool(-1)) {
const val = stack.get(-1);
stack.push(val);
}
break;
}
case opcodes.OP_DEPTH: {
stack.pushInt(stack.length);
break;
}
case opcodes.OP_DROP: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.pop();
break;
}
case opcodes.OP_DUP: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(stack.get(-1));
break;
}
case opcodes.OP_NIP: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.remove(-2);
break;
}
case opcodes.OP_OVER: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(stack.get(-2));
break;
}
case opcodes.OP_PICK:
case opcodes.OP_ROLL: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const num = stack.getInt(-1, minimal, 4);
stack.pop();
if (num < 0 || num >= stack.length)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const val = stack.get(-num - 1);
if (op.value === opcodes.OP_ROLL)
stack.remove(-num - 1);
stack.push(val);
break;
}
case opcodes.OP_ROT: {
if (stack.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.swap(-3, -2);
stack.swap(-2, -1);
break;
}
case opcodes.OP_SWAP: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.swap(-2, -1);
break;
}
case opcodes.OP_TUCK: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.insert(-2, stack.get(-1));
break;
}
case opcodes.OP_SIZE: {
if (stack.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.pushInt(stack.get(-1).length);
break;
}
case opcodes.OP_EQUAL:
case opcodes.OP_EQUALVERIFY: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const v1 = stack.get(-2);
const v2 = stack.get(-1);
const res = v1.equals(v2);
stack.pop();
stack.pop();
stack.pushBool(res);
if (op.value === opcodes.OP_EQUALVERIFY) {
if (!res)
throw new ScriptError('EQUALVERIFY', op, ip);
stack.pop();
}
break;
}
case opcodes.OP_1ADD:
case opcodes.OP_1SUB:
case opcodes.OP_NEGATE:
case opcodes.OP_ABS:
case opcodes.OP_NOT:
case opcodes.OP_0NOTEQUAL: {
if (stack.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
let num = stack.getNum(-1, minimal, 4);
let cmp;
switch (op.value) {
case opcodes.OP_1ADD:
num.iaddn(1);
break;
case opcodes.OP_1SUB:
num.isubn(1);
break;
case opcodes.OP_NEGATE:
num.ineg();
break;
case opcodes.OP_ABS:
num.iabs();
break;
case opcodes.OP_NOT:
cmp = num.isZero();
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_0NOTEQUAL:
cmp = !num.isZero();
num = ScriptNum.fromBool(cmp);
break;
default:
assert(false, 'Fatal script error.');
break;
}
stack.pop();
stack.pushNum(num);
break;
}
case opcodes.OP_ADD:
case opcodes.OP_SUB:
case opcodes.OP_BOOLAND:
case opcodes.OP_BOOLOR:
case opcodes.OP_NUMEQUAL:
case opcodes.OP_NUMEQUALVERIFY:
case opcodes.OP_NUMNOTEQUAL:
case opcodes.OP_LESSTHAN:
case opcodes.OP_GREATERTHAN:
case opcodes.OP_LESSTHANOREQUAL:
case opcodes.OP_GREATERTHANOREQUAL:
case opcodes.OP_MIN:
case opcodes.OP_MAX: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const n1 = stack.getNum(-2, minimal, 4);
const n2 = stack.getNum(-1, minimal, 4);
let num, cmp;
switch (op.value) {
case opcodes.OP_ADD:
num = n1.iadd(n2);
break;
case opcodes.OP_SUB:
num = n1.isub(n2);
break;
case opcodes.OP_BOOLAND:
cmp = n1.toBool() && n2.toBool();
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_BOOLOR:
cmp = n1.toBool() || n2.toBool();
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_NUMEQUAL:
cmp = n1.eq(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_NUMEQUALVERIFY:
cmp = n1.eq(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_NUMNOTEQUAL:
cmp = !n1.eq(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_LESSTHAN:
cmp = n1.lt(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_GREATERTHAN:
cmp = n1.gt(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_LESSTHANOREQUAL:
cmp = n1.lte(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_GREATERTHANOREQUAL:
cmp = n1.gte(n2);
num = ScriptNum.fromBool(cmp);
break;
case opcodes.OP_MIN:
num = ScriptNum.min(n1, n2);
break;
case opcodes.OP_MAX:
num = ScriptNum.max(n1, n2);
break;
default:
assert(false, 'Fatal script error.');
break;
}
stack.pop();
stack.pop();
stack.pushNum(num);
if (op.value === opcodes.OP_NUMEQUALVERIFY) {
if (!stack.getBool(-1))
throw new ScriptError('NUMEQUALVERIFY', op, ip);
stack.pop();
}
break;
}
case opcodes.OP_WITHIN: {
if (stack.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const n1 = stack.getNum(-3, minimal, 4);
const n2 = stack.getNum(-2, minimal, 4);
const n3 = stack.getNum(-1, minimal, 4);
const val = n2.lte(n1) && n1.lt(n3);
stack.pop();
stack.pop();
stack.pop();
stack.pushBool(val);
break;
}
case opcodes.OP_RIPEMD160: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(ripemd160.digest(stack.pop()));
break;
}
case opcodes.OP_SHA1: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(sha1.digest(stack.pop()));
break;
}
case opcodes.OP_SHA256: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(sha256.digest(stack.pop()));
break;
}
case opcodes.OP_HASH160: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(hash160.digest(stack.pop()));
break;
}
case opcodes.OP_HASH256: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(hash256.digest(stack.pop()));
break;
}
case opcodes.OP_BLAKE160: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(blake2b.digest(stack.pop(), 20));
break;
}
case opcodes.OP_BLAKE256: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(blake2b.digest(stack.pop()));
break;
}
case opcodes.OP_SHA3: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(sha3.digest(stack.pop()));
break;
}
case opcodes.OP_KECCAK: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(keccak.digest(stack.pop()));
break;
}
case opcodes.OP_CODESEPARATOR: {
lastSep = ip + 1;
break;
}
case opcodes.OP_CHECKSIG:
case opcodes.OP_CHECKSIGVERIFY: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const sig = stack.get(-2);
const key = stack.get(-1);
const subscript = this.getSubscript(lastSep);
validateSignature(sig, flags);
validateKey(key, flags);
let res = false;
if (sig.length > 0) {
const type = sig[sig.length - 1];
const hash = tx.signatureHash(
index,
subscript,
value,
type
);
res = checksig(hash, sig, key);
}
if (!res && (flags & Script.flags.VERIFY_NULLFAIL)) {
if (sig.length !== 0)
throw new ScriptError('NULLFAIL', op, ip);
}
stack.pop();
stack.pop();
stack.pushBool(res);
if (op.value === opcodes.OP_CHECKSIGVERIFY) {
if (!res)
throw new ScriptError('CHECKSIGVERIFY', op, ip);
stack.pop();
}
break;
}
case opcodes.OP_CHECKMULTISIG:
case opcodes.OP_CHECKMULTISIGVERIFY: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
let i = 1;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
let n = stack.getInt(-i, minimal, 4);
let okey = n + 2;
let ikey, isig;
if (n < 0 || n > consensus.MAX_MULTISIG_PUBKEYS)
throw new ScriptError('PUBKEY_COUNT', op, ip);
opCount += n;
if (opCount > consensus.MAX_SCRIPT_OPS)
throw new ScriptError('OP_COUNT', op, ip);
i += 1;
ikey = i;
i += n;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
let m = stack.getInt(-i, minimal, 4);
if (m < 0 || m > n)
throw new ScriptError('SIG_COUNT', op, ip);
i += 1;
isig = i;
i += m;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
const subscript = this.getSubscript(lastSep);
let res = true;
while (res && m > 0) {
const sig = stack.get(-isig);
const key = stack.get(-ikey);
validateSignature(sig, flags);
validateKey(key, flags);
if (sig.length > 0) {
const type = sig[sig.length - 1];
const hash = tx.signatureHash(
index,
subscript,
value,
type
);
if (checksig(hash, sig, key)) {
isig += 1;
m -= 1;
}
}
ikey += 1;
n -= 1;
if (m > n)
res = false;
}
while (i > 1) {
if (!res && (flags & Script.flags.VERIFY_NULLFAIL)) {
if (okey === 0 && stack.get(-1).length !== 0)
throw new ScriptError('NULLFAIL', op, ip);
}
if (okey > 0)
okey -= 1;
stack.pop();
i -= 1;
}
if (stack.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
if (stack.get(-1).length !== 0)
throw new ScriptError('SIG_NULLDUMMY', op, ip);
stack.pop();
stack.pushBool(res);
if (op.value === opcodes.OP_CHECKMULTISIGVERIFY) {
if (!res)
throw new ScriptError('CHECKMULTISIGVERIFY', op, ip);
stack.pop();
}
break;
}
default: {
throw new ScriptError('BAD_OPCODE', op, ip);
}
}
if (stack.length + alt.length > consensus.MAX_SCRIPT_STACK)
throw new ScriptError('STACK_SIZE', op, ip);
}
if (state.length !== 0)
throw new ScriptError('UNBALANCED_CONDITIONAL');
}
/**
* Find a data element in a script.
* @param {Buffer} data - Data element to match against.
* @returns {Number} Index (`-1` if not present).
*/
indexOf(data) {
for (let i = 0; i < this.code.length; i++) {
const op = this.code[i];
if (op.value === -1)
break;
if (!op.data)
continue;
if (op.data.equals(data))
return i;
}
return -1;
}
/**
* Test a script to see if it is likely
* to be script code (no weird opcodes).
* @returns {Boolean}
*/
isCode() {
for (const op of this.code) {
if (op.value === -1)
return false;
if (op.isDisabled())
return false;
switch (op.value) {
case opcodes.OP_RESERVED:
case opcodes.OP_NOP:
case opcodes.OP_VER:
case opcodes.OP_VERIF:
case opcodes.OP_VERNOTIF:
case opcodes.OP_RESERVED1:
case opcodes.OP_RESERVED2:
return false;
}
if (op.value > opcodes.OP_CHECKSEQUENCEVERIFY)
return false;
}
return true;
}
/**
* Inject properties from a pay-to-pubkey script.
* @param {Buffer} key
* @returns {this}
*/
fromPubkey(key) {
assert(Buffer.isBuffer(key) && key.length === 33);
this.raw = Buffer.allocUnsafe(35);
this.raw[0] = 33;
key.copy(this.raw, 1);
this.raw[34] = opcodes.OP_CHECKSIG;
key = this.raw.slice(1, 34);
this.code.length = 0;
this.code.push(Opcode.fromPush(key));
this.code.push(Opcode.fromOp(opcodes.OP_CHECKSIG));
return this;
}
/**
* Create a pay-to-pubkey script.
* @param {Buffer} key
* @returns {Script}
*/
static fromPubkey(key) {
return new this().fromPubkey(key);
}
/**
* Inject properties from a pay-to-pubkeyhash script.
* @private
* @param {Buffer} hash
*/
fromPubkeyhash(hash) {
assert(Buffer.isBuffer(hash) && hash.length === 20);
this.raw = Buffer.allocUnsafe(25);
this.raw[0] = opcodes.OP_DUP;
this.raw[1] = opcodes.OP_BLAKE160;
this.raw[2] = 0x14;
hash.copy(this.raw, 3);
this.raw[23] = opcodes.OP_EQUALVERIFY;
this.raw[24] = opcodes.OP_CHECKSIG;
hash = this.raw.slice(3, 23);
this.code.length = 0;
this.code.push(Opcode.fromOp(opcodes.OP_DUP));
this.code.push(Opcode.fromOp(opcodes.OP_BLAKE160));
this.code.push(Opcode.fromPush(hash));
this.code.push(Opcode.fromOp(opcodes.OP_EQUALVERIFY));
this.code.push(Opcode.fromOp(opcodes.OP_CHECKSIG));
return this;
}
/**
* Create a pay-to-pubkeyhash script.
* @param {Buffer} hash
* @returns {Script}
*/
static fromPubkeyhash(hash) {
return new this().fromPubkeyhash(hash);
}
/**
* Inject properties from pay-to-multisig script.
* @private
* @param {Number} m
* @param {Number} n
* @param {Buffer[]} keys
*/
fromMultisig(m, n, keys) {
assert((m & 0xff) === m && (n & 0xff) === n);
assert(Array.isArray(keys));
assert(keys.length === n, '`n` keys are required for multisig.');
assert(m >= 1 && m <= n);
assert(n >= 1 && n <= 15);
this.clear();
this.pushSmall(m);
for (const key of sortKeys(keys))
this.pushData(key);
this.pushSmall(n);
this.pushOp(opcodes.OP_CHECKMULTISIG);
return this.compile();
}
/**
* Create a pay-to-multisig script.
* @param {Number} m
* @param {Number} n
* @param {Buffer[]} keys
* @returns {Script}
*/
static fromMultisig(m, n, keys) {
return new this().fromMultisig(m, n, keys);
}
/**
* Get the standard script type.
* @returns {common.types}
*/
getType() {
if (this.isPubkey())
return scriptTypes.PUBKEY;
if (this.isPubkeyhash())
return scriptTypes.PUBKEYHASH;
if (this.isMultisig())
return scriptTypes.MULTISIG;
return scriptTypes.NONSTANDARD;
}
/**
* Test whether a script is of an unknown/non-standard type.
* @returns {Boolean}
*/
isUnknown() {
return this.getType() === scriptTypes.NONSTANDARD;
}
/**
* Test whether the script is standard by policy standards.
* @returns {Boolean}
*/
isStandard() {
const [m, n] = this.getMultisig();
if (m !== -1) {
if (n < 1 || n > 3)
return false;
if (m < 1 || m > n)
return false;
return true;
}
return this.getType() !== scriptTypes.NONSTANDARD;
}
/**
* Calculate the size of the script
* excluding the varint size bytes.
* @returns {Number}
*/
getSize() {
return this.raw.length;
}
/**
* Calculate the size of the script
* including the varint size bytes.
* @returns {Number}
*/
getVarSize() {
return encoding.sizeVarBytes(this.raw);
}
/**
* Get the sha3 of the raw script.
* @returns {Hash}
*/
sha3() {
return sha3.digest(this.encode());
}
/**
* Test whether the output script is pay-to-pubkey.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Boolean}
*/
isPubkey(minimal) {
if (minimal) {
return this.raw.length === 35
&& this.raw[0] === 33
&& this.raw[0] + 2 === this.raw.length
&& this.raw[this.raw.length - 1] === opcodes.OP_CHECKSIG;
}
if (this.code.length !== 2)
return false;
return this.getLength(0) === 33
&& this.getOp(1) === opcodes.OP_CHECKSIG;
}
/**
* Get P2PK key if present.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Buffer|null}
*/
getPubkey(minimal) {
if (!this.isPubkey(minimal))
return null;
if (minimal)
return this.raw.slice(1, 1 + this.raw[0]);
return this.getData(0);
}
/**
* Test whether the output script is pay-to-pubkeyhash.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Boolean}
*/
isPubkeyhash(minimal) {
if (minimal || this.raw.length === 25) {
return this.raw.length === 25
&& this.raw[0] === opcodes.OP_DUP
&& this.raw[1] === opcodes.OP_BLAKE160
&& this.raw[2] === 0x14
&& this.raw[23] === opcodes.OP_EQUALVERIFY
&& this.raw[24] === opcodes.OP_CHECKSIG;
}
if (this.code.length !== 5)
return false;
return this.getOp(0) === opcodes.OP_DUP
&& this.getOp(1) === opcodes.OP_BLAKE160
&& this.getLength(2) === 20
&& this.getOp(3) === opcodes.OP_EQUALVERIFY
&& this.getOp(4) === opcodes.OP_CHECKSIG;
}
/**
* Get P2PKH hash if present.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Buffer|null}
*/
getPubkeyhash(minimal) {
if (!this.isPubkeyhash(minimal))
return null;
if (minimal)
return this.raw.slice(3, 23);
return this.getData(2);
}
/**
* Test whether the output script is pay-to-multisig.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Boolean}
*/
isMultisig(minimal) {
if (this.code.length < 4 || this.code.length > 19)
return false;
if (this.getOp(-1) !== opcodes.OP_CHECKMULTISIG)
return false;
const m = this.getSmall(0);
if (m < 1)
return false;
const n = this.getSmall(-2);
if (n < 1 || m > n)
return false;
if (this.code.length !== n + 3)
return false;
for (let i = 1; i < n + 1; i++) {
const op = this.code[i];
if (op.toLength() !== 33)
return false;
if (minimal && !op.isMinimal())
return false;
}
return true;
}
/**
* Get multisig m and n values if present.
* @param {Boolean} [minimal=false] - Minimaldata only.
* @returns {Array} [m, n]
*/
getMultisig(minimal) {
if (!this.isMultisig(minimal))
return [-1, -1];
return [this.getSmall(0), this.getSmall(-2)];
}
/**
* Test whether the output script is unspendable.
* @returns {Boolean}
*/
isUnspendable() {
if (this.raw.length > consensus.MAX_SCRIPT_SIZE)
return true;
return this.raw.length > 0 && this.raw[0] === opcodes.OP_RETURN;
}
/**
* Test the script against a bloom filter.
* @param {BloomFilter} filter
* @returns {Boolean}
*/
test(filter) {
for (const op of this.code) {
if (op.value === -1)
break;
if (!op.data || op.data.length === 0)
continue;
if (filter.test(op.data))
return true;
}
return false;
}
/**
* Test the script to see if it contains only push ops.
* Push ops are: OP_1NEGATE, OP_0-OP_16 and all PUSHDATAs.
* @returns {Boolean}
*/
isPushOnly() {
for (const op of this.code) {
if (op.value === -1)
return false;
if (op.value > opcodes.OP_16)
return false;
}
return true;
}
/**
* Count the sigops in the script.
* @returns {Number} sigop count
*/
getSigops() {
let total = 0;
let lastOp = -1;
for (const op of this.code) {
if (op.value === -1)
break;
switch (op.value) {
case opcodes.OP_CHECKSIG:
case opcodes.OP_CHECKSIGVERIFY:
total += 1;
break;
case opcodes.OP_CHECKMULTISIG:
case opcodes.OP_CHECKMULTISIGVERIFY:
if (lastOp >= opcodes.OP_1 && lastOp <= opcodes.OP_16)
total += lastOp - 0x50;
else
total += consensus.MAX_MULTISIG_PUBKEYS;
break;
}
lastOp = op.value;
}
return total;
}
/*
* Mutation
*/
get(index) {
if (index < 0)
index += this.code.length;
if (index < 0 || index >= this.code.length)
return null;
return this.code[index];
}
pop() {
const op = this.code.pop();
return op || null;
}
shift() {
const op = this.code.shift();
return op || null;
}
remove(index) {
if (index < 0)
index += this.code.length;
if (index < 0 || index >= this.code.length)
return null;
const items = this.code.splice(index, 1);
if (items.length === 0)
return null;
return items[0];
}
set(index, op) {
if (index < 0)
index += this.code.length;
assert(Opcode.isOpcode(op));
assert(index >= 0 && index <= this.code.length);
this.code[index] = op;
return this;
}
push(op) {
assert(Opcode.isOpcode(op));
this.code.push(op);
return this;
}
unshift(op) {
assert(Opcode.isOpcode(op));
this.code.unshift(op);
return this;
}
insert(index, op) {
if (index < 0)
index += this.code.length;
assert(Opcode.isOpcode(op));
assert(index >= 0 && index <= this.code.length);
this.code.splice(index, 0, op);
return this;
}
/*
* Op
*/
getOp(index) {
const op = this.get(index);
return op ? op.value : -1;
}
popOp() {
const op = this.pop();
return op ? op.value : -1;
}
shiftOp() {
const op = this.shift();
return op ? op.value : -1;
}
removeOp(index) {
const op = this.remove(index);
return op ? op.value : -1;
}
setOp(index, value) {
return this.set(index, Opcode.fromOp(value));
}
pushOp(value) {
return this.push(Opcode.fromOp(value));
}
unshiftOp(value) {
return this.unshift(Opcode.fromOp(value));
}
insertOp(index, value) {
return this.insert(index, Opcode.fromOp(value));
}
/*
* Data
*/
getData(index) {
const op = this.get(index);
return op ? op.data : null;
}
popData() {
const op = this.pop();
return op ? op.data : null;
}
shiftData() {
const op = this.shift();
return op ? op.data : null;
}
removeData(index) {
const op = this.remove(index);
return op ? op.data : null;
}
setData(index, data) {
return this.set(index, Opcode.fromData(data));
}
pushData(data) {
return this.push(Opcode.fromData(data));
}
unshiftData(data) {
return this.unshift(Opcode.fromData(data));
}
insertData(index, data) {
return this.insert(index, Opcode.fromData(data));
}
/*
* Length
*/
getLength(index) {
const op = this.get(index);
return op ? op.toLength() : -1;
}
/*
* Push
*/
getPush(index) {
const op = this.get(index);
return op ? op.toPush() : null;
}
popPush() {
const op = this.pop();
return op ? op.toPush() : null;
}
shiftPush() {
const op = this.shift();
return op ? op.toPush() : null;
}
removePush(index) {
const op = this.remove(index);
return op ? op.toPush() : null;
}
setPush(index, data) {
return this.set(index, Opcode.fromPush(data));
}
pushPush(data) {
return this.push(Opcode.fromPush(data));
}
unshiftPush(data) {
return this.unshift(Opcode.fromPush(data));
}
insertPush(index, data) {
return this.insert(index, Opcode.fromPush(data));
}
/*
* String
*/
getString(index, enc) {
const op = this.get(index);
return op ? op.toString(enc) : null;
}
popString(enc) {
const op = this.pop();
return op ? op.toString(enc) : null;
}
shiftString(enc) {
const op = this.shift();
return op ? op.toString(enc) : null;
}
removeString(index, enc) {
const op = this.remove(index);
return op ? op.toString(enc) : null;
}
setString(index, str, enc) {
return this.set(index, Opcode.fromString(str, enc));
}
pushString(str, enc) {
return this.push(Opcode.fromString(str, enc));
}
unshiftString(str, enc) {
return this.unshift(Opcode.fromString(str, enc));
}
insertString(index, str, enc) {
return this.insert(index, Opcode.fromString(str, enc));
}
/*
* Small
*/
getSmall(index) {
const op = this.get(index);
return op ? op.toSmall() : -1;
}
popSmall() {
const op = this.pop();
return op ? op.toSmall() : -1;
}
shiftSmall() {
const op = this.shift();
return op ? op.toSmall() : -1;
}
removeSmall(index) {
const op = this.remove(index);
return op ? op.toSmall() : -1;
}
setSmall(index, num) {
return this.set(index, Opcode.fromSmall(num));
}
pushSmall(num) {
return this.push(Opcode.fromSmall(num));
}
unshiftSmall(num) {
return this.unshift(Opcode.fromSmall(num));
}
insertSmall(index, num) {
return this.insert(index, Opcode.fromSmall(num));
}
/*
* Num
*/
getNum(index, minimal, limit) {
const op = this.get(index);
return op ? op.toNum(minimal, limit) : null;
}
popNum(minimal, limit) {
const op = this.pop();
return op ? op.toNum(minimal, limit) : null;
}
shiftNum(minimal, limit) {
const op = this.shift();
return op ? op.toNum(minimal, limit) : null;
}
removeNum(index, minimal, limit) {
const op = this.remove(index);
return op ? op.toNum(minimal, limit) : null;
}
setNum(index, num) {
return this.set(index, Opcode.fromNum(num));
}
pushNum(num) {
return this.push(Opcode.fromNum(num));
}
unshiftNum(num) {
return this.unshift(Opcode.fromNum(num));
}
insertNum(index, num) {
return this.insert(index, Opcode.fromNum(num));
}
/*
* Int
*/
getInt(index, minimal, limit) {
const op = this.get(index);
return op ? op.toInt(minimal, limit) : -1;
}
popInt(minimal, limit) {
const op = this.pop();
return op ? op.toInt(minimal, limit) : -1;
}
shiftInt(minimal, limit) {
const op = this.shift();
return op ? op.toInt(minimal, limit) : -1;
}
removeInt(index, minimal, limit) {
const op = this.remove(index);
return op ? op.toInt(minimal, limit) : -1;
}
setInt(index, num) {
return this.set(index, Opcode.fromInt(num));
}
pushInt(num) {
return this.push(Opcode.fromInt(num));
}
unshiftInt(num) {
return this.unshift(Opcode.fromInt(num));
}
insertInt(index, num) {
return this.insert(index, Opcode.fromInt(num));
}
/*
* Bool
*/
getBool(index) {
const op = this.get(index);
return op ? op.toBool() : false;
}
popBool() {
const op = this.pop();
return op ? op.toBool() : false;
}
shiftBool() {
const op = this.shift();
return op ? op.toBool() : false;
}
removeBool(index) {
const op = this.remove(index);
return op ? op.toBool() : false;
}
setBool(index, value) {
return this.set(index, Opcode.fromBool(value));
}
pushBool(value) {
return this.push(Opcode.fromBool(value));
}
unshiftBool(value) {
return this.unshift(Opcode.fromBool(value));
}
insertBool(index, value) {
return this.insert(index, Opcode.fromBool(value));
}
/*
* Symbol
*/
getSym(index) {
const op = this.get(index);
return op ? op.toSymbol() : null;
}
popSym() {
const op = this.pop();
return op ? op.toSymbol() : null;
}
shiftSym() {
const op = this.shift();
return op ? op.toSymbol() : null;
}
removeSym(index) {
const op = this.remove(index);
return op ? op.toSymbol() : null;
}
setSym(index, symbol) {
return this.set(index, Opcode.fromSymbol(symbol));
}
pushSym(symbol) {
return this.push(Opcode.fromSymbol(symbol));
}
unshiftSym(symbol) {
return this.unshift(Opcode.fromSymbol(symbol));
}
insertSym(index, symbol) {
return this.insert(index, Opcode.fromSymbol(symbol));
}
/**
* Inject properties from bitcoind test string.
* @param {String} code - Script string.
* @throws Parse error.
*/
fromString(code) {
assert(typeof code === 'string');
code = code.trim();
if (code.length === 0)
return this;
const items = code.split(/\s+/);
const bw = bio.write();
for (const item of items) {
let symbol = item;
if (symbol.charCodeAt(0) & 32)
symbol = symbol.toUpperCase();
if (!/^OP_/.test(symbol))
symbol = `OP_${symbol}`;
const value = opcodes[symbol];
if (value == null) {
if (item[0] === '\'') {
assert(item[item.length - 1] === '\'', 'Invalid string.');
const str = item.slice(1, -1);
const op = Opcode.fromString(str);
bw.writeBytes(op.encode());
continue;
}
if (/^-?\d+$/.test(item)) {
const num = ScriptNum.fromString(item, 10);
const op = Opcode.fromNum(num);
bw.writeBytes(op.encode());
continue;
}
assert(item.indexOf('0x') === 0, 'Unknown opcode.');
const hex = item.substring(2);
const data = Buffer.from(hex, 'hex');
assert(data.length === hex.length / 2, 'Invalid hex string.');
bw.writeBytes(data);
continue;
}
bw.writeU8(value);
}
return this.decode(bw.render());
}
/**
* Verify an input and output script, and a witness if present.
* @param {Witness} witness
* @param {Address} addr
* @param {TX} tx
* @param {Number} index
* @param {AmountValue} value
* @param {VerifyFlags} flags
* @throws {ScriptError}
*/
static verify(witness, addr, tx, index, value, flags) {
if (flags == null)
flags = Script.flags.STANDARD_VERIFY_FLAGS;
assert(addr.version <= 31);
if (addr.version === 31)
throw new ScriptError('OP_RETURN');
if (witness.items.length > consensus.MAX_SCRIPT_STACK)
throw new ScriptError('STACK_SIZE');
const stack = witness.toStack();
let redeem = null;
if (addr.version === 0) {
if (addr.hash.length === 32) {
if (stack.length === 0)
throw new ScriptError('WITNESS_PROGRAM_WITNESS_EMPTY');
const witnessScript = stack.pop();
if (witnessScript.length > consensus.MAX_SCRIPT_SIZE)
throw new ScriptError('SCRIPT_SIZE');
if (!sha3.digest(witnessScript).equals(addr.hash))
throw new ScriptError('WITNESS_PROGRAM_MISMATCH');
redeem = Script.decode(witnessScript);
} else if (addr.hash.length === 20) {
if (stack.length !== 2)
throw new ScriptError('WITNESS_PROGRAM_MISMATCH');
redeem = Script.fromPubkeyhash(addr.hash);
} else {
// Failure on version=0 (bad program data length).
throw new ScriptError('WITNESS_PROGRAM_WRONG_LENGTH');
}
} else {
if (flags & Script.flags.VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM)
throw new ScriptError('DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM');
return;
}
// Witnesses still have push limits.
for (let j = 0; j < stack.length; j++) {
if (stack.get(j).length > consensus.MAX_SCRIPT_PUSH)
throw new ScriptError('PUSH_SIZE');
}
// Verify the redeem script.
redeem.execute(stack, flags, tx, index, value);
// Verify the stack values.
if (stack.length !== 1 || !stack.getBool(-1))
throw new ScriptError('EVAL_FALSE');
}
/**
* Inject properties from buffer reader.
* @param {bio.BufferReader} br
*/
read(br) {
return this.decode(br.readVarBytes());
}
/**
* Inject properties from serialized data.
* @param {Buffer} data
* @returns {this}
*/
decode(data) {
const br = bio.read(data);
this.raw = data;
while (br.left())
this.code.push(Opcode.read(br));
return this;
}
/**
* Test whether an object a Script.
* @param {Object} obj
* @returns {Boolean}
*/
static isScript(obj) {
return obj instanceof Script;
}
}
/**
* Script opcodes.
* @enum {Number}
* @default
*/
Script.opcodes = common.opcodes;
/**
* Opcodes by value.
* @const {RevMap}
*/
Script.opcodesByVal = common.opcodesByVal;
/**
* Script and locktime flags. See {@link VerifyFlags}.
* @enum {Number}
*/
Script.flags = common.flags;
/**
* Sighash Types.
* @enum {SighashType}
* @default
*/
Script.hashType = common.hashType;
/**
* Sighash types by value.
* @const {RevMap}
*/
Script.hashTypeByVal = common.hashTypeByVal;
/**
* Output script types.
* @enum {Number}
*/
Script.types = common.types;
/**
* Output script types by value.
* @const {RevMap}
*/
Script.typesByVal = common.typesByVal;
/*
* Helpers
*/
function sortKeys(keys) {
return keys.slice().sort((a, b) => {
return a.compare(b);
});
}
/**
* Test whether the data element is a valid key if VERIFY_STRICTENC is enabled.
* @param {Buffer} key
* @param {VerifyFlags?} flags
* @returns {Boolean}
* @throws {ScriptError}
*/
function validateKey(key, flags) {
assert(Buffer.isBuffer(key));
assert(typeof flags === 'number');
if (!common.isKeyEncoding(key))
throw new ScriptError('PUBKEY_ENCODING');
return true;
}
/**
* Test whether the data element is a valid signature based
* on the encoding, S value, and sighash type. Requires
* VERIFY_DERSIG|VERIFY_LOW_S|VERIFY_STRICTENC, VERIFY_LOW_S
* and VERIFY_STRING_ENC to be enabled respectively. Note that
* this will allow zero-length signatures.
* @param {Buffer} sig
* @param {VerifyFlags?} flags
* @returns {Boolean}
* @throws {ScriptError}
*/
function validateSignature(sig, flags) {
assert(Buffer.isBuffer(sig));
assert(typeof flags === 'number');
// Allow empty sigs
if (sig.length === 0)
return true;
if (!common.isSignatureEncoding(sig))
throw new ScriptError('SIG_ENCODING');
return true;
}
/**
* Verify a signature, taking into account sighash type.
* @param {Buffer} msg - Signature hash.
* @param {Buffer} sig
* @param {Buffer} key
* @returns {Boolean}
*/
function checksig(msg, sig, key) {
return secp256k1.verify(msg, sig.slice(0, -1), key);
}
/*
* Expose
*/
module.exports = Script;