fcoin/lib/bcoin/script.js
2015-12-17 16:05:48 -08:00

1018 lines
26 KiB
JavaScript

var bcoin = require('../bcoin');
var bn = require('bn.js');
var constants = bcoin.protocol.constants;
var utils = bcoin.utils;
var assert = bcoin.utils.assert;
var script = exports;
script.decode = function decode(s) {
if (!s)
return [];
var opcodes = [];
for (var i = 0; i < s.length;) {
var b = s[i++];
// Next `b` bytes should be pushed to stack
if (b >= 0x01 && b <= 0x4b) {
opcodes.push(s.slice(i, i + b));
i += b;
utils.hidden(opcodes[opcodes.length - 1], 'pushdata', {
opcode: null,
len: b
});
continue;
}
// Zero
if (b === 0) {
opcodes.push([]);
continue;
}
// Raw number (-1 and 1-16)
if (b === 0x4f || (b >= 0x51 && b <= 0x60)) {
opcodes.push(b - 0x50);
continue;
}
var opcode = constants.opcodesByVal[b];
if (opcode === 'pushdata1') {
// NOTE: pushdata1 could be substituted with 0x01-0x4b
// later if less than or equal to 0x4b.
// bad when passed back into encode().
var len = s[i];
i += 1;
opcodes.push(s.slice(i, i + len));
i += len;
utils.hidden(opcodes[opcodes.length - 1], 'pushdata', {
opcode: opcode,
len: len
});
} else if (opcode === 'pushdata2') {
// NOTE: len could theoretically be less than 0xffff
// here. bad when passed back into encode().
var len = utils.readU16(s, i);
i += 2;
opcodes.push(s.slice(i, i + len));
i += len;
utils.hidden(opcodes[opcodes.length - 1], 'pushdata', {
opcode: opcode,
len: len
});
} else if (opcode === 'pushdata4') {
// NOTE: len could theoretically be less than 0xffffffff
// here. bad when passed back into encode().
var len = utils.readU32(s, i);
i += 4;
opcodes.push(s.slice(i, i + len));
i += len;
utils.hidden(opcodes[opcodes.length - 1], 'pushdata', {
opcode: opcode,
len: len
});
} else {
opcodes.push(opcode || b);
}
}
return opcodes;
};
script.encode = function encode(s) {
if (!s)
return [];
var opcodes = constants.opcodes;
var res = [];
for (var i = 0; i < s.length; i++) {
var instr = s[i];
// Push value to stack
if (Array.isArray(instr)) {
// Check for nonstandard pushdatas that
// may have been decoded from before.
if (instr.pushdata) {
if (instr.pushdata.opcode === null) {
res = res.concat(instr.pushdata.len, instr);
} else if (instr.pushdata.opcode === 'pushdata1') {
res = res.concat(opcodes.pushdata1, instr.pushdata.len, instr);
} else if (instr.pushdata.opcode === 'pushdata2') {
res.push(opcodes.pushdata2);
utils.writeU16(res, instr.pushdata.len, res.length);
res = res.concat(instr);
} else if (instr.pushdata.opcode === 'pushdata4') {
res.push(opcodes.pushdata4);
utils.writeU32(res, instr.pushdata.len, res.length);
res = res.concat(instr);
}
continue;
}
if (instr.length === 0) {
// OP_FALSE
res.push(0);
} else if (1 <= instr.length && instr.length <= 0x4b) {
res = res.concat(instr.length, instr);
} else if (instr.length <= 0xff) {
res = res.concat(opcodes.pushdata1, instr.length, instr);
} else if (instr.length <= 0xffff) {
res.push(opcodes.pushdata2);
utils.writeU16(res, instr.length, res.length);
res = res.concat(instr);
} else {
res.push(opcodes.pushdata4);
utils.writeU32(res, instr.length, res.length);
res = res.concat(instr);
}
continue;
}
res.push(opcodes[instr] || instr);
}
return res;
};
script.subscript = function subscript(s, lastSep) {
if (!s)
return [];
if (lastSep == null) {
lastSep = -1;
for (var i = 0; i < s.length; i++) {
if (s[i] === 'codesep')
lastSep = i;
else if (s[i] === 'checksig' ||
s[i] === 'checksigverify' ||
s[i] === 'checkmultisig' ||
s[i] === 'checkmultisigverify') {
break;
}
}
}
var res = [];
for (var i = lastSep + 1; i < s.length; i++)
if (s[i] !== 'codesep')
res.push(s[i]);
return res;
};
script.verify = function verify(hash, sig, pub) {
var k = bcoin.ecdsa.keyFromPublic(pub);
// Points at Infinity make verify() throw.
// This specifically throws on wallet-test.js
// where [1] is concatted to the pubkey.
if (k.getPublic().isInfinity())
return false;
// Use a try catch in case there are
// any uncaught errors for bad inputs in verify().
try {
return bcoin.ecdsa.verify(hash, sig, pub);
} catch (e) {
return false;
}
};
script._next = function(to, s, pc) {
var depth = 0;
while (s[pc]) {
var o = s[pc];
if (o === 'if_' || o === 'notif')
depth++;
else if (o === 'else_')
depth--;
else if (o === 'endif')
depth--;
if (depth < 0)
break;
if (depth === 0 && o === to)
return pc;
if (o === 'else_')
depth++;
pc++;
}
return -1;
};
script.execute = function execute(s, stack, tx, index) {
s = s.slice();
if (s.length > 10000)
return false;
var lastSep = -1;
stack.alt = stack.alt || [];
for (var pc = 0; pc < s.length; pc++) {
var o = s[pc];
if (Array.isArray(o)) {
stack.push(o);
continue;
}
if (o === -1 || (o >= 1 && o <= 16)) {
stack.push([o]);
continue;
}
switch (o) {
case 'nop1':
case 'nop3':
case 'nop4':
case 'nop5':
case 'nop6':
case 'nop7':
case 'nop8':
case 'nop9':
case 'nop10': {
break;
}
case 'if_':
case 'notif': {
var val = false;
if (stack.length < 1)
return false;
var v = stack.pop();
val = new bn(v).cmpn(0) !== 0;
if (o === 'notif')
val = !val;
var if_ = pc;
var else_ = script._next('else_', s, pc);
var endif = script._next('endif', s, pc);
// Splice out the statement blocks we don't need
if (val) {
if (endif === -1)
return false;
if (else_ === -1) {
s.splice(endif, 1);
s.splice(if_, 1);
} else {
s.splice(else_, (endif - else_) + 1);
s.splice(if_, 1);
}
} else {
if (endif === -1)
return false;
if (else_ === -1) {
s.splice(if_, (endif - if_) + 1);
} else {
s.splice(endif, 1);
s.splice(if_, (else_ - if_) + 1);
}
}
// Subtract one since we removed the if/notif opcode
pc--;
break;
}
case 'else_': {
return false;
}
case 'endif': {
return false;
}
case 'verify': {
if (stack.length === 0)
return false;
if (new bn(stack[stack.length - 1]).cmpn(0) === 0)
return false;
break;
}
case 'ret': {
return false;
}
case 'toaltstack': {
if (stack.length === 0)
return false;
stack.alt.push(stack.pop());
break;
}
case 'fromaltstack': {
if (stack.alt.length === 0)
return false;
stack.push(stack.alt.pop());
break;
}
case 'ifdup': {
if (stack.length === 0)
return false;
if (new bn(stack[stack.length - 1]).cmpn(0) !== 0)
stack.push(new bn(stack[stack.length - 1]).toArray());
break;
}
case 'depth': {
stack.push(new bn(stack.length).toArray());
break;
}
case 'drop': {
if (stack.length === 0)
return false;
stack.pop();
break;
}
case 'dup': {
if (stack.length === 0)
return false;
stack.push(stack[stack.length - 1]);
break;
}
case 'nip': {
if (stack.length < 2)
return false;
stack.splice(stack.length - 2, 1);
break;
}
case 'over': {
if (stack.length < 2)
return false;
stack.push(stack[stack.length - 2]);
break;
}
case 'pick':
case 'roll': {
if (stack.length < 2)
return false;
var n = new bn(stack.pop()).toNumber();
if (n < 0 || n >= stack.length)
return false;
var v = stack[-n - 1];
if (o === 'roll')
stack.splice(stack.length - n - 1, 1);
stack.push(v);
break;
}
case 'rot': {
if (stack.length < 3)
return false;
var v3 = stack[stack.length - 3];
var v2 = stack[stack.length - 2];
var v1 = stack[stack.length - 1];
stack[stack.length - 3] = v2;
stack[stack.length - 2] = v3;
v2 = stack[stack.length - 2];
stack[stack.length - 2] = v1;
stack[stack.length - 1] = v2;
break;
}
case 'swap': {
if (stack.length < 2)
return false;
var v2 = stack[stack.length - 2];
var v1 = stack[stack.length - 1];
stack[stack.length - 2] = v1;
stack[stack.length - 1] = v2;
break;
}
case 'tuck': {
if (stack.length < 2)
return false;
stack.splice(stack.length - 2, 0, stack[stack.length - 1]);
break;
}
case 'drop2': {
if (stack.length < 2)
return false;
stack.pop();
stack.pop();
break;
}
case 'dup2': {
if (stack.length < 2)
return false;
var v1 = stack[stack.length - 1];
var v2 = stack[stack.length - 2];
stack.push(v1);
stack.push(v2);
break;
}
case 'dup3': {
if (stack.length < 3)
return false;
var v1 = stack[stack.length - 1];
var v2 = stack[stack.length - 2];
var v3 = stack[stack.length - 3];
stack.push(v1);
stack.push(v2);
stack.push(v3);
break;
}
case 'over2': {
if (stack.length < 4)
return false;
var v1 = stack[stack.length - 4];
var v2 = stack[stack.length - 3];
stack.push(v1);
stack.push(v2);
break;
}
case 'rot2': {
if (stack.length < 6)
return false;
var v1 = stack[stack.length - 6];
var v2 = stack[stack.length - 5];
stack.splice(stack.length - 6, 2);
stack.push(v1);
stack.push(v2);
break;
}
case 'swap2': {
if (stack.length < 4)
return false;
var v4 = stack[stack.length - 4];
var v3 = stack[stack.length - 3];
var v2 = stack[stack.length - 2];
var v1 = stack[stack.length - 1];
stack[stack.length - 4] = v2;
stack[stack.length - 2] = v4;
stack[stack.length - 3] = v1;
stack[stack.length - 1] = v3;
break;
}
case 'size': {
if (stack.length < 1)
return false;
stack.push(new bn(stack[stack.length - 1].length || 0).toArray());
break;
}
case 'add1':
case 'sub1':
case 'negate':
case 'abs':
case 'not':
case 'noteq0': {
if (stack.length < 1)
return false;
var n = new bn(stack.pop());
switch (o) {
case 'add1':
n.iadd(1);
break;
case 'sub1':
n.isub(1);
break;
case 'negate':
n = n.neg();
break;
case 'abs':
if (n.cmpn(0) < 0)
n = n.neg();
break;
case 'not':
n = n.cmpn(0) === 0;
break;
case 'noteq0':
n = n.cmpn(0) !== 0;
break;
default:
return false;
}
stack.push(n.toArray());
break;
}
case 'add':
case 'sub':
case 'booland':
case 'boolor':
case 'numeq':
case 'numeqverify':
case 'numneq':
case 'lt':
case 'gt':
case 'lte':
case 'gte':
case 'min':
case 'max': {
switch (o) {
case 'add':
case 'sub':
case 'booland':
case 'boolor':
case 'numeq':
case 'numeqverify':
case 'numneq':
case 'lt':
case 'gt':
case 'lte':
case 'gte':
case 'min':
case 'max':
if (stack.length < 2)
return false;
var n2 = new bn(stack.pop());
var n1 = new bn(stack.pop());
var n = new bn(0);
switch (o) {
case 'add':
n = n1.add(b2);
break;
case 'sub':
n = n1.sub(n2);
break;
case 'booland':
n = n1.cmpn(0) !== 0 && n2.cmpn(0) !== 0;
break;
case 'boolor':
n = n1.cmpn(0) !== 0 || n2.cmpn(0) !== 0;
break;
case 'numeq':
n = n1.cmp(n2) === 0;
break;
case 'numeqverify':
n = n1.cmp(n2) === 0;
break;
case 'numneq':
n = n1.cmp(n2) !== 0;
break;
case 'lt':
n = n1.cmp(n2) < 0;
break;
case 'gt':
n = n1.cmp(n2) > 0;
break;
case 'lte':
n = n1.cmp(n2) <= 0;
break;
case 'gte':
n = n1.cmp(n2) >= 0;
break;
case 'min':
n = n1.cmp(n2) < 0 ? n1 : n2;
break;
case 'max':
n = n1.cmp(n2) > 0 ? n1 : n2;
break;
default:
return false;
}
var res = n.cmpn(0) !== 0;
if (o === 'numeqverify') {
if (!res)
return false;
} else {
stack.push(n.toArray());
// stack.push(res ? [ 1 ] : []);
}
break;
case 'within':
if (stack.length < 3)
return false;
var n3 = new bn(stack.pop());
var n2 = new bn(stack.pop());
var n1 = new bn(stack.pop());
var val = n2.cmp(n1) <= 0 && n1.cmp(n3) < 0;
stack.push(val.cmpn(0) !== 0 ? [ 1 ] : []);
break;
}
break;
}
case 'codesep': {
lastSep = pc;
break;
}
case 'ripemd160': {
if (stack.length === 0)
return false;
stack.push(utils.ripemd160(stack.pop()));
break;
}
case 'sha1': {
if (stack.length === 0)
return false;
stack.push(utils.sha1(stack.pop()));
break;
}
case 'sha256': {
if (stack.length === 0)
return false;
stack.push(utils.sha256(stack.pop()));
break;
}
case 'hash256': {
if (stack.length === 0)
return false;
stack.push(utils.dsha256(stack.pop()));
break;
}
case 'hash160': {
if (stack.length === 0)
return false;
stack.push(utils.ripesha(stack.pop()));
break;
}
case 'eqverify':
case 'eq': {
if (stack.length < 2)
return false;
var res = utils.isEqual(stack.pop(), stack.pop());
if (o === 'eqverify') {
if (!res)
return false;
} else {
stack.push(res ? [ 1 ] : []);
}
break;
}
case 'checksigverify':
case 'checksig': {
if (!tx || stack.length < 2)
return false;
var pub = stack.pop();
var sig = stack.pop();
var type = sig[sig.length - 1];
if (!constants.rhashType[type & 0x1f])
return false;
if (!script.isValidSig(sig))
return false;
var subscript = script.subscript(s, lastSep);
var hash = tx.subscriptHash(index, subscript, type);
var res = script.verify(hash, sig.slice(0, -1), pub);
if (o === 'checksigverify') {
if (!res)
return false;
} else {
stack.push(res ? [ 1 ] : []);
}
break;
}
case 'checkmultisigverify':
case 'checkmultisig': {
if (!tx || stack.length < 3)
return false;
var n = stack.pop();
if (n.length !== 1 || !(1 <= n[0] && n[0] <= 15))
return false;
n = n[0] || 0;
if (stack.length < n + 1)
return false;
var keys = [];
for (var i = 0; i < n; i++) {
var key = stack.pop();
if (!(33 <= key.length && key.length <= 65))
return false;
keys.push(key);
}
var m = stack.pop();
if (m.length !== 1 || !(1 <= m[0] && m[0] <= n))
return false;
m = m[0] || 0;
if (stack.length < m + 1)
return false;
var subscript = script.subscript(s, lastSep);
// Get signatures
var succ = 0;
for (var i = 0; i < m; i++) {
var sig = stack.pop();
var type = sig[sig.length - 1];
if (!constants.rhashType[type & 0x1f])
return false;
if (!script.isValidSig(sig))
return false;
var hash = tx.subscriptHash(index, subscript, type);
// Strict order:
var res = script.verify(hash, sig.slice(0, -1), keys.pop());
if (res)
succ++;
}
// Extra value
stack.pop();
var res = succ >= m;
if (o === 'checkmultisigverify') {
if (!res)
return false;
} else {
stack.push(res ? [ 1 ] : []);
}
break;
}
case 'checklocktimeverify': {
// OP_CHECKLOCKTIMEVERIFY = OP_NOP2
// input: [[], sig1, sig2, 1]
// prev_out: [[lock], 'checklocktimeverify', 'drop',
// 'dup', 'hash160', pubkey, 'equalverify', 'checksig']
if (!tx || stack.length === 0)
return false;
var lock = new bn(stack[stack.length - 1]).toNumber();
if (lock < 0)
return false;
var threshold = constants.locktimeThreshold;
if (!(
(tx.lock < threshold && lock < threshold) ||
(tx.lock >= threshold && lock >= threshold)
)) {
return false;
}
if (lock > tx.lock)
return false;
if (!tx.inputs[index] || tx.inputs[index].seq === 0xffffffff)
return false;
break;
}
case 'eval_': {
// OP_EVAL = OP_NOP1
// var evalScript = script.decode(stack.pop());
// if (!Array.isArray(evalScript))
// return false;
// var res = script.execute(evalScript, stack, tx, index);
// if (!res)
// return false;
break;
}
default: {
// Unknown operation
return false;
}
}
}
if (stack.length + stack.alt.length > 1000)
return false;
return true;
};
script.multisig = function(keys, m, n) {
if (keys.length < m)
throw new Error('Wrong amount of pubkeys for multisig script');
assert(m >= 1 && m <= n);
assert(n >= 1 && n <= 15);
while (keys.length < n)
keys.push([]);
// Keys need to be in a predictable order.
keys = keys.sort(function(a, b) {
return new bn(a).cmp(new bn(b)) > 0;
});
return [ m ].concat(
keys,
[ n, 'checkmultisig' ]
);
};
script.isPubkeyhash = function isPubkeyhash(s, hash) {
if (s.length !== 5)
return false;
var match = s[0] === 'dup' &&
s[1] === 'hash160' &&
Array.isArray(s[2]) &&
s[3] === 'eqverify' &&
s[4] === 'checksig';
if (!match)
return false;
if (hash)
return utils.isEqual(s[2], hash);
else
return s[2];
};
script.isSimplePubkeyhash = function isSimplePubkeyhash(s, hash) {
if (s.length !== 2)
return false;
var match = Array.isArray(s[0]) && s[1] === 'checksig';
if (!match)
return false;
if (hash)
return utils.isEqual(s[0], hash);
else
return s[0];
};
script.isMultisig = function isMultisig(s, key) {
if (s.length < 4)
return false;
var m = s[0];
if (typeof m === 'number' && m >= 1 && m <= 15)
m = [m];
if (!Array.isArray(m) || m.length !== 1)
return false;
m = m[0] || 0;
if (s[s.length - 1] !== 'checkmultisig')
return false;
var n = s[s.length - 2];
if (typeof n === 'number' && n >= 1 && n <= 15)
n = [n];
if (!Array.isArray(n) || n.length !== 1)
return false;
n = n[0] || 0;
if (n + 3 !== s.length)
return false;
var keys = s.slice(1, 1 + n);
var isArray = keys.every(function(k) {
return Array.isArray(k);
});
if (!isArray)
return false;
if (!key)
return keys;
return m === keys.filter(function(k) {
return utils.isEqual(k, key);
}).length;
};
script.isPubkeyhashInput = function isPubkeyhashInput(s) {
if (s.length !== 2)
return false;
return 9 <= s[0].length && s[0].length <= 73 &&
33 <= s[1].length && s[1].length <= 65;
};
script.isScripthash = function isScripthash(s, hash) {
if (s.length !== 3)
return false;
var ret = s[0] === 'hash160' &&
Array.isArray(s[1]) &&
s[1].length === 20 &&
s[2] === 'eq';
if (!ret)
return false;
if (hash)
return utils.isEqual(s[1], hash);
return true;
};
script.isNullData = function isNullData(s) {
if (s.length !== 2)
return false;
return s[0] === 'ret' &&
Array.isArray(s[1]) &&
s[1].length <= 40;
};
// https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki
/**
* A canonical signature exists of: <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
* Where R and S are not negative (their first byte has its highest bit not set), and not
* excessively padded (do not start with a 0 byte, unless an otherwise negative number follows,
* in which case a single 0 byte is necessary and even required).
*
* See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623
*
* This function is consensus-critical since BIP66.
*/
script.isValidSig = function(sig) {
// Empty signature. Not strictly DER encoded, but allowed to provide a
// compact way to provide an invalid signature for use with CHECK(MULTI)SIG
if (sig.length === 0)
return true;
// 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.
var 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.
var 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;
};
script.format = function(input, output) {
var scripts = [];
if (input) {
var script = input.script;
scripts.push(script);
if (input.out.tx && input.out.tx.outputs[input.out.index]) {
var prev = input.out.tx.outputs[input.out.index].script;
scripts.push(prev);
if (script.isScripthash(prev)) {
var redeem = script.decode(input.script[input.script.length - 1]);
scripts.push(redeem);
}
}
} else if (output) {
scripts.push(output);
}
scripts = scripts.map(function(script) {
return script.map(function(chunk) {
if (Array.isArray(chunk)) {
if (chunk.length === 0)
return 0 + '';
return utils.toHex(chunk);
}
if (typeof chunk === 'number')
return chunk + '';
return chunk;
}).join(' ');
});
return scripts;
};