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27b18c0fd2
fcoin/lib/bcoin/script.js
Christopher Jeffrey 27b18c0fd2
work. mutable scripts.
2016-06-14 16:26:26 -07:00

4385 lines
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/*!
* script.js - script interpreter for bcoin
* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
* Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
* https://github.com/bcoin-org/bcoin
*/
'use strict';
var bcoin = require('./env');
var bn = require('bn.js');
var constants = bcoin.protocol.constants;
var utils = require('./utils');
var assert = utils.assert;
var BufferWriter = require('./writer');
var BufferReader = require('./reader');
var opcodes = constants.opcodes;
var STACK_TRUE = new Buffer([1]);
var STACK_FALSE = new Buffer([]);
var STACK_NEGATE = new Buffer([0x81]);
var ScriptError = bcoin.errors.ScriptError;
/**
* Refers to the witness field of segregated witness transactions.
* @exports Witness
* @constructor
* @param {Buffer[]|Buffer|NakedWitness} items - Array of
* stack items or raw witness buffer.
* @property {Buffer[]} items
* @property {Script?} redeem
*/
function Witness(items) {
if (!(this instanceof Witness))
return new Witness(items);
if (!items)
items = [];
if (items.items)
items = items.items;
this.items = items;
this.redeem = null;
assert(Array.isArray(this.items));
}
Witness.prototype.toArray = function toArray() {
return this.items.slice();
};
Witness.fromArray = function fromArray(items) {
return new Witness(items);
};
/**
* Inspect a Witness object.
* @returns {String} Human-readable script.
*/
Witness.prototype.inspect = function inspect() {
return '<Witness: ' + this.toString() + '>';
};
/**
* Convert a Witness object to a String.
* @returns {String} Human-readable script.
*/
Witness.prototype.toString = function toString() {
return Witness.format(this.items);
};
/**
* Format the witness object as bitcoind asm.
* @param {Boolean?} decode - Attempt to decode hash types.
* @returns {String} Human-readable script.
*/
Witness.prototype.toASM = function toASM(decode) {
return Script.formatASM(Script.parseArray(this.items), decode);
};
/**
* Clone the witness object. Note that the raw
* encoded witness data will be lost. This is
* because the function assumes you are going
* to be altering the stack items by hand.
* @returns {Witness} A clone of the current witness object.
*/
Witness.prototype.clone = function clone() {
return new Witness(this.items.slice());
};
/**
* Convert the Witness to a Stack object.
* This is usually done before executing
* a witness program.
* @returns {Stack}
*/
Witness.prototype.toStack = function toStack() {
return new Stack(this.items.slice());
};
/**
* "Guess" the type of the witness.
* This method is not 100% reliable.
* @returns {String}
*/
Witness.prototype.getInputType = function getInputType() {
return (this.isPubkeyhashInput() && 'witnesspubkeyhash')
|| (this.isScripthashInput() && 'witnessscripthash')
|| 'unknown';
};
/**
* "Guess" the address of the witness.
* This method is not 100% reliable.
* @returns {String|null}
*/
Witness.prototype.getInputAddress = function getInputAddress() {
return bcoin.address.fromWitness(this);
};
/**
* "Test" whether the witness is a pubkey input.
* Always returns false.
* @returns {Boolean}
*/
Witness.prototype.isPubkeyInput = function isPubkeyInput() {
return false;
};
/**
* "Guess" whether the witness is a pubkeyhash input.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Witness.prototype.isPubkeyhashInput = function isPubkeyhashInput() {
return this.items.length === 2
&& Script.isSignatureEncoding(this.items[0])
&& Script.isKeyEncoding(this.items[1]);
};
/**
* "Test" whether the witness is a multisig input.
* Always returns false.
* @returns {Boolean}
*/
Witness.prototype.isMultisigInput = function isMultisigInput() {
return false;
};
/**
* "Guess" whether the witness is a scripthash input.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Witness.prototype.isScripthashInput = function isScripthashInput() {
return this.items.length > 0 && !this.isPubkeyhashInput();
};
/**
* "Guess" whether the witness is an unknown/non-standard type.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Witness.prototype.isUnknownInput = function isUnknownInput() {
return this.getInputType() === 'unknown';
};
/**
* Test the witness against a bloom filter.
* @param {Bloom} filter
* @returns {Boolean}
*/
Witness.prototype.test = function test(filter) {
var i, chunk;
for (i = 0; i < this.items.length; i++) {
chunk = this.items[i];
if (chunk.length === 0)
continue;
if (filter.test(chunk))
return true;
}
return false;
};
/**
* Grab and deserialize the redeem script from the witness.
* @returns {Script} Redeem script.
*/
Witness.prototype.getRedeem = function getRedeem() {
var redeem;
if (!this.redeem) {
redeem = this.items[this.items.length - 1];
if (!redeem)
return;
this.redeem = new Script(redeem);
}
return this.redeem;
};
/**
* Does nothing currently.
*/
Witness.prototype.compile = function compile() {
// NOP
};
/**
* Find a data element in a witness.
* @param {Buffer} data - Data element to match against.
* @returns {Number} Index (`-1` if not present).
*/
Witness.prototype.indexOf = function indexOf(data) {
return utils.indexOf(this.items, data);
};
/**
* Encode the witness to a Buffer.
* @param {String} enc - Encoding, either `'hex'` or `null`.
* @returns {Buffer|String} Serialized script.
*/
Witness.prototype.toRaw = function toRaw(enc) {
var data = bcoin.protocol.framer.witness(this);
if (enc === 'hex')
data = data.toString('hex');
return data;
};
Witness.prototype.unshift = function unshift(data) {
return this.items.unshift(Witness.encodeItem(data));
};
Witness.prototype.push = function push(data) {
return this.items.push(Witness.encodeItem(data));
};
Witness.prototype.shift = function shift() {
return this.items.shift();
};
Witness.prototype.pop = function push(data) {
return this.items.pop();
};
Witness.prototype.remove = function remove(i) {
return this.items.splice(i, 1)[0];
};
Witness.prototype.insert = function insert(i, data) {
assert(i <= this.items.length, 'Index out of bounds.');
this.items.splice(i, 0, Witness.encodeItem(data))[0];
};
Witness.prototype.get = function get(i) {
return this.items[i];
};
Witness.prototype.getNumber = function getNumber(i) {
var item = this.items[i];
if (!item || item.length > 5)
return;
return Script.num(item, constants.flags.VERIFY_NONE, 5);
};
Witness.prototype.getString = function getString(i) {
var item = this.items[i];
if (!item)
return;
return item.toString('utf8');
};
Witness.prototype.set = function set(i, data) {
assert(i <= this.items.length, 'Index out of bounds.');
this.items[i] = Witness.encodeItem(data);
};
Witness.prototype.__defineGetter__('length', function() {
return this.code.length;
});
Witness.prototype.__defineSetter__('length', function(len) {
return this.code.length = len;
});
Witness.encodeItem = function encodeItem(data) {
if (typeof data === 'number') {
if (data === opcodes.OP_1NEGATE)
data = -1;
else if (data === opcodes.OP_0)
data = 0;
else if (data >= opcodes.OP_1 && data <= opcodes.OP_16)
data -= 0x50;
else
throw new Error('Non-push opcode in witness.');
return Script.array(data);
}
if (bn.isBN(data))
return Script.array(data);
if (typeof data === 'string')
return new Buffer(data, 'utf8');
return data;
};
/**
* Create a witness from a serialized buffer.
* @param {Buffer|String} data - Serialized witness.
* @param {String?} enc - Either `"hex"` or `null`.
* @returns {Object} Naked witness object.
*/
Witness.parseRaw = function parseRaw(data, enc) {
if (enc === 'hex')
data = new Buffer(data, 'hex');
return bcoin.protocol.parser.parseWitness(data);
};
/**
* Create a Witness from a serialized buffer.
* @param {Buffer|String} data - Serialized witness.
* @param {String?} enc - Either `"hex"` or `null`.
* @returns {Witness}
*/
Witness.fromRaw = function fromRaw(data, enc) {
return new Witness(Witness.parseRaw(data, enc));
};
/**
* Parse a test script/array
* string into a witness object. _Must_
* contain only stack items (no non-push
* opcodes).
* @param {String|String[]} items - Script string.
* @returns {Witness}
* @throws Parse error.
*/
Witness.fromString = function fromString(items) {
var i, result;
if (!Array.isArray(items)) {
if (typeof items !== 'string')
return new Witness();
items = items.trim().split(/\s+/);
}
if (items.length === 0)
return new Witness();
result = new Array(items.length);
for (i = 0; i < items.length; i++)
result[i] = new Buffer(items[i], 'hex');
return new Witness(result);
};
/**
* Format script code into a human readable-string.
* @param {Array} code
* @returns {String} Human-readable string.
*/
Witness.format = function format(items) {
return items.map(function(chunk) {
return chunk.toString('hex');
}).join(' ');
};
/**
* Test an object to see if it is a Witness.
* @param {Object} obj
* @returns {Boolean}
*/
Witness.isWitness = function isWitness(obj) {
return obj
&& Array.isArray(obj.items)
&& typeof obj.toStack === 'function';
};
/**
* Represents the stack of a Script during execution.
* @exports Stack
* @constructor
* @param {Buffer[]?} items - Stack items.
* @property {Buffer[]} items - Stack items.
* @property {Number} length - Size of stack.
*/
function Stack(items) {
if (!(this instanceof Stack))
return new Stack(items);
this.items = items || [];
}
/**
* Inspect the stack.
* @returns {String} Human-readable stack.
*/
Stack.prototype.inspect = function inspect() {
return '<Stack: ' + this.toString() + '>';
};
/**
* Convert the stack to a string.
* @returns {String} Human-readable stack.
*/
Stack.prototype.toString = function toString() {
return Witness.format(this.items);
};
/**
* Format the stack as bitcoind asm.
* @param {Boolean?} decode - Attempt to decode hash types.
* @returns {String} Human-readable script.
*/
Stack.prototype.toASM = function toASM(decode) {
return Script.formatASM(this.items, decode);
};
Stack.prototype.__defineGetter__('length', function() {
return this.items.length;
});
Stack.prototype.__defineSetter__('length', function(value) {
return this.items.length = value;
});
/**
* Pop the redeem script off the stack and deserialize it.
* @returns {Script|null} The redeem script.
*/
Stack.prototype.getRedeem = function getRedeem() {
var redeem = this.items[this.items.length - 1];
if (!redeem)
return;
return new Script(redeem);
};
/**
* Clone the stack.
* @returns {Stack} Cloned stack.
*/
Stack.prototype.clone = function clone() {
return new Stack(this.items.slice());
};
/**
* Get total size of the stack, including the alt stack.
* @param {Array} alt - Alt stack.
* @returns {Number}
*/
Stack.prototype.getSize = function getSize(alt) {
return this.items.length + alt.length;
};
/**
* Push item onto stack.
* @see Array#push
* @param {Buffer} item
* @returns {Number} Stack size.
*/
Stack.prototype.push = function push(item) {
return this.items.push(item);
};
/**
* Unshift item from stack.
* @see Array#unshift
* @param {Buffer} item
* @returns {Number}
*/
Stack.prototype.unshift = function unshift(item) {
return this.items.unshift(item);
};
/**
* Slice out part of the stack items.
* @param {Number} start
* @param {Number} end
* @see Array#slice
* @returns {Buffer[]}
*/
Stack.prototype.slice = function slice(start, end) {
return this.items.slice(start, end);
};
/**
* Splice stack items.
* @see Array#splice
* @param {Number} index
* @param {Number} remove
* @param {Buffer?} insert
* @returns {Buffer[]}
*/
Stack.prototype.splice = function splice(i, remove, insert) {
if (insert === undefined)
return this.items.splice(i, remove);
return this.items.splice(i, remove, insert);
};
/**
* Pop a stack item.
* @see Array#pop
* @returns {Buffer|null}
*/
Stack.prototype.pop = function pop() {
return this.items.pop();
};
/**
* Shift a stack item.
* @see Array#shift
* @returns {Buffer|null}
*/
Stack.prototype.shift = function shift() {
return this.items.shift();
};
/**
* Get a stack item by index.
* @param {Number} index
* @returns {Buffer|null}
*/
Stack.prototype.get = function get(i) {
return this.items[i];
};
/**
* Get a stack item relative to
* the top of the stack.
* @example
* stack.top(-1);
* @param {Number} index
* @returns {Buffer|null}
*/
Stack.prototype.top = function top(i) {
return this.items[this.items.length + i];
};
/**
* Set stack item at index.
* @param {Number} index
* @param {Buffer} value
* @returns {Buffer}
*/
Stack.prototype.set = function set(i, value) {
return this.items[i] = value;
};
Stack.prototype._swap = function _swap(i1, i2) {
var v1, v2;
i1 = this.items.length + i1;
i2 = this.items.length + i2;
v1 = this.items[i1];
v2 = this.items[i2];
this.items[i1] = v2;
this.items[i2] = v1;
};
/**
* Perform the OP_TOALTSTACK operation.
* @param {Array} alt - Alt stack.
* @throws {ScriptError}
*/
Stack.prototype.toalt = function toalt(alt) {
if (this.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_TOALTSTACK);
alt.push(this.pop());
};
/**
* Perform the OP_FROMALTSTACK operation.
* @param {Array} alt - Alt stack.
* @throws {ScriptError}
*/
Stack.prototype.fromalt = function fromalt(alt) {
if (alt.length === 0)
throw new ScriptError('INVALID_ALTSTACK_OPERATION', opcodes.OP_FROMALTSTACK);
this.push(alt.pop());
};
/**
* Perform the OP_IFDUP operation.
* @throws {ScriptError}
*/
Stack.prototype.ifdup = function ifdup() {
if (this.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_IFDUP);
if (Script.bool(this.top(-1)))
this.push(Script.array(this.top(-1)));
};
/**
* Perform the OP_DEPTH operation.
* @throws {ScriptError}
*/
Stack.prototype.depth = function depth() {
this.push(Script.array(this.length));
};
/**
* Perform the OP_DROP operation.
* @throws {ScriptError}
*/
Stack.prototype.drop = function drop() {
if (this.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_DROP);
this.pop();
};
/**
* Perform the OP_DUP operation.
* @throws {ScriptError}
*/
Stack.prototype.dup = function dup() {
if (this.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_DUP);
this.push(this.top(-1));
};
/**
* Perform the OP_NIP operation.
* @throws {ScriptError}
*/
Stack.prototype.nip = function nip() {
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_NIP);
this.splice(this.length - 2, 1);
};
/**
* Perform the OP_OVER operation.
* @throws {ScriptError}
*/
Stack.prototype.over = function over() {
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_OVER);
this.push(this.top(-2));
};
/**
* Perform the OP_PICK operation.
* @param {VerifyFlags} flags
* @throws {ScriptError}
*/
Stack.prototype.pick = function pick(flags) {
return this._pickroll(opcodes.OP_PICK, flags);
};
/**
* Perform the OP_ROLL operation.
* @param {VerifyFlags} flags
* @throws {ScriptError}
*/
Stack.prototype.roll = function roll(flags) {
return this._pickroll(opcodes.OP_ROLL, flags);
};
Stack.prototype._pickroll = function pickroll(op, flags) {
var val, n;
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op);
val = this.pop();
n = Script.num(val, flags).toNumber();
if (n < 0 || n >= this.length)
throw new ScriptError('INVALID_STACK_OPERATION', op);
val = this.top(-n - 1);
if (op === opcodes.OP_ROLL)
this.splice(this.length - n - 1, 1);
this.push(val);
};
/**
* Perform the OP_ROT operation.
* @throws {ScriptError}
*/
Stack.prototype.rot = function rot() {
if (this.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_ROT);
this._swap(-3, -2);
this._swap(-2, -1);
};
/**
* Perform the OP_SWAP operation.
* @throws {ScriptError}
*/
Stack.prototype.swap = function swap() {
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_SWAP);
this._swap(-2, -1);
};
/**
* Perform the OP_TUCK operation.
* @throws {ScriptError}
*/
Stack.prototype.tuck = function tuck() {
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_TUCK);
this.splice(this.length - 2, 0, this.top(-1));
};
/**
* Perform the OP_2DROP operation.
* @throws {ScriptError}
*/
Stack.prototype.drop2 = function drop2() {
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_2DROP);
this.pop();
this.pop();
};
/**
* Perform the OP_2DUP operation.
* @throws {ScriptError}
*/
Stack.prototype.dup2 = function dup2() {
var v1, v2;
if (this.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_2DUP);
v1 = this.top(-2);
v2 = this.top(-1);
this.push(v1);
this.push(v2);
};
/**
* Perform the OP_3DUP operation.
* @throws {ScriptError}
*/
Stack.prototype.dup3 = function dup3() {
var v1, v2, v3;
if (this.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_3DUP);
v1 = this.top(-3);
v2 = this.top(-2);
v3 = this.top(-1);
this.push(v1);
this.push(v2);
this.push(v3);
};
/**
* Perform the OP_2OVER operation.
* @throws {ScriptError}
*/
Stack.prototype.over2 = function over2() {
var v1, v2;
if (this.length < 4)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_2OVER);
v1 = this.top(-4);
v2 = this.top(-3);
this.push(v1);
this.push(v2);
};
/**
* Perform the OP_2ROT operation.
* @throws {ScriptError}
*/
Stack.prototype.rot2 = function rot2() {
var v1, v2;
if (this.length < 6)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_2ROT);
v1 = this.top(-6);
v2 = this.top(-5);
this.splice(this.length - 6, 2);
this.push(v1);
this.push(v2);
};
/**
* Perform the OP_2SWAP operation.
* @throws {ScriptError}
*/
Stack.prototype.swap2 = function swap2() {
if (this.length < 4)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_2SWAP);
this._swap(-4, -2);
this._swap(-3, -1);
};
/**
* Perform the OP_SIZE operation.
* @throws {ScriptError}
*/
Stack.prototype.size = function size() {
if (this.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', opcodes.OP_SIZE);
this.push(Script.array(this.top(-1).length));
};
/**
* Test an object to see if it is a Stack.
* @param {Object} obj
* @returns {Boolean}
*/
Stack.isStack = function isStack(obj) {
return obj && Array.isArray(obj.items) && typeof obj.swap2 === 'function';
};
/**
* Represents a input or output script.
* @exports Script
* @constructor
* @param {Buffer|Array|Object|NakedScript} code - Array
* of script code or a serialized script Buffer.
* @property {Array} code - Script code.
* @property {Buffer?} raw - Serialized script.
* @property {Script?} redeem - Redeem script.
*/
function Script(raw) {
if (raw instanceof Script)
return raw;
if (!(this instanceof Script))
return new Script(raw);
if (!raw)
raw = STACK_FALSE;
if (raw.raw)
raw = raw.raw;
this.raw = null;
this.code = null;
this.redeem = null;
if (Array.isArray(raw)) {
raw = Script.parseArray(raw);
this.raw = Script.encode(raw);
this.code = raw;
} else {
this.raw = raw;
this.code = Script.decode(raw);
}
assert(Buffer.isBuffer(this.raw));
assert(Array.isArray(this.code));
}
/**
* Convert the script to an array of
* Buffers (pushdatas) and Numbers
* (opcodes).
* @returns {Array}
*/
Script.prototype.toArray = function toArray() {
var code = [];
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
code.push(op.data || op.value);
}
return code;
};
/**
* Instantiate script from an array
* of buffers and numbers.
* @returns {Script}
*/
Script.fromArray = function fromArray(code) {
return new Script(code);
};
/**
* Clone the script.
* @returns {Script} Cloned script.
*/
Script.prototype.clone = function clone() {
return new Script(this.raw);
};
/**
* Inspect the script.
* @returns {String} Human-readable script code.
*/
Script.prototype.inspect = function inspect() {
return '<Script: ' + this.toString() + '>';
};
/**
* Convert the script to a bitcoind test string.
* @returns {String} Human-readable script code.
*/
Script.prototype.toString = function toString() {
return Script.format(this.code);
};
/**
* Format the script as bitcoind asm.
* @param {Boolean?} decode - Attempt to decode hash types.
* @returns {String} Human-readable script.
*/
Script.prototype.toASM = function toASM(decode) {
return Script.formatASM(this.code, decode);
};
/**
* Encode the script to a Buffer. Note that this
* will _not_ contain the varint size before it.
* This allows it to be hashed for scripthashes.
* @returns {Buffer} Serialized script.
*/
Script.prototype.encode = function encode() {
return this.raw;
};
/**
* Re-encode the script internally. Useful if you
* changed something manually in the `code` array.
*/
Script.prototype.compile = function compile() {
this.raw = Script.encode(this.code);
};
/**
* Encode the script to a Buffer. See {@link Script#encode}.
* @param {String} enc - Encoding, either `'hex'` or `null`.
* @returns {Buffer|String} Serialized script.
*/
Script.prototype.toRaw = function toRaw(enc) {
var data = this.encode();
if (enc === 'hex')
data = data.toString('hex');
return data;
};
/**
* Get the script's "subscript" starting at a separator.
* @param {Number?} lastSep - The last separator to sign/verify beyond.
* @returns {Script} Subscript.
*/
Script.prototype.getSubscript = function getSubscript(lastSep) {
var code = [];
var i, op;
if (lastSep === 0)
return this.clone();
for (i = lastSep; i < this.code.length; i++) {
op = this.code[i];
if (op.value === -1)
break;
code.push(op);
}
return new Script(code);
};
/**
* 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 {Script} Subscript.
*/
Script.prototype.removeSeparators = function removeSeparators() {
var code = [];
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.value === -1)
break;
if (op.value !== opcodes.OP_CODESEPARATOR)
code.push(op);
}
if (code.length === this.code.length)
return this.clone();
return new Script(code);
};
/**
* 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 {Number?} version - Signature hash version (0=legacy, 1=segwit).
* @throws {ScriptError} Will be thrown on VERIFY failures, among other things.
* @returns {Boolean} Whether the execution was successful.
*/
Script.prototype.execute = function execute(stack, flags, tx, index, version) {
var ip = 0;
var lastSep = 0;
var opCount = 0;
var alt = [];
var state = [];
var negate = 0;
var op, val, v1, v2, v3;
var n, n1, n2, n3;
var res, key, sig, type, subscript, hash;
var i, j, m, ikey, isig;
var locktime;
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (this.getSize() > constants.script.MAX_SIZE)
throw new ScriptError('SCRIPT_SIZE');
for (ip = 0; ip < this.code.length; ip++) {
op = this.code[ip];
if (op.value === -1)
throw new ScriptError('BAD_OPCODE', op, ip);
if (op.data) {
if (op.data.length > constants.script.MAX_PUSH)
throw new ScriptError('PUSH_SIZE', op, ip);
// Note that minimaldata is not checked
// on unexecuted branches of code.
if (negate === 0) {
if (!Script.checkMinimal(op.data, op.value, flags))
throw new ScriptError('MINIMALDATA', op, ip);
stack.push(op.data);
}
continue;
}
op = op.value;
if (op > opcodes.OP_16 && ++opCount > constants.script.MAX_OPS)
throw new ScriptError('OP_COUNT', op, ip);
// It's very important to make a distiction
// here: these opcodes will fail _even if they
// are in unexecuted branches of code_. Whereas
// a totally unknown opcode is fine as long as it
// is unexecuted.
if (op === opcodes.OP_CAT
|| op === opcodes.OP_SUBSTR
|| op === opcodes.OP_LEFT
|| op === opcodes.OP_RIGHT
|| op === opcodes.OP_INVERT
|| op === opcodes.OP_AND
|| op === opcodes.OP_OR
|| op === opcodes.OP_XOR
|| op === opcodes.OP_2MUL
|| op === opcodes.OP_2DIV
|| op === opcodes.OP_MUL
|| op === opcodes.OP_DIV
|| op === opcodes.OP_MOD
|| op === opcodes.OP_LSHIFT
|| op === opcodes.OP_RSHIFT) {
throw new ScriptError('DISABLED_OPCODE', op, ip);
}
if (op >= opcodes.OP_IF && op <= opcodes.OP_ENDIF) {
switch (op) {
case opcodes.OP_IF:
case opcodes.OP_NOTIF: {
if (negate === 0) {
if (stack.length < 1)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
val = Script.bool(stack.pop());
if (op === opcodes.OP_NOTIF)
val = !val;
state.push(val === true ? 1 : 0);
if (!val)
negate++;
} else {
state.push(0);
negate++;
}
break;
}
case opcodes.OP_ELSE: {
if (state.length === 0)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
state[state.length - 1] ^= 1;
if (state[state.length - 1] === 0)
negate++;
else
negate--;
break;
}
case opcodes.OP_ENDIF: {
if (state.length === 0)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
if (state.pop() === 0)
negate--;
break;
}
case opcodes.OP_VERIF:
case opcodes.OP_VERNOTIF: {
throw new ScriptError('BAD_OPCODE', op, ip);
}
default: {
assert.fatal(false, 'Fatal script error.');
}
}
continue;
}
if (negate !== 0)
continue;
switch (op) {
case opcodes.OP_0: {
stack.push(STACK_FALSE);
break;
}
case opcodes.OP_1NEGATE: {
stack.push(STACK_NEGATE);
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.push(new Buffer([op - 0x50]));
break;
}
case opcodes.OP_NOP: {
break;
}
case opcodes.OP_CHECKLOCKTIMEVERIFY: {
// OP_CHECKLOCKTIMEVERIFY = OP_NOP2
if (!(flags & constants.flags.VERIFY_CHECKLOCKTIMEVERIFY)) {
if (flags & constants.flags.VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
throw new ScriptError('DISCOURAGE_UPGRADABLE_NOPS', op, ip);
break;
}
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
locktime = Script.num(stack.top(-1), flags, 5);
if (locktime.cmpn(0) < 0)
throw new ScriptError('NEGATIVE_LOCKTIME', op, ip);
locktime = locktime.uand(utils.U32).toNumber();
if (!Script.checkLocktime(locktime, tx, index))
throw new ScriptError('UNSATISFIED_LOCKTIME', op, ip);
break;
}
case opcodes.OP_CHECKSEQUENCEVERIFY: {
// OP_CHECKSEQUENCEVERIFY = OP_NOP3
if (!(flags & constants.flags.VERIFY_CHECKSEQUENCEVERIFY)) {
if (flags & constants.flags.VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
throw new ScriptError('DISCOURAGE_UPGRADABLE_NOPS', op, ip);
break;
}
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
locktime = Script.num(stack.top(-1), flags, 5);
if (locktime.cmpn(0) < 0)
throw new ScriptError('NEGATIVE_LOCKTIME', op, ip);
locktime = locktime.uand(utils.U32).toNumber();
if ((locktime & constants.sequence.DISABLE_FLAG) !== 0)
break;
if (!Script.checkSequence(locktime, tx, index))
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 & constants.flags.VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
throw new ScriptError('DISCOURAGE_UPGRADABLE_NOPS', op, ip);
break;
}
case opcodes.OP_VERIFY: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
if (!Script.bool(stack.pop()))
throw new ScriptError('VERIFY', op, ip);
break;
}
case opcodes.OP_RETURN: {
throw new ScriptError('OP_RETURN', op, ip);
}
case opcodes.OP_TOALTSTACK: {
stack.toalt(alt);
break;
}
case opcodes.OP_FROMALTSTACK: {
stack.fromalt(alt);
break;
}
case opcodes.OP_2DROP: {
stack.drop2();
break;
}
case opcodes.OP_2DUP: {
stack.dup2();
break;
}
case opcodes.OP_3DUP: {
stack.dup3();
break;
}
case opcodes.OP_2OVER: {
stack.over2();
break;
}
case opcodes.OP_2ROT: {
stack.rot2();
break;
}
case opcodes.OP_2SWAP: {
stack.swap2();
break;
}
case opcodes.OP_IFDUP: {
stack.ifdup();
break;
}
case opcodes.OP_DEPTH: {
stack.depth();
break;
}
case opcodes.OP_DROP: {
stack.drop();
break;
}
case opcodes.OP_DUP: {
stack.dup();
break;
}
case opcodes.OP_NIP: {
stack.nip();
break;
}
case opcodes.OP_OVER: {
stack.over();
break;
}
case opcodes.OP_PICK: {
stack.pick(flags);
break;
}
case opcodes.OP_ROLL: {
stack.roll(flags);
break;
}
case opcodes.OP_ROT: {
stack.rot();
break;
}
case opcodes.OP_SWAP: {
stack.swap();
break;
}
case opcodes.OP_TUCK: {
stack.tuck();
break;
}
case opcodes.OP_SIZE: {
stack.size();
break;
}
case opcodes.OP_EQUAL:
case opcodes.OP_EQUALVERIFY: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
res = utils.equal(stack.pop(), stack.pop());
if (op === opcodes.OP_EQUALVERIFY) {
if (!res)
throw new ScriptError('EQUALVERIFY', op, ip);
} else {
stack.push(res ? STACK_TRUE : STACK_FALSE);
}
break;
}
case opcodes.OP_1ADD:
case opcodes.OP_1SUB:
case opcodes.OP_2MUL:
case opcodes.OP_2DIV:
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);
n = Script.num(stack.pop(), flags);
switch (op) {
case opcodes.OP_1ADD:
n.iaddn(1);
break;
case opcodes.OP_1SUB:
n.isubn(1);
break;
case opcodes.OP_2MUL:
n.iushln(1);
break;
case opcodes.OP_2DIV:
n.iushrn(1);
break;
case opcodes.OP_NEGATE:
n.ineg();
break;
case opcodes.OP_ABS:
if (n.cmpn(0) < 0)
n.ineg();
break;
case opcodes.OP_NOT:
n = n.cmpn(0) === 0;
break;
case opcodes.OP_0NOTEQUAL:
n = n.cmpn(0) !== 0;
break;
default:
assert.fatal(false, 'Fatal script error.');
}
if (typeof n === 'boolean')
n = new bn(n ? 1 : 0);
stack.push(Script.array(n));
break;
}
case opcodes.OP_ADD:
case opcodes.OP_SUB:
case opcodes.OP_MUL:
case opcodes.OP_DIV:
case opcodes.OP_MOD:
case opcodes.OP_LSHIFT:
case opcodes.OP_RSHIFT:
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: {
switch (op) {
case opcodes.OP_ADD:
case opcodes.OP_SUB:
case opcodes.OP_MUL:
case opcodes.OP_DIV:
case opcodes.OP_MOD:
case opcodes.OP_LSHIFT:
case opcodes.OP_RSHIFT:
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);
n2 = Script.num(stack.pop(), flags);
n1 = Script.num(stack.pop(), flags);
n = new bn(0);
switch (op) {
case opcodes.OP_ADD:
n = n1.add(n2);
break;
case opcodes.OP_SUB:
n = n1.sub(n2);
break;
case opcodes.OP_MUL:
n = n1.mul(n2);
break;
case opcodes.OP_DIV:
n = n1.div(n2);
break;
case opcodes.OP_MOD:
n = n1.mod(n2);
break;
case opcodes.OP_LSHIFT:
if (n2.cmpn(0) < 0 || n2.cmpn(2048) > 0)
throw new ScriptError('UNKNOWN_ERROR', 'Bad shift.');
n = n1.ushln(n2.toNumber());
break;
case opcodes.OP_RSHIFT:
if (n2.cmpn(0) < 0 || n2.cmpn(2048) > 0)
throw new ScriptError('UNKNOWN_ERROR', 'Bad shift.');
n = n1.ushrn(n2.toNumber());
break;
case opcodes.OP_BOOLAND:
n = n1.cmpn(0) !== 0 && n2.cmpn(0) !== 0;
break;
case opcodes.OP_BOOLOR:
n = n1.cmpn(0) !== 0 || n2.cmpn(0) !== 0;
break;
case opcodes.OP_NUMEQUAL:
n = n1.cmp(n2) === 0;
break;
case opcodes.OP_NUMEQUALVERIFY:
n = n1.cmp(n2) === 0;
break;
case opcodes.OP_NUMNOTEQUAL:
n = n1.cmp(n2) !== 0;
break;
case opcodes.OP_LESSTHAN:
n = n1.cmp(n2) < 0;
break;
case opcodes.OP_GREATERTHAN:
n = n1.cmp(n2) > 0;
break;
case opcodes.OP_LESSTHANOREQUAL:
n = n1.cmp(n2) <= 0;
break;
case opcodes.OP_GREATERTHANOREQUAL:
n = n1.cmp(n2) >= 0;
break;
case opcodes.OP_MIN:
n = n1.cmp(n2) < 0 ? n1 : n2;
break;
case opcodes.OP_MAX:
n = n1.cmp(n2) > 0 ? n1 : n2;
break;
default:
assert.fatal(false, 'Fatal script error.');
}
if (typeof n === 'boolean')
n = new bn(n ? 1 : 0);
if (op === opcodes.OP_NUMEQUALVERIFY) {
if (!Script.bool(n))
throw new ScriptError('NUMEQUALVERIFY', op, ip);
} else {
stack.push(Script.array(n));
}
break;
}
break;
}
case opcodes.OP_WITHIN: {
if (stack.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
n3 = Script.num(stack.pop(), flags);
n2 = Script.num(stack.pop(), flags);
n1 = Script.num(stack.pop(), flags);
val = n2.cmp(n1) <= 0 && n1.cmp(n3) < 0;
stack.push(val ? STACK_TRUE : STACK_FALSE);
break;
}
case opcodes.OP_RIPEMD160: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(utils.ripemd160(stack.pop()));
break;
}
case opcodes.OP_SHA1: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(utils.sha1(stack.pop()));
break;
}
case opcodes.OP_SHA256: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(utils.sha256(stack.pop()));
break;
}
case opcodes.OP_HASH256: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(utils.dsha256(stack.pop()));
break;
}
case opcodes.OP_HASH160: {
if (stack.length === 0)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
stack.push(utils.ripesha(stack.pop()));
break;
}
case opcodes.OP_CODESEPARATOR: {
lastSep = ip;
break;
}
case opcodes.OP_CHECKSIGVERIFY:
case opcodes.OP_CHECKSIG: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
key = stack.pop();
sig = stack.pop();
subscript = this.getSubscript(lastSep);
if (version === 0)
subscript.removeData(sig);
Script.validateSignature(sig, flags);
Script.validateKey(key, flags);
type = sig[sig.length - 1];
hash = tx.signatureHash(index, subscript, type, version);
res = Script.checksig(hash, sig, key, flags);
if (op === opcodes.OP_CHECKSIGVERIFY) {
if (!res)
throw new ScriptError('CHECKSIGVERIFY', op, ip);
} else {
stack.push(res ? STACK_TRUE : STACK_FALSE);
}
break;
}
case opcodes.OP_CHECKMULTISIGVERIFY:
case opcodes.OP_CHECKMULTISIG: {
if (!tx)
throw new ScriptError('UNKNOWN_ERROR', 'No TX passed in.');
i = 1;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
n = Script.num(stack.top(-i), flags).toNumber();
if (!(n >= 0 && n <= constants.script.MAX_MULTISIG_PUBKEYS))
throw new ScriptError('PUBKEY_COUNT', op, ip);
opCount += n;
if (opCount > constants.script.MAX_OPS)
throw new ScriptError('OP_COUNT', op, ip);
i++;
ikey = i;
i += n;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
m = Script.num(stack.top(-i), flags).toNumber();
if (!(m >= 0 && m <= n))
throw new ScriptError('SIG_COUNT', op, ip);
i++;
isig = i;
i += m;
if (stack.length < i)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
subscript = this.getSubscript(lastSep);
for (j = 0; j < m; j++) {
sig = stack.top(-isig - j);
if (version === 0)
subscript.removeData(sig);
}
res = true;
while (res && m > 0) {
sig = stack.top(-isig);
key = stack.top(-ikey);
Script.validateSignature(sig, flags);
Script.validateKey(key, flags);
type = sig[sig.length - 1];
hash = tx.signatureHash(index, subscript, type, version);
if (Script.checksig(hash, sig, key, flags)) {
isig++;
m--;
}
ikey++;
n--;
if (m > n)
res = false;
}
while (i-- > 1)
stack.pop();
if (stack.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
if (flags & constants.flags.VERIFY_NULLDUMMY) {
if (!Script.isDummy(stack.top(-1)))
throw new ScriptError('SIG_NULLDUMMY', op, ip);
}
stack.pop();
if (op === opcodes.OP_CHECKMULTISIGVERIFY) {
if (!res)
throw new ScriptError('CHECKMULTISIGVERIFY', op, ip);
} else {
stack.push(res ? STACK_TRUE : STACK_FALSE);
}
break;
}
case opcodes.OP_CAT: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
v2 = stack.pop();
v1 = stack.pop();
stack.push(Buffer.concat([v1, v2]));
if (stack.top(-1).length > constants.script.MAX_PUSH)
throw new ScriptError('PUSH_SIZE', op, ip);
break;
}
case opcodes.OP_SUBSTR: {
if (stack.length < 3)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
v3 = Script.num(stack.pop(), flags).toNumber(); // end
v2 = Script.num(stack.pop(), flags).toNumber(); // begin
v1 = stack.pop(); // string
if (v2 < 0 || v3 < v2)
throw new ScriptError('UNKNOWN_ERROR', 'String out of range.');
if (v2 > v1.length)
v2 = v1.length;
if (v3 > v1.length)
v3 = v1.length;
stack.push(v1.slice(v2, v3));
break;
}
case opcodes.OP_LEFT:
case opcodes.OP_RIGHT: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
v2 = Script.num(stack.pop(), flags).toNumber(); // size
v1 = stack.pop(); // string
if (v2 < 0)
throw new ScriptError('UNKNOWN_ERROR', 'String size out of range.');
if (v2 > v1.length)
v2 = v1.length;
if (op === opcodes.OP_LEFT)
v1 = v1.slice(0, v2);
else
v1 = v1.slice(v1.length - v2);
stack.push(v1);
break;
}
case opcodes.OP_INVERT: {
if (stack.length < 1)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
val = utils.copy(stack.pop());
for (i = 0; i < val.length; i++)
val[i] = ~val[i] & 0xff;
stack.push(val);
break;
}
case opcodes.OP_AND:
case opcodes.OP_OR:
case opcodes.OP_XOR: {
if (stack.length < 2)
throw new ScriptError('INVALID_STACK_OPERATION', op, ip);
v2 = stack.pop();
v1 = utils.copy(stack.pop());
if (v1.length < v2.length) {
v3 = new Buffer(v2.length - v1.length);
v3.fill(0);
v1 = Buffer.concat([v1, v3]);
}
if (v2.length < v1.length) {
v3 = new Buffer(v1.length - v2.length);
v3.fill(0);
v2 = Buffer.concat([v2, v3]);
}
if (op === opcodes.OP_AND) {
for (i = 0; i < v1.length; i++)
v1[i] &= v2[i];
} else if (op === opcodes.OP_OR) {
for (i = 0; i < v1.length; i++)
v1[i] |= v2[i];
} else if (op === opcodes.OP_XOR) {
for (i = 0; i < v1.length; i++)
v1[i] ^= v2[i];
}
stack.push(v1);
break;
}
default: {
throw new ScriptError('BAD_OPCODE', op, ip);
}
}
}
if (stack.getSize(alt) > constants.script.MAX_STACK)
throw new ScriptError('STACK_SIZE', op, ip);
if (state.length !== 0)
throw new ScriptError('UNBALANCED_CONDITIONAL', op, ip);
return true;
};
/**
* Verify the nLockTime of a transaction.
* @param {Number} locktime - Locktime to verify against (max=u32).
* @param {TX} tx - Transaction to verify.
* @param {Number} index - Index of input being verified (for IsFinal).
* @returns {Boolean}
*/
Script.checkLocktime = function checkLocktime(locktime, tx, i) {
var threshold = constants.LOCKTIME_THRESHOLD;
if (!(
(tx.locktime < threshold && locktime < threshold)
|| (tx.locktime >= threshold && locktime >= threshold)
)) {
return false;
}
if (locktime > tx.locktime)
return false;
if (tx.inputs[i].sequence === 0xffffffff)
return false;
return true;
};
/**
* Verify the nSequence locktime of a transaction.
* @param {Number} sequence - Locktime to verify against (max=u32).
* @param {TX} tx - Transaction to verify.
* @param {Number} index - Index of input being verified.
* @returns {Boolean}
*/
Script.checkSequence = function checkSequence(sequence, tx, i) {
var txSequence = tx.inputs[i].sequence;
var locktimeMask, txSequenceMasked, sequenceMasked;
if (tx.version < 2)
return false;
if (txSequence & constants.sequence.DISABLE_FLAG)
return false;
locktimeMask = constants.sequence.TYPE_FLAG
| constants.sequence.MASK;
txSequenceMasked = txSequence & locktimeMask;
sequenceMasked = sequence & locktimeMask;
if (!(
(txSequenceMasked < constants.sequence.TYPE_FLAG
&& sequenceMasked < constants.sequence.TYPE_FLAG)
|| (txSequenceMasked >= constants.sequence.TYPE_FLAG
&& sequenceMasked >= constants.sequence.TYPE_FLAG)
)) {
return false;
}
if (sequenceMasked > txSequenceMasked)
return false;
return true;
};
/**
* Cast a big number or Buffer to a bool.
* @see CastToBool
* @param {BN|Buffer} value
* @returns {Boolean}
*/
Script.bool = function bool(value) {
var i;
if (bn.isBN(value))
return value.cmpn(0) !== 0;
assert(Buffer.isBuffer(value));
for (i = 0; i < value.length; i++) {
if (value[i] !== 0) {
// Cannot be negative zero
if (i === value.length - 1 && value[i] === 0x80)
return false;
return true;
}
}
return false;
};
/**
* Create a CScriptNum.
* @param {Buffer} value
* @param {Number?} flags - Script standard flags.
* @param {Number?} size - Max size in bytes.
* @returns {BN}
* @throws {ScriptError}
*/
Script.num = function num(value, flags, size) {
var result;
assert(Buffer.isBuffer(value));
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (size == null)
size = 4;
if (value.length > size)
throw new ScriptError('UNKNOWN_ERROR', 'Script number overflow.');
if ((flags & constants.flags.VERIFY_MINIMALDATA) && value.length > 0) {
// If the low bits on the last byte are unset,
// fail if the value's second to last byte does
// not have the high bit set. A number can't
// justify having the last byte's low bits unset
// unless they ran out of space for the sign bit
// in the second to last bit. We also fail on [0]
// to avoid negative zero (also avoids positive
// zero).
if (!(value[value.length - 1] & 0x7f)) {
if (value.length === 1 || !(value[value.length - 2] & 0x80)) {
throw new ScriptError(
'UNKNOWN_ERROR',
'Non-minimally encoded Script number.');
}
}
}
if (value.length === 0)
return new bn(0);
result = new bn(value, 'le');
// If the input vector's most significant byte is
// 0x80, remove it from the result's msb and return
// a negative.
// Equivalent to:
// -(result & ~(0x80 << (8 * (value.length - 1))))
if (value[value.length - 1] & 0x80)
result.setn((value.length * 8) - 1, 0).ineg();
return result;
};
/**
* Create a script array. Will convert Numbers and big
* numbers to a little-endian buffer while taking into
* account negative zero, minimaldata, etc.
* @example
* assert.deepEqual(Script.array(0), new Buffer([]));
* assert.deepEqual(Script.array(0xffee), new Buffer([0xee, 0xff, 0x00]));
* assert.deepEqual(Script.array(new bn(0xffee)), new Buffer([0xee, 0xff, 0x00]));
* assert.deepEqual(Script.array(new bn(0x1e).ineg()), new Buffer([0x9e]));
* @param {Buffer|Number|BN} value
* @returns {Buffer}
*/
Script.array = function(value) {
var neg, result;
if (Buffer.isBuffer(value))
return value;
if (utils.isNumber(value))
value = new bn(value);
assert(bn.isBN(value));
if (value.cmpn(0) === 0)
return STACK_FALSE;
// If the most significant byte is >= 0x80
// and the value is positive, push a new
// zero-byte to make the significant
// byte < 0x80 again.
// If the most significant byte is >= 0x80
// and the value is negative, push a new
// 0x80 byte that will be popped off when
// converting to an integral.
// If the most significant byte is < 0x80
// and the value is negative, add 0x80 to
// it, since it will be subtracted and
// interpreted as a negative when
// converting to an integral.
neg = value.cmpn(0) < 0;
result = value.toArray('le');
if (result[result.length - 1] & 0x80)
result.push(neg ? 0x80 : 0);
else if (neg)
result[result.length - 1] |= 0x80;
return new Buffer(result);
};
/**
* Remove all matched data elements from
* a script's code (used to remove signatures
* before verification). Note that this
* compares and removes data on the _byte level_.
* It also reserializes the data to a single
* script with minimaldata encoding beforehand.
* A signature will _not_ be removed if it is
* not minimaldata.
* @see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2014-November/006878.html
* @see https://test.webbtc.com/tx/19aa42fee0fa57c45d3b16488198b27caaacc4ff5794510d0c17f173f05587ff
* @param {Buffer} data - Data element to match against.
* @returns {Number} Total.
*/
Script.prototype.removeData = function removeData(data) {
var index = [];
var i, op;
// We need to go forward first. We can't go
// backwards (this is consensus code and we
// need to be aware of bad pushes).
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.value === -1)
break;
if (!op.data)
continue;
if (!Script.checkMinimal(op.data, op.value))
continue;
if (utils.equal(op.data, data))
index.push(i);
}
if (index.length === 0)
return 0;
// Go backwards and splice out the data.
for (i = index.length - 1; i >= 0; i--)
this.code.splice(index[i], 1);
this.raw = Script.encode(this.code);
return index.length;
};
/**
* Find a data element in a script.
* @param {Buffer} data - Data element to match against.
* @returns {Number} Index (`-1` if not present).
*/
Script.prototype.indexOf = function indexOf(data) {
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.value === -1)
break;
if (!op.data)
continue;
if (utils.equal(op.data, data))
return i;
}
return -1;
};
/**
* Check to see if a pushdata Buffer abides by minimaldata.
* @param {Buffer} value - Pushdata op from script code
* (must be from a deserialized script).
* @param {Number?} flags
* @returns {Boolean}
*/
Script.checkMinimal = function checkMinimal(data, opcode, flags) {
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (!(flags & constants.flags.VERIFY_MINIMALDATA))
return true;
if (!data)
return true;
if (data.length === 0)
return opcode === opcodes.OP_0;
if (data.length === 1 && data[0] >= 1 && data[0] <= 16)
return false;
if (data.length === 1 && data[0] === 0x81)
return false;
if (data.length <= 75)
return opcode === data.length;
if (data.length <= 255)
return opcode === opcodes.OP_PUSHDATA1;
if (data.length <= 65535)
return opcode === opcodes.OP_PUSHDATA2;
return true;
};
/**
* Test a buffer to see if it is valid script code (no non-existent opcodes).
* @param {Buffer} raw
* @returns {Boolean}
*/
Script.isCode = function isCode(raw) {
var i, op, code;
if (!raw)
return false;
if (!Buffer.isBuffer(raw))
return false;
code = Script.decode(raw);
for (i = 0; i < code.length; i++) {
op = code[i];
if (op.data)
continue;
if (op.value === -1)
return false;
if (constants.opcodesByVal[op.value] == null)
return false;
}
return true;
};
/**
* Create a pay-to-pubkey script.
* @param {Buffer} key
* @returns {Script}
*/
Script.createPubkey = function createPubkey(key) {
assert(key.length >= 33);
return new Script([key, opcodes.OP_CHECKSIG]);
};
/**
* Create a pay-to-pubkeyhash script.
* @param {Buffer} hash
* @returns {Script}
*/
Script.createPubkeyhash = function createPubkeyhash(hash) {
assert(hash.length === 20);
return new Script([
opcodes.OP_DUP,
opcodes.OP_HASH160,
hash,
opcodes.OP_EQUALVERIFY,
opcodes.OP_CHECKSIG
]);
};
/**
* Create a pay-to-multisig script.
* @param {Buffer[]} keys
* @param {Number} m
* @param {Number} n
* @returns {Script}
*/
Script.createMultisig = function createMultisig(keys, m, n) {
var code = [];
var i;
assert(keys.length === n, '`n` keys are required for multisig.');
assert(m >= 1 && m <= n);
assert(n >= 1 && n <= 15);
keys = utils.sortKeys(keys);
code.push(m + 0x50);
for (i = 0; i < keys.length; i++)
code.push(keys[i]);
code.push(n + 0x50);
code.push(opcodes.OP_CHECKMULTISIG);
return new Script(code);
};
/**
* Create a pay-to-scripthash script.
* @param {Buffer} hash
* @returns {Script}
*/
Script.createScripthash = function createScripthash(hash) {
assert(hash.length === 20);
return new Script([
opcodes.OP_HASH160,
hash,
opcodes.OP_EQUAL
]);
};
/**
* Create a nulldata/opreturn script.
* @param {Buffer} flags
* @returns {Script}
*/
Script.createNulldata = function createNulldata(flags) {
assert(Buffer.isBuffer(flags));
assert(flags.length <= constants.script.MAX_OP_RETURN, 'Nulldata too large.');
return new Script([
opcodes.OP_RETURN,
flags
]);
};
/**
* Create a witness program.
* @param {Number} version
* @param {Buffer} data
* @returns {Script}
*/
Script.createWitnessProgram = function createWitnessProgram(version, data) {
assert(typeof version === 'number' && version >= 0 && version <= 16);
assert(data.length >= 2 && data.length <= 32);
return new Script([version === 0 ? 0 : version + 0x50, data]);
};
/**
* Create a witness block commitment.
* @param {Buffer} hash
* @params {String|Buffer} flags
* @returns {Script}
*/
Script.createCommitment = function createCommitment(hash, flags) {
var p;
if (!flags)
flags = 'mined by bcoin';
if (typeof flags === 'string')
flags = new Buffer(flags, 'utf8');
p = new BufferWriter();
p.writeU32BE(0xaa21a9ed);
p.writeHash(hash);
return new Script([
opcodes.OP_RETURN,
p.render(),
flags
]);
};
/**
* Grab and deserialize the redeem script.
* @returns {Script|null} Redeem script.
*/
Script.prototype.getRedeem = function getRedeem() {
var redeem;
if (!this.redeem) {
if (!this.isPushOnly())
return;
redeem = this.code[this.code.length - 1];
if (!redeem || !redeem.data)
return;
this.redeem = new Script(redeem.data);
}
return this.redeem;
};
/**
* Get the standard script type.
* @returns {String} Script script (can be
* any of 'witnesspubkeyhash', 'witnessscripthash',
* 'pubkey', 'multisig', 'scripthash', 'nulldata',
* or 'unknown').
*/
Script.prototype.getType = function getType() {
if (this.isWitnessProgram()) {
if (this.isWitnessPubkeyhash())
return 'witnesspubkeyhash';
if (this.isWitnessScripthash())
return 'witnessscripthash';
return 'unknown';
}
return (this.isPubkey() && 'pubkey')
|| (this.isPubkeyhash() && 'pubkeyhash')
|| (this.isMultisig() && 'multisig')
|| (this.isScripthash() && 'scripthash')
|| (this.isNulldata() && 'nulldata')
|| 'unknown';
};
/**
* Test whether a script is of an unknown/non-standard type.
* @returns {Boolean}
*/
Script.prototype.isUnknown = function isUnknown() {
return this.getType() === 'unknown';
};
/**
* Test whether the script is standard by policy standards.
* @returns {Boolean}
*/
Script.prototype.isStandard = function isStandard() {
var type = this.getType();
var m, n;
if (type === 'multisig') {
m = this.getSmall(0);
n = this.getSmall(-2);
if (n < 1 || n > 3)
return false;
if (m < 1 || m > n)
return false;
}
return type !== 'unknown';
};
/**
* Test whether the program is standard (i.e. would it fail verification
* with non-mandatory flags).
* @returns {Boolean}
*/
Script.prototype.isStandardProgram = function isStandardProgram(witness, flags) {
var program = this.getWitnessProgram();
var i;
assert(program);
assert((flags & constants.flags.VERIFY_WITNESS) !== 0);
if (program.version === 0) {
if (program.data.length === 32) {
if (witness.items.length === 0)
return false;
} else if (program.data.length === 20) {
if (witness.items.length !== 2)
return false;
} else {
return false;
}
} else {
if (flags & constants.flags.VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM)
return false;
return true;
}
for (i = 0; i < witness.items.length; i++) {
if (witness.items[i].length > constants.script.MAX_PUSH)
return false;
}
return true;
};
/**
* Calculate size of script excluding the varint size bytes.
* @returns {Number}
*/
Script.prototype.getSize = function getSize() {
return this.raw.length;
};
/**
* "Guess" the address of the input script.
* This method is not 100% reliable.
* @returns {Base58Address|null}
*/
Script.prototype.getInputAddress = function getInputAddress() {
return bcoin.address.fromInputScript(this);
};
/**
* Get the address of the script if present. Note that
* pubkey and multisig scripts will be treated as though
* they are pubkeyhash and scripthashes respectively.
* @returns {Base58Address|null}
*/
Script.prototype.getAddress = function getAddress() {
return bcoin.address.fromScript(this);
};
/**
* Test whether the output script is pay-to-pubkey.
* @param {Boolean} [sloppy=false] - Allow non-minimal scripts.
* @returns {Boolean}
*/
Script.prototype.isPubkey = function isPubkey(sloppy) {
if (sloppy) {
return this.code.length === 2
&& Script.isKey(this.code[0].data)
&& this.code[1].value === opcodes.OP_CHECKSIG;
}
return this.raw[0] >= 33 && this.raw[0] <= 65
&& this.raw[0] + 2 === this.raw.length
&& this.raw[this.raw.length - 1] === opcodes.OP_CHECKSIG;
};
/**
* Test whether the output script is pay-to-pubkeyhash.
* @param {Boolean} [sloppy=false] - Allow non-minimal scripts.
* @returns {Boolean}
*/
Script.prototype.isPubkeyhash = function isPubkeyhash(sloppy) {
if (sloppy) {
return this.code.length === 5
&& this.code[0].value === opcodes.OP_DUP
&& this.code[1].value === opcodes.OP_HASH160
&& Script.isHash(this.code[2].data)
&& this.code[3].value === opcodes.OP_EQUALVERIFY
&& this.code[4].value === opcodes.OP_CHECKSIG;
}
return this.raw.length === 25
&& this.raw[0] === opcodes.OP_DUP
&& this.raw[1] === opcodes.OP_HASH160
&& this.raw[2] === 0x14
&& this.raw[23] === opcodes.OP_EQUALVERIFY
&& this.raw[24] === opcodes.OP_CHECKSIG;
};
/**
* Test whether the output script is pay-to-multisig.
* @returns {Boolean}
*/
Script.prototype.isMultisig = function isMultisig() {
var m, n, i;
if (this.raw.length < 41)
return false;
if (this.raw[this.raw.length - 1] !== opcodes.OP_CHECKMULTISIG)
return false;
n = Script.getSmall(this.raw[this.raw.length - 2]);
if (n < 1)
return false;
m = Script.getSmall(this.raw[0]);
if (!(m >= 1 && m <= n))
return false;
if (n + 3 !== this.code.length)
return false;
for (i = 1; i < n + 1; i++) {
if (!Script.isKey(this.code[i].data))
return false;
}
return true;
};
/**
* Test whether the output script is pay-to-scripthash. Note that
* bitcoin itself requires scripthashes to be in strict minimaldata
* encoding. Using `OP_HASH160 OP_PUSHDATA1 [hash] OP_EQUAL` will
* _not_ be recognized as a scripthash.
* @returns {Boolean}
*/
Script.prototype.isScripthash = function isScripthash() {
return this.raw.length === 23
&& this.raw[0] === opcodes.OP_HASH160
&& this.raw[1] === 0x14
&& this.raw[22] === opcodes.OP_EQUAL;
};
/**
* Test whether the output script is nulldata/opreturn.
* @param {Boolean} [sloppy=false] - Allow non-minimal scripts.
* @returns {Boolean}
*/
Script.prototype.isNulldata = function isNulldata(sloppy) {
var i, op;
if (this.raw.length > constants.script.MAX_OP_RETURN_BYTES)
return false;
if (this.raw.length === 0)
return false;
if (this.raw[0] !== opcodes.OP_RETURN)
return false;
if (sloppy) {
for (i = 1; i < this.code.length; i++) {
op = this.code[i];
if (op.data)
continue;
if (op.value === -1)
return false;
if (op.value > opcodes.OP_16)
return false;
}
return true;
}
if (this.raw[1] >= 0x01 && this.raw[1] <= 0x4b) {
if (this.raw[1] + 2 !== this.raw.length)
return false;
return true;
}
if (this.raw[1] === opcodes.OP_PUSHDATA1) {
if (this.raw[2] + 3 !== this.raw.length)
return false;
return true;
}
return false;
};
/**
* Test whether the output script is a segregated witness
* commitment. Note that commitments are a superset of nulldata
* as they can have multiple pushdata ops. When validating for
* standardness, commitments should not be allowed in anything
* but coinbases.
* @returns {Boolean}
*/
Script.prototype.isCommitment = function isCommitment() {
if (this.raw.length < 38)
return false;
if (this.raw[0] !== opcodes.OP_RETURN)
return false;
if (this.raw[1] !== 0x24)
return false;
if (this.raw.readUInt32BE(2, true) !== 0xaa21a9ed)
return false;
return true;
};
/**
* Get the commitment hash if present.
* @returns {Buffer|null}
*/
Script.prototype.getCommitmentHash = function getCommitmentHash() {
if (!this.isCommitment())
return;
return this.raw.slice(6, 38);
};
/**
* Test whether the output script is a witness program.
* Note that this will return true even for malformed
* witness v0 programs.
* @return {Boolean}
*/
Script.prototype.isWitnessProgram = function isWitnessProgram() {
if (!(this.raw.length >= 4 && this.raw.length <= 42))
return false;
if (this.raw[0] !== opcodes.OP_0
&& !(this.raw[0] >= opcodes.OP_1 && this.raw[0] <= opcodes.OP_16)) {
return false;
}
if (this.raw[1] + 2 !== this.raw.length)
return false;
return true;
};
/**
* Get the witness program if present.
* @returns {Program|null}
*/
Script.prototype.getWitnessProgram = function getWitnessProgram() {
var version, data, type;
if (!this.isWitnessProgram())
return;
version = Script.getSmall(this.raw[0]);
data = this.raw.slice(2);
if (version > 0) {
// No interpretation of script (anyone can spend)
type = 'unknown';
} else if (version === 0 && data.length === 20) {
type = 'witnesspubkeyhash';
} else if (version === 0 && data.length === 32) {
type = 'witnessscripthash';
} else {
// Fail on bad version=0
type = null;
}
return {
version: version,
type: type,
data: data
};
};
/**
* Test whether the output script is a pay-to-witness-pubkeyhash script.
* @returns {Boolean}
*/
Script.prototype.isWitnessPubkeyhash = function isWitnessPubkeyhash() {
return this.raw.length === 22
&& this.raw[0] === opcodes.OP_0
&& this.raw[1] === 0x14;
};
/**
* Test whether the output script is a pay-to-witness-scripthash script.
* @returns {Boolean}
*/
Script.prototype.isWitnessScripthash = function isWitnessScripthash() {
return this.raw.length === 34
&& this.raw[0] === opcodes.OP_0
&& this.raw[1] === 0x20;
};
/**
* Test whether the output script is unspendable.
* @returns {Boolean}
*/
Script.prototype.isUnspendable = function isUnspendable() {
return this.raw.length > 0 && this.raw[0] === opcodes.OP_RETURN;
};
/**
* "Guess" the type of the input script.
* This method is not 100% reliable.
* @returns {String}
*/
Script.prototype.getInputType = function getInputType() {
return (this.isPubkeyInput() && 'pubkey')
|| (this.isPubkeyhashInput() && 'pubkeyhash')
|| (this.isMultisigInput() && 'multisig')
|| (this.isScripthashInput() && 'scripthash')
|| 'unknown';
};
/**
* "Guess" whether the input script is an unknown/non-standard type.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Script.prototype.isUnknownInput = function isUnknownInput() {
return this.getInputType() === 'unknown';
};
/**
* Automatically build an output script from any number of options.
* @example
* Script.createOutputScript({ address: '1HT7xU2Ngenf7D4yocz2SAcnNLW7rK8d4E' });
* @param {Object} options
* @param {(Address|Base58Address)?} options.address - Address to send to.
* @param {Buffer?} options.flags - Nulldata flags.
* @param {Buffer?} options.key - Key for pay-to-pubkey.
* @param {Buffer?} options.keyHash - Key has for pay-to-pubkeyhash.
* @param {Buffer[]?} options.keys - Keys for pay-to-multisig.
* @param {Buffer} options.scriptHash - Whether to create a scripthash
* @returns {Script}
*/
Script.createOutputScript = function createOutputScript(options) {
var m, n, flags, address;
if (!options)
options = {};
if (options.address) {
address = options.address;
if (typeof address === 'string')
address = bcoin.address.fromBase58(address);
return address.toScript();
}
if (options.flags) {
flags = options.flags;
if (typeof flags === 'string')
flags = new Buffer(flags, 'utf8');
return Script.createNulldata(flags);
}
if (options.key)
return Script.createPubkey(options.key);
if (options.keyHash) {
if (options.version != null)
return Script.createWitnessProgram(options.version, options.keyHash);
return Script.createPubkeyhash(options.keyHash);
}
if (options.keys) {
m = options.m;
n = options.n || options.keys.length;
return Script.createMultisig(options.keys, m, n);
}
if (options.scriptHash) {
if (options.version != null)
return Script.createWitnessProgram(options.version, options.scriptHash);
return Script.createScripthash(options.scriptHash);
}
return new Script();
};
/**
* "Guess" whether the input script is pay-to-pubkey.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Script.prototype.isPubkeyInput = function isPubkeyInput() {
if (this.raw.length < 14)
return false;
if (this.raw.length > 78)
return false;
if (this.raw[0] > opcodes.OP_PUSHDATA4)
return false;
return this.code.length === 1 && Script.isSignature(this.code[0].data);
};
/**
* "Guess" whether the input script is pay-to-pubkeyhash.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Script.prototype.isPubkeyhashInput = function isPubkeyhashInput() {
if (this.raw.length < 52)
return false;
if (this.raw.length > 148)
return false;
if (this.raw[0] > opcodes.OP_PUSHDATA4)
return false;
return this.code.length === 2
&& Script.isSignature(this.code[0].data)
&& Script.isKey(this.code[1].data);
};
/**
* "Guess" whether the input script is pay-to-multisig.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Script.prototype.isMultisigInput = function isMultisigInput() {
var i;
if (this.raw.length < 28)
return false;
if (this.raw[0] !== opcodes.OP_0)
return false;
if (this.raw[1] > opcodes.OP_PUSHDATA4)
return false;
// We need to rule out scripthash
// because it may look like multisig.
if (this.isScripthashInput())
return false;
if (this.code.length < 3)
return false;
if (this.code[0].value !== opcodes.OP_0)
return false;
for (i = 1; i < this.code.length; i++) {
if (!Script.isSignature(this.code[i].data))
return false;
}
return true;
};
/**
* "Guess" whether the input script is pay-to-scripthash.
* This method is not 100% reliable.
* @returns {Boolean}
*/
Script.prototype.isScripthashInput = function isScripthashInput() {
var raw;
if (this.raw.length < 2)
return false;
// Grab the raw redeem script.
raw = this.code[this.code.length - 1].data;
// Last data element should be an array
// for the redeem script.
if (!Buffer.isBuffer(raw))
return false;
// Testing for scripthash inputs requires
// some evil magic to work. We do it by
// ruling things _out_. This test will not
// be correct 100% of the time. We rule
// out that the last data element is: a
// null dummy, a valid signature, a valid
// key, and we ensure that it is at least
// a script that does not use undefined
// opcodes.
if (Script.isDummy(raw))
return false;
if (Script.isSignatureEncoding(raw))
return false;
if (Script.isKeyEncoding(raw))
return false;
if (!Script.isCode(raw))
return false;
return true;
};
/**
* Get coinbase height.
* @returns {Number} `-1` if not present.
*/
Script.prototype.getCoinbaseHeight = function getCoinbaseHeight() {
return Script.getCoinbaseHeight(this.raw);
};
/**
* Get coinbase height.
* @param {Buffer} raw - Raw script.
* @returns {Number} `-1` if not present.
*/
Script.getCoinbaseHeight = function getCoinbaseHeight(raw) {
var height;
if (raw.length === 0)
return -1;
height = Script.getSmall(raw[0]);
if (height != null)
return height;
if (raw[0] <= 0x06 && raw.length >= 1 + raw[0])
return -1;
return new bn(raw.slice(1, 1 + raw[0]), 'le').toNumber();
};
/**
* Get info about a coinbase script.
* @returns {Object} Object containing `height`,
* `extraNonce`, `flags`, and `text`.
*/
Script.prototype.getCoinbaseFlags = function getCoinbaseFlags() {
var index = 0;
var height = this.getCoinbaseHeight();
var extraNonce, flags, text;
if (height !== -1)
index++;
if (this.code[1].data && this.code[1].data.length <= 6)
extraNonce = new bn(this.code[1].data, 'le').toNumber();
else
extraNonce = this.getSmall(1);
flags = Script.encode(this.code.slice(index));
text = flags.toString('utf8');
text = text.replace(/[\u0000-\u0019\u007f-\u00ff]/g, '');
return {
height: height,
extraNonce: extraNonce,
flags: flags,
text: text
};
};
/**
* Test the script against a bloom filter.
* @param {Bloom} filter
* @returns {Boolean}
*/
Script.prototype.test = function test(filter) {
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.value === -1)
break;
if (!op.data || op.data.length === 0)
continue;
if (filter.test(op.data))
return true;
}
return false;
};
Script.prototype.unshift = function unshift(data) {
return this.code.unshift(Opcode.from(data));
};
Script.prototype.push = function push(data) {
return this.code.push(Opcode.from(data));
};
Script.prototype.shift = function shift() {
var op = this.code.shift();
if (!op)
return;
return op.data || op.value;
};
Script.prototype.pop = function push(data) {
var op = this.code.pop();
if (!op)
return;
return op.data || op.value;
};
Script.prototype.remove = function remove(i) {
var op = this.code.splice(i, 1)[0];
if (!op)
return;
return op.data || op.value;
};
Script.prototype.insert = function insert(i, data) {
assert(i <= this.code.length, 'Index out of bounds.');
this.code.splice(i, 0, Opcode.from(data))[0];
};
Script.prototype.get = function get(i) {
var op = this.code[i];
if (!op)
return;
return op.data || op.value;
};
Script.prototype.getNumber = function getNumber(i) {
var op = this.code[i];
if (!op || !op.data || op.data.length > 5)
return;
return Script.num(op.data, constants.flags.VERIFY_NONE, 5);
};
Script.prototype.getString = function getString(i) {
var op = this.code[i];
if (!op || !op.data)
return;
return op.data.toString('utf8');
};
Script.prototype.set = function set(i, data) {
assert(i <= this.code.length, 'Index out of bounds.');
this.code[i] = Opcode.from(data);
};
Script.prototype.__defineGetter__('length', function() {
return this.code.length;
});
Script.prototype.__defineSetter__('length', function(len) {
return this.code.length = len;
});
/**
* Test whether the data element is a ripemd160 hash.
* @param {Buffer?} hash
* @returns {Boolean}
*/
Script.isHash = function isHash(hash) {
return Buffer.isBuffer(hash) && hash.length === 20;
};
/**
* Test whether the data element is a public key. Note that
* this does not verify the format of the key, only the length.
* @param {Buffer?} key
* @returns {Boolean}
*/
Script.isKey = function isKey(key) {
return Buffer.isBuffer(key) && key.length >= 33 && key.length <= 65;
};
/**
* Test whether the data element is a signature. Note that
* this does not verify the format of the signature, only the length.
* @param {Buffer?} sig
* @returns {Boolean}
*/
Script.isSignature = function isSignature(sig) {
return Buffer.isBuffer(sig) && sig.length >= 9 && sig.length <= 73;
};
/**
* Test whether the data element is a null dummy (a zero-length array).
* @param {Buffer?} data
* @returns {Boolean}
*/
Script.isDummy = function isDummy(data) {
return Buffer.isBuffer(data) && data.length === 0;
};
/**
* Test whether the data element is a null dummy or an OP_0.
* @private
* @param {Buffer?} data
* @returns {Boolean}
*/
Script.isZero = function isZero(op) {
if (op === opcodes.OP_0)
return true;
return Script.isDummy(op);
};
/**
* Test whether the data element is a valid key if VERIFY_STRICTENC is enabled.
* @param {Buffer} key
* @param {VerifyFlags?} flags
* @returns {Boolean}
* @throws {ScriptError}
*/
Script.validateKey = function validateKey(key, flags) {
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (!Buffer.isBuffer(key))
throw new ScriptError('BAD_OPCODE');
if (flags & constants.flags.VERIFY_STRICTENC) {
if (!Script.isKeyEncoding(key))
throw new ScriptError('PUBKEYTYPE');
}
return true;
};
/**
* Test whether the data element is a valid key.
* @param {Buffer} key
* @returns {Boolean}
*/
Script.isKeyEncoding = function isKeyEncoding(key) {
if (!Buffer.isBuffer(key))
return false;
if (key.length < 33)
return false;
if (key[0] === 0x04) {
if (key.length !== 65)
return false;
} else if (key[0] === 0x02 || key[0] === 0x03) {
if (key.length !== 33)
return false;
} else {
return false;
}
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}
*/
Script.validateSignature = function validateSignature(sig, flags) {
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (!Buffer.isBuffer(sig))
throw new ScriptError('BAD_OPCODE');
// Allow empty sigs
if (sig.length === 0)
return true;
if ((flags & constants.flags.VERIFY_DERSIG)
|| (flags & constants.flags.VERIFY_LOW_S)
|| (flags & constants.flags.VERIFY_STRICTENC)) {
if (!Script.isSignatureEncoding(sig))
throw new ScriptError('SIG_DER');
}
if (flags & constants.flags.VERIFY_LOW_S) {
if (!Script.isLowDER(sig))
throw new ScriptError('SIG_HIGH_S');
}
if (flags & constants.flags.VERIFY_STRICTENC) {
if (!Script.isHashType(sig))
throw new ScriptError('SIG_HASHTYPE');
}
return true;
};
/**
* Test a signature to see if it abides by BIP66.
* @see https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki
* @param {Buffer} sig
* @returns {Boolean}
*/
Script.isSignatureEncoding = function isSignatureEncoding(sig) {
var lenR, lenS;
if (!Buffer.isBuffer(sig))
return false;
// Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S] [sighash]
// * total-length: 1-byte length descriptor of everything that follows,
// excluding the sighash byte.
// * R-length: 1-byte length descriptor of the R value that follows.
// * R: arbitrary-length big-endian encoded R value. It must use the shortest
// possible encoding for a positive integers (which means no null bytes at
// the start, except a single one when the next byte has its highest bit set).
// * S-length: 1-byte length descriptor of the S value that follows.
// * S: arbitrary-length big-endian encoded S value. The same rules apply.
// * sighash: 1-byte value indicating what data is hashed (not part of the DER
// signature)
// Minimum and maximum size constraints.
if (sig.length < 9)
return false;
if (sig.length > 73)
return false;
// A signature is of type 0x30 (compound).
if (sig[0] !== 0x30)
return false;
// Make sure the length covers the entire signature.
if (sig[1] !== sig.length - 3)
return false;
// Extract the length of the R element.
lenR = sig[3];
// Make sure the length of the S element is still inside the signature.
if (5 + lenR >= sig.length)
return false;
// Extract the length of the S element.
lenS = sig[5 + lenR];
// Verify that the length of the signature matches the sum of the length
// of the elements.
if (lenR + lenS + 7 !== sig.length)
return false;
// Check whether the R element is an integer.
if (sig[2] !== 0x02)
return false;
// Zero-length integers are not allowed for R.
if (lenR === 0)
return false;
// Negative numbers are not allowed for R.
if (sig[4] & 0x80)
return false;
// Null bytes at the start of R are not allowed, unless R would
// otherwise be interpreted as a negative number.
if (lenR > 1 && (sig[4] === 0x00) && !(sig[5] & 0x80))
return false;
// Check whether the S element is an integer.
if (sig[lenR + 4] !== 0x02)
return false;
// Zero-length integers are not allowed for S.
if (lenS === 0)
return false;
// Negative numbers are not allowed for S.
if (sig[lenR + 6] & 0x80)
return false;
// Null bytes at the start of S are not allowed, unless S would otherwise be
// interpreted as a negative number.
if (lenS > 1 && (sig[lenR + 6] === 0x00) && !(sig[lenR + 7] & 0x80))
return false;
return true;
};
/**
* Test a signature to see whether it contains a valid sighash type.
* @param {Buffer} sig
* @returns {Boolean}
*/
Script.isHashType = function isHashType(sig) {
var type;
if (!Buffer.isBuffer(sig))
return false;
if (sig.length === 0)
return false;
type = sig[sig.length - 1] & ~constants.hashType.ANYONECANPAY;
if (!constants.hashTypeByVal[type])
return false;
return true;
};
/**
* Test a signature to see whether it contains a low S value.
* @param {Buffer} sig
* @returns {Boolean}
*/
Script.isLowDER = function isLowDER(sig) {
if (!sig.s) {
if (!Buffer.isBuffer(sig))
return false;
if (!Script.isSignatureEncoding(sig))
return false;
sig = sig.slice(0, -1);
}
return bcoin.ec.isLowS(sig);
};
/**
* Format script code into a human readable-string.
* @param {Array} code
* @returns {String} Human-readable string.
*/
Script.format = function format(code) {
var out = [];
var i, op, data, value, size;
for (i = 0; i < code.length; i++) {
op = code[i];
data = op.data;
value = op.value;
if (data) {
size = data.length.toString(16);
while (size.length % 2 !== 0)
size = '0' + size;
if (!constants.opcodesByVal[value]) {
value = value.toString(16);
if (value.length < 2)
value = '0' + value;
value = '0x' + value + ' 0x' + data.toString('hex');
out.push(value);
continue;
}
value = constants.opcodesByVal[value];
value = value + ' 0x' + size + ' 0x' + data.toString('hex');
out.push(value);
continue;
}
assert(typeof value === 'number');
if (constants.opcodesByVal[value]) {
value = constants.opcodesByVal[value];
out.push(value);
continue;
}
value = value.toString(16);
if (value.length < 2)
value = '0' + value;
value = '0x' + value;
out.push(value);
}
return out.join(' ');
};
/**
* Format script code into bitcoind asm format.
* @param {Array} code
* @param {Boolean?} decode - Attempt to decode hash types.
* @returns {String} Human-readable string.
*/
Script.formatASM = function formatASM(code, decode) {
var out = [];
var i, op, type, symbol, data, value;
for (i = 0; i < code.length; i++) {
op = code[i];
data = op.data;
value = op.value;
if (value === -1) {
out.push('[error]');
break;
}
if (data) {
if (data.length <= 4) {
data = Script.num(data, constants.flags.VERIFY_NONE);
out.push(data.toString(10));
continue;
}
if (decode && code[0] !== opcodes.OP_RETURN) {
symbol = '';
if (Script.isSignatureEncoding(data)) {
type = data[data.length - 1];
symbol = constants.hashTypeByVal[type & 0x1f] || '';
if (symbol) {
if (type & constants.hashType.ANYONECANPAY)
symbol += '|ANYONECANPAY';
symbol = '[' + symbol + ']';
}
data = data.slice(0, -1);
}
out.push(data.toString('hex') + symbol);
continue;
}
out.push(data.toString('hex'));
continue;
}
value = constants.opcodesByVal[value] || 'OP_UNKNOWN';
out.push(value);
}
return out.join(' ');
};
/**
* 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}
*/
Script.prototype.isPushOnly = function isPushOnly() {
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.data)
continue;
if (op.value == -1)
return false;
if (op.value > opcodes.OP_16)
return false;
}
return true;
};
/**
* Count the sigops in the script.
* @param {Boolean} accurate - Whether to enable accurate counting. This will
* take into account the `n` value for OP_CHECKMULTISIG(VERIFY).
* @returns {Number} sigop count
*/
Script.prototype.getSigops = function getSigops(accurate) {
var total = 0;
var lastOp = -1;
var i, op;
for (i = 0; i < this.code.length; i++) {
op = this.code[i];
if (op.data)
continue;
if (op.value === -1)
break;
switch (op.value) {
case opcodes.OP_CHECKSIG:
case opcodes.OP_CHECKSIGVERIFY:
total++;
break;
case opcodes.OP_CHECKMULTISIG:
case opcodes.OP_CHECKMULTISIGVERIFY:
if (accurate && lastOp >= opcodes.OP_1 && lastOp <= opcodes.OP_16)
total += lastOp - 0x50;
else
total += constants.script.MAX_MULTISIG_PUBKEYS;
break;
}
lastOp = op.value;
}
return total;
};
/**
* Count the sigops in the script, taking into account redeem scripts.
* @param {Script} input - Input script, needed for access to redeem script.
* @returns {Number} sigop count
*/
Script.prototype.getScripthashSigops = function getScripthashSigops(input) {
var i, op, redeem;
if (!this.isScripthash())
return this.getSigops(true);
for (i = 0; i < input.code.length; i++) {
op = input.code[i];
if (op.data)
continue;
if (op.value === -1)
return 0;
if (op.value > opcodes.OP_16)
return 0;
}
if (!op.data)
return 0;
redeem = new Script(op.data);
return redeem.getSigops(true);
};
/**
* Count the sigops for a program.
* @param {Program} program
* @param {Witness} witness
* @param {VerifyFlags} flags
* @returns {Number} sigop count
*/
Script.witnessSigops = function witnessSigops(program, witness, flags) {
var redeem;
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (program.version === 0) {
if (program.data.length === 20)
return 1;
if (program.data.length === 32 && witness.items.length > 0) {
redeem = witness.getRedeem();
return redeem.getSigops(true);
}
}
return 0;
};
/**
* Count the sigops in a script, taking into account witness programs.
* @param {Script} input
* @param {Script} output
* @param {Witness} witness
* @param {VerifyFlags} flags
* @returns {Number} sigop count
*/
Script.getWitnessSigops = function getWitnessSigops(input, output, witness, flags) {
var redeem;
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if ((flags & constants.flags.VERIFY_WITNESS) === 0)
return 0;
assert((flags & constants.flags.VERIFY_P2SH) !== 0);
if (output.isWitnessProgram())
return Script.witnessSigops(output.getWitnessProgram(), witness, flags);
// This is a unique situation in terms of consensus
// rules. We can just grab the redeem script without
// "parsing" (i.e. checking for pushdata parse errors)
// the script. This is because isPushOnly is called
// which checks for parse errors and will return
// false if one is found. Even the bitcoind code
// does not check the return value of GetOp.
if (output.isScripthash() && input.isPushOnly()) {
redeem = input.getRedeem();
if (redeem && redeem.isWitnessProgram())
return Script.witnessSigops(redeem.getWitnessProgram(), witness, flags);
}
return 0;
};
/**
* Parse a bitcoind test script
* string into a script object.
* @param {String} items - Script string.
* @returns {Script}
* @throws Parse error.
*/
Script.fromString = function fromString(code) {
var i, op, symbol, p;
if (typeof code !== 'string')
return new Script();
code = code.trim();
if (code.length === 0)
return new Script();
code = code.split(/\s+/);
p = new BufferWriter();
for (i = 0; i < code.length; i++) {
op = code[i];
symbol = op.toUpperCase();
if (symbol.indexOf('OP_') !== 0)
symbol = 'OP_' + symbol;
if (opcodes[symbol] == null) {
if (op[0] === '\'') {
assert(op[op.length - 1] === '\'', 'Unknown opcode.');
op = op.slice(1, -1);
op = new Buffer(op, 'ascii');
p.writeBytes(Script.encodePush(op));
continue;
}
if (/^-?\d+$/.test(op)) {
op = new bn(op, 10);
op = Script.array(op);
p.writeBytes(Script.fromArray([op]).raw);
continue;
}
assert(op.indexOf('0x') === 0, 'Unknown opcode.');
op = op.substring(2);
assert(utils.isHex(op), 'Unknown opcode.');
op = new Buffer(op, 'hex');
p.writeBytes(op);
continue;
}
p.writeU8(opcodes[symbol]);
}
return new Script(p.render());
};
/**
* Get a small integer from an opcode (OP_0-OP_16).
* @param {Number} index
* @returns {Number}
*/
Script.prototype.getSmall = function getSmall(i) {
if (i < 0)
i = this.code.length + i;
return Script.getSmall(this.code[i].value);
};
/**
* Get a small integer from an opcode (OP_0-OP_16).
* @param {Number} index
* @returns {Number}
*/
Script.getSmall = function getSmall(op) {
if (typeof op !== 'number')
return null;
if (op === opcodes.OP_0)
return 0;
if (op >= opcodes.OP_1 && op <= opcodes.OP_16)
return op - 0x50;
return -1;
};
/**
* Convert a number to a small integer (OP_0-OP_16).
* @param {Number} num
* @returns {Number} opcode
*/
Script.toSmall = function toSmall(op) {
assert(op >= 0 && op <= 16);
if (op === 0)
return opcodes.OP_0;
return op + 0x50;
};
/**
* Verify an input and output script, and a witness if present.
* @param {Script} input
* @param {Witness} witness
* @param {Script} output
* @param {TX} tx
* @param {Number} i
* @param {VerifyFlags} flags
* @returns {Boolean}
* @throws {ScriptError}
*/
Script.verify = function verify(input, witness, output, tx, i, flags) {
var copy, raw, redeem, hadWitness;
var stack = new Stack();
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (flags & constants.flags.VERIFY_SIGPUSHONLY) {
if (!input.isPushOnly())
throw new ScriptError('SIG_PUSHONLY');
}
// Execute the input script
input.execute(stack, flags, tx, i, 0);
// Copy the stack for P2SH
if (flags & constants.flags.VERIFY_P2SH)
copy = stack.clone();
// Execute the previous output script
output.execute(stack, flags, tx, i, 0);
// Verify the script did not fail as well as the stack values
if (stack.length === 0 || !Script.bool(stack.pop()))
throw new ScriptError('EVAL_FALSE');
if ((flags & constants.flags.VERIFY_WITNESS) && output.isWitnessProgram()) {
hadWitness = true;
// Input script must be empty.
if (input.raw.length !== 0)
throw new ScriptError('WITNESS_MALLEATED');
// Verify the program in the output script
Script.verifyProgram(witness, output, flags, tx, i);
// Force a cleanstack
stack.length = 0;
}
// If the script is P2SH, execute the real output script
if ((flags & constants.flags.VERIFY_P2SH) && output.isScripthash()) {
// P2SH can only have push ops in the scriptSig
if (!input.isPushOnly())
throw new ScriptError('SIG_PUSHONLY');
// Reset the stack
stack = copy;
// Stack should not be empty at this point
if (stack.length === 0)
throw new ScriptError('EVAL_FALSE');
// Grab the real redeem script
raw = stack.pop();
redeem = new Script(raw);
// Execute the redeem script
redeem.execute(stack, flags, tx, i, 0);
// Verify the script did not fail as well as the stack values
if (stack.length === 0 || !Script.bool(stack.pop()))
throw new ScriptError('EVAL_FALSE');
if ((flags & constants.flags.VERIFY_WITNESS) && redeem.isWitnessProgram()) {
hadWitness = true;
// Input script must be exactly one push of the redeem script.
if (!utils.equal(input.raw, Script.encodePush(raw)))
throw new ScriptError('WITNESS_MALLEATED_P2SH');
// Verify the program in the redeem script
Script.verifyProgram(witness, redeem, flags, tx, i);
// Force a cleanstack
stack.length = 0;
}
}
// Ensure there is nothing left on the stack
if (flags & constants.flags.VERIFY_CLEANSTACK) {
assert((flags & constants.flags.VERIFY_P2SH) !== 0);
// assert((flags & constants.flags.VERIFY_WITNESS) !== 0);
if (stack.length !== 0)
throw new ScriptError('CLEANSTACK');
}
// If we had a witness but no witness program, fail.
if (flags & constants.flags.VERIFY_WITNESS) {
assert((flags & constants.flags.VERIFY_P2SH) !== 0);
if (!hadWitness && witness.items.length > 0)
throw new ScriptError('WITNESS_UNEXPECTED');
}
return true;
};
/**
* Verify a witness program. This runs after regular script
* execution if a witness program is present. It will convert
* the witness to a stack and execute the program.
* @param {Witness} witness
* @param {Script} output
* @param {VerifyFlags} flags
* @param {TX} tx
* @param {Number} i
* @throws {ScriptError}
*/
Script.verifyProgram = function verifyProgram(witness, output, flags, tx, i) {
var program = output.getWitnessProgram();
var stack = witness.toStack();
var witnessScript, redeem, j;
assert(program, 'verifyProgram called on non-witness-program.');
assert((flags & constants.flags.VERIFY_WITNESS) !== 0);
if (program.version === 0) {
if (program.data.length === 32) {
if (stack.length === 0)
throw new ScriptError('WITNESS_PROGRAM_WITNESS_EMPTY');
witnessScript = stack.pop();
if (!utils.equal(utils.sha256(witnessScript), program.data))
throw new ScriptError('WITNESS_PROGRAM_MISMATCH');
redeem = new Script(witnessScript);
} else if (program.data.length === 20) {
if (stack.length !== 2)
throw new ScriptError('WITNESS_PROGRAM_MISMATCH');
redeem = Script.createPubkeyhash(program.data);
} else {
// Failure on version=0 (bad program data length)
throw new ScriptError('WITNESS_PROGRAM_WRONG_LENGTH');
}
} else {
// Anyone can spend (we can return true here
// if we want to always relay these transactions).
// Otherwise, if we want to act like an "old"
// implementation and only accept them in blocks,
// we can use the regalar output script which will
// succeed in a block, but fail in the mempool
// due to VERIFY_CLEANSTACK.
if (flags & constants.flags.VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM)
throw new ScriptError('DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM');
return true;
}
for (j = 0; j < stack.length; j++) {
if (stack.get(j).length > constants.script.MAX_PUSH)
throw new ScriptError('PUSH_SIZE');
}
redeem.execute(stack, flags, tx, i, 1);
// Verify the script did not fail as well as the stack values
if (stack.length !== 1 || !Script.bool(stack.pop()))
throw new ScriptError('EVAL_FALSE');
return true;
};
/**
* Verify a signature, taking into account sighash type
* and whether the signature is historical.
* @param {Buffer} msg - Signature hash.
* @param {Buffer} sig
* @param {Buffer} key
* @param {VerifyFlags?} flags - If none of VERIFY_DERSIG,
* VERIFY_LOW_S, or VERIFY_STRICTENC are enabled, the signature
* is treated as historical, allowing odd signature lengths
* and high S values.
* @returns {Boolean}
*/
Script.checksig = function checksig(msg, sig, key, flags) {
var historical = false;
var high = false;
if (flags == null)
flags = constants.flags.STANDARD_VERIFY_FLAGS;
if (!Buffer.isBuffer(sig))
return false;
// Attempt to normalize the signature
// length before passing to elliptic.
// Note: We only do this for historical data!
// https://github.com/indutny/elliptic/issues/78
if (!((flags & constants.flags.VERIFY_DERSIG)
|| (flags & constants.flags.VERIFY_LOW_S)
|| (flags & constants.flags.VERIFY_STRICTENC))) {
historical = true;
}
if (!(flags & constants.flags.VERIFY_LOW_S))
high = true;
return bcoin.ec.verify(msg, sig.slice(0, -1), key, historical, high);
};
/**
* Sign a message, appending the sighash type.
* @param {Buffer} msg - Signature hash.
* @param {Buffer} key - Public key.
* @param {Number} type - Sighash type.
* @returns {Buffer} signature
*/
Script.sign = function sign(msg, key, type) {
var sig = bcoin.ec.sign(msg, key);
var p = new BufferWriter();
// Add the sighash type as a single byte
// to the signature.
p.writeBytes(sig);
p.writeU8(type);
return p.render();
};
/**
* Parse a serialized script, returning the "naked"
* representation of a Script object (the same
* properties, but it is not instantiated -- suitable
* as an options object for Script).
* @param {Buffer|String} data - Serialized script.
* @param {String?} enc - Either `"hex"` or `null`.
* @returns {Object} Naked script object.
*/
Script.parseRaw = function parseRaw(data, enc) {
if (enc === 'hex')
data = new Buffer(data, 'hex');
return {
raw: data
};
};
/**
* Create a script from a serialized buffer.
* @param {Buffer|String} data - Serialized script.
* @param {String?} enc - Either `"hex"` or `null`.
* @returns {Script}
*/
Script.fromRaw = function fromRaw(data, enc) {
return new Script(Script.parseRaw(data, enc));
};
/**
* Decode a serialized script into script code.
* Note that the serialized script must _not_
* include the varint size before it. Parse
* errors will output an opcode with a value
* of -1.
*
* @param {Buffer} raw - Serialized script.
* @returns {Opcode[]} Script code.
*/
Script.decode = function decode(raw) {
var p = new BufferReader(raw, true);
var code = [];
var op, size, data;
assert(Buffer.isBuffer(raw));
while (p.left()) {
op = p.readU8();
if (op >= 0x01 && op <= 0x4b) {
if (p.left() < op) {
code.push(new Opcode(-1));
continue;
}
data = p.readBytes(op);
code.push(new Opcode(op, data));
} else if (op === opcodes.OP_PUSHDATA1) {
if (p.left() < 1) {
code.push(new Opcode(-1));
continue;
}
size = p.readU8();
if (p.left() < size) {
code.push(new Opcode(-1));
continue;
}
data = p.readBytes(size);
code.push(new Opcode(op, data));
} else if (op === opcodes.OP_PUSHDATA2) {
if (p.left() < 2) {
code.push(new Opcode(-1));
continue;
}
size = p.readU16();
if (p.left() < size) {
code.push(new Opcode(-1));
continue;
}
data = p.readBytes(size);
code.push(new Opcode(op, data));
} else if (op === opcodes.OP_PUSHDATA4) {
if (p.left() < 4) {
code.push(new Opcode(-1));
continue;
}
size = p.readU32();
if (p.left() < size) {
code.push(new Opcode(-1));
continue;
}
data = p.readBytes(size);
code.push(new Opcode(op, data));
} else {
code.push(new Opcode(op));
}
}
return code;
};
/**
* Encode and serialize script code. This will _not_
* include the varint size at the start.
* @param {Array} code - Script code.
* @returns {Buffer} Serialized script.
*/
Script.encode = function encode(code, writer) {
var p = new BufferWriter(writer);
var i, op;
for (i = 0; i < code.length; i++) {
op = code[i];
if (op.value === -1)
throw new Error('Cannot reserialize a parse error.');
if (op.data) {
if (op.value <= 0x4b) {
p.writeU8(op.data.length);
p.writeBytes(op.data);
} else if (op.value === opcodes.OP_PUSHDATA1) {
p.writeU8(opcodes.OP_PUSHDATA1);
p.writeU8(op.data.length);
p.writeBytes(op.data);
} else if (op.value === opcodes.OP_PUSHDATA2) {
p.writeU8(opcodes.OP_PUSHDATA2);
p.writeU16(op.data.length);
p.writeBytes(op.data);
} else if (op.value === opcodes.OP_PUSHDATA4) {
p.writeU8(opcodes.OP_PUSHDATA4);
p.writeU32(op.data.length);
p.writeBytes(op.data);
} else {
throw new Error('Unknown pushdata opcode.');
}
continue;
}
p.writeU8(op.value);
}
if (!writer)
p = p.render();
return p;
};
/**
* Convert an array of Buffers and
* Numbers into an array of Opcodes.
* @param {Array} code
* @returns {Opcode[]}
*/
Script.parseArray = function parseArray(code) {
var out = [];
var i, op;
if (code[0] instanceof Opcode)
return code;
for (i = 0; i < code.length; i++) {
op = code[i];
if (Buffer.isBuffer(op)) {
out.push(Opcode.fromData(op));
continue;
}
assert(typeof op === 'number');
out.push(new Opcode(op));
}
return out;
};
/**
* Encode a single push op. Note that this
* will _always_ be a PUSHDATA. Analagous to
* bitcoind's `CScript() << vector`.
* @param {Buffer} data
* @returns {Buffer}
*/
Script.encodePush = function encodePush(data) {
var p = new BufferWriter();
if (data.length <= 0x4b) {
p.writeU8(data.length);
p.writeBytes(data);
} else if (data.length <= 0xff) {
p.writeU8(opcodes.OP_PUSHDATA1);
p.writeU8(data.length);
p.writeBytes(data);
} else if (data.length <= 0xffff) {
p.writeU8(opcodes.OP_PUSHDATA2);
p.writeU16(data.length);
p.writeBytes(data);
} else if (data.length <= 0xffffffff) {
p.writeU8(opcodes.OP_PUSHDATA4);
p.writeU32(data.length);
p.writeBytes(data);
} else {
throw new Error('Pushdata size too large.');
}
return p.render();
};
/**
* Calculate the size (including
* the opcode) of a pushdata.
* @param {Number} num - Pushdata data length.
* @returns {Number} size
*/
Script.sizePush = function sizePush(num) {
if (num <= 0x4b)
return 1;
if (num <= 0xff)
return 2;
if (num <= 0xffff)
return 3;
return 5;
};
/**
* Test whether an object a Script.
* @param {Object} obj
* @returns {Boolean}
*/
Script.isScript = function isScript(obj) {
return obj
&& Buffer.isBuffer(obj.raw)
&& typeof obj.getSubscript === 'function';
};
/**
* A simple struct which contains
* an opcode and pushdata buffer.
* @exports Opcode
* @constructor
* @param {Number} value - Opcode.
* @param {Buffer?} data - Pushdata buffer.
* @property {Number} value
* @property {Buffer|null} data
*/
function Opcode(value, data) {
if (!(this instanceof Opcode))
return new Opcode(value, data);
this.value = value;
this.data = data || null;
}
/**
* Encode the opcode.
* @returns {Buffer}
*/
Opcode.prototype.toRaw = function toRaw() {
return Script.encode([this]);
};
/**
* Instantiate an opcode from a number.
* @param {Number} op
* @returns {Opcode}
*/
Opcode.fromOp = function fromOp(op) {
return new Opcode(op);
};
/**
* Instantiate a pushdata opcode from
* a buffer (will encode minimaldata).
* @param {Buffer} data
* @returns {Opcode}
*/
Opcode.fromData = function fromData(data) {
if (data.length === 0)
return new Opcode(opcodes.OP_0);
if (data.length === 1) {
if (data[0] >= 1 && data[0] <= 16)
return new Opcode(data[0] + 0x50);
if (data[0] === 0x81)
return new Opcode(opcodes.OP_1NEGATE);
}
return Opcode.fromPush(data);
};
/**
* Instantiate a pushdata opcode from a
* buffer (this differs from fromData in
* that it will _always_ be a pushdata op).
* @param {Buffer} data
* @returns {Opcode}
*/
Opcode.fromPush = function fromPush(data) {
if (data.length <= 0x4b)
return new Opcode(data.length, data);
if (data.length <= 0xff)
return new Opcode(opcodes.OP_PUSHDATA1, data);
if (data.length <= 0xffff)
return new Opcode(opcodes.OP_PUSHDATA2, data);
if (data.length <= 0xffffffff)
return new Opcode(opcodes.OP_PUSHDATA4, data);
throw new Error('Pushdata size too large.');
};
/**
* Instantiate an opcode from a Number.
* @param {Number|BN} num
* @returns {Opcode}
*/
Opcode.fromNumber = function fromNumber(num) {
if (bn.isBN(num)) {
if (!(num.cmpn(-1) >= 0 && num.cmpn(16) <= 0))
return Opcode.fromData(Script.array(num));
num = num.toNumber();
}
if (num >= 1 && num <= 16)
return Opcode.fromOp(num + 0x50);
if (num === -1)
return Opcode.fromOp(opcodes.OP_1NEGATE);
return Opcode.fromData(Script.array(num));
};
/**
* Instantiate a pushdata opcode from a string.
* @param {String} data
* @returns {Opcode}
*/
Opcode.fromString = function fromString(data, enc) {
if (typeof data === 'string')
data = new Buffer(data, enc);
return Opcode.fromPush(data);
};
/**
* Instantiate a pushdata opcode from anything.
* @params {String|Buffer|Number|BN|Opcode} data
* @returns {Opcode}
*/
Opcode.from = function from(data) {
if (data instanceof Opcode)
return data;
if (typeof data === 'number')
return Opcode.fromOp(data);
if (bn.isBN(data))
return Opcode.fromNumber(data);
if (typeof data === 'string')
return Opcode.fromString(data, 'utf8');
return Opcode.fromPush(data);
};
/**
* Test whether an object an Opcode.
* @param {Object} obj
* @returns {Boolean}
*/
Opcode.isOpcode = function isOpcode(obj) {
return obj
&& typeof obj.value === 'number'
&& (Buffer.isBuffer(obj.data) || obj.data === null);
};
/*
* Expose
*/
exports = Script;
exports.opcodes = constants.opcodes;
exports.opcodesByVal = constants.opcodesByVal;
exports.Script = Script;
exports.Opcode = Opcode;
exports.Stack = Stack;
exports.Witness = Witness;
module.exports = exports;
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