From 2f446286047557f8ac9356c068bf55797ace5f73 Mon Sep 17 00:00:00 2001
From: Daniel Cousens <github@dcousens.com>
Date: Thu, 29 May 2014 01:20:13 +1000
Subject: [PATCH] Transaction: refactor hashForSignature
Adds asserts to ensure only valid hashes are created (until the
implementation is complete).
Also uses `Script.without` to remove OP_CODESEPARATOR from the Scripts
as required by the protocol.
---
src/transaction.js | 49 ++++++++++++++++------------------------------
1 file changed, 17 insertions(+), 32 deletions(-)
diff --git a/src/transaction.js b/src/transaction.js
index 8090b3b..0135a1b 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -9,6 +9,7 @@ var convert = require('./convert')
var crypto = require('./crypto')
var ECKey = require('./eckey')
var ecdsa = require('./ecdsa')
+var opcodes = require('./opcodes')
var DEFAULT_SEQUENCE = 0xffffffff
@@ -196,49 +197,37 @@ var SIGHASH_ANYONECANPAY = 0x80
* hashType, serializes and finally hashes the result. This hash can then be
* used to sign the transaction input in question.
*/
-Transaction.prototype.hashForSignature =
- function (connectedScript, inIndex, hashType)
-{
- var txTmp = this.clone()
+Transaction.prototype.hashForSignature = function(scriptPubKey, inIndex, hashType) {
+ assert(inIndex >= 0, 'Invalid vin index')
+ assert(inIndex < this.ins.length, 'Invalid vin index')
+ assert(scriptPubKey instanceof Script, 'Invalid Script object')
- // In case concatenating two scripts ends up with two codeseparators,
- // or an extra one at the end, this prevents all those possible
- // incompatibilities.
- /*scriptCode = scriptCode.filter(function (val) {
- return val !== OP_CODESEPARATOR
- });*/
+ var txTmp = this.clone()
+ var hashScript = scriptPubKey.without(opcodes.OP_CODESEPARATOR)
// Blank out other inputs' signatures
txTmp.ins.forEach(function(txin) {
txin.script = new Script()
})
+ txTmp.ins[inIndex].script = hashScript
- txTmp.ins[inIndex].script = connectedScript
+ var hashTypeModifier = hashType & 0x1f
+ if (hashTypeModifier === SIGHASH_NONE) {
+ assert(false, 'SIGHASH_NONE not yet supported')
- // Blank out some of the outputs
- if ((hashType & 0x1f) == SIGHASH_NONE) {
- txTmp.outs = []
+ } else if (hashTypeModifier === SIGHASH_SINGLE) {
+ assert(false, 'SIGHASH_SINGLE not yet supported')
- // Let the others update at will
- txTmp.ins.forEach(function(txin, i) {
- if (i != inIndex) {
- txTmp.ins[i].sequence = 0
- }
- })
-
- } else if ((hashType & 0x1f) == SIGHASH_SINGLE) {
- // TODO: Implement
}
- // Blank out other inputs completely, not recommended for open transactions
if (hashType & SIGHASH_ANYONECANPAY) {
- txTmp.ins = [txTmp.ins[inIndex]]
+ assert(false, 'SIGHASH_ANYONECANPAY not yet supported')
}
- var htB = new Buffer(4)
- htB.writeUInt32LE(hashType, 0)
+ var hashTypeBuffer = new Buffer(4)
+ hashTypeBuffer.writeInt32LE(hashType, 0)
- var buffer = Buffer.concat([txTmp.toBuffer(), htB])
+ var buffer = Buffer.concat([txTmp.toBuffer(), hashTypeBuffer])
return crypto.hash256(buffer)
}
@@ -364,11 +353,7 @@ Transaction.prototype.sign = function(index, key, type) {
Transaction.prototype.signScriptSig = function(index, scriptPubKey, key, type) {
type = type || SIGHASH_ALL
-
- assert((index >= 0), 'Invalid vin index')
- assert(scriptPubKey instanceof Script, 'Invalid Script object')
assert(key instanceof ECKey, 'Invalid private key')
-// assert.equal(type & 0x7F, type, 'Invalid type') // TODO
var hash = this.hashForSignature(scriptPubKey, index, type)
var signature = key.sign(hash)